On Thu, 21 Apr 2005 00:53:18 GMT, carl mciver wrote:
"Gary Brady" wrote in message
ink.net...
| Karl Vorwerk wrote:
| I have to remove remove some mastic from a concrete floor where there
were
| vinyl tiles. Is a hot air gun enough or do I need my propane torch. Are
| solvents a good idea?
| Second problem:
| Mastic again. This time on a concrete wall that is probably going to be
| painted. What's the best way to prep for painting?
| Thanks
| Karl

I know that if you get it cold, the mastic gets brittle like old tar
chunks. That said, you can get some dry ice and put it where you want to
scrape. Not sure how well it will work, but it might be worth trying.

If you've got a source of liquid nitrogen, that might be another answer
(well, for the floor at least). Note that both dry ice, and liquid nitrogen,
will displace oxygen from the room. If you enjoy breathing, caution is
advised (lots of ventilation). CO2 will pool, which is inconvenient if
you pass out. Liquid nitrogen is inexpensive _if_ you have a local source.

I read somewhere that you put a box of dry ice over the vinyl tile you
want to remove and after moving it out of the way you smack it with a hammer
and tile leaves in lots of small pieces. Same idea.

I have to try that.