WarmGlass.com

I am trying to up cycle an old stain glass panel into a mosiac. Any hints on removing the old puddy?

That sounds a bit scary! Make sure it's not a medieval masterpiece or even a contemporary one, first.

If the putty is old and brittle it will probably simply scrape off once the lead is cut and pulled off. Ditto if it's soft. A heat gun may help and I believe I read somewhere that saturating with linseed oil and bleach helps. Google it!

I've only done a couple of restorations requiring removal of putty and they were not difficult but I'm sure someone else will have more experience and better advice. Jen

putty.

it's a mixture of linseed oil and whiting (calcium carbonate). the oil polymerizes, and you typically can't get it back to the liquid state without dissolving it with a solvent (more oil won't make it unpolymerize). perhaps lacquer thinner would work. if it's really dried hard, you can typically just wiggle it free from the came. if not, cut off the leaves of the came and you should be able to pry the glass out using a a plastic fid, an old spatula, or thin screwdriver. i wouldn't use motor driven things, because you'd be tossing lead dust everywhere, which you probably don't want. you'll want to use rubber gloves and a breathing mask because putty dust would contain lead. put down lots of newspaper so you can just wad it up and toss. if you're doing this as part of a business or in a shop, the city will want you to do testing and perhaps lead abatement if they find out what you're doing.