I'd like to get some opinions on the use of heat from a torch to help loosen up various bolts. I'm curious about both frozen nuts and things like exhaust manifold bolts that broke off but left you something to get ahold of. Is it best to heat them up to say red hot and immediately start working on them or is it best to let them cool off then go to town? Any experiences with this problem will be helpful as I run into this problem more often than I'd like with a lower success rate than I'd like to admit to.:spank: Thanks
A lot of people go crazy with the heat when they don't need to. The best luck I've had is to moderately heat the fastener, but not to the point of glowing...then quench with cold water before I even put a wrench or socket on it. Rapid contraction from the quench can make an amazing difference. Penetrating oil like Kroil helps too, but never add it while the parts are really hot since you'll be breathing nasty fumes. Remember that whenever you use a lot of heat on a fastener to remove it, it should be replaced. Devon
I had a bunch of broken bolts in some heads. I welded a nut to the stump of bolt sticking up, brought the temp up to just starting to turn red and they would back out. If the color went away, ie got colder, the welded nut would break off again. After that, I just heated it up to red before turning and kept the heat on until the bolt was all the way out.
I'll heat a nut till it's red to get it off, but using that method on bolts can result in a broken bolt. WAX applied to a heated bolt will wick into the frozen threads and make it easier to remove. Try a few heat/cool cycles to get the wax worked in there well.
The trick is to heat the area around the bolt, while trying to not directly heat the broken or frozen fastener as much. You don't want the broken bolt to expand more than the area around it. I've had good luck with my torch.
I've used PB Blaster as a penetrating oil and heard of others heating the part and melting a crayon on the hot metal and allowing the wax to be absorbed by the bold or nut. Either of these should help, if anything beside drilling a tapping the will work.
all those methods will work,,,, i have drilled a very small hole into the bolt from the side and injected trans fluid with a srynge and needle..... and let it soak into the threads..... this works with the bolts that are in a aluminum timing gear cover......they are the hardest to deal with.... but the best cure is prevention to start with.... use anti-seize compound ..... :Brow::Brow:
X2. The method just varies with the situation. I recently had three flexplate bolts in a RAIV Pontiac that wouldn't come out even with an impact gun. I finally rounded off one of the heads trying and they wouldn't budge. I certainly didn't want to heat the back of the crankshaft so I heated the bolts until the head started to glow just a little, let them cool off for about 10 mintues, repeated that and then let them cool completely for an hour or so and they came right out, even the one I had rounded the head off of.
Heat if used correctly is a great tool. Ive thought of it as a grease. when hot the bolt/nut turns. as it cools down it gets tight. Used a torch for stubborn stuff for years. Just be careful under a car with it. Ive got a tear drop shaped scar on my upper lip from a blob of melted plastic from a speedo cable while cutting an exhaust system off in my uncles muffler shop many moons ago.
I hear ya,,,, I have lost count of all the scars..... If it aint worth bleeding over, it aint worth nothin.....:laugh::laugh:
