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Mark Dolan
09-22-2011, 11:01 AM
I am about to fire up a new electric crucible furnace (Evenheat Crucible 8) and I 'm wondering what type of glass I should melt. From the many posts on this subject, it appears I should be heading towards cullet and not batch. If so, where can I find 50 lb bags of cullet in pellet form? I'd like to not have to deal with dust if possible and it seems glass in pellet form helps avoid this hazard.

Thanks

Pete VanderLaan
09-22-2011, 11:14 AM
Richrd Huntrods has been successfully melting Spruce Pine Batch in a wire melter for a long time and at this point that is what I would recommend.

Currently there are three boutique cullets out in the market. One is profoundly caustic on your pot and furnace, one has an unacceptably high expansion co-efficient and one has substantial production problems. Until the production problems for Spruce Pine cullet are dealt with, which should take 6-8 months, I can't conscientiously recommend any cullet at all.

Mark Dolan
09-22-2011, 11:21 AM
Thanks Pete. When you say SP is having production problems, are you referring to their ability to get their product to market or is your concern more of a product performance issue?

Pete VanderLaan
09-22-2011, 11:51 AM
Spruce Pine was having their cullet melted at Fenton Glass which seemed a reasonable idea at the time since Fenton had unused capacity. It took about one year and Fenton announced it was going out of business leaving no where to melt the product. Spruce Pine is in talks now to have furnaces built right at the batch plant so they can control the entire process in house. That will take some time to actualize, but my opinion is that it will make for an excellent product that has stood the test of time over 25 years.

I did the initial product testing for melting, expansion, etc for Spruce Pine when the cullet was initially introduced and found it to be an easily melted product that was not corrosive on the furnaces or their crucibles which has not been my experience with other products. It is the standard against which all other commercial glasses are constantly compared. While I think that the issues surrounding melting it at Fenton have been problematic, I fully expect that keeping the operation under one roof is the best plan for melting trouble free glasses down the road.

Scott Novota
09-22-2011, 11:55 AM
Old nuggets will eat out a vent in the lid of your wire melter in about 2 years if you melt 2 to 3 times a week.

Just to give you and idea what will happen over time with the old nuggets. Even knowing that I use them because they are perfect for a couple things that I make where the shorter working time is spot on. I just make a new lid.

I have been melting the new nuggets in a different wire melter and have no problems at all that have to do with the nuggets. Problems with me on the other hand are rampant.

Mark Dolan
09-22-2011, 12:33 PM
Thanks again Pete. So what you're saying is, if I can find SP batch cullet, then go ahead and use it. Below is the link to the product I'm looking at. Otherwise, use SP batch.

http://www.sprucepinebatch.com/spruce_pine_cullet.htm

Andrew Brott
09-22-2011, 12:53 PM
Mark-
funny you should be posting this as I am at the same point, and was planning to melt;
http://www.glasscolor.com/batch/system_96_nuggets.aspx
Where can you get SP cullet?
Felt like I had to use 96 until another solution was found as to make sure I fit the strawberry 139 and 218 colors I normally build from.
Thanks,
Andy

Mark Dolan
09-22-2011, 01:03 PM
Andy

I just called SP and they said they were trying to get back into production of cullet in a month. That was my only source.

Mark Dolan
09-22-2011, 01:08 PM
Thanks Scott. I've heard that System 96 nuggets are hard on wiremelters from others as well. To get started, I think I will go with the batch until SP can come back on line with the cullet.

Andrew Brott
09-22-2011, 02:34 PM
So...
What is harder on wire melters.
SP batch vs system 96 cullet-
a loaded question with way too many right answers for the wrong application...
I think I'm going to go the 96 route, as I see cullet as doing less damage.
This sucks.
AB

Bob Meyer
09-22-2011, 03:29 PM
I've used the system 96 nuggets for about 4 years, and just don't see the problems often mentioned here. And I know about 4-5 other blowers in this area that use them, and don't hear anyone talk about unusual wear.

Bob Meyer
09-22-2011, 03:30 PM
I've used the system 96 nuggets for about 4 years, and just don't see the problems often mentioned here. And I know about 4-5 other blowers in this area that use them, and don't hear anyone talk about unusual wear from them, either.

Scott Novota
09-22-2011, 06:09 PM
The first batch of 2000 pounds of nuggets did a lot of damage. The 4000 pounds the eletroglass furnace melted did a lot of damage.

The new nuggets have done no damage that I can tell.

I have melted about 2000 pounds of the Standard nuggets after coming back online after repairs and it is a much newer batch melt from the ones that did the damage. It seems to not be eating at the lid so far but time will tell. Maybe something changed....I will let you know when I have finished off the pile I have and can shut down and take a very good look.

I like the nugget product and it's ease of use.

I like the Sp cullet as well.

I like glass and will take any path to play with fire that the law allows.

Andrew Brott
09-23-2011, 10:53 AM
Thanks Scott-
I am turning on (strange not to say firing up...) a Jenken Double Walled Crucible - http://jenkenkilns.com/dwcrucible.aspx using Peter's 0016 crucible http://stores.intuitwebsites.com/crucibleconnection/-strse-18/FC0016/Detail.bok.
I may (and hopefully always will) be a kiln fired first kind of glass person, but have an extensive hot shop background, so I know what I'm in for, but still very excited to explore the ROI of inexpensive wire melters when used with a "real" glory hole.
Not to say a wire melter is not real, they are, as I saw what a former students John Witt and Ian Whitt had simply built in their Mississippi home/studio.
Worked fine. http://www.sweetwaterglassstudios.com/hot_glass.htm
But "real" furnaces are real expensive to build, run, and maintain.
This fact alone makes artists live in tents and sends them to markets.
A furnace on dictates design.
I don't have the time now (gotta build a shop ASAP) and this is maybe not the right place to post and discuss, but I think technology exists today to make a easy up, easy down inexpensive free standing electric (hybrid? (just a concept- would need MUCH testing) with protected elements to safely control keep crucible safe at temps below 1800f- then to gas?) pot furnace. The problem is in the details- i.e. the 100+ variables that need to be tweaked maintained with back ups to redundancies to make this concept work.
Glass choice is one of the biggest, and I plan to vent as I charge with preheated Spectrum 96 (thanks again Scott).
- batch off gasses too much for my taste + these wires and lids-
Sorry for the long rant...
AB
p.s. I am working with the folks at Jenken to retrofit/improve what they have thus far with their Crucble Kiln using Guadalupe pots, and they will be in my New Orleans Studio on the 17th of October- will post and share and ask for your input as we get close to that date.
Thanks to all...

Scott Novota
09-23-2011, 11:37 AM
Andrew, the JenKen is what I have as well as an older aim that is back in the corner cold. It was on for 3 years.

I put a vent in the lid for when I charge Mike would have done if for me had I asked. That kiln could be made just a little bit different and save some more energy. For one it could use an extra set of bricks on the bottom which is one of the tweeks I put in by just putting a extra layer down there. Shoving in some frax on the side will save a lot if it had a shell that would work for it.

On a side note be sure to get a really good seal on the pot to the lid. I use a one inch ring a frax compressed flat between them. If you keep the gas off from getting to the wires they will last about a year in my experience. If you don't, like me when I get in a hurry, they will last about three months.

Richard Huntrods
09-23-2011, 02:26 PM
I built my furnace in 2003. It ran until 2006 24/7. I only ever melted spruce pine in it.

The very first run was SP cullet from a good friend. I overcooked it and it boiled over; I had to rebuild part of the furnace.

After that, I only ever melted Spruce Pine BATCH in my furnace.

SP Batch has not had ANY negative impact on my furnace. The innards look almost brand new to this day.

The only maintenance required was rebuilding the lids a few times due to glass drips from gathering. Last rebuild I replaced the gathering port with rammable and it still looks like brand new.

SUMMARY: Spruce Pine BATCH simply cannot be worse for a wire melter than what I'm hearing about cullet on this board. There is no way I'd put up with the crap cullet is causing.

SP batch does not need to be cooked to death. Just be SURE your wire melter is actually delivering the temp showing on the thermocouple and follow a good melting / cooking schedule and it's good. You also do not need to cook for a long time unless you cannot get heat into the center of the crucible.

Which brings up one key point: I think 99% of all SP batch "cooking" problems are due to under-heating the CENTER of the crucible mass. You have to have thermal equilibrium to the very center of the crucible or you are not getting the temperatures you think you are getting.

Caveat: I'm only melting in a 40lb wire melter. I think the practical limit of wire is between 75 and 100 lbs, simply due to getting the center of the pot hot enough. Keeping the wires really hot (above 2200 F) for a long time will shorten their life, so trying to cook really big pots of glass basically puts you at the limits of wire heating, IMO.

Cheers,

-Richard

Pete VanderLaan
09-23-2011, 03:37 PM
I would agree with every single thing you have said. Thanks Richard.

Andrew Brott
09-23-2011, 05:56 PM
Thank you!!!
Richard-
please look here-
I just ordered these:
http://stores.guadalupeglass.com/-strse-18/FC0016/Detail.bok
for this:
http://jenkenkilns.com/dwcrucible.aspx
should I have ordered-
http://stores.guadalupeglass.com/-strse-13/FC0014/Detail.bok
?
FYI: have this double walled crucible wired for 3 phase (maybe a touch stronger (?) than the 36 AMP single)
+ I know what I'm up against with a wire melter- and how I will never will get or keep glass "goblet hot"- fine with that, but am worried about charging/melt times and not having to put a potato on the end of a punty...
This was part of the reason I wanted to melt cullet, the other was the off gassing of batch. Would feel safer with a 14" pot for SP batch. Wish I could get the cullet and make the 16" work.- (or at 110 lbs of glass would it with Jenken)

After speaking to several others, these WM loose heat quick, and I need to unlearn how to blow glass goodly and go full out stupid!!!!!- i.e. get most of my heat from a glory hole than from a proper gather.
FYI: Never ever say your not going to make a living blowing x-mass balls- it may come back to haunt U...
So to do these, we make long tubes then just blow single balls off the end (off the hump)... Then its' gather, rinse, and repeat (joke) on top get more glass when your close to the end/moil. One blowpipe can = many hours/balls...
As to the long flat cane pulls; if I get big stupid cold gathers that I'm forced to cut with casting shears as to not drip on the door- so be it-
I will just go straight to the glory hole +
Thanks,
Andy
p.s.- To any of ex-students reading- u can only get away with using these wrong, BAD BAD BAD ways of working because I learned how to gather the right way first...

Franklin Sankar
09-25-2011, 07:14 AM
Andy what is the right way and is it specific for an item? Sorry your last post lost me.
Franklin

Andrew Brott
09-25-2011, 09:21 AM
F-
Typing from my phone so please excuse my brevity
And spelling on a very complicated subject.
What I refer to as wrong, bad, and what I see as the way NOT to blow and or work hot glass is to gain even heats from a reheating furnace I.e.- a glory hole- instaed of gather properly at the right tempuratures (if you are doing multiple gathers) and get done as much as you can using the heat left in the glass from the furnace.
I know everbody works in differnt ways or styles, but what impresses me the most with those who many consider the best, is the speed they get things done. Hope that helps my phone battery says shut up an plug me in..

Pete VanderLaan
09-25-2011, 09:35 AM
Shorty Finley always referred to it as "Glass has a Life". You can get an awful lot done without reheating if you know where you're going and when.

David Hopman
09-25-2011, 12:16 PM
I've been using the East Bay Electric batch in my electric for almost 3 years now and am extremely happy with it.

Scott Novota
09-26-2011, 11:06 AM
In the JenKen I can without reservation say that dead center in a 14 inch pot showing 2125f is about 20f cooler than the glass close the the wall for about 4 inches.

Gather accordingly.

Scott.
.

Andrew Brott
09-26-2011, 11:58 AM
Scott-
Have 16" pots coming- am I in trouble?
Should I see if PV has shipped and drop to 14" wide?
About to call u thanks!!!!
and or call me asap
Thanks
Andy

Scott Novota
09-26-2011, 12:32 PM
I run the FC0014 from Pete, which is 14.5 inches in diameter.

If I remember correctly it is 19 inches in diameter across the inside. Which left 4.5 inch or about 2.25 on each side to the wall.

16 3/8 would leave you about 1 inch to each side if my numbers are correct. You will have plenty of height. I don't know the "rule of thumb" for how far a crucible should be from the wall so I don't know what your problems will be if any.

I am interested to know how it works if you stick with the 16 as I might switch over if it works for you.


Scott.
.

Pete VanderLaan
09-26-2011, 01:41 PM
What is really at issue is whether you have the amps to drive the larger pot. That's a question for the kiln makers. You need 2200 watts per cu ft to get toasty.

Franklin Sankar
09-27-2011, 08:42 AM
QUOTE....and get done as much as you can using the heat left in the glass from the furnace......
Easy to do when you can work fast. To work fast you must know what the glass will do next. For sure it will freeze next. Thanks Andrew.
Fraklin

Pete VanderLaan
09-27-2011, 09:01 AM
Actually, its to know all of the things that have to happen to make the piece without hesitation or fumbling for tools. Just the simple search for jacks at the bench when you sit down costs you a reheat every time.

Then using a glass with a good life really helps. Sometimes it's too good.

Andrew Brott
09-27-2011, 10:10 AM
and best to learn on glass that's quick to set up and great for casting,
makes u have to work fast....
claimed to have and did retire from the teaching, but when I was one of my favorite exercises was the 5 minute tumbler.
- u gather and have five min to have that done and in the box, or it goes back in the furnace as cullet.
Loads o phun...
AB

Franklin Sankar
09-27-2011, 08:38 PM
You did not say it had to look perfectly good. haha too late.
Franklin

Sandy Dukeshire
09-27-2011, 09:10 PM
Thank you!!!

should I have ordered-
http://stores.guadalupeglass.com/-strse-13/FC0014/Detail.bok
?.


I'm thinking this is a better choice. with 14 1/2 inches as your OD, you will be left with about an inch of space from the outside of your pot wall to the tip of the TC. Also, the larger pot will really be asking a lot from the jenken even if you can squeek it in without touching the TC.

Andrew Brott
09-27-2011, 09:20 PM
Sandy-
many thanks, do you have experience using this same Jenken?
Thanks to peter have not processed order but need to in the next 24 hrs...
I am so damn on the fence, as I feel like I need those extra 30lbs of glass.
I know it would be cold in the center, but hot enough to safely melt Spectrum 96?...
Thanks,
Andy

Hugh Jenkins
09-28-2011, 02:53 AM
Cautious or adventurous. 30# stands between a fairly secure glass quality and the maybe alright result. Bear or bull? As crazy as the adventures I have had with glass might seem, I am very cautious about each new step. The quality of the glass is the bottom line for me. Otherwise I have to go back to the last known acceptable stage and go from there.

You can't know the result of two experiments at the same time, unless you have two parallel furnaces to work with. That never happens, so choose knowing what it is you are looking for as a result.

I know this seems kind of analytical, but it comes from many years of going down both paths.

Sandy Dukeshire
09-28-2011, 07:12 AM
Andrew Darling, you are making yourself crazy. you dont need 30 extra pounds of glass sitting cold and giving you crappy gathers. think about it. will you use all of 110 lbs in a day? think about the poor TC - shoved face first into the pot wall - that cant be good. and i'm thinking about comming up to working temp from idle, it will take a long time, and the center will still be cold even longer. why not start small then down the road go larger if things look to be a go?

i have run my jenken for almost 6 years worry free years melting the old nuggies. yes, gass off is an issue, and when its time to reorder i'm thinking i will switch to sp cullet, because sp is so nice to work.

When Mike comes to visit, tell him a built in lid vent would be a bonus, and the lowest element will get buried in the event of a cracked pot/boil over/whatever. i would like to see more space between that element and the floor.

and Andrew, unless you like unsticking the lid from the gathering port my bet is you will learn to gather different pretty quick. the vertical gather is an art in itself. i will gather for anyone looking the least bit confused, and it has paid off in that Baby still has her pretty face.

and Scott, are you saying your working temp is 2125? i use 2150.

Pete VanderLaan
09-28-2011, 08:03 AM
You can't know the result of two experiments at the same time, unless you have two parallel furnaces to work with.
*******
Most days I don't even think you can know that. Always , I am remembering Lino's semi cryptic observation " Melt glass where it wants to be melted" He wasn't kidding.


If, in the Jen Ken you try to keep a larger mass at a constant temperature and it has borderline power, it will be on full much more of the time. That's going to wear things down. I do think you might be better off with an SCR supplying the power to the elements since it will make the power delivery a lot smoother and will retard the attempts at arcing that are going to occur. . But that is more expensive. You have to remember it's a wire element furnace. I'm building a 130 lb moly furnace for someone right now and it will be infinitely more responsive but that comes at a substantial price.

Pay close attention to your wiring from the main panel.

Pete VanderLaan
09-28-2011, 08:05 AM
Andrew Darling, you are making yourself crazy. .
********
I could not have said that better.

Andrew Brott
09-28-2011, 09:41 AM
Sandy and Hugh-
thanks-
Your both right, and I don't need to make myself any crazier than I already am. I will start with 14". That said- some say and I agree- "It's better to make good work out of bad glass, than bad work out of good glass", so most of my hot work does not rely on perfect- bubble free Scandinavianesk glass- would be nice, but not totally necessary- + Johnny Watson + Me= blow many glass- many quick, so I still want to try the 16", but only later after I get done what is needed -
Your advise is of GREAT HELP and badly needed thanks.
Best,
Andy
p.s on a somewhat related side note, I may not blow glass much anymore (my wrists luv me), but thanks to specific exercises from athlete friends + the right exercises equipment http://www.bayoufitness.com/total-trainer-dlx?gclid=CJXz6OD_v6sCFQTu7Qodg1K0rA
I a much stronger (better (?) glass blower at 42 (yes- u are old) than I was at 22 or 32 when I was NOT working out...
With pro athletes getting so much bigger, stronger, and faster (look at NFL etc.) are the pro glass blowers (NBL?) doing the same?
Is work getting bigger, stronger, faster?
AB
p.s. As you can read above, I can't spend much more time on this board, as I end up wasting time...
OUT>>>>>>>>
AB

Randy Kaltenbach
09-28-2011, 10:52 AM
42 (yes- u are old)Youngling you are.

Andrew Brott
09-28-2011, 11:07 AM
42 (yes- u are old)
that was intended to remind other readers reading who knew me when I was... I is all growed up now!!!!, and granted I may still act like I'm 12 years old (Jean H says 11) but I can actually sit still long enough to?....
Granted my ADHD meds help...
AB

Andrew Brott
09-28-2011, 11:43 AM
I do think you might be better off with an SCR supplying the power to the elements since it will make the power delivery a lot smoother and will retard the attempts at arcing that are going to occur. . But that is more expensive. You have to remember it's a wire element furnace.
Having Mike jenken look into this as from Watlow-
any links?
Hope to outline my furnace/wire melting "Target" concept in a later post, but it deals with glass as the center of a "target", then each successive ring of "hardware" (i.e. refractory/elements) outside of it this becomes more permanent all the way to the steel frame and stand. Glass is first to go- frame is last- Know this is how every furnce/melter works but want to isolate, analyze, and improve each target ring into easy (easier) to change components.
Think back to Kathal K-Blocks.
Dick Huss had these- frigging brilliant!!!!!!!
Elements/wire vacuum formed in INS bored- elements not exposed to air (or only partially).
Then back @ the "target" ring components-
Peters got the crucible science nailed better than anyone, and keep working your way out to frame.
If integrated with SCR, computer software, and right cullet and most importantly economy of scale we could have a supper efficient easy/safer- up/down low cost free standing wire melter affordable (joking for here on): for export to Asia so we can have even more low price Chihullllly knock off chandeliers.
I can't use the board any more today- I need to work...
OUT!!! and thanks,
Andy

Scott Novota
09-30-2011, 05:15 PM
Charge, melt, blow all 2125f

Pete VanderLaan
09-30-2011, 07:24 PM
They should name the furnace the Isotoner. "One size fits all"

Dave Bross
10-03-2011, 06:25 AM
Furn-o-matic!!!!! it slices, it dices! ......But wait!!!!....There's more!

Scott Novota
10-03-2011, 03:18 PM
If you order now we will toss in the magic mountain glass.

Pete VanderLaan
10-03-2011, 05:05 PM
where the lead is leached out harmlessly...

I miss Heidi Broderbund. What a snake oil salesperson.

Andrew Brott
10-05-2011, 10:27 AM
Spoke to the folks (brandon) at spectrum yesterday as to make sure my color fits before I ordered 500lbs...
discussed the caustic nature of this glass- what he said made sense:
- batch gets melted a higher temp (he said 24- I say 2350)-
- flux off gasses at higher temps burns off, that's the corrosive shiat that eats non contact refractory (contact? + petes pots?), but @ higher temps is quickly burned off and gone.
These nuggets only get melted at 22 to 2150- (as read below to "win the election and gives u an erec......")
so they must be slowly farting the sbd like vegan who ate a stuffed flounder- (my fresh material- feel free to use/share).
Make sense and my eyes water...
No more time to spend on this, but I should have asked them then why don't they melt higher temp and get the gas out before they form the nuggets?
But know there must be some flux/melt thingys needed + there will be no "right" answers.
Form follows function- and my first need is to fit r139 + 218's
AB
p.s. what ever happened with the Seattle Batch that went to China (?) as as batch and came back as a cullet?

Pete VanderLaan
10-05-2011, 01:09 PM
Your guy at Spectrum is saying what real world circumstances aren't proving out. The experience people have with the nuggets has been that they eat up silicates and fireclays and aluminas. It's particularly difficult for electric furnaces without venting.

First Spruce Pine batch doesn't need to be melted at 2400F, or even 2350. I melt my own at 2275F.

Not all batch is the same. Both Spectrums glass and Gaffers batch contain a lot of Borax and both eat at silicates and fireclays. It's kind of in the nature of a material that lowers the melting points of silicates that it would do that. It really lowers the melting point of everything. Think of glass as the universal solvent.

Melting completely in my opinion takes more time and therefore costs more money.

Seattle Batch had a glass coming from China that was in effect the formula from Gaffer, or so said Gaffer. It lacked one of the actual expensive ingredients. SB received shipment after shipment and the linear expansions on each shipment varied wildly which was not surprising since the price suggested that it could not be sufficiently controlled at that price. It did not take long before people no longer wanted to risk using it. Then, Gaffer pulled SB's license to mix Gaffer Batch for reasons I won't go in to here. . End of SB more or less in the batch biz. That was about five years ago as I recall. You need to get out more.

Thomas Chapman
10-05-2011, 02:41 PM
Their advertising had Lino, Dante, and Sonja recommending it. The most interesting thing that came out of that short-lived campaign was the "Pi" rods. There was a pretty full colour palette of 18-inch long cane, perfectfly parallel and 1/4 inch in diameter. The ends were even cold-worked. They were bundled, hand-tied, bubble-wrapped and boxed in great detail. They also had "hot-dots"-- hand-chopped murrini by the box. I wish that cane was still available.

Pete VanderLaan
10-05-2011, 04:54 PM
Sometimes personal endorsements as favors aren't really a swell idea. I had someone last week hoping I would suggest to a local fire chief that solenoids on gas lines weren't necessary from the point of view of a former fire chief of a much larger department. .

I passed.

Richard Huntrods
10-05-2011, 04:55 PM
Spoke to the folks (brandon) at spectrum yesterday as to make sure my color fits before I ordered 500lbs...
discussed the caustic nature of this glass- what he said made sense:
- batch gets melted a higher temp (he said 24- I say 2350)-
- flux off gasses at higher temps burns off, that's the corrosive shiat that eats non contact refractory (contact? + petes pots?), but @ higher temps is quickly burned off and gone.
These nuggets only get melted at 22 to 2150- (as read below to "win the election and gives u an erec......")
so they must be slowly farting the sbd like vegan who ate a stuffed flounder- (my fresh material- feel free to use/share).
Make sense and my eyes water...
No more time to spend on this, but I should have asked them then why don't they melt higher temp and get the gas out before they form the nuggets?
But know there must be some flux/melt thingys needed + there will be no "right" answers.
Form follows function- and my first need is to fit r139 + 218's
AB
p.s. what ever happened with the Seattle Batch that went to China (?) as as batch and came back as a cullet?

I'm sorry, but like Pete I call BS on that 'expert'. Sadly, he has a stake in the outcome, so is not a neutral party.

By it's very description, cullet/nuggets/shards are FULLY MELTED GLASS that has been cooled and busted up in some way. All the melting and cooking and fining should have been done long before the bag shows up at the shop door.

If the glass was sitting in a pot and was not harming that pot, then cooling it and busting it up and then re-heating it simply CANNOT transform it into caustic shit. CANNOT.

If you take good, properly melted and cooked Spruce Pine batch (and it is SOOO easy to do), then cool it and bust it up, you can't harm the pot by remelting it. Now, if you're a damned fool like me and crank it up to cooking temps, then you will reboil the glass (even SP) and get a mess that will eat your furnace, but that is pretty dramatic and rapid. Anyway, just remelting the glass at blowing temp should give you back almost exactly what you stared with - a pot of great SP glass.

I blow at 2100. I should be able to melt a properly made cullet at that temp - no special treatment. If I have to wash the stuff (even just once), then pre-heat it and gently scoop it in, all just to avoid harming my furnace or to avoid getting seedy crap glass, then why not just melt Spruce Pine Batch?

(Load at 2100 until full. Cook at 2250 for 3 hours "at crucible equilibrium*", then quickly cool to 1900 overnight and you have awesome glass.

*crucible equilibrium is why some batch cooking takes 8+ hours while mine takes 3. In a 40lb pot, you can have the center of the glass mass at 2250 within an hour of raising the temp, but for huge masses of glass, that will take considerably longer. If you don't get all the glass to 2250, then your cooking won't be right. This is probably why some with larger furnaces report batch isn't working well, or why cook times are reported as so long.

Cheers,

-Richard

Pete VanderLaan
10-05-2011, 04:58 PM
*crucible equilibrium is why some batch cooking takes 8+ hours while mine takes 3. In a 40lb pot, you can have the center of the glass mass at 2250 within an hour of raising the temp, but for huge masses of glass, that will take considerably longer. If you don't get all the glass to 2250, then your cooking won't be right. This is probably why some with larger furnaces report batch isn't working well, or why cook times are reported as so long.

Cheers,

-Richard
*********
Bingo, yet again. Stop using clocks, Use your eyes.

Josh Bernbaum
10-05-2011, 09:50 PM
*********
Bingo, yet again. Stop using clocks, Use your eyes.

I've seen you say this time after time here, Pete, that you look for big bubbles with clear space between them, and that is a glass ready to squeeze.

For a relative newbie like myself, could you elaborate on what we'd probably see when taking a gather to look at if it were either too early before or too late after that glass should be done being cooked?

Pete VanderLaan
10-06-2011, 07:12 AM
Too early: A bazillion tiny bubbles and the glass still feels a little fat- it doesn't just run off the pipe.

Too Long- 3/4 of the crucible wall in your gather.

It's hard to go too long but I was only half joking. Once you start seeing those little bubbles joining up with each other, they will be large and stay large. There will be noticeable spaces between the bubbles that are just clear glass. The glass will really not clear up more at this point. The chemical reaction is done. All that you ar doing at that point is wearing out the pot.

Those bubbles have to go and they won't rise out of the melt unless you have a profoundly low viscosity glass, which SP87 is not. Many fluorines will. Spectrum nuggets might for all I know but I've never allowed it to and there is a huge cost to those low viscosity glasses. They are so fluid that they can attack through the interstitial spaces in the crucible. Some are so fluid that they can both be attacking the liner and gassing off materials that attack the rest of your furnace as well at the same time. I melt my fluorines at about 2100F from raw batch and the melts are done in three hours.
So, when you see these really big bubbles it's time to squeeze. The "Squeeze" as the slang goes is doing two things at the same time. Firstly, The antimony in your glass is monovalent at normal melting temperatures. That means it only has space for one electron on the outer ring of the atom. When it is cooled down to around 2000F, it changes to a pentavalent state and then has space for five electrons on the outer ring, so it begins to absorb gases around it. At the same time, the cooling of the glass is causing it to shrink at a rate equivalent to it's linear expansion coefficient
So, the glass is shrinking and the gas is being absorbed. What you see is the bubbles getting smaller and smaller until they are reabsorbed into the glass.

But they are still there. If you don't believe it, take a clean gather and hit it really hard with an air gun for about 45 seconds and then stop. Huge bubbles will suddenly appear in your gather that will then gradually shrink and go back in to solution.

That effect is known in glass slang as "reboil " and it occurs when you turn your pot of nice glass up too high- usually around 2200F and the antimony converts back to a monovalent state. It suddenly sheds all those gases.

But there's more to this. When you have finished your melt, using a clock which most people unfortunately do, the glass actually needs to be stirred, the more the better. Corning uses stirring machines, so did Steuben. Your alternatives are to stir with compressed air or to use a potato. Ed likes compressed air, I use potatoes. I get to coach about five people a year through trying it the first time and it does really give you better glass. If there are people who want me to expand on cooking starchy stuff that gives you type II diabetes quickly, I will but this is getting a little long winded.

Andrew Brott
10-06-2011, 10:20 AM
Pete VanderLaan- You need to get out more.
yea, yea- u be right- but who's going to pay me to do that?
+ If u saw where I work/sleep/live/eat/swim
www.thenewfreret.com u would c I have little reason to go a 1/2 mile from my Freretian nirvana. Especially now that i will have a hot shop.
+ this coming from u is like the pot, calling the corroded kettle cracked...
How do U ever "get out" and find the time to freely and thankfully write this stuff...
+ do "Super Moderator" person man- complete with lightning and quips on unobtainium (added that as your theories sometimes need this to work)
+ and have a life outside of being a total friggin glass science/art geek.
U like myself and many others, must have wonderful help/support, and or a very understanding life companion...
As always- a big shout out and HURRAH to u Mr. PV for your input/help.

As to the glass...
I know from experience how amazing (flows like honey in molds at 1350/1400) the high lead (45%+) Gaffer Casting glass is.
Side note for kiln casters:
If u have NOT tried this or high lead/low temp glass DO IT!!!
it pays for itself.
but also know one of the main reasons we do not blow high lead content glass to (correct me if i'm wrong) is they are extremely corrosive.
Great low temp, but...
Like time over temp- there is the risk vs reward ratio + many, many factors at play in the ROI (return on investment) on what glass to use and it's properties.
I have to use these 96 nuggets (sorry I skipped the details in your valuable tech input)- but "form follows function", so with a wire melter (untested for me), limited time and $, + MOST importantly the need to fit my colors, they present the least risk.
Besides I read it on the internet, so it has to be true..
Many thanks for all the input- will post and share results/findings.
Best-
Andy Brott
www.brottworks.com

Dave Bross
10-07-2011, 06:07 AM
Well, if you must, here's an idea.

I made something like the tear offs for a dirt bike face shield. Stacks of rigidized frax with Kanthal wire "staples" to hold them to the bottom of the lid...which is drilled through the brick for the staple "legs". The lid does takes major abuse in a top loader with nuggies. Wear 'em out, tear 'em off....rinse, repeat,...

I've used a lot of nuggets just because they're easy to get locally and because I can fill 'er up when done in the PM and have good glass by mid morning the next day. Batch adds an extra day to that. I know, I know, as a southerner I'm not supposed to be in a hurry, but you know how the holidays are...and yeah, I should have started sooner. Just leaving the furnace at the same temp all the time appeals to my inner lazy person too. This leaves me time to savor those vegetarian vapor trails.

Andrew Brott
10-07-2011, 08:29 AM
I made something like the tear offs for a dirt bike face shield. Stacks of rigidized frax with Kanthal wire "staples" to hold them to the bottom of the lid...
Friggin brilliant!!!
Was this for a wire melter?
Jenken?
Could do the same or similar with INS board or shelf paper gasket.
Now for the bigger question- noticed were u live, does this mean we have to talk SEC smack?
If so Geaux Tigers!!!!! and stop by if your ever in NOLA.
Thanks-
Andy

Dave Bross
10-07-2011, 01:55 PM
Wire melter? - Ubetcha! Homemade though, not near so fancy as them there store-boughten ones.

I do have a stack of old kilns that will get the doctor demento treatment one day...or was that Frankenkiln...furnace....or.....Look! up there in the sky! It's a bird! it's a plane! no, wait, it's a wire melter.

SEC? I'm football impaired. Clueless....well, I do know it's south eastern conference but I think that's the limit of my knowledge. All my female friends watch football and the men go shopping. I do think orange and blue is a most unfortunate color combination and it's being inflicted on the natives to excess. Alien mind control conspiracies undoubtedly...get the tinfoil.

I suspect the paper would disintegrate once hot and make you very unhappy.

Thanks for the invite!

Andrew Brott
10-30-2012, 10:47 PM
And for a limited time I share the picks...
https://plus.google.com/u/0/photos/102856509543103740617/albums/5805287642749382993
don't have too much time for details...
Jenken is great, will use them again, but I have made improvements...
My GB5 runs it using a type S.
That second controller has an alarm as pictured that calls my cell if issues arise- was able to jump leg and split the S signal so read by both computers.
Working on Type K placement as to eliminate the need for very fragile S.
Thanks to Pete that 14" crucible works great.
Now Pete please don't read the next 2 lines...
I put a 2" high density frax gasket that rests directly on top on top of his pot.
This separates the glass from the elements.
Added Piano hinge to make element replacement easy.
I use and open those ceramic plug sets at the very bottom of the melter to allow fresh air in as I charge like a Webber grill does when you cook-
Have the lid lifted and re-welded to make room for Frax.
Have hydrated + other alumina inside to help grab glass if any cracks happen crucible (from frax gasket...?).
System 96 bad on all, so Using Premuim Nuggets, talked to NC the other day Still not SP cullet.
So sticking to Spectrum.
As I just told the AACG group that was in the studio, I get all my equipment from ceramics companies...
Saves HUGE $...
So that other Jenken pictured is my annealer.
+ Y'all can make fun of my cheap ass hoopy gloryhole.], but Pine Ridge makes a great burner and we are hot quick- and my pipe warmer/garage is powered by that harbor freight weed burner head- I bored out wider to make fit my commercial NG pressure.
Glory hole is on wheels, so we roll out of they way when cool and done.
I try not to blow glass that much- and should not- as our best work/innovations are still kiln fired-
http://brottworks.com/portfolio/printmaking/
Glass blowing is soooo 20th century....
But what's great about our under 7K hot shop, is we still make big work using a hobby setup and go up only when we need to and back down quick. A few days a month. And with the even heat of a wire melter- it's 1.5days up, charge,blow a few hundred pounds, then back down.
Use it only when you have to.
Gotta run- FYI- I have to pull the picks from public soon (China is watching and I don't want them to notice my floor sweeping robot as pictured), so if you read this later - and the link is bad to picks please email me at brottworks.com and I will share, but only if your cool...
Best from Freret,
Andy

Andrew Brott
10-30-2012, 10:49 PM
And for a limited time I share the picks...
https://plus.google.com/u/0/photos/102856509543103740617/albums/5805287642749382993
don't have too much time for details...
Jenken is great, will use them again, but I have made improvements...
My GB5 runs it using a type S.
That second controller has an alarm as pictured that calls my cell if issues arise- was able to jump leg and split the S signal so read by both computers.
Working on Type K placement as to eliminate the need for very fragile S.
Thanks to Pete that 14" crucible works great.
Now Pete please don't read the next 2 lines...
I put a 2" high density frax gasket that rests directly on top on top of his pot.
This separates the glass from the elements.
Added Piano hinge to make element replacement easy.
I use and open those ceramic plug sets at the very bottom of the melter to allow fresh air in as I charge like a Webber grill does when you cook-
Have the lid lifted and re-welded to make room for Frax.
Have hydrated + other alumina inside to help grab glass if any cracks happen crucible (from frax gasket...?).
System 96 bad on all, so Using Premium Nuggets, talked to NC the other day Still not SP cullet.
So sticking to Spectrum.
As I just told the AACG group that was in the studio, I get all my equipment from ceramics companies...
Saves HUGE $...
So that other Jenken pictured is my annealer.
+ Y'all can make fun of my cheap ass hoopy gloryhole.], but Pine Ridge makes a great burner and we are hot quick- and my pipe warmer/garage is powered by that harbor freight weed burner head- I bored out wider to make fit my commercial NG pressure.
Glory hole is on wheels, so we roll out of they way when cool and done.
I try not to blow glass that much- and should not- as our best work/innovations are still kiln fired-
http://brottworks.com/portfolio/printmaking/
Glass blowing is soooo 20th century....
But what's great about our under 7K hot shop, is we still make big work using a hobby setup and go up only when we need to and back down quick. A few days a month. And with the even heat of a wire melter- it's 1.5days up, charge,blow a few hundred pounds, then back down.
Use it only when you have to.
Gotta run- FYI- I have to pull the picks from public soon (China is watching and I don't want them to notice my floor sweeping robot look at the 1st picture), so if you read this later - and the link is bad to picks please email me at brottworks.com and I will share, but only if your cool...
Best from Freret,
Andy