chipping bent glass

[Doug Bernhardt]

I'm sure this has been discussed before but need my mind refreshed anywho. Have an upcoming job that will require me to have a large (2x7 ft.) piece of glass bent in advance of chipping. I had it in mind to bend after acid and chipping treatments but the company doing the slumping insists it be done otherwise. I'm pretty sure it can be done in advance as that is how the old masters accomplished this. All advice is welcomed.

[Patrick Mackle]

Doug,
I would do your work while it is flat. Much easier. And as you mentioned, the way it used to be done in the past.
Now the important part since you do not bend these yourself in house on regular occasion.
You will have put a lot of time and labor into this piece before handing it over to the bender.
I be certain they are well versed in bending.
Tips: They should-
Heat the glass slowly and evenly, soak it for an even bend. Slowly ramp up to the temperature at where the glass will fully bend taking on the least amount of mold marks and kiln wash indentations.
Too high a heat will take(Flame polish) any white acid frosts right out, and turn them to satin.
Sometimes if possible I will leave extra glass at both ends of the glass for weight or to continue the perfect radius without flattened ends. Then cut the extra lengths off after annealing.
I personally like to baby sit my kiln with a job like this, rather than rely 100% on the computer controller. Too much time invested for a failure.
Hope this helps,
Pat

[Jerry Berg]

Hi Doug,

I just let the glue dry to a brushable consistancy and kind of lettered it on.
Here is an example that were for gasoline pump globes. Hope this helps.

[BruceJackson]

Good answer Pat,

It also fits in with my limited experience in working with kiln-formed glass. The last one I did, I did the glue-chipping first and kiln-slumped the glass into a convex later. The texture of the glue-chipping was unchanged. I also left a 50mm flange for support that was later cut-off.

Jerry, I recognize that design....How's Chad?

Makes me realize, we are working in essentially a small world. There have been several occasions in which I have shared clients with members of this forum.