Need advice on removing exh. manifold bolts

Anyone have any tricks for getting out exhaust manifold bolts without breaking them? I'm going to take mine off to get Jet Hot coated when I replace the rest of the exhaust. Hopefully I won't break any off in the process.
Thanks,
Matt

Heat! See link below.

http://www.VetteRegistry.net/vrforums/message_go.asp?MID=36582

John

|UPDATED|5/16/2004 12:07:15 PM (AZT)|/UPDATED|

Use a oxy-acetylene torch to heat the area (manifold) around the bolt. Gently tug on the bolt with a wrench. If it doesn't break free, keep reheating around the bolt until it does breaks free. If the the bolt starts to get tight while backing it out. Stop and reheat and resume removing the bolt. Be very patient.
Good luck!
Sarge

If you don't want to go through the trouble of using a torch, you could also try PB Blaster. I've used 5 cans of it so far and, in combination with a breaker bar, i've only had the body mounting bolts free spin/break on me. You can purchase PB blaster at any auto store or Wal-Mart for around $4 per can. And, unlike most other penetrating oils, this stuff really works. You'll actually be able to watch it "disappear" into the threads.

Good luck to ya

If you can get the bolts heated apply some parafin (candle wax) while hot on the bolt, as it cools it draws the wax inside around the threads making it easier to remove (sometimes)