Q: Lead free pigments and safety concerns

Q: I just ordered my second copy of your book, "Silver Stain".  I gave my first copy to a colleague as a gift.  You have a lot of expertise regarding painting on stained glass.  I hope that I am not imposing on you too much if I ask for some quick advice.  Have you ever used Reusche's Lead and Cadmium free paints?  What do you think of them?   What do you think is the best source for safety advice/data regarding painting with vitreous paints and silver stains?  I am hoping to take one of your courses eventually.

A: I use them all the time. They need a little more heat than the lead versions to get the same sheen but otherwise I haven't noticed a difference. Reusche does not rate them as "weather resistant" so that is my only concern. However, unlike the artist's of prior centuries I haven't done many installations in which the window did not have some kind of protective exterior glazing. In doing restoration work, I use the leaded paints. FYI all of the transparent enamels (regardless of manufacturer) have lead - transparency without lead doesn't seem to be an option.
As for safety, when you purchase art making materials you should request a material data safety sheet also
known as an MSDS. I keep these in a three ring binder in my studio. Familiarize yourself with how to read them. When working with glass pigments inhalation or ingestion are the primary reasons for concern. Wear a respirator when handling the pigments in their dry form and adopt a wet system for cleaning things up. The respirator option I like is a disposable 3M 8233 N100 particulate respirator. It will protect you from pigment dusts but it is not sufficient for soldering fumes. You can get more information from http://www.artscraftstheatersafety.org

Firing Guidelines

I get this question all the time so here are my FIRING GUIDELINES:

Let's assume for the moment that you are firing Reusche Tracing Black 57R001 or some other "High Fire" glass stainers color. You have applied this to a conservatively cut piece of glass of a thickness around 1/8". Your glass is not etched flashed glass, a piece with an extreme inside curve that you've taken a grinder or saw to achieve nor have you drilled any holes drilled through it. If you do have an atypical piece read the caution below*.

According to the Reusche catalogue your pigment fires between 1100F and 1400 F.

ELECTRIC KILN:
A general guideline would be to bring the kiln up slowly - for thin glass (1/8") in an electric kiln I recommend you take a minimum of 1 hour to reach 1000F after that you can climb quickly to the firing temperature then do a short hold. Going slowly on the way up is good for the glass and also kinder on the kiln. If your kiln is made of hard brick - heat it more gently, if it is all soft insulation you can go faster. Shut off the kiln when finished and let it cool on its own.

I am often disappointed by texture that I pick up on the back of soft glass. To reduce this I lower the firing temperature to 1135F  - 1150F and hold at that temperature for 20-40 minutes. I would suggest this as a starting point. Up the temperature by 20-25 degrees if you find that the fired paint is not glossy enough. This will also depend on the kind of glass you have painted on as some glass is softer than others. Keep a kiln log and experiment until you know how your kiln fires. Use kiln wash, a bed of whiting or fiber paper as a separator on the shelf.

If you are using a repurposed ceramic kiln made of fire brick it will hold a lot of heat so it will not be necessary to do a ramped firing on the cooling end of the cycle. For 1/8" glass I don't do an annealing cycle in any of my kilns. If you start fusing or painting on glass thicker than 1/4" you will have to revisit this issue and add a ramped cycle up and down - but for now you should be ok. 

You can crack the lid of the kiln 1" at 400F, 6" at 200F and open the lid all the way when the pyrometer reads 100F. It's safe to remove the glass when you can hold your hand on it. If you must push it - remove the whole shelf and cover the glass to protect it from drafts with a stack for newspapers - as long as they don't catch fire! 

This is all pretty conservative and you may become bolder as you get some experience. I find that I get pretty bold in a workshop situation then I back off once something cracks! As always if you have put a lot of work into the piece - be more conservative. 

HOAF GAS KILN:
Understand first my Hoaf is totally manual. After lighting the kiln I turn the gas regulator down to 40% and let it climb until it reaches 1000F before I turn it to full blast. I shoot for 1250F with no hold time. Turn it off and let the kiln cool on its own.

*CAUTION: When refiring glass that you may have pushed in the initial cooling or if you are firing one of the atypical cuts mentioned above - be even more conservative when reheating. You'll want to take 3 hours to reach 1000F on the ramp up in an electric kiln and then hold there for 20 mins. Once you've done that you can proceed as before. Unfortunately this scenario is not recommended (nor possible) in my manual HOAF gas kiln - if this is your situation just give it your best guess and err on the side of caution. Personally I fire these ticklish pieces in my electric kiln.

STAINS AND ENAMELS:
Fire as above to 1000F. For stains I fire to 1050F; for enamels 1125F - no hold in the Hoaf but I will give a 20 min hold in my electric kiln.

Fall 2013: Stained Glass Tours & Workshops at Glencairn Museum

Glencairn Museum. Bryn Athyn PA

September 14, 2013 – TOUR/DEMO: The Bryn Athyn Experiment – Replicating Medieval Glass

In the 1920’s the craftsmen of Bryn Athyn began a great experiment to rediscover techniques of Medieval Stained Glass. In the process they worked out their own unique methods for glass making and painting in the medieval style. This 3 hour tour will include an in depth look at the works created for the home of Raymond Pitcairn paired with the extraordinary collection of 12^th Century glass that inspired them. The tour will conclude in the studio for a demonstration of techniques based on the discoveries of the Bryn Athyn craftsmen many of which blur the distinction between restoration and forgery.

Tour/Demo: The Bryn Athyn Experiment - Replicating Medieval Glass

FEE: $35pp 

DATE: Sept 14, 1-4PM

Maximum Size: 10

Register at Glencairn 

Contact Doreen Carey at 267-502-2981 or doreen.carey@glencairnmuseum.org 

November 9&16, 2013 – WORKSHOP: Glass Painted Panels using Historic Techniques

This class will introduce traditional techniques of glass painting used by stained glass artisans in the medieval and renaissance period. Participants will be given a choice of patterns and produce a small panel during the workshop. Students will learn to mix and apply glass based pigments. Proper brush techniques will be covered in detail. All materials provided. No experience necessary.

Students make a panel like this!

FEE: $225 

Class length: 2 Days

DATES: November 9 & 16, 2013

Daily schedule: Saturday 12:00 – 4:30 PM

Maximum Class Size: 10

Register at Glencairn 

Contact Doreen Carey at 267-502-2981 or doreen.carey@glencairnmuseum.org 

ABOUT THE INSTRUCTOR:

J. Kenneth Leap has been painting on glass for 25 years. He currently holds a position as President of the American Glass Guild. He is the Stained Glass Artist in Residence at Glencairn Museum and teaches at Bryn Athyn College. He is an associate artist at the Wheaton Arts & Cultural Center in Millville, NJ where he maintains a studio and offers additional classes. For more information please visit www.jkennethleap.com.

ABOUT GLENCAIRN:

Glencairn, located in Bryn Athyn, PA was the home of Raymond and Mildred Pitcairn, built in the Romanesque style between 1928 and 1939. Glencairn now serves as a museum of the history of religion. The museum houses an extraordinary collection of French medieval stained glass panels on par with the finest examples in the Cloisters or the Metropolitan Museum of Art. For more information about Glencairn visit www.glencairnmuseum.org

Question about Flashed Glass

We're all just wild about Harry (Clarke)

Q: When you blast off a flash, do you prefer to then trace and matt on the blasted side or on the clear side?

or get down and dirty and trace into that rough stuff, but keep the images "registered"...

WWKLD??

WWHCD????

A: Well, Harry Clarke would acid etch the flash with hydrofluoric acid leaving the surface brilliant and eminently paint-able. I mix it up. If the panel is going to be viewed at very close range and I am concerned with "registration" then I put the flash to the inside sandblast it off and fire polish it in my kiln. What is fire polishing you ask? Getting the glass hot enough to melt down the rough surface left over from sandblasting. Usually 1350 with a 20 minute hold will do the trick. Watch out for shrinkage. The result is not as nice as acid etching but a lot more manageable in my studio step-up. (Read - Sigh, I would prefer to acid etch). When registration is not a concern then I put the flash to the exterior, sand blast and paint on the smooth, non-flashed side.