LinR Posted March 31, 2016 Report Share Posted March 31, 2016 I want to make up a Yellow Salt glaze that I found on the ^10Glazes U of Tennessee site. I am familiar with recipes which are written with the ingredients adding up to 100, then the colourants are written as add 1% rd iron oxide plus percentages for whatever other colourants there are. The recipes on this site often do not divide off the main chemicals from the add ons, nor do they always add up to 100. To make up the glaze should I recalculate the main ingredients to 100 and also recalculate the colourants or does the percentage of colourants remain the same as written? The example for Yellow Salt is- Neph sy - 63.9 dolomite - 21.1 zircopax - 16.0 ball clay - 4.3 bentonite - 4.0 red iron oxide - 1.0 Thanks for whatever help you can give me. Lin Link to comment Share on other sites More sharing options...
MatthewV Posted March 31, 2016 Report Share Posted March 31, 2016 Adding up to 100 just helps with batch sizes and other calculations. There is no reason you would have to recalculate the total of 110 down to 100 when making the glaze. Link to comment Share on other sites More sharing options...
Mark C. Posted March 31, 2016 Report Share Posted March 31, 2016 Just move the decimal point over until you get the amount you want to mix-so that means 639 for the 1st ingrediant neph ay-if you need more add a zero to all the numbers then move the decimal point.-forget about a 100 total. Link to comment Share on other sites More sharing options...
Girts Posted March 31, 2016 Report Share Posted March 31, 2016 Seems to me these are just 'parts'. So for 1 part red iron oxide you use 63.9 parts Neph sy and so on. So those parts can be anything you want - grams, pounds, sacks, bushells or teaspoons! Girts Link to comment Share on other sites More sharing options...
maga Posted March 31, 2016 Report Share Posted March 31, 2016 Seems to me these are just 'parts'. So those parts can be anything you want - grams, pounds, sacks, bushells or teaspoons! Girts No, Sorry, It didn't work this way. Have to use the measure unit given in recipe. Link to comment Share on other sites More sharing options...
bciskepottery Posted March 31, 2016 Report Share Posted March 31, 2016 My recipe for Yellow Salt is: Neph Sye, 71.6 Ball clay, 4.8 Dolomite, 23.6 Total, 100 Add -- Red iron oxide, 1.12 Zircopax, 17.9 Bentonite, 4 from John Britt's Complete Guide to High Fire Glazes Link to comment Share on other sites More sharing options...
neilestrick Posted March 31, 2016 Report Share Posted March 31, 2016 Working in 100% is simplest in terms of understanding the makeup of the glaze, for making alterations to the glaze, and for comparing glazes. Convert it. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted March 31, 2016 Report Share Posted March 31, 2016 Seems to me these are just 'parts'. So for 1 part red iron oxide you use 63.9 parts Neph sy and so on. So those parts can be anything you want - grams, pounds, sacks, bushells or teaspoons! Girts It only works for weight units like that NOT volume units. Experiment,........... take a cup measure and casually scoop up some feldspar. Level off the top with a straight edge. Weigh the feldspar on an accurate (+/- 0.1 grams) scale. Now scoop up another one... but this time kinda' pack it in. Level off the top with a straight edge. Weight it again. It'll be different. It alls depends on how you schoop as to how much weight gets into a volume measure. Adds variables. If you can somehow manage to do it EXACTLY the same every time.... might work OK with a non finnicky glaze constituent material. best, ........................john Link to comment Share on other sites More sharing options...
Girts Posted March 31, 2016 Report Share Posted March 31, 2016 Good point about dry volume variability. I've always thought teaspoons and cups were ludicrous ways to measure ingredients for baking for precisely that reason John! So in my mind I was thinking in terms of weight and then digressed when I got to bushells and teaspoons. Inaccurate - profuse apologies. Girts Link to comment Share on other sites More sharing options...
Min Posted March 31, 2016 Report Share Posted March 31, 2016 I believe Bruce’s recipe is virtually identical to the first one posted by Lin. If you put the bentonite, iron and zirco in after the base is 100 Lin’s recipe base would be Nepsy 71.56 Dolomite 23.63 Ball 4.82 total 100 round of the hundredth place settings and you get Bruce’s figures. plus rio, zirco and bentonite as Bruce posted. Link to comment Share on other sites More sharing options...
neilestrick Posted March 31, 2016 Report Share Posted March 31, 2016 I make kiln wash by volume, but it doesn't require the precision that glazes do. My current wash recipe is 2 scoops alumina hydrate, 2 scoops silica, 2 scoops kaolin. Silica weighs about twice as much as kaolin, alumina weighs about 2.5 times as much as kaolin (by volume). If you do the math, its about 45% alumina, 40% silica, 15% kaolin. When I'm weighing out glazes, I use a stainless steel 1 cup measuring scoop. Most of the fluxes and such come out to roughly 300 grams per generous scoop. Clays are closer to 150 grams. It's easy to get very close to the amounts I need counting scoops that way. Link to comment Share on other sites More sharing options...
LinR Posted March 31, 2016 Author Report Share Posted March 31, 2016 Thanks for all your input. I was concerned that as the recipe adds up to 105.3, by increasing the batch to 2000 I would be multiplying the difference between say 1% of red iron oxide in 105.3 gms and 1% of red iron oxide in 100 gms. Perhaps the difference is not that great in using such a small amount of iron. However wouldn't there be a greater effect if the colourant was a strong one such as cobalt? Link to comment Share on other sites More sharing options...
Babs Posted March 31, 2016 Report Share Posted March 31, 2016 That is where I always wonder. I convert everything in the base glaze to percentages ie adding up to 100. But for given additions of colourants etc, I have always taken from the first recipe as if percentages, then if on testing the colour, opacity etc is not what I want then I play with it. Or I make them easy to use, rio 1% Zirco 18% Bentonite 4% I guess where this falls down would be if I made a large quantity prior to testing..... Link to comment Share on other sites More sharing options...
Min Posted April 1, 2016 Report Share Posted April 1, 2016 Thanks for all your input. I was concerned that as the recipe adds up to 105.3, by increasing the batch to 2000 I would be multiplying the difference between say 1% of red iron oxide in 105.3 gms and 1% of red iron oxide in 100 gms. Perhaps the difference is not that great in using such a small amount of iron. However wouldn't there be a greater effect if the colourant was a strong one such as cobalt? If you take out the zirco, rio and bentonite (feel like I should call that bento ) from your recipe then the base glaze totals 89.3 If you take the same ingredients out of Bruce's recipe the base glaze totals 100 So, pretend you want to have the glaze a little less white, you would decrease the zirco right? Trying to do the math on what percentage to decrease from a base of 89.3 is less clear than on a base of 100. Example would be I would try 1, 2 and 3% less zirco therefore same base of 100 but would try 16.9, 15.9 and 14.9 zirco. The only difference between your recipe and Bruce's is yours has a tiny bit more silica and alumina since the bentonite clay didn't increase in the other recipe. Same amount of sodium, potassium, magnesium, iron etc in both glazes. If you multiply your recipe out to 2000 grams then everything is multiplied by the same factor therefore percentages stay the same. Make any sense? Link to comment Share on other sites More sharing options...
neilestrick Posted April 1, 2016 Report Share Posted April 1, 2016 Thanks for all your input. I was concerned that as the recipe adds up to 105.3, by increasing the batch to 2000 I would be multiplying the difference between say 1% of red iron oxide in 105.3 gms and 1% of red iron oxide in 100 gms. Perhaps the difference is not that great in using such a small amount of iron. However wouldn't there be a greater effect if the colourant was a strong one such as cobalt? Exactly. 0.1% of iron won't be noticeable, but the same percentage of cobalt will be. 100% is just simpler to work with because it's what we're used to. We spend our whole lives working with a base 10 number system, why complicate it at this point? Link to comment Share on other sites More sharing options...
LinR Posted April 1, 2016 Author Report Share Posted April 1, 2016 Thanks again for all your input. I'm ceratinly convinced that converting is the best bet. Lin Link to comment Share on other sites More sharing options...
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