I recently freed a dozen studs from a set of rusty exhaust manifolds.
My method was to apply heat (in this case a propane torch) and tap on
the stud lightly with a hammer. Next I would try to unscrew the stud.
If it wouldn't turn, I repeated the process. For good measure I sprayed
on a little Mouse Milk (a penetrating oil sold by Aircraft Spruce), but
I'm not a big believer in penetrating oils in general.
Eventually I got all of the studs out without breaking any of them off.
The down side was that most of the thread material in the stud holes
came out with the studs, mostly in the form of rust.
If I recall, the heads in question are aluminum. Steel and aluminum can
really "weld" themselves to each other, so be careful. Also Aluminum is
a very good conductor of heat, so you may have trouble concentrating
enough heat in the area to do much good.
Roland
>
> Strange but Seemingly True Dept.
> I have read of, and tried once, the following trick- (
> successfully):
> With your trusty Bernzomatic torch, heat up the offending
> bolts-fairly hot- and then apply a wax crayon ( eg. Crayola ) to the
> interface under the bolt head. The crayon should melt readily, smoke is a
> good sign... the melted parrafin seems especially good at finding its way
> into the rusty threads. The wax will solidify, but it is fairly slippery
> and helps to release the fastener without twisting off the stud, etc. Of
> course the parrafin is flammable, so be careful if you make a second attempt
> with the torch! ( Usual cautions apply..)
> I have been a PB Blaster advocate, I think it is better than the
> others ( WD40/liquid wrench/LPS/Kroil, etc...) The crayon trick MIGHT be
> the answer to your problem. It worked for me when the other methods failed.
> Good Luck
> Bob Westerdale
> 59 3A TS36967E
>
>
> I have been spraying the exhaust manifold bolts with PB Blaster for a week
> or
> so, in hopes that they will come off when my replacement manifold shows up.
>
>
> But I'm still concerned that a bolt may break off in the head, leading to
> all
> sorts of drilling and re-threading that I definitely don't want to get into.
>
> So, any other suggestions on how to increase my chances that the bolts will
> come out?
>
> Thanks, and have a good weekend.
>
> Bruce
> 1980 Inca Yellow TR7
> Chapel Hill, NC
>
>
>
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