Copper exhaust pipe... how to bend?

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Mike B

Mike B

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That was done with BernzOmatic copper phospherous flux coated rod available at your local hardware store. Melts at ~1400F. Just a little less than pure copper, so be careful. The cool thing is this rod will braze copper to steel - :)

You need to get the metal red hot and it will flow just like solder. A swirl mapp torch will work for light work, but you may need oxy-acetylene for bigger work.

Brazing is just high temp soldering.
 
silverbear

silverbear

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By "Swirl Map torch" is that just a map gas cylinder in place of a propane tank, or does it have to be the setup which uses map gas plus oxygen? Interesting. Thanks, Mr. B.
SB
 
Mike B

Mike B

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Just mapp-air should work for small stuff.

I actually got a small piece of steel hot enough with propane-air to test if the stuff stuck to steel. Copper is harder though, it is so heat conductive that it really pulls the heat away from the fire.
 
silverbear

silverbear

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I understand what you're saying about the heat conductivity of copper. In making a copper gas tank a year ago for a cantilever Schwinn with my friend Dan, the tinsmith, I saw how quickly the copper sucked the heat out of the soldering iron (making for slow going) and how quickly the heat transferred some distance away from the spot being soldered. The properties of different metals is interesting and not something I gave much thought to before this bicycle motor madness. I hadn't known that copper gets harder when bent repeatedly. You'd think it would be the opposite and behave like steel. Different stuff entirely with it's own set of rules, as different as pine is from oak. I'm just beginning to glimpse into this world of metal working and can see that a real metal worker, a real welder for example, knows a whole lot. And the best of them, the real stand outs, are like wizards in their kind of sixth sense... as if seeing into the metal on a molecular level. I have to marvel at what some people can do... just amazing.
SB
 
MEASURE TWICE

MEASURE TWICE

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I think there are some torches that mention can uses map gas and have mix with air and no oxy tank, but I would like to know how big work can be done, I mean are all swirl tip about the same amount of heat or area that can be heated. I know that even if it is a map torch and pencil size tip if that is all the valve allows to be attached or is fixed with one size tip may be a disappointment.

I have an oxy map one with pencil tip and that is all it is made for. Maybe 35-40 years ago and still sit there, unless I start making jewelry.


This web site show a few brand and I think an adjustable size flame is better than just on/off. What do you think it could be useful for? I have thought of like 16 th inch sheet metal steel to want to work with. I have a MIG and with AR CO2 if I don't use flux core, but I hear it is more trouble to be working thin stuff with the electric?


Buy 19070 Bernzomatic Trigger Start with Flame Adjustment Propane & Mapp Torches from UseEnco



MT

Latest work on motor bike OHV and prospective art vehicle cover when motor bike is up an running

See post #9

http://motorbicycling.com/f36/motor-bike-diyer-build-add-side-29678.html#post356448
 
Mike B

Mike B

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That torch is about as good as an air torch gets.

The best alloy for copper is 56% silver, melts at 1200F but is brutally expensive.

Sold by troy oz or pound. Over $350 / pound.
 
2door

2door

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Last edited:
chainmaker

chainmaker

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Kevlarr said:
Forget the bender altogether SB, take your length of pipe, sweat a cap on one end, fill the pipe with sand (packing it tight), sweat a cap on the other end then bend around a block of wood cut to the curve you're looking for. The sand will keep the pipe from collapsing.
Click to expand...

Exactly what I was going to suggest SB !!
 
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