Fein has a couple of scraper blade for the Multimaster that are designed for removing caulk. The are actually chisel like blades which you can sharpen that vibrate side-to-side and cut right through caulk. I've used it on cured polyurethane with good results.
http://www.fe> I guess the moral of this story is that it's always possible to learn the hard > way.
A roofing contractor calls me frequently to do follow-up carpentry after his
> roofing jobs, and this one was to replace the cedar trim around some windows
> in a mansard roof. When I checked the job out and gave a price, I didn't
> notice that the roofers had caulked the flashing to the rotten cedar that I had
> to remove, on the 8 windows, all along the top, which in some cases was
> 12 feet. When I started the job, first thing I found out is that cured poly-
> urethane sealant is practically impregnable to razor knives, chisels, or > scrapers.
> To simply tear the wood off the flashing was impossible, the flashing
> would've been bent to smithereens, so after an hour of research on the cell
> phone I bought one of those flame diverters for propane torches and
> modified it into a scraper shape on the end and mounted it to the torch
> tip with small hose clamps. It was very effective in separating the caulk
> from the flashing, but what a time consuming mess! The caulk would
> begin smoldering and spluttering and throwing off little blobs ( I have the
> burn blisters to prove it) andproduce the most noxious fumes imaginable
> which were hard not to breathe being up on a scaffold. I hadn't included
> the cost of a hazmat outfit in the job. And then there was the cleanup,
> because the burned caulk turned into a permanent, gooey mess and got
> all over the equipment. The moral being, small details are the most
> important aspect of bidding jobs. By the way, is there such a thing as
> an electrically heated scraper for removing caulk?
>