Proper way to heat before removing a bolt

[earlthegoat2]

An old thread made mention of this and I am wondering the applications in which heat would be SOP.

Diesel research was the one specifically who made mention about it. He mentioned it like it was a regular part of his work. This leads me to ask the question of whether there are specific tools that will make this easier such as a butane torch or just stick with MAPP.

Is there a tool that will very easily heat the area surrounding the bolt to loosen up the purchase a little and/or the instances where red loctite has to be heated to loosen it up is there a technique to heat the bolt and not cause it to expand too much.

 

[outcast]

i just use the torches and heat the female side(bolts), or the nuts. sometimes that is not possible. so i just heat everything. then let the nut/bolt cool to where it is not red.

 

[outcast]

oh. my rule is , if i take the torch out for a car. i don't put it away until the job is done.

 

[pipsters]

If you were doing it all the time, induction heaters seem to work really well, really quickly.

 

[glenmore]

Yes, someone posted a link to a video of a manufacturer (Snap-On?) demo of an induction heater and it seemed to work like a charm.

 

[jjjrmx5]

If you were doing it all the time, induction heaters seem to work really well, really quickly.

^^^^^
Yep.

I only use MAPP on O2 sensors if/when replacing.

Everything else for vehicles/cars I use std. propane in the tall skinny tank.
It tends to release the fastener without the need to use a new one I have found. MAPP or acetelyne torch tends to ****** up the bolt unless used very carefully,

 

[DrkMtnDew]

the Mini-Ductor II is the way to go, if you got the dough.

 

[back2class]

Never have much luck with mapp or propaine. Just not enough heat. What happens when done right is;;; heat the bolt up cherry red and it heats faster than the material around it. This expansion from heat puts tons of pressure on the fastener. Then when it cools it shrinks back down, only now a little smaller than it was before as it has been compressed. Also the different rates of expansion cause a mechanical movement that breaks it free some more. Best to heat the fastener, but heat to either or both work ok.

mapp or propaine....may help, but don't expect much.

 

[2oolhound]

When you think about it many of the components in an engine or other machinery is shrink fit into place. Valve guides and many bearing races for example require one part be cooled while the other is heated to allow a friction fit at operating temperature. To cause a seized nut to release from a stud you have to expand it by heating it faster than the stud so there is some differential in size so it must be done fast before the heat can transfer from the nut to the stud. A hot flame like oxy/acetylene works well and care must be taken to work around the nut without heating the stud at the same time.