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Pete VanderLaan 03-05-2006 12:34 PM

when I say it's not a casing glass, I mean it is not an intense color than thins well.

Green is not a good color to find in your red. Pale blue, yes. Wheat, yes but not green.I usually associate that with having tried using white tin, not black tin. The former is an opacifier and the latter a reducing agent. White tin ain't gonna make a red. It does make insanely tantalizing streaks of red though.

"so you'll have all the answers when I'm stumped." hah! Maybe dave, not me. I will however offer condolences.

And, you aren't going to get a white out of cullet unless of course it's white cullet. Then it isn't going to fit.

Kevin Bethea 03-05-2006 03:40 PM

I've heard Ralph is still around and I asked my teacher and he said every now and then he pokes in the studio early in the morning. I have only been here a couple months so I guess I just haven't seen him yet. I know Ralph knows more than 2 colors but that was just what one of the advanced students told me. I thought it was kind of funny. I think it is just a lack of interest that caused us to be where we are right now. I heard he was a great guy but the way people talk about him it's like he died a long time ago with as many times as I hear "when Ralph was still here." If you want people to listen you just have to start the sentence with, "what Ralph told me to do was..." and people stop to listen. I know we had to have had somebody here melting colors because there are pieces all over the building with interesting colors. Ralph's notes are probably there somewhere too but I am willing to experiment on my own until I track him down. I am still finding new rooms in the building but I'll track down as much info as possible and experiment.
I understand the casing part now so I'll remember not to blow out the color on that one. I'll have to ask about the tin oxide we have. It may very well be white and that would explain the problem with his red. I know he added cream of tartar. I don't know what it does but he said it was necessary so he went grocery shopping before he tried it. I know white isn't possible now but one day I'll have a whole new ball game with batch and dangerous chemicals like Dave and I'll be up many a night just babysitting a melt while killing all vegetation in my neighborhood. Ok, so you guys might not have all the answers but I bet creative suggestions will be just as fun to try. We are on spring break right now but I will get Ralph's number from my teacher when he gets back. I have been looking forward to meeting him and he sounds like a helpful guy. I just have to hope he'll have time to talk. If not I'll just go ahead and try stuff and see what happens. I am a pretty good listener and I am interested in learning so we'll see how far that gets me. Getting things to fit is a whole different problem so I will just do testing. That's a whole class worth of info. we may have used different glass back then too. They switched from spectrum to 4c this semester but I don't know what they had before that. I just thought about that. hmmm...I'll find out. I ordered moden glass practice this morning so I will have some more reading to do. so far I know enough to possibly fix the red problem and I'll have room for one more pot so maybe I'll get the guy to try it again with my notes that I have so far and we'll try something new in the other pot. he's about to graduate so very soon I will be able to melt anything that I want to for a while I guess but I can use the help while he's here. I'll collect more supplies and read some more but when I get something you guys will know about it. I am interested in what you can get out of the guys in Cincinnati too Warren so if you have time I would appreciate that info too. I'll be here for a while so if they or anyone else ever happens to go past Americus Georgia they should stop by but it's not on the way to or near anything really. I think we're 3 hours south of Atlanta. We have 3 visiting artists that were past students coming in this semester and I hope to assist them as much as they let me so I can learn some stuff. I heard we might have to shut down for the summer if the class isn't large enough so I am kind of bummed so I don't know what I'll do if I can't get in there to blow glass. There are a few places in atlanta but that would get expensive so I will just hope for the best I guess.
Thanks again everybody,
kevin bethea

Pete VanderLaan 03-05-2006 04:19 PM

You should try to track down Frank Kulasiewitz in Valdosta if he is still alive. Frank was melting lead colors from batch back in 1971 which was just about unheard of. He published a book on glasmaking which is quite obscure. Henry didn't like his book much and had safety issues with it. Frank was something of a "free spirit" when it came to code but he was out there doing it outside of the university system. He would be in his seventies now at least.

Ted Trower 03-05-2006 05:05 PM


Originally posted by Pete VanderLaan
You should try to track down Frank Kulasiewitz in Valdosta if he is still alive. Frank was melting lead colors from batch back in 1971 which was just about unheard of. He published a book on glasmaking which is quite obscure. Henry didn't like his book much and had safety issues with it. Frank was something of a "free spirit" when it came to code but he was out there doing it outside of the university system. He would be in his seventies now at least.
Obscure, but not unavailable:

Kevin Bethea 03-05-2006 08:21 PM

with the periwinkel you said to try one gram cobalt to 30 grams of copper. When you say copper you mean cuprous oxide(red copper) and not the copper carbonate that we have already, correct? I am pretty sure that I need the red copper but I wanted to double check so I can add it to my notes.
Kevin Bethea

Dave Bross 03-05-2006 08:36 PM

Pete liked the concept of me having all the answers!!!!!!!

Actually, Pete was the one who taught me all the basics and he knows a hell of a lot more than I do.

NO ONE has all the answers 'cause we still haven't even found all the questions.

Back to the concept of oxygen in the glass.

The oxygen has to be chemically combined with the glass to affect the oxides you use for color. In glasses that want oxidation for color you add more oxygen.

The oxygen has to be cut way back in colors that want reduction.

If you are going after a color that needs a greater amount of oxygen to go to the valance where it shows a particular color, it's best to get that oxygen in there via one of the chemicals going into the glass.

If you have a color that wants reduction, then you have to start with a glass formula that doesn't have any oxidisers, and also add reducing agents like some form of carbon or the black tin for copper ruby.

In the case of your cullet experiments you want to put in enough reducing agent to reduce the excess oxygen that is already there in the cullet.

The old timey way of making copper ruby was to re-melt and frit the cullet a number of times to reduce the oxygen in the glass.

The potassium tartrate your guy was adding is a reducing agent, but he probably didn't get enough in there.

Try sugar for reduction in cullet. The sugar becomes carbon when heated. Old time glass melters would chuck things like grain or coal into a glass to get reduction.

The potassium in the potassium tartrate is also moving the expansion of the glass higher and that's not going to help when you try to fit different glasses together.

The furnace atmosphere has a much smaller effect on the level of oxygen in the glass than chemical additions do. You can't ignore it though, it can change things enough to screw them up.

You can use the copper carbonate to replace the copper oxides in most things, you just have to do a little math to compensate because the carbonate has less percentage of copper in it. Here's a pretty good on line source for the percentages in materials:

Pete VanderLaan 03-05-2006 09:10 PM

on the other hand copper carb is chock full of oxygen which doesn't particularly bother me since I tend to overwhelm it with stannous oxide. Do not think that stannous and stanic sound so much alike that they should be interchangeable. They aren't. Your white tin won't work.

I think starting with red is not the best plan since it's a very toucy color to achieve. Better maybe to start with the simpler stuff and just become familiar with the processof mixing and melting first..

..and there isn't that much potassium in tartar sauce. I think the formula is KNa2C4O6.4H2O so it's sort of a mixed bag I think I remember that since I was sending some to Mark Peiser two days ago and I actually bothered to read the bottle.

Kevin Bethea 03-05-2006 09:35 PM

I'd be really happy if I got into this enough to have questions that you guys couldn't answer but I think we are safe on that one for a while. I know I could really mess something up but the answer to that question is to try it again and see what happens and keep notes. I'll understand it more as I get into it. I thought I understood about adding the oxygen but it's more important here to remove it for some colors. It makes a lot more sense now. Now I know what the cream of tartar does. I'll have to ask how much he added. How much sugar would I stick in with the 7 pound melt to replace the 20 grams of black tin? I saw a box with SnOx tin oxide on it but I think it might be white and not black but I will ask. Is it a one time thing or do you have to keep adding sugar periodically as it melts? remelting the cullet sounds like a good way to remove the oxygen too but adding sugar is a lot less work. Thanks for the reference for the percentages. I'll figure it up and make sure I bump the number up a little bit for the periwinkle. my book should be here in a week or so so thanks for that link too. I guess that would also work for the opal swirl too but I need get the silver nitrate first. Pete said to reduce it heavily but does that mean reduce it while it is melting or in the glory hole to get the swirls?
thanks for the explaining all that,
Kevin Bethea

Kevin Bethea 03-05-2006 10:04 PM

Pete and I were typing at the same time and he beat me to the post button. I bet the extra oxygen would mess up the opal swirl so I should just wait until I get the cuprous oxide for that one too. I don't think starting with red is the best idea either, I was just thinking we have a pot for red already and I might can get the guy to try it again with sugar if we don't have black tin and kind of learn from that. I'll try the purpley browns, blues, and greens and then maybe I will have some success with the periwinkle and opal swirl whan I know more about what I am doing. I was blowing when I heard the guy remember out loud that he almost forgot the cream of tartar. I thought he was kidding but he left to go to the store. I had to go to class so I missed him when he got back. I missed it when he added it to know how much he used. I heard him shaking the bucket when I was working so I missed it when he mixed the other stuff to add to the cullet to know what he tried. I'll see him soon and I'll ask him as much as I can to see what there is to gain before he leaves. I am soaking it all in and we'll see what happens. thanks for the nudge in the best way to gratification. I know what you mean.
Kevin Bethea

Dave Bross 03-06-2006 01:07 PM

Extremely good chance you will get to experience many, many, of Pete's condolences if you go after the red, but, then again, if you get it, you've accomplished something major.

I sound like a used car salesman.


I'll give you some suggestions and then you get to late night experiment until MAYBE you get something that will work.

First problem....gotta have tin with the copper for it to go red gracefully. It can be white tin but then you need something else to take care of reducing the oxygen. Pull out your copy of Weyl, read page 343, read pages 420 thru 432. Rough rule of thumb, start with equal amounts of tin and copper.

The problem is that the tin doesn't want to melt. Hence the streaks Pete mentions. Other than mixing it up with lithium or some other alkalai, which will move the expansion up radically, your best way around this may be high temps for melting. Note: you can always bump up the expansion of your clear cullet with a bit of alkalai to match expansions if you absolutely have to have the lithium to melt the tin in the ruby.I've also thought about using stannous chloride for the tin, but the chlorine would cut back on the "pretty" in the glass and we're talking expensive chemicals again with stannous chloride.

Second problem.....Reducing the oxygen. Black tin really cuts down on problem one and two, but let's see if we can get around having to use it because it's VERY expensive and hard to find.

Sugar used as a reduction agent in copper ruby batch without oxidisers is used around 5 grams to 20 pounds of batch. Thank Dudley Gibberson for that number. Using cullet, you will be fighting oxygen already present in the glass so you will need more reduction.
To give you a speculative maximum number, you can theoretically make an amber glass from cullet by reduction only, using 18 grams of sugar per pound of cullet. Thanks to Rollin Karg for this amber recipe. This will be a "test and tune" situation. If you reduce the glass too far you get livery colored glass, not enough reduction and you get no red.

Ok, I'm done yelling now.
The way antimony is usually used is as a fining agent. It changes valance as you come down from cooking temp and sucks up large quantities of oxygen, which were put in there originally by the nitrates and other oxidisers in the batch.I'm sure you see where this is going. Putting more antimony in with the already melted and fined cullet sucks even more oxygen out of the glass, making for reduction. Thanks to Rollin Karg, I actually have an antimony reduced cullet recipe:

20# cullet
1# soda ash
17 grams antimony
45 grams tin oxide (white tin)
45 grams zinc oxide
45 grams red copper oxide

Antimony in this quantity in a clear glass would discolor it yellow-grey, but that could actually help the red color a bit in this application. The grey may detract a bit from the "pretty".

Problem number three is to get it to fine out. High temps to reduce the glass viscosity so the bubbles can rise is probably your best bet. You can't use the traditional nitrate/antimony combo in reduction glasses because of all the oxygen in the nitrate, and antimony by itself doesn't do much towards fining.

Pete VanderLaan 03-06-2006 01:39 PM

Tin Chloride will work much better than white tin. The material should break down to SnO and CL which will help with the fining. If you start with white tin you already have two strikes against you. It is not very soluable at all. The Chloride aspect may induce livering. Better to me to start with the right materials.

Dave Bross 03-06-2006 05:33 PM

So very true, but, black tin is impossible to find in small quantity. I would love for someone to prove me wrong on finding small quantities.

I've still got a good bit of what I got from you. I never could find it otherwise, short of a 45 pound drum.

I think that when I get up and going again I may buy the drum of black tin anyway.

With the price/availability problems of selenium, it's looking like a very good time to develop higher skill in copper ruby.

Pete VanderLaan 03-06-2006 06:20 PM

I sell black tin at 15.00 lb but I won't sell less than 100 dollars worth. Some things aren't worth packing amd I'm busy.

I was under the impression that Seattle Pottery sold black tin at it's normal usurous rates but I don't know that for sure.

I just can't equate the color from Cad/Selenium to that of copper Ruby now that I melt the Selenium regularly. It's a lot like life after you've gotten laid for the first time. hard to go back.

Scott Novota 03-06-2006 06:58 PM

Am I to understand that if I drag my happy ass up there I can get some free blow time with you?

I have been looking for a road trip.


Dave Bross 03-06-2006 07:41 PM

I suspect copper could approach or surpass the selenium reds in the right overlay situation. All by itself, no. Although I wonder what might be done based on the recipe in the archives here that combined silver with the copper ruby. The silver yellow might be a nice color tone addition to copper red.

Charles, Barb, Rich and I saw a copper ruby vase in the Tiffany show that we all declared our favorite piece without input from each other. Wet dream red like we've never seen before.

That's good to know you're still game to sell some black tin. If anyone else wants some and can't swing the $100 I'll go in with you. I still have plenty but I'll offer that in case it's needed.

Pete VanderLaan 03-06-2006 09:37 PM

I can only assume that youi think I still buy my Black Tin from Goldschmidts since that was my last known reference when I still was allowed to post at Handmade. I gave up on them a long time ago. Nice stuff but too much at a time and too pricey.

The interesting thing I am doing right now with the cad sel red is making five inch diameter logs from it about 16 inches tall. When cooled, I cut them up ( I'm practising for logging in New Hampshire) and make them into 3/4 inch thick rectangles and then polish them. The color is not to be believed! I will use them in some solid optics pieces I am going to start in May. Copper reds can't compare and I was hooked on copper ruby for thirty five years. This is mo bettah.

Kevin Bethea 03-07-2006 11:20 AM

Thanks for the reference in Weyl. I was in the shop for about 13 hours yesterday so I was too tired last night. I am sometimes bad about trying stuff that really isn't worth it. Yesterday I tried to switch an axis and then pick up a cup from the hot box all by myself. I know, bad plan. It took me over 2 hours and I got overheated and it hit the floor. I saved it but somewhere between almost passing out and the huge panic attack that came next it really didn't turn out like I wanted it to. It was looking good for a little while but I boxed it so now at least I'll have a visual aid for when I tell the story to my friends. I found the color book but it is only about 3 pages and pretty much just basic instructions. Lots of wisdom in there though. Very big on the first page it says to use fritted cullet only. I saw the guy that melts the black yesterday and he said he uses the stuff in the bottom of the strip off bucket eventhough it gets color in there sometimes. The black felt different and then I figured out he mixed it in the red pot so I bet that had some effect. I think I'll sponge up more info, get the right stuff if possible, and then figure out how to get pots from Pete. I haven't called Seattle Pottery yet because I want to ship it to the school and I haven't seen my teacher yet to make sure it's ok. I don't know what kind of address to give them so after spring break I'll order stuff and then start out the best way possible. Thanks for offering to go in on a bunch with me Dave but we'll see if they have it first. I know if I tried the red that it wouldn't work out with the best of conditions so why start with so many strikes. It will be a long time before I get something pretty but I will be learning the whole time so it's worth the trip down the road to happiness. I hope Pete's good at giving condolences. That's amazing that that little bit of sugar can do a big job. I was thinking lots of sugar. Thanks for all of the advice and information. The guy that melts the black was there under Ralph but he said it's more worth his time to buy color but he agreed to try some stuff with me that he hasn't done in a long time. I started to repeat stuff I learned here and I gave credit to you guys of course but I sounded like I knew what I was talking about so he got really interested. Especially when I told him I had my book coming because he couldn't find it for less than $200 or something like that when he wanted it. I'll add the new stuff to my notes. I think I am going to go light the glory holes, read the pages you suggested, and drink coffee at the bench. I agreed to do some maintenance on the color furnace lid today too so I'll be there all day. Yesterday I felt something totally new with the jacks. I guess I am just now really getting the feel for the glass. Its about time I guess but it was a really good tingly sort of feeling. Anybody remember getting that for the first time? I am really interested in Henry's purple foam lava glass so if anybody can elaborate on that one I'd appreciate it. I don't think that's in Glass Notes but I just found the colorants for cullet section and I want to go back and reread the stuff on silver nitrate that I know is in there somewhere. I haven't pulled it out in a while. I like leaving it face down because there's a picture of Henry on the back that reminds me to do something productive but maybe that's just me. Scott, if you make the road trip, I'll get us in the studio. It's a long drive but it's pretty coming up from your direction. I took my mom down to Havannah to go antique shopping and there are lots of old tobacco barns and scenic things along the way. I still feel bad for not making it over to pensacola but you can crash here if you are ever interested in visiting for sure. you'd get to see our annealers made out of 55 gallon drums. I had never seen this design before but they work. My teacher switches the hinges everynow and then when all of the right hand gloves are worn out he'll switch it until the left ones are worn out too. Whatever works I guess. Thanks for the help guys.
Kevin Bethea

Dave Bross 03-07-2006 12:13 PM


Davens Ceramics is in Atlanta (I think) and will have most of what you'll need at decent prices for a pottery supply and right close to you, so quick shipping. I can buy some things from them in large quantity that are actually cheaper than the chemical suppliers here.

I think you missed that Pete will sell the black tin he has? You won't need Seattle Pottery.

Scott Novota 03-07-2006 12:39 PM


E-mail me if you still have my address. You know just put a @ sign between my first and last name and add a .com at you have it.

We will make it happen I am hankering for a road trip as soon as my soon to be father in law visits I will be free and clear.


Jim Huston 03-07-2006 12:49 PM

Will the info above work with SP87?? Or are some changes needed. Just a newbie question.

Dave Bross 03-07-2006 05:55 PM

Dudley used to hand out a sheet of color recipes to match SP87 in his classes. Here's the copper ruby recipe.

19 pounds color base batch (no oxidisers)
60 grams red copper oxide
100 grams white tin
100 grams zinc oxide
60 grams borax
80 grams soda ash
5 grams sugar.

Of course you'll have to test and tune to get it to match when melting in your equipment.

Peet Robison 03-07-2006 06:05 PM

That is very similar to the red I made using the sp87 cullet. Try it, I think it would work.!

Pete VanderLaan 03-07-2006 06:12 PM

I think it will be way high on expansion and streaky. In my own formula, I need to add silica to bring the expansion down and I use a good deal less zinc, and tin.

In my class, we just took21 lbs of SP color base and added 60 grams of zinc 60 grams of copper red and sixty grams of black tin and 100 grams of silica. We hit red on the first try and it fit

I genuinely don't understand the insistence on trying to get white tin to do the job of black tin. they are as different as night and day, not to mention that white tin really does not melt well.

Peet Robison 03-07-2006 07:14 PM

I would have to agree the formula posted by Dave would be high in expansion. I certainly don't know why Soda Ash would be added. I don't insist on using SnO2, it's just much easier to find small quantities. And as far as I am concerned tin is tin and it is a necesaary part of ruby. Black tin (SnO) doesn't "reduce" glass it is just less oxygen to begin with. If your glass base doesn't contain much oxygen such as cullet or sp batch minus the oxidizers then it is quite easy to make a red using SnO2. I am sure stannous chloride would work too. I never noticed a problem melting either form of tin. It melts at 450 deg F.

Pete VanderLaan 03-07-2006 08:17 PM

metallic tin may melt at 450F but according to Ceramics Industry, white tin oxide melts at 1130C or 2066 compared to Soda Ash going down at 1567F and Potash at 1616F. Red copper is at 1947F.

You can get to this color going thru the door or thru the wall. It's your choice. I just know that you won't find a single old formula that calls for White Tin and there's a good reason. If abandoning conventional wisdom on rubies is soley based on the availablity of a chemical, the chemical isn't hard to find if you really look. As I said, Seattle Pottery has it and I will order it.

To put the costs in perspective, 21lbs of ruby would use 60 grams of Stannous oxide. At a price of 14 dollars per 454 grams, it would use about about one seventh of a pound or two dollars worth of tin to make about 10KG of the red. Now when I look at the price of ruby rod, I think it's over thirty dollars a Kg. This red is costing approximately as follows

SP87 20 lbs- 10.00 at .50 lb
tin- 2.00
copper .75
zinc .50
heat- 20.00

So that's about 33 dollars for about 10KG of the color or about $3.00 per KG. All this assumes you have the color pot and furnace.

Now white tin lists in my 2001 Standard Ceramics Cataloge at 13.50 for one pound and 12.50 per lb for five pounds. I am reasonably certain this price hasn't dropped in five years so I have to express some surprise when it is suggested ( by Dave) that Black tin is really expensive.

I mean I will raise the price if it makes people more comfortable but it seems to me that choosing a material that is going to give you trouble as opposed to choosing a material which is known to work well and further allows you to reduce the amounts of zinc and tin in the mix thereby saving money is just plain penny wise and pound foolish.

Oh, and when it doesn't work, or doesn't work well and you are throwing out the melt, take note that 66 percent of the cost of the color was in the BTU's to melt it. So, as they say, it's your money....

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