[cstreit]

Make sure you have some air circulation and try and keep the heater above ground. Many flammable fumes are heavier than air and will settle at the floor level. An open flame and BOOM!

Now that I've covered liability, I really like my 50k BTU propane torpedo heater. No smell at all. Even after hours of running no activity on the CO meter. However in a smaller garage these things will suck up the oxygen pretty quick too so keep a window open a little otherwise you'll find you start getting a little "hazy". Be SUPER careful about solvent use, when they burn even in small quantities they produce some nasty nasty stuff.