[oldroadiedog]

To Weld or Not To Weld.

I'm about to replace the rear muffler and tail pipe on my '72 GT. From what I've seen so far all the joints on the original exhaust have clamps and have been welded. Was the welding done at the factory or was this something that the original owner did? Do the joints need to be welded when I install the new components? I'm not replacing the front muffler at this time and would like the option to do so later with less trouble.

 

[BQS4]

I would weld all your joints. Adds strength to the entire system and seals leaks.

 

[oldroadiedog]

I've seen guys "weld" steel with a torch and metal coat hangers. Sounds crazy but it worked. Is this an option on the exhaust?

 

[Dan]

My dad used to weld up exhaust with the old torch and hangar method.

He likes to clamp the joints then weld 1/2 to 3/4. It leaves a little room for expansion of the pipe and if you leave the top unwelded you can still grind it away and remove the pipe.

 

[oldroadiedog]

A quick stop at Home Depot and I've got a torch. In the same section there was some all purpose solder. The solder's melting temp is 435F so it should serve well on the exhaust. I'll most likely experiment with both solder and the ol' coat hangers on the removed pipe and muffler and then decide which to use on the new parts. Will advise on results.

 

[kwilford]

Umm, you bought a torch from Home Depot? And solder? What kind of torch? To weld or even braze (a type of solder for steel, which uses a brass rod coated with flux, that melts and "bonds" to the unmelted base metal) you need a LOT more than 435 F.

If you bought a propane torch and lead/tin solder, you are about to learn that "solder" can only be used for copper and brass connections (such as household plumbing), not steel or iron. To gas weld (which uses a steel alloy rod, which the hangar is used in place of) or to even low-temperature metal braze, an oxygen/acetylene torch is required (or a MIG/Arc welder with a carbon-arc attachment). You can buy small versions (actually a propane/oxygen kit) that are really just toys, but at least they generate enough heat to actually braze. But I don't think they can get a hot enough flame to gas weld, which requires the rod AND base metal to melt.

 

[oldroadiedog]

kwilford Umm, you bought a torch from Home Depot? And solder? What kind of torch? To weld or even braze (a type of solder for steel, which uses a brass rod coated with flux, that melts and "bonds" to the unmelted base metal) you need a LOT more than 435 F.

Thanks for the info kwilford. I did experiment with the torch. You're right it will not melt the hanger or the pipe. The all purpose solder did adhere nicely to the steel pipe but I guess in a technical sense it isn't truely bonded. I'm going to try the solder (keep in mind it's the last two joints) and avoid purchasing a welding rig. If the joints begin to fail I'll take it to a shop and have the real deal done.

 

[husker]

If you want it done right but don't want to pay for a welding setup just go to your local discount muffler shop and give them a few bucks to weld up the last few pieces.

Coathangers and solder don't sound like the right way to go.