Properly Using A Propane Torch

[Bingster]

There are many bolts and water valves that won't free up using conventional ways.  I'd like some pointers on using those hardware store torches, you know, blue flame and stuff like that. I don't wants to burn up parts.

[Plymouthy Adams]

I have never found a butane torch really worthy of heating rusted bolts on large metal objects like engine blocks and other heavy metal...the flame is not hot enough to heat the item without having to superheat the object it is threaded into...oxy-acetylene will over come this obstacle and if broken in a blind hole in cast iron the ability to blow a bolt out with no thread damage is ideal with the professional torch...modern cars are even worse these days...plastic bolted to aluminum with steel bolts of how we say too light a grade fastener to begin with...ask me how I know...wait, don't ask me...nightmare is past, let it stay in the past...

[Flatie46]

Yep, pretty much what Tim said.  I will say this, them small hand held propane torches are pretty good for starting a campfire and I have used 'em to light my wood stove. I'm sure there is a way they could some how be misused in this purpose and possibly be dangerous so I guess I shouldn't recommend it.

[Dartgame]

Depends on what you are trying to do. Propane torches can often be helpful with stuck fasteners - heat it up red hot and use penetrating oil to cool the hot part and then try removing. If you can't heat it red hot you need an oxy acetylene torch.

[Bingster]

Sometimes it's difficult to sift through the opinions and decide on the right procedure.  Logic tells me that the propane torch at least puts out a hot flame that has the potential to loosen a frozen bolt.  Since every situation is unique, there is always a possibility that it will work.  The torch is pretty inexpensive, and I've always found to try the least amount of force first and move up from there.  Since $$ prohibits me from buying a welding torch, it seems that the propane route is at least a shot.

As far as the penitrant, I've been lurking around  other boards and found a chart that lists how much torque is needed to loosen a frozen bolt with various types of penitrants.  Seems a 50/50 mix of acetone and tranny fluid is the winner. Wintergreen oil was another but the 50/50 mix won out.

[Plymouthy Adams]

ok..one more point...and that is very point itself....the propane will not come anywhere near the pencil tip concentrated heat of the oxy-acetylene so you losing much of your effective heat in surrounding area due to the fan of the flame...but you will find other uses for the propane over time...

[Don Coatney]

Suggest you buy a MAPP gas torch as opposed to propane. About the same price but MAPP gas is much hotter.

[Bingster]

I'll look into that, Don. Thanks.  I'll Google and check it out.

This reminds me of a Star Trek episode.  A creature stuck on Spock's back and messed up his nervous system. McCoy figured out that a high intensity light theoretically might kill the creature.  So Spock goes into this chamber and McCoy bombards him with this light.  Spock emerges and reports that the creature is gone, but that he is "quite blind".

Kirk gets mad at McCoy, telling him that he didn't need to have thrown the entire spectrum of light at Spoke to cure him.  A smaller power of light would have done it without blinding Spock.

I've always remembered this lesson.  Do the lesser first and not risk ruining something.

[Flatie46]

I've tried propane torches in the past at home trying to loosen a stuck fastener or broken bolt ,never had any success,  At work I have access to oxey- acetylene and use it often for this purpose. Maybe I didn't have the patience  for the propane process or technique. I know at work using  oxey- acetylene it makes short work of it.  Maybe it's spoiled me. I do understand what your saying about doing the lesser and being worried about ruining something. A little training is all you would need.  If you have a buddy that has a torch set up and let you get a bit of practice with it you would probably love it. You could check with your state area Voc Tech school on a welding/torch class.  Ours is 300bucks a trimester, a bargin for the skills you will develop. I've went back several times over the years for welding certifications and most recently a PLC class. Last time I was in the welding class there was a retired lady in there learning torch skills so she could build abstract yard art. She went from jumping and giggling nervously when lighting a torch to being pretty darn good with it in a matter of weeks.

[Plymouthy Adams]

the idea of lesser is not true here as you will leave a bigger flame over a wider areas with less control and thus get nowhere on the average while heat is saturated over a larger area for no real purpose as it will by mass alone prevent it from getting to the correct temp with the lower heat and less concentrated flame over a very extended period of time...been using the torch for over 50  years.....there is really no substitute....except maybe farm it out to the next man...

[Dodgeb4ya]

The OXY/Acetylene  Blue tip is best and right to the point!

[John Reddie]

8 hours ago, Don Coatney said:

Suggest you buy a MAPP gas torch as opposed to propane. About the same price but MAPP gas is much hotter.

This is true. I have had success with the MAAP gas torches but for large bolts or areas, the Oxy/Acetylene is best. 

John R

[keithb7]

I have been busting my knuckles, stripping heads and breaking hardware for years. School of hard knocks I guess. No real training. I just kept learning from my mistakes.  I have never used anything hotter than propane. It sucks in many situations but in some smaller-ish applications I've had luck. The reason I've tried nothing else is, I have no access to oxy/acetyne torches. I have never welded, and no access to one.

The older I got I found that I had more patience. I learned a few tricks. I learned to take my time. Soaking parts in penetrating oil and leaving it overnight has worked sometimes.  Tapping the tool end with a small hammer helps free things up sometimes too .

Then lastly theres the reverse drill bits and easyouts. Hand-filing to re-shape bolt heads, was a good lesson to remind younger me to use the right tool for the job. 

If you've got nothing else, take some heat to it. Even propane might help. Worth a try. Some oil. Some tap, tap tapping. Add Time. Try fastnee and repeat as necessary. Fast it ain't. I've gotten things done one way or another. 

[48hoopty]

Don Coatney is right.  Don't waste a penny on propane, get MAPP gas. If that don't work oxy/acetylene is the next answer. I use it all the time, just let the metal cool down naturally don't pour water on it. Also another trick with MAPP gas is to pour warm soapy water on the offending nut or bolt. Sometimes that might help if you don't have access to an O/A setup. 

[keithb7]

MAPP gas and air: 2,020 °C (3,670 °F)

Propane and air: 3,623 degrees Fahrenheit or 1,995 degrees Celsius

The difference appears negligible based on the info I found. 

[Plymouthy Adams]

map is generally considered a safer gas to use .....

[Los_Control]

I have used both, but prefer mapp for copper plumbing.

Interesting little piece here I just read about using the proper torch with mapp for higher heat. Will have to try it out

 

.MAP-Pro gas burns at a temperature of 3,730 degrees Fahrenheit, while propane burns at 3,600 F. Because it heats copper faster and to a higher temperature, MAP-Pro gas is a superior alternative to propane for soldering. If you opt to use it, the manufacturer recommends using a specially designed torch. Adding oxygen to the flame raises the temperature to 5,200 F, which is suitable for cutting and welding steel when precision is not required.

 

 

[DonaldSmith]

I've heard that mapp gas is heavier than air, like carbon monoxide, while propane is lighter.  Mapp might settle in confined areas, or find its way to a pilot light. Just another caution, to be cautious about.  

[Bingster]

I finally did get both the heater valve on the engine block and the eater pump by-pass tube free.  I used a heat gun.  Just happy it worked!