On Mon, 24 Sep 2007 04:56:55 -0700, wrote:

If it really is putty, heat softens linseed putty. If its silicone,
that can be sliced, but I gather from what you say its real putty. No
quickie option for that I'm afraid, tough stuff.

I did the installs for 4 stained glass panels last week.

Multimaster and the scraper blade 8-)