Tuesday, July 16, 2013

TECH TIP: Mask for better silver stain application

Stains are corrosive to metals. I use brushes with plastic ferrels, a plastic palette knife, mix stains in plastic or glass containers and use a dedicated badger blender for stains.

Mask the area to be stained with contact paper.

Apply the stain broadly with a brush - keep the entire area evenly damp. The mixture should not be too wet. Consider this as a guideline: If you applied it to a horizontal surface the mixture would not drip.

Blend it with a badger blender.

Stop blending before the stain starts to dry. Dry the stain at this point with a hair dryer but be careful not to disturb it with too much "wind". When dry, remove the mask and watch for any stray flakes of dry stain that cling to the glass by static electricity. Remove these with a soft brush. Fire the stain face up in the kiln. It will contaminate the kiln shelf if fired face down. If you must fire the stain down use a removable barrier layer - like disposable fiber paper or a dusting of whiting.

You can blend the wet stain in a complex shape by masking as described above.

Here is another example of shading the application of stain. 

Q: What medium do I mix Silver Stain with?

Q: Can you help me with a simple question?  I'm ready to complete a silver stained piece and can't remember what medium we mixed to liquify the silver stain. 

I took the Silver Stain Workshop at Glencairn in Nov 2011.

Are you offering the classes again this fall; I know of someone who is interested in taking the class. Is there any room? Could you send a schedule of future classes.
Thanks again,


A: 99% of the time I mix silver stain only with water as shown in my book and on this blog. For the purpose of testing I mixed the silver stain with distilled water but at home I don't bother to be that precise. I never add gum arabic as the stain already has its own binder added. Brush marks definitely show in your silver stain work so you want to paint boldly so the entire stained area is the same wetness and then blend it with a badger. Laboring or futzing in the application of the stain will lead to terrible results - blotchy and inconsistent. The best method I have found is to mask the area to be stained with contact paper, apply broadly with an applicator brush then blend with the badger. Dry the wet stain stain with a hair dryer uniformly making sure not to disturb it as it dries with too much "wind". When dry remove the remove the masking. I do this by holding the piece upside down over the trash can and pealing off the contact paper. Any stray flakes of dried stain should be discarded in this way as they will stain the glass if left in contact with it. Be on the alert for flakes that cling by static electricity and remove these with a soft dry brush. Neatness counts! Do not breath the dust from the stains - wear a mask if necessary. The other 1% of the time I will mix silver stain with oil if I want to apply line work with a tracing brush or if I have very small areas that are impractical to mask.
You can also refer to this post

REGARDING CLASSES: It will take you a few clicks but start with the TAB marked CLASSES at the top of this blog and you can navigate to my upcoming workshops. You will also find information about private classes if nothing fits your schedule.

Success story

Here's the panel with a second coat of stain

I am happy to report that I made that pale stain work for my purpose! After studying your book, I laid the stain on nice and thick, turned the temp up to 1075 and held for 20 min as opposed to original 5. It came out gorgeous amber I needed. Thank you again! I am attaching a photo. May be your blog followers will find it helpful.

Thanks for sharing your success story! Here is a link to more of Ekaterina's stained glass

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!

Wednesday, April 17, 2013

Walpole Wrath: Oster on Desag

Q: I was wondering if you might assist with a question: I am using Oster
Walpole on Desag clear, fired at 1050 ish, It's come up very wimpy, even
with 2 coatings. Should I try refiring w/o repainting hotter to get that
amber of my dreams? Don't want to screw up all the prior work...

A:Sorry to report your problem is not the stain or the temperature it's the glass itself. Desag's formula includes chemicals to make it more brilliant (less of an iron green) and subsequently the glass does not have the "receptors" for the stains. If you look at this chart from my tests on Oster stains you will see the reactions you can expect on various clear glasses. 
Oster stains go Amber on the tin side of float glass but if you want to get a deep amber on Desag you will need to switch to Reusche's Amber stain.
The last alternative to explore would be to try adding a small amount of sodium sulfate to the Oster stains. Unfortunately I can only point you in this direction as I have done no direct experimenting with Oster stain and sodium sulfate. It's mentioned in Albinas Elskus' book, The Art of Painting on Glass (pg 117) and I have tried it with Reusche stains. It will darken the stain but you will also get "metaling". You'll have to do your own battery of testing if you choose to go this route. If you are really trying to achieve the historic color that borders on deep orange - you're even more out of luck as it can only be achieved on a special glass known as "kelp or staining glass" which was produced in Britain in the 19th century. No one makes it today. However you can add your voice to my "petition" to Lambert's to research and recreate this formula for the benefit of us all.

Thursday, January 3, 2013

The Dreaded Pink Blush

Q: I did a couple of tests with Debitus silver stain on Waterglass and Spectrum clear vintage. You are right about 40% silver sulfide: It was the best. 20% sulfide was good to ( only for vintage ). Silver Chloride - poor results. But I still have a problem: on some samples I have some foggy light brown-reddish color that is impossible to remove in the areas where the stain is light. I don't know what could be (with Reusche in the past I did not have such problem).
I mixed the stains with sandalwood oil and little lavender oil and fired at 1050 F ( electric kiln ) - 500 F/hour, ramp hold -1 hour, off. I'm sending in attach a photo with 3 samples. Where the stain have a very light appearance - in reflective light I can see this brown-reddish foggy color Any idea what is wrong?

A: You are not alone in reporting this problem. I have experienced it myself with some stains. I do not know the exact cause. It may be related to the clay body firing onto the glass. A dilute solution of hydrofluoric acid would probably do the trick. Personally I have found it easier to switch to a different stain. I typically reach for Reusche 1383 as my go to stain these days. I find the gum in clay body is not as impossibly virulent as some of the other stains allowing me to even stipple the application with a scrub if I need to. Also I have not experienced the dreaded pink blush that you describe with this stain. If you do use hydrofluoric exercise the appropriate safe guards. If anyone reading this  can suggest another solution please speak up!

Question about Float Glass & Texture

Q: I will be contacting you in the next couple of weeks about scheduling the private class with you. In the meantime, I have another question. Is it OK to paint on regular float glass assuming that I will use enamels later on it or is that a no-no? If so, what do you do if you do not want any texture on the glass you are painting on. Artique works great, but the kind I have has A LOT of texture and I would rather use something flat. What do you think?
A: Float glass has a tin coating on one side that will affect silver stain and some enamel colors. You should always test float glass with a short wave ultraviolet light (sometimes marketed as a Tinscope or Tin-light). Mark the appropriate side of the glass for your use. Silver stain takes more intensely on the tin side of float glass. Enamels are another story. Sometimes interaction with the tin side is bad. I have had problems with some blue, green & turquoise enamels going grey or black. Other enamels, especially gold based colors – like pink, magenta, red & violet actually are more intense and saturated on the tin side - go figure! The answer, if you haven’t guessed it, is to test each color first.
Here is the link to the page on this blog that references UV light & Float Glass: http://thepaintedwindow.blogspot.com/search/label/UV%20light

As far as texture goes, that’s a subjective call. Personally, I paint on mouth-blown Lambert's or Desag (which is similar to Artique). I prefer the texture of these glasses. If I’m painting a face I would avoid a mouth blown glass with a lot of seeds and choose something smoother but surface striations are OK by me – that’s what we’re paying the extra money for after all! If you really find the Artique texture objectionable you can always flip it over – the back side is considerably smoother.
Happy painting!