stuck bolts,screws...want to try heat, but how...

[whit_iii]

I have stuck bolts,screws,etc on a 58 austin healey. I have tried using the extractors, but I have broken them twice.

Folks have suggested using heat to remove them, but I am not sure what type of heat source to use. Is it bad to remove these using heat? The car has sat for almost 30 years so it has been next to impossible to remove the bolts, screws, etc.

Any thoughts on what type of heat source to use as well as a specific brand?

Thanks.

 

[Biff]

I'll assume since you didn't say that you have soaked these bolts with some form of penetrate before trying to remove them. WD-40 is not a penetrate! Use a good name brand penetrate like PB Blaster or some plain old kerosene. Soak the bolt(s) daily for a number of days, while just trying to get them to turn. Don't use enough force to break them. When that fails then you can use heat. A handheld propane torch with a pin point flame head will do. If you have access to a acetylene torch that will also work. Heat the bolt head and let it cool a few times with some penetrate between heat - cool cycles. You can also try tightening the bolt before trying to loosen it as this will sometimes help break the rust bond. If you are trying to remove suspension bushings where the bolt goes through a rubber bushing then cutting may be the only option. Rubber bushings have a steel inner liner which will over time weld it to the bolt with rust. Cutting the bolt between the bushing and bracket sometimes is the only option.

 

[ThomP]

Re: stuck bolts,screws...want to try heat, but how

If the bolt is already broken and you have resorted to extractors, I suggest you purchase a left handed bit to drill out the bolt for the extractor! The heat from drilling and the torque in the correct direction often makes the bolt "walk" right out without the extractor!

Heat is a last resort. It can destroy the temper of the surrounding metals and make them too soft to perform their job. If you have to, you have to.

 

[DrEntropy]

Re: stuck bolts,screws...want to try heat, but how

PB Blaster, and wire brush whatever rust/grot you can too. Heat helps as described by Biff. Sparingly, tho. Patience is the best tool you can have when it comes to this work.

 

[John Loftus]

Re: stuck bolts,screws...want to try heat, but how

If you are forced to use heat, get it red hot with a torch and then quench with a wet rag. As others have said, try the penetrating liquid over the course of several days, give it time to work. I also find it better to try to tighten the screw/bolt first to break it loose.

Good luck!
John

 

[LLAngus]

Re: stuck bolts,screws...want to try heat, but how

Per the Doc PD BLASTER--I'm a believer since he shamed me into using it. If the bolt is broken and you can get to it. I really suggest you drill and tap. On sheet metal screws you can hit the head with a punch (back and forth) and it will loosen up. I have taken an arc welder and hit the top ofr a stuck bolt to get heat to it. BUT you have to know what you are doing to do that. Good luck and remember PB Blaster and let it work.

Bruce L /ubbthreads/images/graemlins/cheers.gif

 

[Banjo]

Re: stuck bolts,screws...want to try heat, but how

All out of PB blaster? try Dot3 brake fluid. You'll be amazed at how well it works. Just don't let it get on any painted surface. I also advocate using PB blaster and patients. It's good stuff.
If you can't afford an Oxy Acetlyne torch set, try a bottle of MAP gas with a screw on torch head. It's much hotter than propane (not as hot as Oxy Acetlyne) and usually will do the job on stuck fasteners.

 

[beaulieu]

Re: stuck bolts,screws...want to try heat, but how

one more thing , if you can get to the back of the bolt spray there too, sometimes the extra threads are out in the air and rust , especially with fender bolts etc.

I am spoiled out here in California where most of the bolts come right out , I never would have been a mechanic if I lived in the Rust belt !

Beaulieu

 

[70herald]

Re: stuck bolts,screws...want to try heat, but how

If the bolts are on a part which is "portable" drill out the bolt with a drill press using a slightly smaller drill bit than the inner diameter of the thread. This way you will only have the "thread" part of the bolt left in the bolt side. Start out with a much smaller than needed drill bit, and be fanatically careful about centering, and drilling straight!
If it is a particularly valuable part that you are working on, bring it to an experienced machinist! They have lots of experience with removing broken bolts.
Other options are EDM Electro discharge milling. Here the inner part is eaten away with an electro arm milling machine. These can take out even ultra hardened bits of metal. This is also big $$$$$. If you break off an extractor you very well might find out just how many $$$$.
Yisrael

 

[Roger]

Re: stuck bolts,screws...want to try heat, but how

Violence can help, too. A drift of the right diameter so as not to burr anything, smartly struck with a BFH, can help free up reluctant bolts.

 

[IanF]

Re: stuck bolts,screws...want to try heat, but how

An air-powered cutting tool (whizzer-wheel) can also do the trick if the nut/bolt has become mauled... Just last night I had to cut off one of the axle u-joint flange bolts.

Mmm... power tools... /ubbthreads/images/graemlins/hammer.gif