Using Spray A Plus

[mharrigan]

I recently bought Spray A Plus and had a problem the first timei used it. I used it on 2 pieces I was slumping.  I brushed it on, using a small brush — maybe it was uneven, though t tried to make sure it was smooth and none was puddled.  I took the kiln up to 1335′ holding for 30 minutes, using a usual ramp down.  (I know, a weird slumping schedule.)

Both pieces had rusty looking red stains on them, one had it only in one spot and the other had it all around the dark green border of a plate.

any ideas of what I did wrong? The directions say that you just have to go over 1300 degrees for it to work.

[wordana]

Is the “rusty stain” just a thin border around the edges of the glass pieces? If so, it is a reaction between the two glasses and has nothing to do with the spray.

 

Dana W.

Jester’s Baubles Fused Glass Designs

http://www.jestersbaubles.com

[mharrigan]

No, it’s all over most of the border of dark green glass, which is almost an inch wide on all four sides.  There is no reaction on the bottom of the glass.  It’s rough in texture, I’ve never seen anything like it in my 8 years fusing glass.

Merrilee

[Stephen Richard]

It’s normal to apply the devit solution ( whatever it is – propriotary, borax, clear powder or frit, or something abrasive like sandblasting) while the piece is still flat.  Doing it in the mould is inconsistent, and reduces the probable life of your mould. From your description I have no idea of what it might be.  You could try an abrasive solution – sandblasting or abrading with fine wet and dry sandpaper and then fire polishing again.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/ and  http://www.glasstips.blogspot.com/

[mharrigan]

It was flat when I put it on the mold, my purpose was to prevent devit as it was slumping; I took it up to a higher temperature than usual in a slump to get a better fire polish (I realize I was taking a shortcut- and I see that’s not a good idea!)

Thanks for the feedback, I appreciate your thoughts.

Merrilee

 

[mharrigan]

Ah, here is a clue. I had put a small piece of French vanilla with fine silver wire, as an experiment.  I recall that silver in a kiln cam affect other glass pieces in the same firing. Does it make sense that the silver could have caused this problem, even though the glass that got the stain (bullseye jade green, 145) is copper bearing but as far as I know doesn’t react with silver?

Merrilee

[Stephen Richard]

According to Bullseye’s chart

http://www.stained-glass-supply.co.uk/Media/Default/Resources/Bullseye-Reactive-Potential.pdf

0145 does react with silver.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/ and  http://www.glasstips.blogspot.com/

[mharrigan]

Well, i guess that must be the answer.  thanks for helping.

are all copper earring glasses reactive with silver? I was actually looking for that information and didn’t fine it on the bullseye site.

cheers and happy new year!

Merrilee

[Stephen Richard]

If you use the link in my previous post it will take you to a copy.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/ and  http://www.glasstips.blogspot.com/

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