Saturday, June 1, 2013

Q: Yellow #3 - why is it so pale?


Q: Hello, Ken!

I am using silver stain for the first time on my own. WHO-HOO! I ran a sample of Silver stain #3 I think it is 1784 catalogue number, and it came out very pale (afap/1025/5). How do I increase intensity of it? Do I need to hold it at the temperature longer? Also it came out  blotchy, although I applied it very evenly with airbrush. Could you possibly give me insight as to why this may be happening? I am attaching pics of the samples.

Thank you so much for all your help!

A: Can it possibly be that you don't have my book or haven't read my articles for the American Glass Guild newsletters?! 1784 Yellow #3 is one of the palest stains. Below are the key points to remember.

The 4 factors which influence the intensity of stain are:
1. the formula of the stain
2. the formula of the glass
3. density of application
4. firing temperature

To answer your question I need to know what glass you are attempting to stain. If it is GNA, you are out of luck - the "clarifying" agents introduced by the Germans in the glass making formula to make the glass more "colorless" seem to resist the stain. Your best option for the Yellow #3 is the tin side of float glass. (You can check out a chart of how Yellow #3 reacts on the whole control group of clear glasses I tested by following this link. I did make one mistake with this set - both of the float glass samples were done on the tin side by accident - you should expect the non-tin side to resemble the others in this series). Your cycle seems ok but I would suggest the optimal would be 1050F with a 20 minute hold. 

Before applying the stain make sure the glass is completely clean - rub it down with alcohol or acetone and if using an airbrush - apply the stain gradually allowing each layer to dry before adding more. My guess is you are not really applying it as evenly as you think and those darker areas actually got a thicker application with the airbrush. Hold the airbrush 8" to 12" away for a broader application and stay perpendicular to the glass surface. Move gradually from side to side and work from the top down.

You can always consider a different stain. Yellow #3 is one of the least expensive because it has less silver in it - try 1383 from Reusche - I personally like it better. All of the Oster stains are fantastic and many use nothing else. If you want to go very dark (like amber dark) then you need Reusche's Amber Stain - you can find everything that's in my book also here on my blog but you will need to hunt through all of the entries. Don't overlook the blog archive index on the right menu.

Good luck!
Ken

2 comments:

  1. Ken, I am using Spectrum artique glass, and cannot change it this deep into the project.And quite unfortunately, neither do I have time to order 1383 :( Do you think I may be able to get it darker by applying it a bit thicker? And you are quite right, I do not have your book, that is really my bad - I should have acquired it a long ago!

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