How to heat up a bolt without damaging stuff around it

DominicHillsun@lemmy.world to Cars - For Car Enthusiasts@lemmy.world – 6 points –

I am working on my integra's front suspension, but 3 bolts are rust welded. My impact gun managed to get one off, but the others wont budge. I hit them so much that the impact bit got too hot to the touch. Sprayed with penetrating fluid, hit it with a hammer etc.

My only other option is heat, but the problem is, that it's a wheel well and it traps heat, not to mention there is a brake hose which is very close to the area I will be heating.

How can I contain my propane torch heat to this specific bolt without damaging other areas?

17

Soak them overnight in penetrant and then use the biggest breaker bar you can find. 36 or 48 inch, usually 3/4 or 1 inch drive.

You could also try cutting a notch and using an air chisel to try and vibrate the rust loose while spinning the bolt.

Remember, left is loose, right is tight.

EDIT: Also, what impact are you using? Cordless half inch? Pneumatic 1 inch? What's its reverse torque?

Also, depending on how parts have worn, you can try using a floorjack under the wheel to try and relieve some pressure on the bolt. Not a lot of lift is needed, but sometimes bushings go bad and the suspension locks its own bolts in.

Left is loose, right is right. And orientation flips psychologically when the nut points toward the ground.

Not going to say how I learned that the hard way...

If that scares you, wait until you find out about left-hand thread bolts. For those bolts, left is tight and right is loose.

I always hated that expression of left is loose, right is tight. Bolt is not a line, it's a spiral.

Clockwise to tighten (numbers on clock go bigger) Counterclockwise to untighten (numbers on clock go smaller)

The answer to the question in the title is an induction heating device.

But for this particularly issue I would use a combination of an air hammer and penetrating oil. Hammer it to break up the rust, spray it with oil, wait overnight and try to remove. Rinse and repeat until it comes out.

Which bolts? can you remove the part they are stuck in? Might be a lot more work but way better than a car fire in a garage

Barring that what about the mats that plumbers use when using a torch to solder copper pipes in the walls?

You'll melt the bushing if you heat up the bolt on the lower control arm. I would grind off the nut with an angle grinder, probably the easiest way. Make sure to load up the suspension a bit to get the bolt out easier.

Edit: After getting the lower bolt off you can remove the entire strut from the car and figure out how to get off the shock clamp bolt.

No, I cannot, not enough vertical space for that. I have managed to remove the lower bolt on one side because it was greased before bolted in and I have to remobe both bolts to remove the strut.

To get the strut out, you also have to unbolt the upper control arm at the ball joint. I had this car for 16 years and have done it this way several times.

Edit: also unbolt the sway bar if have not done so.

You could always try using electricity if you can get to the other side of the bolt. Hook up each side to a voltage source and if you pump enough electricity into it you can make it glow