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Pete VanderLaan
06-25-2008, 07:42 AM
I am pleased to introduce High Temp Refractory Company of Portland Oregon. I have been working with this 40 year old company for the last year developing crucibles for the studio glass industry. It is now the original equipment supplier for all of Steve Stadelman's Moly furnaces and has become my primary supplier for larger crucibles in the glass trade. Currently, I am the exclusive representative for High Temp Crucibles .

We have been field testing a 92 percent alumina body for these pots and have found them to perform extremely well in the field. The quality of the castings is superior in every way, the freight, handled by Fed-Ex Freight and UPS ground are extremely reasonable in their rates.

They cost a good deal less than any of their competitors.

We are currently selling a 34 inch pot, a 24 inch pot , a 28, a 19, a 16 a 14.5 inch pot and a 7 inch pot. The capacities of each of these pots will be similar to those of Engineered Ceramics. More sizes will come in the fall . We decided to concentrate on pots that are in wide usage first and to field test them. Those results have been excellent without problems of any sort over a prolonged period. I placed them with both experienced and inexperienced shops so I could get a good handle on the levels of abuse they would tolerate. The initial pots placed with Rick Satava had him melting his silver cobalt lustre glass which is profoundly corrosive. After three months in the furnace, we took the pots and diamond sawed them to show that these glasses had not penetrated the casting in any way. Currently Boyd Suguki and Josh Simpson are using the 24 inch pot as the primary melter and are happy campers. Steve Stadelman thinks enough of the pots that he is using them exclusively in his new furnaces.

High Temp makes and sells all sorts of refractory products for extreme temperature applications. I will also have available a variety of bricks, castables, mortars and insulating materials that will ship from Portland at reasonable prices. I will initially maintain these products in Portland only to keep from having to ship them twice, thereby keeping costs down. I will post a link to those products and their pricing soon. They are all available now.

Current Pricing for crucibles is as follows:

34 inch pot (600lb) $1984.00
28 inch pot (400lb) $1305.00
26 inch pot (393lb) $1228.00
24 inch pot (270lb ) $ 689.00
22 inch pot (190lb) $ 665.00
19 inch pot (145 lb) $ 526.00
14.5 inch pot (80lb) $ 286.00
11.5 inch pot (37LB) $ 168.00 straight wall
12.5 inch pot (92lb) $ 306.00 Straight wall 16 inch tall
11 inch pot (33lb) $ 165.00
7 inch pot (18lb) $ 55.00 Straight wall

COMING SOON ! 11 INCH POTS

All FOB Portland OR. Visit our Store www.crucibleconnection.com

Rich Federici
06-25-2008, 03:42 PM
Dear Pete,

Is the 7" pot a flat bottom or round bottom? And... do you feel that it is made with a coarser or finer grog than the EC pots.

The reason I ask is that the EC flat bottom (3772) didn't seem to last very long, especially with cobalt. Not so much as failure due to cracks, but pinholes.

Pete VanderLaan
06-25-2008, 04:56 PM
It is a fine slipcast for that size pot and it held up really well. We never lost one, we simply pulled them from the furnace so we could saw them up. That particular pot does not look as clean as the EC pot but in my opinion, it really delivered the goods. The larger pots are coarse grain tabular alumina as are the ones from EC but the casting is a lot tighter.

I don't want to bad mouth one manufacturer over another as I never bad mouth LaClede and I will still supply EC pots for those that want them . I am saying that the castings from High Temp are simply superior in quality as to the castings and the diamond sawing results were everything I could have hoped for. Steve switched to High temp so I suppose he might offer up his opinion. I don't know. I do think that when I am able to sit on the floor in the production facility with the president of the company drawing on the floor that I am in my element. This is a big operation , making major components for industry but they are giving this project their rapt attention. I like these guys.

Steve Stadelman
06-27-2008, 12:18 AM
These pots will be fantastic. The E.C. pots would come with a layer of slip smeared over the entire pot to hide defects like lip dings and hairline cracks in the potwall, the large sizes were especially bad. Les at High Temp will simply not allow it. If a pot is bad in any way they will not knowingly release it. Because of the initial blanket orders from Pete they understand the importance of our niche and want to work to supply the best possible product. I have the luxury of being able to drop in at any time and wander through the plant and they are not slacking.

Garner Britt
06-27-2008, 09:17 AM
Any idea how these will handle thermal shock compared to the EC? Just wondering on behalf of those of us that run wiremelters part time.

garner

Steve Stadelman
06-27-2008, 09:57 AM
Les has paid a lot of attention to the coefficients of all the ingredients to these Garner. It is a balancing act of coe and particle size and les has 30+ years doing this and I am very confident that they will be better than E.C. in the thermal shock arena.

Patrick Casanova
06-27-2008, 01:35 PM
Congratulations Pete!


Will you be making the 22 x 13 or was demand too light to warrant it?

Holly Wallace
06-27-2008, 02:44 PM
I have experienced problems with EC pots- slip covered defects, hairline cracks and extremely unsatisfactory customer service. EC pots are tough, having survived power failures without damage. I hope the new pots are as good as they say.

Virgil Jones
06-28-2008, 07:53 AM
These pots will be fantastic. The E.C. pots would come with a layer of slip smeared over the entire pot to hide defects like lip dings and hairline cracks in the potwall, the large sizes were especially bad. Les at High Temp will simply not allow it. If a pot is bad in any way they will not knowingly release it. Because of the initial blanket orders from Pete they understand the importance of our niche and want to work to supply the best possible product. I have the luxury of being able to drop in at any time and wander through the plant and they are not slacking.

Steve (and Pete),

Are you saying the crack in my pot in my new Stadelman furnace is definitely a factory defect? If that is the case then I assume I will be reimbursed for the price of replacement. The vertical hairline crack WAS slightly noticeable at first as I informed both you and Pete. After a short amount of use it's very much there now!! I am changing the pot today with one of the THREE I just purchased from Pete...Are you telling me that I might be putting a defective EC pot in the furnace...One that has been camouflaged by the factory????

Virgil Jones

Pete VanderLaan
06-28-2008, 09:43 AM
Steve (and Pete),

Are you saying the crack in my pot in my new Stadelman furnace is definitely a factory defect? If that is the case then I assume I will be reimbursed for the price of replacement. The vertical hairline crack WAS slightly noticeable at first as I informed both you and Pete. After a short amount of use it's very much there now!! I am changing the pot today with one of the THREE I just purchased from Pete...Are you telling me that I might be putting a defective EC pot in the furnace...One that has been camouflaged by the factory????

Virgil Jones

***************

The only "camouflage" I ever see on EC pots is at the rims where they try to cover up small bite size munches in the lip Virgil. They irritate me because it doesn't make the "munch" go away. What should be happening there is that the "munch" shouldn't exist in the first place in my opinion and that trying to cover it up doesn't inspire much confidence either. EC however does not think that this is a serious problem and will not warranty it. I have yet to see a "munch" actually cause a failure of a pot.

I never know about cracks. EC takes the position that you need to inspect the pot extremely carefully when you receive it. Their position is that it may have been cracked in shipping. Maybe true, maybe not true. I can usually tell the difference between a shipping crack and a firing crack when the pot is new but once it has been run, it's impossible to say. Fine tooth comb inspection is really important.

My understanding regarding the pot you had in service is that it in fact never leaked which doesn't qualify as a defective pot from EC's point of view. I know this because I have tried to make claims on such issues in the past. I have seen hairline cracks in pots run for very long periods of time with no incident.

Even so, cracks happen and cracks happening early should be dealt with through a complaint process. Steve tells me that he asked for photos and he never received any from you. Without photos, nothing is going to happen. At this point, I doubt that anything will happen since too much time has passed, the pot doesn't seem to be leaking, You can certainly E mail me photos of the pot, with a complaint and I will take it to EC and give it my best representation.

Bringing it to a public forum is not particularly helpful.

I would like to make it clear that I have never seen EC try to cover up a crack of any substance. They cover little ones on the lip and that irritates me to no end. Further, they don't seem to have real difficulties with pots smaller than 19 inch in diameter. Yours I believe was a 16 inch. They do seem to have some issues with voids in their castings which is why we have been talking about the superiority of the castings at High Temp.

I am trying to introduce a product that I believe is superior in its castings and firings in every way. We have worked long and hard on this and are well pleased with the results. We are offering what I believe to be a superior product at a lower price. That I think should be viewed as a good thing but not as an opportunity to attack EC. EC has issues, LaClede certainly has issues. Ipsen had issues.Corhart has issues. I am sure that High Temp will have issues. For years, EC was the low cost alternative to LaClede. They have certainly gotten more expensive in a relatively short period of time. I am offering an alternative to that. There are people who are totally committed to La Clede and there are people who are totally committed to EC. There are people who hate all of them. They all try, some do better than others at one time or another. Life goes on. These are crucibles for melting glass and are frequently abused badly by the users. If I can find evidence that the user didn't bash the pot, I try to represent that to the manufacturer. It's one of the advantages of buying the pot through me. At that point you have a track record. When you buy direct, you pay the same price but you are on your own if there is a problem. It's up to the consumer as to how they want to proceed.

But I don't believe EC is fatally flawed at all. I just have a new alternative.

Pete VanderLaan
06-28-2008, 09:50 AM
Congratulations Pete!


Will you be making the 22 x 13 or was demand too light to warrant it?
************

There were two 22 inch pots. One was round bottomed and one was shaped like a cone. I haven't sold the conic one in years. There is a mold in the works that Steve is making for a pot that will hold 200 lbs which is very close to the capacity of the 22 inch pot with the round bottom. We never did sell very many pots of that size. I can still get it but my gut reaction is to buy the 24 inch pot from High Temp which is close to the price of the 22 inch pot from EC. Then, don't fill it all the way, go home early and get some sleep for a change.

Are you still doing land development Pat?

Kenny Pieper
06-28-2008, 10:22 AM
Pete any Idea what a mold charge would be if I had a specific pot size that I wanted produced. I'm thinking of a color pot around 9 3/4" x 10" high

Virgil Jones
06-28-2008, 10:54 AM
Thanks for your response, Pete.

First I will say that I did not bring it the public forum...I woke up this morning to find Steve's comments:
"The E.C. pots would come with a layer of slip smeared over the entire pot to hide defects like lip dings and hairline cracks in the potwall, the large sizes were especially bad. Les at High Temp will simply not allow it. If a pot is bad in any way they will not knowingly release it."
Having run tank furnaces for years and being new to freestanding pots with my new Stadelman furnace that was a comment that got my immediate attention.
In my discussion with you concerning the initial sighting of the crack you asked for pictures, which I sent to you. At running temp my camera couldn't catch it...possibly my photographic skills. At that time you said the horizontal line was a "batching line" and not to worry about it. You also said the vertical line might or might not be a problem for a long time. After running the new furnace for less than two months the vertical crack is very evident at any temp. In talking to Steve, he was surprised I was changing it before it actually leaked. My thoughts are that I can't afford surprises in the middle of production AND that you said it could go at any time (now or later), BUT, that it WOULD leak.
I will photograph the pot after I take it out of the furnace, which I'm in the process of doing today. I will send both you and Steve the Photos.
Let me say that I do appreciate both this forum and my new furnace. I will pursue the pot issue "off the air".
Thanks, Virgil




The only "camouflage" I ever see on EC pots is at the rims where they try to cover up small bite size munches in the lip Virgil. They irritate me because it doesn't make the "munch" go away. What should be happening there is that the "munch" shouldn't exist in the first place in my opinion and that trying to cover it up doesn't inspire much confidence either. EC however does not think that this is a serious problem and will not warranty it. I have yet to see a "munch" actually cause a failure of a pot.

I never know about cracks. EC takes the position that you need to inspect the pot extremely carefully when you receive it. Their position is that it may have been cracked in shipping. Maybe true, maybe not true. I can usually tell the difference between a shipping crack and a firing crack when the pot is new but once it has been run, it's impossible to say. Fine tooth comb inspection is really important.

My understanding regarding the pot you had in service is that it in fact never leaked which doesn't qualify as a defective pot from EC's point of view. I know this because I have tried to make claims on such issues in the past. I have seen hairline cracks in pots run for very long periods of time with no incident.

Even so, cracks happen and cracks happening early should be dealt with through a complaint process. Steve tells me that he asked for photos and he never received any from you. Without photos, nothing is going to happen. At this point, I doubt that anything will happen since too much time has passed, the pot doesn't seem to be leaking, You can certainly E mail me photos of the pot, with a complaint and I will take it to EC and give it my best representation.

Bringing it to a public forum is not particularly helpful.

I would like to make it clear that I have never seen EC try to cover up a crack of any substance. They cover little ones on the lip and that irritates me to no end. Further, they don't seem to have real difficulties with pots smaller than 19 inch in diameter. Yours I believe was a 16 inch. They do seem to have some issues with voids in their castings which is why we have been talking about the superiority of the castings at High Temp.

I am trying to introduce a product that I believe is superior in its castings and firings in every way. We have worked long and hard on this and are well pleased with the results. We are offering what I believe to be a superior product at a lower price. That I think should be viewed as a good thing but not as an opportunity to attack EC. EC has issues, LaClede certainly has issues. Ipsen had issues.Corhart has issues. I am sure that High Temp will have issues. For years, EC was the low cost alternative to LaClede. They have certainly gotten more expensive in a relatively short period of time. I am offering an alternative to that. There are people who are totally committed to La Clede and there are people who are totally committed to EC. There are people who hate all of them. They all try, some do better than others at one time or another. Life goes on. These are crucibles for melting glass and are frequently abused badly by the users. If I can find evidence that the user didn't bash the pot, I try to represent that to the manufacturer. It's one of the advantages of buying the pot through me. At that point you have a track record. When you buy direct, you pay the same price but you are on your own if there is a problem. It's up to the consumer as to how they want to proceed.

But I don't believe EC is fatally flawed at all. I just have a new alternative.[/QUOTE]

Holly Wallace
06-28-2008, 01:15 PM
True, initial one on one communication with supplier/manufacturer is the first line of communication but if that proves to be unsatisfactory then we all need to be made aware. I think a public forum IS a good place to discuss problems that may affect others, whether it is with crucibles, galleries, software, shows, knock offs, etc, etc, etc. It's not just dirty laundry, it adds the power of numbers and other opinions to help resolve issues that may be an issue that others have encountered. We're all in this hot little boat together.

Eben Horton
06-28-2008, 01:32 PM
No product is perfect. That being said, the EC pots were a huge jump in quality from laclede. When i say quality, I done mean appearance, I mean longevity, glass quality, and tolerance to heat shock.. I could care less what the thing looks like around the lip... I usually wear a notch on the pot from gathering anyway.

Pete VanderLaan
06-29-2008, 05:25 AM
I recall a photo that showed absolutely nothing that I could take back to EC and they do require a good photo. Most people can take good photos if they have to. I have never seen an EC pot crack absolutely horizontally unless it was really worn. Shipping cracks are big and ugly for the most part and they are not very hard to spot. It is amazing to me how few people inspect their pots when they arrive for damage and that is the time it needs to be done. EC won't warranty a cracked pot. They will warranty a pot that has voids in the casting but you never see them until the pot suddenly fails. Then they prorate the amount of time the pot was in service based on a total anticipated life of 10 months, assuming weekly charges.

Actually, it is amazing to me that they warranty at all. La Clede doesn't do it, Ipsen didn't do it and EC didn't do it until I made a lot of noise about it. Even so, it is limited since they cannot control how a pot is used. I rarely get a crack claim Through QC and that's a fact. Occasionally, they honor a claim that I find to be extremely dubious but I still submit it. As Eben said, quality was a major issue for him with LaClede yet tons of people still buy them and still pay premium prices compared to EC.

My point in this thread was (again) that I have been working long and hard to get a crucible made that I think is going to be the best quality out there. And it will cost less. I

That should be good news.

Brian Gingras
06-29-2008, 07:01 AM
I see a 19" pot, but no 16" pot that is similar to the 108lb?

Virgil Jones
06-29-2008, 08:08 AM
Pete, since you decided to continue my pot situation "on the air", I have a comment and couple of questions.

The pot came in the furnace...no inspection possible.

If, as Steve said previously:
"The E.C. pots would come with a layer of slip smeared over the entire pot to hide defects like lip dings and hairline cracks in the potwall",
how does one detect cracks in the pre-installation inspection?
Are the three pots I just purchased from you covered with slip? If so, AND they do appear to be, how do I inspect them for cracks,etc. that are not shipping related?

TO BE CLEAR...I am very pleased with my Stadelman furnace, I will say that Steve is doing his best to handle my complaint in a professional manner. Also, his other "customer service" has been great.

Virgil




I recall a photo that showed absolutely nothing that I could take back to EC and they do require a good photo. Most people can take good photos if they have to. I have never seen an EC pot crack absolutely horizontally unless it was really worn. Shipping cracks are big and ugly for the most part and they are not very hard to spot. It is amazing to me how few people inspect their pots when they arrive for damage and that is the time it needs to be done. EC won't warranty a cracked pot. They will warranty a pot that has voids in the casting but you never see them until the pot suddenly fails. Then they prorate the amount of time the pot was in service based on a total anticipated life of 10 months, assuming weekly charges.

Actually, it is amazing to me that they warranty at all. La Clede doesn't do it, Ipsen didn't do it and EC didn't do it until I made a lot of noise about it. Even so, it is limited since they cannot control how a pot is used. I rarely get a crack claim Through QC and that's a fact. Occasionally, they honor a claim that I find to be extremely dubious but I still submit it. As Eben said, quality was a major issue for him with LaClede yet tons of people still buy them and still pay premium prices compared to EC.

My point in this thread was (again) that I have been working long and hard to get a crucible made that I think is going to be the best quality out there. And it will cost less. I

That should be good news.

Virgil Jones
06-29-2008, 10:19 AM
Being a complete novice to pots, I dont know what is passable and what is not. At this point I guess I need an education. I prefer that education to cost me as little production time as possible.

As I inspect the three new pots again.

A revision in the previous post: The pots seem to have slip on spots on the top and the lower inside has kind of a swirl affect and rumply bottoms. I dont know if this is part of the casting process or post casting. I thought the swirl affect was the slip covering talked about earlier, but, might have assumed to quickly.

What are the black spots surrounded by a brown halo imbedded on the inside of the pots? Is this a problem?

One pot has a pencil mark on the outside leading to the lip. On the inside corner of the lip from that pencil line there is an approx. half by eighth inch spot that that looks like it is ready to chip out. Is this a problem?

On another pot there is a very tiny crack on the top of the pot, by the inside wall. It travels that corner approx. 1/8 to a inch. Touching that crack and going about 1 inches down inside the pot is a raised rough line. Is this a problem?

Thanks for your help and patience.
Virgil

Patrick Casanova
06-29-2008, 07:33 PM
Thanks Pete, I'll probably go down in size. Ever since seeing your furnace in Santa Fe I've been intrigued by your concept for multiple pots in a single furnace.

Thank God we weren't in the Land Development business! The company that I went back to work for is a High End Custom Home builder. They've been doing it since the late 70's. And in times like these it's their reputation and quality is what is keeping people working. In our market place every trade is taking work just to keep their good people employed and cover the bare overhead. But it has been brutal, a lot of really good companies are going down. I didn't close my studio, I quit wholesale. I've been blessed to have my glass to help off set things. Not that glass is flying off the shelves... but because of working for them for our livelihood, it allowed me to focus on developing new work and new markets. Oh, and to enjoy glass again!

Pete VanderLaan
06-29-2008, 07:59 PM
Being a complete novice to pots, I dont know what is passable and what is not. At this point I guess I need an education. I prefer that education to cost me as little production time as possible.

As I inspect the three new pots again.

A revision in the previous post: The pots seem to have slip on spots on the top and the lower inside has kind of a swirl affect and rumply bottoms. I dont know if this is part of the casting process or post casting. I thought the swirl affect was the slip covering talked about earlier, but, might have assumed to quickly.

What are the black spots surrounded by a brown halo imbedded on the inside of the pots? Is this a problem?

One pot has a pencil mark on the outside leading to the lip. On the inside corner of the lip from that pencil line there is an approx. half by eighth inch spot that that looks like it is ready to chip out. Is this a problem?

On another pot there is a very tiny crack on the top of the pot, by the inside wall. It travels that corner approx. 1/8 to a inch. Touching that crack and going about 1 inches down inside the pot is a raised rough line. Is this a problem?

Thanks for your help and patience.
Virgil

******************

The black spots are not unusual in a crucible. They will not affect performance.

EC puts the slip on to cover cosmetic blemishes on the pot and sometimes to cover non consequential chips at the lip area. This irritates me to no end. As long as they are confined to the lip they are not an issue.

It is not possible to put the slip on a crack and to sucessfully cover a crack. You will still see the crack if one exists. Putting the slip over such a thing is stupid and doesn't work. I really don't see junk like that as frequently as this thread might suggest.

The entire pot is not covered with slip. The slip is a noticably different shade of white. It was added after the pot was fired. You can't miss it.

The thing ready to chip out will not be a problem.

The rumply bottom is part of the casting process.

When you get the pot out of the furnace that has the running crack in it, take a good photo of it and I will represent you to EC. Again, they don't respond well to cracks but we can try. The photo has to be good or it is a total waste of time. One of the troubles with trying to do this is that the time track on the pot gets lost easily. The pot in question could have been shipped to Steve last year and sat around. Then it goes out with your furnace . More time passes. Then there are problems and I file a complaint. EC asks where the pot came from. Who Knows? Again this doesn't happen all that often. With High Temp we are getting superior castings.

Steve and I have worked out a way to keep track of the pots. Now he writes on the pot the invoice number that was tied to the pot. That way we know its history. Its a live and learn process.

Pete VanderLaan
06-29-2008, 08:04 PM
There will be a 16 inch pot from High Temp. Look for it in the fall. I still have 16 inch pots from EC.

Kenny: You would have to buy a lot of pots to get High Temp to make a mold for a special pot. I have to wait six months to get molds made. EC will do it for five hundred bucks. Let me look at the EC pot list and see what might be close to the one you want. They can handle smaller pots fine.

Steve is making a mold for a 22 inch pot. Apparantly he has nothing to do at night.

Glenn Randle
06-29-2008, 09:54 PM
34 inch pot (600lb) $1945.00
28 inch pot (400lb) $1362.00 AVAILABLE AUG'08
24 inch pot (270lb ) $ 675.00
19 inch pot (145 lb) $ 515.00 AVAILABLE SEPT '08


The prices are sort of funny with the various sizes. The 270 is a "steal",....or I guess you could see the others as pricey.
I'm sure everyone has there reasons for running the pot(s) they choose, but I'd have a hard time paying more than double for a 400 when you could have 2 270's which are almost as large as the 600 (in capacity). I guess the furnace to hold them would be quite a bit larger.
I wonder why the prices aren't more even, relative to capacity?

Btw,
I've run EC pots with fine cracks, some 2/3's down the side without any trouble. I admit it's hard on the nerves, but Pete/EC adjusted the price and I just ordered another spare. I doubt anyone here has abused any pot more than I have the ECs. 2200f to 850f in about 6 hours, full blower & no fuel! I'd call that ABUSE! It happened to the same pot multiple times, flame impingement killed my early pots. Never had issues with thermal shock.
I'm just saying this to let you know not to worry. I'm not paid for endorsements. ;)

I'm glad to hear Pete's found another great product to offer. Competition is good. Sometimes one supplier might be out of stock and the competitor will have just what you need. It's good for prices too. Freight might make the difference for us on the east coast.

Pete, any idea what is used as a binder for the tabular alumina? I priced it a while ago from Remet and but they "couldn't" tell me the binder to use. It's always seemed like the interior castings of a glass furnace should be made from something as "bomb-proof" as the crucibles we use. Would colloidal alumina work? Or is it something else?

Brian Gingras
06-30-2008, 05:30 AM
There will be a 16 inch pot from High Temp. Look for it in the fall. I still have 16 inch pots from EC.

Kenny: You would have to buy a lot of pots to get High Temp to make a mold for a special pot. I have to wait six months to get molds made. EC will do it for five hundred bucks. Let me look at the EC pot list and see what might be close to the one you want. They can handle smaller pots fine.

Steve is making a mold for a 22 inch pot. Apparantly he has nothing to do at night.

thanks pete, I love my EC pots, but it's always good to have an alternative.

Pete VanderLaan
06-30-2008, 05:47 AM
The binder for tabular alumina in this instance is kyanite which converts to mullite at 2150F. Naturally occurring mullite is really rare. You could add calcium aluminate as a cement binder if you wanted to. It is the binder in castables. I actually sell both products.

We didn't "find " the product, we developed it in partnership with High Temp. It has been in the works for quite some time. We are a small project in a very big company. They have made me the exclusive distributor for the product line. The dedication to quality control at High Temp amazes me.

The bigger the pot, the lower the sales, making it more expensive to justify the costs for developing the mold which are extensive if you do it right. I sell 20 270 lb pots for every 1 400 lb pot. The risks involved in firing big things is far greater, involving really long soak times before 212F and also 1000F. Currently the price of alumina is changing every month where it used to be priced once a year. Finally, the big pots take up far more room in the kiln and take longer firing times which cost more as well. These kilns are not small. Forklifts can drive into them and we only work in the small casting shop!

Finally, for the glass shops which find these larger pots appropriate, their true cost is in the cost of going to high temperatures to melt, coupled with the down time for production that they have when they are melting , not working. One shop I supply with the 34 inch pot runs two of those furnaces and they are charged twice a week each. It's a matter of scale. Lino will go through one of the those pots in a single sitting.

But I do agree with you that the 270lb 24 inch pot is the single most efficient for the small studio owner. When people want the 22 inch pot, which is rare, I recommend buying the 24 inch instead and simply not filling it all the way. The real time spent charging a pot is in the last two inches of glass, which always seem to take forever. I prefer putting a last big charge on, setting the controller and going home to sleep. If the glass is down a bit, I still have 225 lbs of good stuff.

Finally, there is no separation of material types in a crucible. There are coarse tabs and very fine particles. When the pot is vibrated, the fines come to the surface of the pots in the molds. The big stuff that prevents thermal shock is hiding out in the middle of the pot. When a pot begins to fail, the fines are being consumed by the glass itself and the big stuff gets exposed. This creates a disproportionate surface area exposing the glass in the pot to far more alumina surface than the new smooth pot had. Subsequently, cords start to form and they are pretty much unavoidable. The pot is failing . This is basically why I don't like investing a crucible. The investment stops an actual leak but the glass is still pretty crappy by my standards. Pots are not engineered to be permanent installations. 70 to 90 charges is what to expect if you want continually good glass which is the whole point of a pot furnace over a tank.

Dave Bross
07-04-2008, 11:04 AM
How tall is the 7" pot?

Pete VanderLaan
07-04-2008, 08:08 PM
right now, 6 inches. We are modifying it to be 8 1/2 inches tall.

Dave Bross
07-13-2008, 08:42 PM
Would these pots stand up to being brought up and down from heat quickly or do they need a slow transition? The application I had in mind was using one in a glory.

Pete VanderLaan
07-14-2008, 08:27 PM
I don't know of any high alumina pot that will really put up with that for any length of time. Fused silica would do it- once.

Eben Horton
07-14-2008, 08:58 PM
I have brought small pots up in my color box over night filled with cullet and then tossed em in the glory as it was coming up.. not when the hole had just been turned on, but at dull orange- then at the end of the day pull it and bring it down in the color box.. I have no idea who made the pots- they were freebies.

Jordan Kube
07-15-2008, 12:48 AM
Only one way to find out!

Dave Bross
07-15-2008, 10:12 AM
Amen, Jordan!

OK, thanks, I'll stick to the old cheap-o mullite assay pots for glory hole abuse. Rude but effective!

Pete VanderLaan
02-22-2009, 08:08 AM
We are having a five percent off sale on any High Temp crucibles ordered online through mar 31st.

www.crucibleconnection.com

Greg Gepp
04-02-2009, 11:31 AM
A few questions.
How much for delivery to Australia ?
Victoria specifically. Does is depend on size ?
Are the pots flat base ?
And cheaper in multiples ? I don't know of any Australian suppliers of crucibles and I personally wish it was easier to get them. I could take a few and pass them on down here.

Pete VanderLaan
04-02-2009, 01:15 PM
Maybe possibly you guys could get together and actually agree on some common pot sizes to use which I would try to help with and then you could order together, bringing the stuff into Sydney ( or I suppose Perth) harbor. There was a woman named Michelle Donde who was bringing them in to Sydney for a while. I know it's a huge country BUT it would be a really good thing. There are volume discounts and shipping really drops with volume.

As to the individual shipment, I need the port of entry for customs and the Aussie version of a zip code with a physical address.

Greg Gepp
04-07-2009, 07:52 AM
how much will it cost me to import four 24" crucibles to Melbourne ?
Can you give me a ball park amount so can talk to people and maybe get a larger order happening
zip code ( that's postal code ?) 3844
I live on Victoria, in Gippsland, look it up on google, we have famous people living here
you guys don't know much about Australia do you

Pete VanderLaan
04-07-2009, 08:00 AM
hey man,I am ,like way insulted. lets head for Broken Hill and duke it out.

Greg Gepp
04-07-2009, 11:38 PM
he hee, bring the crucibles with you

Greg Gepp
04-09-2009, 12:28 AM
ok, no offense intended, I correct myself to some of you guys don't know much about Australia.
You obviously know something, Broken Hill is a bit of an obscure place, unless of course you're someone who lives there or are seriously into the iron ore industry.
How much to ship to Melbourne, four of 24" crucibles? or do I need to ask at the web site ?
Thanks,
Greg.

Pete VanderLaan
04-09-2009, 05:51 AM
No offense. I have been in love with that Sunburnt land since I was a little boy keeping lizards in terrariums and collecting all the stamps from British Oceania. Someday I hope to take the train to Perth across the southern part of the continent. Where else in the world can the prime minister walk into the ocean and vanish?

I am getting a quote for the crating and presuming it is coming into the port of entry in melbourne and being picked up there. If not I need a physical address. . You don't want any little pots for color?

Greg Gepp
04-09-2009, 06:08 AM
Melbourne is good.
No small pots right now. I assume you're suggesting they will pack easily with the others ? If so that deserves some thought.
The four crucibles I'm asking for are only to guide me on shipping costs, I may want a couple of 19" instead of two of the 24 " or I'm not sure right now.
I have one friend interested to begin with but I want to suggest transport costs to him and any others who might be.
Thanks.

Pete VanderLaan
04-09-2009, 06:16 AM
I understand. keep in mind the effort is a weird sort of scale where there is a minimum cost to do anything. Price always improves with volume. This sort of thing will irritate my crating company if you change thing a lot and they will stop taking me seriously.

Greg Gepp
04-09-2009, 06:21 AM
ok I'll talk to people and make my next request a definite.

Greg Gepp
04-09-2009, 06:24 AM
but obviously it would be good if I could give them some figure to budget for to begin with,
Thanks again.

Pete VanderLaan
04-09-2009, 06:25 AM
I'll start with what you asked for.

Pete VanderLaan
04-09-2009, 07:38 PM
Crating all four crucibles with a foam in place ring for each pot will run $475.00. It will meet all applicable import requirements that Oz has. The crucibles will run $675.00 each with a five percent discount applied after the total. The Shipping should run about ( About mind you) $750.00 USD. That is to the freight carriers warehouse at the port in Melbourne. It always needs to get picked up right away or they start to charge storage.

That is not bad when I consider that shipping an individual pot across this country costs about $200.00. The crating is an unfortunate but necessary expense since cargo stuff bound for the south pacific and beyond really takes some harsh handling. We do VISA /MC

I used to go around on Broken Hill with Graham Stone, whose great book "The Schedules" I deeply admire. I also love Australian films "Where the Green ants Dream" was a particular favorite. Do you know Ross Duncan? He was a student of mine at Pilchuck over thirty years ago and he's out there somewhere. I also haven't seen Whitely for some time either .

Pete VanderLaan
04-14-2009, 01:28 PM
The actual shipping quote has come in at $525.00 That averages to less per pot than shipping them around the USA.

Greg Gepp
04-14-2009, 08:02 PM
Thanks heaps Pete,
I know / knew Graham Stone when he was at the Meat Market craft Centre in Melbourne, haqd the opportuity to get a draft copy of the text but was so damn poor couldn't afford to give him the pittance he asked.
No I don't know Ross duncan, but I've rubbed shoulders with a lot of the glassies, since I got into the business when it was just starting to establish itself.
Thanks for the info. I'm going to Melbourne to work out an order so will get back to you soon.

Greg Gepp
05-01-2009, 06:10 PM
Hi again, could you give me some indication of delivery time ?

Pete VanderLaan
05-01-2009, 06:50 PM
I would have to inquire. i would imagine that it would be three weeks or less.

Steve Stadelman
05-01-2009, 09:50 PM
That's my guess also. The crating guy is usually same day, the only holdup is the availability of the crucibles.

Pete VanderLaan
05-02-2009, 06:26 AM
the only holdup is the availability of the crucibles.

********
Which have to be ordered before they can be shipped. (Wink Wink, Nod Nod, nudge nudge)

Greg Gepp
05-05-2009, 10:14 AM
Hi guys, mmmm ... since when did I become a guest ?
I seem to have been dumped from the site again Pete so I re-registered with my same details and while my posts are still on this forum, (though they're now n/a), I've been demoted to guest. I sent a letter to admin so I'm repeating myself somewhat, please excuse using this page for my grumbling instead of help pages.
I'll ask a page relevant question : three weeks to Melbourne sounds very speedy, can you confirm that ? Order coming soon, I'm still negotiating with people to maximise the order.

Steve Stadelman
05-05-2009, 10:47 AM
I have been told 3 weeks. I believe it. We can commonly have stuff down there in that time period.

Pete VanderLaan
05-05-2009, 10:59 AM
Of course I can't guarantee it. If you want air freight it will cost a lot more. Ships are ships. Three weeks is our normal experience. if delivery guarantee is a requisite for the order then you should order it elsewhere. Normal lead time from either LaClede or Engineered is four weeks minimum anyway. High Temp is the only one that regularly stocks inventory.

Pete VanderLaan
11-20-2009, 04:46 PM
..........................................

Slate Grove
03-10-2010, 06:38 AM
Pete,

I'm wondering if the 2) 14.5" crucibles you sen me for our new color furnace will handle opals? The furnace arrived last night and we'll be installing today...planning on starting anew post with pics of the beautiful little furnace in the next couple of days.

Thanks,

Slate

Pete VanderLaan
03-10-2010, 07:36 AM
Well, they handle them as well as any other good high alumina pot will handle them Slate. It isn't fluorine that is hard on a crucible, it's low viscosity.. When I melt opals at about six percent flurorine, I never let the furnace get hotter than 2200F which yield a viscosity similar to that of SP87 at about 2415F. When you look at issues like silver metal drilling a crucible, it's the fact that the metal is like water. There's nothing special about the silver. Think what would happen if you melted SP87 at 2550F. It attacks the porosity of the pots.

I forget who said it ( Fritz would now give me a huge lecture), but it is "think of glass as the universal solvent."

I know that Croucher gets about 25 melts from a fluorine alumina pot as opposed to about 40 melts for his lead transparents in AZS. The price difference is huge. And it's
always a crap shoot.

Slate Grove
03-10-2010, 12:05 PM
Thank you Pete!!! That makes total sense.

Slate Grove
03-10-2010, 04:25 PM
Pete, what's the cost on those pots? The first 2 were included in the furnace cost for us, and I'm going to need to order some backups?

Thanks,

Slate

Pete VanderLaan
03-10-2010, 05:24 PM
If I recall correctly you have the 14.5 inch pot which runs 280.00 each.From High Temp, They ship fed ex freight in multiples and UPS for singles and we always have them in stock.

Slate Grove
03-11-2010, 06:33 AM
You are correct Pete, they are the 14.5" pots. Thanks for the info, I'll get the paperwork together in the next week. Thanks

Pete VanderLaan
03-11-2010, 07:50 AM
You can order them on-line Slate. We will still need a personal contact for the credit card v code but try www.crucibleconnection.com

Justin Thompson
07-20-2010, 01:33 PM
Pete.....

I am thoroughly pleased and pleasantly surprised at how much workable glass I can pull from Hi-Temp's 11" crucible; however, I must being doing something wrong (I usually am).

In the last 6 months, I have gone through 2 pots and am currently running a cracked one that has a creatively monstrous Gerri-rig applied to it (you don't wanna know the details, but some hi-temp cement and a kiln shelf is involved)

At $160 a pot, it isn't the end of the world to replace one, but it adds up and money is hard to come by these days. (I just moved my studio and moving never costs what you expect it to).

Anyway.....I think that I have been OVERLY careful when ramping down and candling up the pot.....but; like I said, I seem to be going through pots unusually quick.

Do you have a ramping cycle (or stress range) for the Hi-Temp pots? I am pretty new at owning a studio; however, I have worked in plenty of other people's studios as the person in charge of costing them money. Lol, you really don't get a feel for how much things cost until the bills have your name on it. :) (Never before now did I realize the value of sorting through crack-offs and lip trims to recycle) =D

Anyway....anything would be helpful.....I shouldn't be going through a pot every 3-4 months, should I?

Pete VanderLaan
07-20-2010, 04:41 PM
No, you shouldn't go through pots that quick but it's entirely possible to do it. You don't give out a boatload of important information:

Is the furnace gas or electric.
If gas, where's the burner?
If electric, how far from the elements is the pot?

What heat up schedule do you use now? The whole schedule please.
What turn down rate do you use.
Is the pot full or empty or hald way when you shut down.
How often do you turn it on and off.
What do you melt?
What temp do you melt at?
How often do you melt?

If our crucibles were lasting as long as you describe in general, I wouldn't have much of a business. Your experience suggests that you are doing at least one and maybe more than one thing in an unfriendly way to the pot. I like to see a pot in my own shop run about 70 cycles, perhaps 90 based on melting at about 2250F and turning the furnace up to 2375 for five hours after the melt cycle is complete. Sometimes ( With the black) I go up to 2410F which Is hard on the pots but they are still putting out.

Time is really irrelevant in melting life. The number of times you go up to temperature and down again is the significant figure here. If you were melting five times a week for 12 weeks that would be 60 melts. If it were being turned on and off, that would do damage to the pot and shorten its life so 60 or less would not surprise me. I think ideally in a studio you want to have enough glass to run for five days and then recharge. That makes for a 70 cycle pot to last over a year and that is what the bulk of my clients get. BUT how you treat it is really significant.

Scott Novota
07-21-2010, 12:14 PM
This simple answer based on what I know about my wire melter over the years is that every time it is ramped down you risk cracking it.

I went though 2 pots in the first 6 months because I was doing up and down.

Once I started to cycle down to 1400f (25f every hour down to 1400) when I was not working for a week instead of turning it all the way down the pot lasted 3 years. You pay one way or the other as Pete likes to say "no free lunch".


Scott.
.

Justin Thompson
07-21-2010, 05:13 PM
Pete.....

Thank you for the info. I was actually not thinking in terms of melting cycles as it effects the life of the pot. I know that makes me sound ignorant; however, in this case...I guess I am. To think of a pot's life in terms of melting cycles; it makes a lot more sense and helps me to think in a different way. As I said, I am pretty new to owning my own studio and being responsible for things like this. My experience with pot furnaces has always been 200lb and above sized pots, and those usually experienced a death as a result of pitting and detereoration. I haven't had much experience with cracked crucibles.

The information that I left out.....

I run a wiremelter (an AIM 1411) and the pot sits about 2.75-3 inches away from the element groove (so about 3-3.25 inches away from the element itself). I have added a layer of soft brick to the sides, so that the elements aren't sitting 1.5 inches from the floor of the furnace (a very poor design IMHO). Because of the added layer of 2300F brick, I have had to elevate the pot about 3 inches off the floor.

I keep the furnace idled at 1900 when not working. When working, I ramp it up (usually over 1.5 hours) to 2160. The furnace stays at 1900 (or above) 24/7. Since I am mainly teaching and doing about 2 days of small production, I find myself charging about once every 4-5 days. During the melt, I ramp it up to 2200 (usually after a day of blowing, so the furnace is already at 2160). BTW, I melt System96 nuggets. I charge at 2200 (usually about 8 lbs/charge cuz of the size of the pot). After the charge, I ramp up to 2300 and soak for 4 hours. From 2300-1900, I run an 8 hour ramp down.

When I have had to turn it down to do maintainance, I usually ramp the pot down over about 4 days. I, of course, ramp it down with a fully empty pot. I pay special attention to the pot during its ramp from 1400-800, usually with a hold and soak at 1400 (for 10 hours) and 1000 (for another 10 hours). I do this because I have been told that the pot is most fragile (to heat) in the range from 800-1400 degrees. There was only one time that I wasn't able to fully empty a pot before a turn-down. I blew an element (on the old 1411's, there are only two sets of elements, so one element isn't able to sustain above 1600). So, I came in to find the furnace at 1600, with about 1/4 pot full of glass. Since I didn't have a torch small enough to fit in the peep hole, I had to ramp the pot down being 1/4 way full. Again, I was careful to ramp down between 1400-800.

The furnace pretty much stays on 24/7 for about 4 months at a time (my elements usually have a life of 4 months), then I need to ramp down to switch out. I have been pretty good at being able to catch the elements in time, before they pop and am forced to ramp the furnace down, as is.

I hope that you don't find my knowledge (or lack there of) too comical and can offer a bit of advice on the ramping schedule for both charging and for the turn-down for maintainance.

Thank you.

Pete VanderLaan
07-21-2010, 08:01 PM
How is the pot supported?


And, that's really pretty hot for system 96. It would be seriously fluid at 2300F which can really wear on a pot. Most people in wire melters melt that stuff at about 2175 and it's pretty much good to go the next day. Viscosity of your glass is a big factor.

Justin Thompson
07-22-2010, 09:42 AM
The pot sits on top of a 1/2" kiln shelf; which in turn, is elevated by a tripod of soft brick.

I guess I thought that the system96 needed to hit that high to fully melt, but I guess that would defeat one of the reasons why nuggets were developed in the first place, huh. I haven't seen much pitting on my pots, so I didn't think that there was much deteroration going on; however, I guess if the glass is liquid enough, it could penetrate a hairline and make it a much bigger issue, huh?

Thank you for the info......

This board is an awesome resource.

Pete VanderLaan
07-22-2010, 12:44 PM
The support sounds good. Turn your melt down. Avoid shutdowns. I think the observation about turning it way down instead of off costs a lot less than replacing pots is a good one.. Just stay above 1100F.

Crucibles are really pretty tough but strength is really relative. It's always a trade off. When you melt a glass like 96, you get a very fluid glass at 2300F- too fluid. The wear on the pot is notable. It's really similar to Fluorine glasses. They aren't any more caustic than anything else. It's the low viscosity that the fluorines ( and the 96) have at regular working temps for a conventional soda lime that eat up your refractories. Imagine taking SP87 up to 2500F. The viscosities would be similar , the wear substantial. Glass really is the universal solvent.

Tom Fuhrman
07-22-2010, 01:03 PM
I never take my wire melter over 2160 and melt all types of cullet very easily. going higher is needless and foreshortens the life of the crucible and the elements. elements aren't really rated to sustain heat above 2200 for any long length of time. I think we hashed this out many months ago on some other threads.
I can get a year out of my elements most of the time and much more than that out of my crucibles.

Justin Thompson
07-22-2010, 01:09 PM
Pete and Tom......

Thank you very much for the advice. If I could get a year+ out of my elements, I would be a very happy camper.

Before I switched over to nuggets, I was only familiar with furnaces melting batch; so, when someone told me that I would get a nice melt by soaking nuggets @ 2300, it made somewhat sense to me (due to my knowledge based in batch language). I guess if I would have thought about it for a second, I would have realized that one of the advantages of nuggets is the lower melt temp.

Oh well....I guess that is one reason why this board exists. Thank you Peter, btw.

I just can't wait for the day when my studio justifies me upgrading to a furnace where I can run Moly elements, instead of a wiremelter......err, wait....maybe I can wait. :)

Pete VanderLaan
07-22-2010, 01:43 PM
Pete and Tom......

Thank you very much for the advice. If I could get a year+ out of my elements, I would be a very happy camper.

:)
You probably would get that kind of life if you didn't exceed 2175F, which was actually the whole point behind the system 96 nuggets.
I just did the benchmark melting for the new SP87 Chips and it melted very nicely at 2175F. The trouble with the Spectrum has been the boron which dissolves any of the fireclay or silicate components of your furnace.

Scott Novota
07-22-2010, 10:29 PM
Justin,


I have the newer version of your furnace with the 3 elements. I have run it for 3 years now with the same crucible.

Now, I know it is on it's last leg at this point. Some of the things that I can tell you from my experience are the following:

#1. The dp connector needs to be replaced with every element replacement. It proved to shorten the life of the elements if I left the old one in the furnace. Hell you can buy them in bulk for like 9 bucks each or just switch them to a merc. Either way I stuck with the DP because it proved to go to 80% about two weeks before my element would go. It was like a shot across the bow.

#2. I could get exactly 13 months out of a dp/element set if I never powered down.

#3. The nuggets ate a channel into the soft brick and created a vent. I plug it with a fiberboard plug when not charging. Leave it open while charging it wants out I want it out it gets out.

#4. I work at 2150. I charge at 2150. I work at 5pm to around 9pm at night. If I charge 15 lbs when I am done, go in take a shower have a beer, come out drop in 15lbs more about 1 hour later I can keep my pot topped off. I will loose around 10% a night until the weekend when I empty it and fill it on sunday. If I toss in my last charge at midnight it will have micro bubbles in the 8am range. If I wait until lunch and look real close I might see some fines, at 4pm it is clear as summer rain.

No need to get fancy. It is such a simple product to melt. I can't wait to melt in my new one that is be built now with SP cullet. I plan to turn the old aim with the old pot into a color pot for a bit then rip it back down and build it up as a 40 lbs pot with the 3 elements. I would really last a lot longer with a smaller foot print. I have two new crucibles waiting on my new ideas.


Scott.
.

Pete VanderLaan
09-08-2011, 08:51 AM
After almost four years, Effective Sept 19th, High Temp will have a 3.5 percent price increase on crucibles across the board. So, if you want a pot at the old prices, now is the time. I'll be posting the adjusted prices on Sept 19th.

Chris Marriner
12-10-2012, 03:34 PM
First post here - so I hope that this is in the right place... or at least an acceptable place...

I have a 14" High temp aluimina crucible.
I have it inside a custom - but similar design to an AIM wire melter.
The main lid is 3" brick with an access port door of 2" brick.
The main lid sits on top of the crucible - the thought was to keep the heat in - when opening the port to gather...

Im guessing that the crucible has some insulating properties and that when heating the temp in the firing chamber will likely be different than inside the pot

For example I stuck my pyrometer into the air chamber above the pot and it is about 200-220 degrees (750 degrees) less than the firing chamber (970 degrees) Presently at 1440 firing - 1250 inside pot...

I assume that at some point this will even out or should we have left approximately 1/2" for air flow??

Is this temo difference stressing out my pot and risking possible shock??

Is there a point where crucibles basically become just a vessel and transfer heat evenly because its lost its insulating property??

As it's heating up... I've got a lot of time to wonder about all these questions...!!!

THANKS!!

Pete VanderLaan
12-10-2012, 05:07 PM
It sounds like there is no controller on the furnace which makes it really dicey. The pot should be brought up at 45F per hr until you hit 1000F and then hold for four hours. Then go to 1100F over four hours and then hold at 1100F for four hours. Then go back to 45F per hour until it starts to glow. Then just turn it up.

It sounds like this particular horse has already left the barn.

Electric furnaces have thermal planes, there's no way around the fact. It's part of why I like it turned up slowly. The pot has zero insulating capacity. You are just seeing reflective heat versus latent heat. You don't say how close the pot is to the elements. Too close is bad. I like about 1.5 inches clearance.

In my opinion, Trying to run a furnace with a pyrometer is a recipe for trouble.

Chris Marriner
12-10-2012, 06:53 PM
Pete -
The horse is on it's way - but fear not!!! I forgot to mention the controller... 3 button Orton - programmable up and down... I have it programmed up 75 degrees per hour - so hopefully the 30degrees isn't a problem... and I missed the soak at 1100... (Fingers crossed - I will build those in for future firings) (See the ramp I'm using at end)

The pyrometer was only to see how well the inside of the crucible was heating...
The thermocouple for the controller is in the "firing chamber" with the elements - so I'm guessing that it won't read the same temp as inside the crucible... until it reaches that stabilization point... Glad to hear it has no insulating properties - and the difference between reflective and latent heat... sounds normal.

Elements are recessed into a t slot in the brick to hold them in place without pins or insulators. The crucible is approx 1.5" from the elements... a little more in the corners of the octagon...

Should there be a gap to allow the heated air from the elements directly into the air space where the crucible is?? or is minimal gap better to reduce the work of the elements??

Melting Spectrum System 96... I know... but it's what I had...

Another thing I'm worried about is heat loss when opening the port to gather... but I guess once the crucible and the glass reach the magic temp - that it will probably retain heat pretty well and its only a few seconds per gather...


75/hr to 2200
hold for 4 hours
down 30/hour - 2000 for squeezing
hold 2.5 hours
up 50/hour to 2125 - working temp...
Indefinite hold... Then I can switch programs to cool down...

Then a separate program for cooling at 50/hour after scraping the pot. Do I need to slow around 1100 on the way down??

I just popped the lid to take a peek and the glass is getting soft!! (and everything still looks intact!!!)

SORRY FOR ALL THE QUESTIONS!! and thanks for the SPEEDY answers.


It sounds like there is no controller on the furnace which makes it really dicey. The pot should be brought up at 45F per hr until you hit 1000F and then hold for four hours. Then go to 1100F over four hours and then hold at 1100F for four hours. Then go back to 45F per hour until it starts to glow. Then just turn it up.

It sounds like this particular horse has already left the barn.

Electric furnaces have thermal planes, there's no way around the fact. It's part of why I like it turned up slowly. The pot has zero insulating capacity. You are just seeing reflective heat versus latent heat. You don't say how close the pot is to the elements. Too close is bad. I like about 1.5 inches clearance.

In my opinion, Trying to run a furnace with a pyrometer is a recipe for trouble.

Pete VanderLaan
12-10-2012, 07:05 PM
A lot of people actually isolate the elements from the open chamber above glass line. With caustic glasses, like the one you are using, their has been some substantial evidence that it prolongs element life

Dennis Hetland
04-22-2017, 10:28 AM
How much is your 100 lb 16" crucible? How many do you have?

Pete VanderLaan
04-22-2017, 12:41 PM
How much is your 100 lb 16" crucible? How many do you have?
*******
$358.00. Holds 108 lbs Normally in stock. It's rare for us to have less than two in stock. I can't do an inventory check on the weekend.

David Russell
04-22-2017, 03:36 PM
I am thinking abut changing out my hi temp 22" this summer, it has been hot for four years. Nuff said.

Pete VanderLaan
04-22-2017, 05:14 PM
I am thinking abut changing out my hi temp 22" this summer, it has been hot for four years. Nuff said.
********
Crucible life is based on frequency of charges at fixed temperatures dependent on the material melted at what temperature also considering how frequently it is turned on and off. In my world, I change out a pot at 70 cycles and never more than 90. I don't have leaks and always have excellent glass. Turning pots on and off reduces this by up to 35%. That's my world.

Anything different than this approach, based on 40 plus years of observation is dancing with the devil regardless of who your crucible manufacturer is. Some are sworn by, some are sworn at. None of us do well being made into something we really are not. At High Temp, we have tried to keep pots available on the shelf at very fair prices. That was not the norm ten years ago. People had to wait a minimum of four weeks and up to four months to get a replacement pot. We strive to keep inventory.

David Russell
04-22-2017, 05:19 PM
I do adhere pretty much to those values, even still i think the longevity speaks well for the product, just my 2 cents.

Pete VanderLaan
04-22-2017, 05:21 PM
I have seen strange outliers to the norm. I stick to the norms and don't try to create unreasonable expectations.

Dennis Hetland
05-31-2017, 08:55 AM
How much for your 300 lb pot?

Pete VanderLaan
05-31-2017, 10:28 AM
you can look at all the pots, specs and prices at www.crucibleconnection.com