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Old 03-07-2006, 08:17 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 22,269
Pete VanderLaan is on a distinguished road
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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