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Dave Bross 03-08-2006 12:08 PM

Yeah, there isn't any kind of tin that 's inexpensive. I was basing my perception of the expense based on having to buy a large quantity to get any.
Just another "I brake for hallucinations" kind of thing.

I'll take the door, of course, but I also think there's value in having alternative ways to go. When we finally turn ourselves into a sub-third world nation and China is vacuuming up ALL the really cool minerals we may need ways to make things with alternative materials.
That, and I only melt 10-15 pounds of color at a time so I don't mind it being "educational" in the sense of having to toss it.

I also probably should have best stated the reduction/oxidation explanation in terms of your having to have the CORRECT level of oxygen in the glass, and you would reduce that level down or oxidise it up to get where you want to be.

I got that angle researching the answer to the "why the nitrate" question I kept asking Pete about cad-selenium glasses. The answer being that selenium glasses are probably the most particular about having exactly the right amount of oxygen. If you're off, the selenium switches valence into the invisible zone.

Aaaah. I just love getting the ol'timers riled up. Good for 'em to have to keep all us whippersnappers in line. Heheheheh!

Dave Bross 03-10-2006 09:33 AM


If you want just a few pounds of the black tin I'm getting I'll sell 'em to you.

Kevin Bethea 03-10-2006 09:52 AM

I just replied to Pete that'd I would go with the minimum. I hope I didn't make you spend money you didn't want to since you already had some and don't need it this moment. I guess pete hasn't placed the order yet either so if you don't want to be stuck with it all then we can ask pete real nicely and I am sure he would adjust the order and we can split what you are getting some way. I could get by with a few pounds in my small operation over here but I want to get my hands on it bad enough I am willing to dig deep if I have to. If you want to hang on to what you are getting since it's hard to find then I will be fine with the extra $30 to meet the minimum order. I am going to do some live glassblowing next weekend with a traveling studio and if I make a few things I was told I could put them on their table to sell so maybe it'll work out and not be a problem at all. If not then I'll have fun anyway. If you prefer to split up what you are getting because you go it just for my benefit or something then well handle it that way.
kevin bethea

Pete VanderLaan 03-10-2006 10:34 AM

why don't you two decide what you want and have one of you order it and I'll ship it to one of you and that person can pay me and you guys figure out how to divide it up.

I'm not trying to be a jerk about it but it's my time that I spend packing and invoicing that wrecks my day. I'm not really in the chemical business as I have stated many times. I do have the buying power and the resources to get this stuff and I am willing to do it. Even so, it bothers some people to no end that I would actually profit from the venture. There is way more profit in making one piece of glass than in doing this. I guarantee you I will spend more than one morning ordering and then weighing and then bagging it and packing this up and invoicing it. As they say, no good deed shall go unpunished.

Scott Novota 03-10-2006 11:30 AM



Dave Bross 03-10-2006 09:03 PM

I'm definitely in for 10 pounds. If Kevin needs a couple pounds out of that I'll do that, re-packaging it here and sending it on.

If Kevin hits the big time, sells some work and doesn't need it, that's fine too. I was just gathering up a bit extra beyond what I already have anyway.

Kevin Bethea 03-11-2006 11:47 PM

Thanks Pete and Dave. I think it's be best to just buy a little to start with so I'll PM Dave and we'll work out the rest. Sorry for the trouble and thanks for dealing with it. I really appreciate the kindness from both of you. I don't think I would have hit the big time anyway but I just found that I have to take a stupid standardized test thing on the same day I was going to do the demos and try to sell some stuff for the first time but maybe next time I'll get to make my first sale. I was looking forward to it too. My copy of modern glass practice arrived today and it's in excellent condition. I have read a couple chapters so far and it's very interesting. I told some people at school about buying it and they couldn't believe I found a copy so thanks for the lead on where to find it, Dave. I checked out Daven's ceramics and it looks like I can get anything else I need from them. I'll do some more research and get more stuff together and then I'll let you guys know when I start to try something. I need to stock up on fritted cullet too but I'll do that soon so I can get started.
Thank you,
kevin bethea

Dave Bross 03-12-2006 10:39 AM


No problem. I'll sell you some of what I'm getting. Probably best to email me. The address is in the signature on my posts.

You'll like Davens even better when you do business with them. Nice folks.

Kevin Bethea 03-13-2006 06:50 PM

Hey Warren,
I got a message today from a guy that works with you. I think his name is Zack. I thought I was in trouble when the head of the art department told me she got a call from from an alumni in Cincinatti and he was wondering what was going on and I think he even called Ralph. She is my figure drawing teacher too and I was a little worried since today was also crit day for a self portrait. Today was the first day back from spring break but needless to say I had a talk with my glassblowing teacher today and I'll be calling Ralph soon. It was funny but I think I explained my thirst for knowledge. I think she still called me the village idiot but I kind of said that's why I am asking for the information. It takes a village to raise a glassblower I guess. Anyway, tell him I said hello and he'll probably tell you the funny stuff Laurel said about me. I could only imagine. I found some color samples today but they were from gabbert and not what I thought they were when I saw the box. I'd really like to make the ice blue that I saw though. We'll see what happens.
kevin bethea

Dave Bross 03-14-2006 08:59 AM

The ice blue is just a minimal amount of cobalt, and maybe a touch of copper to change the tone if you want. I don't have numbers because they're packed away but maybe someone else could provide that?

Thats some teacher that would call you an idiot for asking questions!!!!!!!

Stay curious. It will entertain you for a lifetime.

Bruce Troeh 03-15-2006 11:04 AM

In reading through this thread you mentioned the copper ruby from Dudley's formula would be a higher COE. Would it be closer to fitting a 104 Pete or do you have a ballpark estimate you were thinking by adding the silica.
I'll have to stop by the lake Lotowana since it's close one of these times Peet. Bruce

Dave Bross 03-15-2006 04:52 PM


Was wading thru some of my Gabbert cullet today and I may have misled you. The stuff I have marked ice blue looks like straight up copper blue.


Good chance it is. Most of Dudley's glasses were right in that range. All those recipes he had added a good bit of soda so that's making sense that maybe he was adjusting them to his coe. Don't really know for sure. Easy enough to melt it and see, then adjust from there.

Kevin Bethea 03-15-2006 04:56 PM

Thanks for the tip on the ice blue. I'll play with the copper and see what I end up with. My figure drawing teacher really is awesome. It was funny because she was encouraging and then in the same sentence she popped in her remark. She's good at that. Zack is actually really good friends with her and I think that's how he ended up going to our school so that was meant for him I guess. She reminds me of my great grandmother who was the biggest art influence in my life. When I was young I would stay with her in the summer and work in the fields with my great uncle during the day and then my great grandmother and I would make ceramics when we were done working. When she would see me doing something she didn't like she would yell, "What? Are you stupid?" and it worked every time. I have learned a lot about drawing from my teacher and she takes time to explain negative space and all sort of things to me eventhough I have never taken a drawing class before. She calls em like she sees em some times but I wouldn't trade her for the world. She just thought it was so funny when she found out Zack was talking about me. I got a good grade on my drawing that day too. I was going to mix some red by the recipie we have at school today but someone wrote over the original recipie in the color book so we decided to wait. I have no idea why but we didn't know how much copper corbonate, tin oxide, cream of tartar and I think iron to add because the numbers are all wrong now. I don't think it would have worked anyway but I can't wait to show them up one of these days when I get my red right. hopefully anyway.
kevin bethea

Kevin Bethea 03-25-2006 06:39 PM

just an update
I mixed some cobalt blue and a teal last week and they both came out as expected. I fritted the cullet and followed the directions that Ralph had left. One of the advanced students showed me the right way to weigh the bucket, add glass and weigh that, multiply glass wieght by 450 to convert to grams, then muliply to get the percentage of colorants needed, and then mix in the bucket. Nothing too hard but it is a start. We have had visiting artists this week that are alumni of our school and I got a good bit of tips from them also. I met Ralph and he encouraged me to just buy kugler bars since the color selection is limited but he gave me some good tips too. Lots of new stuff for my notes. Soon I hope to try some more of Pete's suggestions and I think I can convert the 7 pound stuff into percentages and I'll see what happens next. It seemed like 21 pounds is easy to mix still so maybe I could just multiply the colorants by 3 and save myself from doing some math too. Thank you so much for all of the great advice. I'll keep going and let you guys know when something comes out.
Kevin Bethea

Dave Bross 03-26-2006 09:25 AM



One suggestion, use 454 grams for a pound. You will want to be in the habit of being very accurate later. Particularly mixing small amounts of things. The errors become more outstanding as the quantity gets smaller.

It's actually 453.59 but that much rounding off to 454 is OK. As an ex car nut it's easy for me to remember because that is the same number as the displacement of a big block Chevy motor.

Don't put iron in your copper ruby. It will brown out the color. The old timers put it in there supposedly as an assist to the crystalization, but you don't need it .

Here's a little memory aid for doing percentages:

Target over total times 100

Say you had seven pounds of one thing and one pound of something else mixed together. Eight pounds total.

You wanted to know what percent the one pound was of the eight pound total. Divide one (the "target" number) by eight (total), which gets you 0.125.

Multiply 0.125 by 100, which is simply done by just moving the decimal point over two numbers to get 12.5.

The one pound is 12.5% of the eight pounds.

In glass batching/color work you don't need any more accuracy than two decimal points, or to say that another way, we only go as far as hundreths of a percent or two numbers to the right of the decimal point.

You'll find this mentioned in Scholes too.

Pete VanderLaan 03-26-2006 12:37 PM

Dave is right about accuracy. In my 20lb formula for peach opal, one gram movement on the sodium nitrate trigger I use changes the color a whole lot.

That's one gram in 9080 grams ( assuming 454grm /lb). That's not much.

Based on your assumpton of 450, that fails to account for 80 grams to get in the proper perspective.

Kevin Bethea 03-26-2006 01:08 PM

Thanks Dave and Pete. I see how the numbers could really mess me up. I posted the process hoping it could be corrected if wrong. I think for what we have at school the variation is acceptable to others since we can't mix much more than 20 something pounds and the inaccuracy in the cobalt isn't as noticeable. I see how it could really mess things up though. I've definitely got it in my notes now. I converted the stuff Pete gave me into percentages and I see how my simplified math can change things too. Thanks for the quick math lesson. I had to fix our scale because it bottomed out at 0 so you could dump in any amount and it would stop and looked balanced. It was simple to correct. A partner of one of our visiting artists attended Pete's color class so he had read all of my questions and pointed out the different colors he used in his work and told me the colorants used. The neodymium oxide color is really pretty. I see what you meant about it not being a casing color but it was awesome the way he used it. The red in our color book is a real strange red from the color samples I have seen. it is more of an opaque brownish red color but not very appelaing to me. The recipie was actually written in the book twice but we still haven't mixed it yet. I am not sure where our sifter is but there were notes to make sure that we sift the stuff first. I'll post a sample of what it looks like if we make some but I won't add anything else to my copper ruby when I get the black tin and try to melt that. I didn't want to add anything to the teal except the copper carbonate but I got out voted. Next time I will cut back on the percentage of copper, not add anything else, and see if it comes out closer to an ice blue. Thanks for all of the help.
Kevin Bethea

Tink Martin 06-05-2006 03:46 AM

Thought I'd resurrect this thread, as I am studying the addition of color to cullet these days :D I am very new to this, but I'm pretty tenacious. I am reading everything I can get my hands on, and trying to learn... really learn... about color.

The image below is of some glass straight out of the furnace. No frits, powders, shards, cookies... This blows my mind. I believe it must have a pretty high level of silver in it, but beyond that, I can't imagine what's in there.

I want to try to make something like this. What the heck is it called? Can I do it with cullet, or would I have to deal with batch? Or is this just a pipe dream?

Virginia Slawson 06-05-2006 12:42 PM


The image below is of some glass straight out of the furnace. No frits, powders, shards, cookies...
Wow. I think you may just have a magic furnace! Now, please tell us more!

(OT: I'm sending you a PM.)

Pete VanderLaan 06-05-2006 01:00 PM

That would be a cullet with about 12 grams silver nitrate in 21 lbs of cullet plus 60 grams of black tin and about 20 grams of Ferrous oxide ( red iron). It may take more silver depending on the state of oxidation in the cullet.

It has the Fritz Dreisbach trade name of silver smaltz. Prinicipally it is the same as my silver opal. It is an ideal glass drawn from the pot as opposed to being used as rod. As a second gather cased again in clear works best.

Steve Stadelman 06-05-2006 01:19 PM

Bill and Sally Worchster made tons of work with that and black in the seventies here in Cannon Beach.

Scott Novota 06-05-2006 02:14 PM

This might sound stupid, but to be honest I have no clue.

Pete when your are adding stuff to cullet, do you melt the cullet down then add to the melt and mix? Do you mix it all up and add it to a cool pot and bring it up and mix? What about batch is it the same process?

I have never melted anything besides clear so I have no clue what the process is and have a missing bit of information at the start.

I don't plan to make color without taking a class but I do hunger for the knowledge of the process.


Tink Martin 06-05-2006 02:32 PM

Pete, you're the best! So when are you coming to Toledo to do a color class????

I have three 7 lb crucibles in my little electric cooker. I figure I'll do one pot with the recipe as given, then change something (not sure what yet) in each of the other pots so that I can compare results. Keeping excellent notes, of course.

So when I traipse up to Detroit to pick up the ingredients, is there anything specific I need to know? For instance, in looking at my supplier's website, Rovin Ceramics, here's what I see as far as Ferrous Oxide:

Iron Oxide - Red Spanish - Fe2O3 - This bright red iron oxide is the most common and economical form. If a recipe calls for iron oxide, use this product. It gives yellows at 2% and browns at 8%.

Iron Oxide - Red/Precipitate - Fe2O3 - A highly concentrated, pigment grade of iron oxide. More expensive than Red Spanish, but due to its higher concentration, will impart more intense colors, especially catsup

I think the Red/Precipitate sounds pretty cool.

I need to call then and see if they have Black Tin and Silver Nitrate, though I'm pretty sure they do.

I'm also looking forward to your response to Scott's post.

Thanks so much!

Pete VanderLaan 06-05-2006 04:56 PM

It's best if you frit some clear and add the chemicals to a damp frit.

Use the Spanish iron. The only thing I want out of it is a valence switcher and any ferrous iron will do.

If you increase anything, make it the silver nitrate. Go slow it's powerful stuff.

No one ever has black tin. Do not confuse it with white tin. they arenot the same. If necessary, use tin chloride, like the fuming agent. It will reduce to tin oxide in its lower form.

You don't need classes to make color. ( It does help though) Buy glassnotes 4.0 Henry had me rewrite the batch section.

Tink Martin 06-05-2006 05:41 PM

I see there's a sticky thread about the Black Tin. Does anyone here still have some available? Like about 500 grams... 1 lb?

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