Torch recommendations

the point-blank question:
will a small-scale butane torch actually work in real life (despite claims of temperature on the advertisements) for getting badly stuck fasteners loose? and not the grill lighter torches. Am I going to be much better off going up in price for a mapp/pro torch - that is, skipping the propane torch offerings entirely? is propane really all I need?

more babblings:
I have been looking for a torch to apply heat to stuck hardware. I have looked at a bunch by now - I can give specific items if needed, but perhaps if you can understand where I am coming from - I am looking for a low-cost torch. For example, the propane or mapp-pro torches in Sears are over $30.00, and for medium-to-large scale work. The least-expensive torch I saw in Harbor Freight runs on butane and is about $9.00 - but there are a number of other small-scale butane torches. I already tried the tiny butane torches that are for lighting the grill and they are abysmal for heating stuck hardware, and I suspect the others are also as bad. Also the various nozzles appear to be propane or mapp/pro specific, despite what I have heard. I am averse to oxy/acetylene torches at the moment.

The effectiveness of a torch depends on the mass of the material that surrounds the stuck fastener.

For example, if you were to try to remove a stuck motor mount bolt out of an engine block, a propane torch wouldn’t heat the bolt up fast enough because the mass of the engine block would act as a heat sink and pull the heat away from the stuck fastener. So you’re basically heating up the bolt and the engine block at the same rate which isn’t going to help in removing the stuck bolt.

Instead you want to apply very high heat to the stuck bolt so the bolt heats up so fast that engine block can’t absorb the heat away from the bolt faster than the heat applied to it. And that’s what gets stuck bolts out once they cool down.

This is why an oxy/acetelene outfit is called the blue wrench.


I have a butane SOLDER-IT PT-500 that has an impressive flame. My mechanics often borrow it and rarely need to go oxy-acet except to cut.

You’re going to spen that 30 bucks easily for a good butane torch.

Oxy-acetylene is very fast and very effective. Butane and propane are slower and less effective. Mapp is somewhat better than propane and butane. Removing the plugs and outlets from Chevrolet SB water pumps was an under 1 minute process with acetylene and I gave up even attempting with propane many years ago.

Just go down to Ace and get a Mapp gas torch for about $20-30. It is much hotter and really takes the place of a propane torch for most household work. Never had much luck though for loosening frozen parts and would recommend PB Blaster instead. After the Mapp torch, then you’re looking at $2-300 for an Oxy/Acet unit plus tanks and just not worth it unless you like to weld. If you want to do small and delicate work maybe a small torch but not for loosening stuck fasteners. Just in my humble opinion anyway.

… it seems I did not get my comment posted correctly… so here’s a crude reconstruction

thanks all for helpful comments. @Tester very good point with rate of heat transfer between parts.

so it sounds like, for stuck fasteners, a mapp/pro torch is minimum. butane/propane not worth it.

@Bing said “weld” with o/a torch - how serious a weld are we talking about? so could I make a crude weld between an old heat shield and a fresh piece of steel from the local Lowe’s/Depot?

also with o/a torches - there are $40.00 kits out there - not worth it?

… ah, it seems I pressed “preview”, then ditched! yes, my attention was that much in demand… oh I and I know why now - the order of the buttons “preview / save draft / post comment” are swapped for the page where a new thread is started… uh oh, I have to go now again. but the idea is that “preview” is where you sometimes see “post comment”… if you are auto-piloting, …

A potential problem with using a torch in an attempt to help loosen a stuck nut or bolt is that the heat can damage something nearby. If that is not the case, then give it a try. I almost never use heat for this, have not had impressive results with the method. One thing that works very well for me when access permits is an inexpensive air operated impact wrench set at first on very low torque using the air valve and then increasing the torque. It seems that this will loosen a stuck bolt or nut when simply applying brute force will break the fastener.

A good torch to get going with is one that uses propane in the 14.1 oz cylinders. Just get a cheap torch without features; the heat output is the same as the power is limited by the evaporation rate of the propane in the cylinder. You will find this tool useful for other jobs as well.

I expect an oxy/acetyl torch would work considerably better, but I’ve had luck removing stuff with just a propane torch or the same torch equipped with MAP. It does take some time though. I’ve used my hand held propane torch and patience to remove rusted brake drums and discs successfully.

The new technology for removing fasteners with heat without using a torch is this.


MAPP seems to be the practical middle ground.

Oxy/Acet is used for gas welding. Gas welding is used for many different applications but requires knowledge and skill. The same outfit is used for cutting steel with a different tip. I believe heat shields are stainles steel which I believe would not be suitable for gas welding. Possibly it can be welded with arc welding, either TIG, MIG, etc. but not for a novice and I’ve never done it. A good muffler shop would be the place to go for repairs to heat shields. Youtube is your friend for basic welding information but not all those folks know what they are talking about.