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

Restoring a Meyer window

I received an inquiry about restoring a Meyer window. The restorer said he would be using Lambert's glass and had access to Reusche and Keracolor stains. These are the images he sent, scroll down for my reply:

MY REPLY: Looking at your images I wanted to first say that not everything is silver stain. Forgive me if you already know this but only the ornamentation in the diamond quarries is silver stain. The yellow brown tone that appears to be fading off is some other pigment. I have attached a photo with some arrows below.

Not everything is stain.

Silver stain is very permanent as it is absorbed into the glass itself and not subject to corrosion from atmospheric weathering like vitreous pigments are.

As to the silver stain, I made many tests as I was preparing my book on stains. Here is a photo of my test on Lamberts glass: 

My tests on Lamberts Glass

I think you will have the best results with Reusche 1383 or Keracolor using a mixture of 1 part 76050 to 4 parts 73028/A. You will need to experiment to get the density of the application correct. Prepare two identical samples with a heavy to thin gradation application on Lamberts glass. Fire one sample and then you can compare the results to the unfired stain. Stains look radically different after they are fired so a fired/unfired sample is extremely beneficial. You can mix the stain with any medium but using oil may allow you to make a more controlled gradation. Silver stain is best fired between 538C/1000F - 593C/1100F Try this schedule as a starting point:

90 min to 540C/1004F

10 min to 580C/1076F

Hold for 45 min

If the stain is too heavy after firing it can be lightened with a cotton swab dipped in hydrofluoric acid - use extreme caution when working with acid in this way.

If you plan to fire the stain several times - make a test for this as well - stains can intensify during successive firings. I had a stain appear to "not take" once I washed off the clay body (all stains are premixed with ochre/clay). I refired the piece - without reapplying stain and it came out beautifully. Even knowing as much as I do - stains can remain a mystery :)! My best advice is to test, test, test and keep a good log - be scientific in your approach.

The REUSCHE Stains

REUSCHE 1382 (Orange #1)

REUSCHE 1383 (Orange #2)

REUSCHE 1384 (Yellow #3)

REUSCHE 1388 (Orange Intense)

REUSCHE 1390 (Amber Intense)

REUSCHE D292465 (Amber H465)