Does anyone have any input for bending light gauge copper?
My sub-contractor says the metal is so soft and so thin it just wants to kink or tear.
We took some to a local muffler shop and my sub was right, the benders at the muff shop wont do it. There has been some talk about placing steel Muffler-pipe within the copper to stop the kinking but the bends are so severe the steel will have to stay…. I am worried about chemical reaction in the metals.
Any Thoughts on This Subject?
Edited 7/21/2008 8:20 pm ET by roundtable
Replies
There is a trick used on small diameter tubing to prevent kinking, but I don't know if it would work on downspout sized tubing. Anyway, you plug the end and fill it with sand then plug the other end. Probably easier to modify fittings, no?
Rich
Sonds like a job for seeyou
Is it round or round corrugated ?
What are you trying to accomplish? To bend copper downspout, the inside radius is folded on itself. There are companies that make copper goosenecks/offsets, but they are typically much heavier gauge than regular downspout. I suspect this lets the outside stretch without tearing. They are pretty guarded about how they do it.
http://grantlogan.net
.......nature abhors a vacuum cleaner.....
Copper needs to be annealed rather than hard-drawn if you're to bend it.
Bending a small radius in a thin-walled pipe without corrugation or flattening/kinking is tough in any metal. At a certain radius, both internal and external bending guides are required.. There is special machinery with internal bending mandrel "fingers" which can do this sort of thing, within limits. Filling with sand does help, but at big sizes it would be a challenge to fill enough length keep the ends effectively plugged. Bending a short piece filled with sand doesn't work as the sand just extrudes out the short end.
I'd be worried about clogging if you leave a piece of steel muffler pipe in place inside a bend to act as an internal guide. It's an ideal place for #### to accumulate.
As to the galvanic problem, the thing that will corrode is the steel, not the copper. So eventually your steel pipe will corrode away. It may take a long while though as the pipe is not continuously wetted and muffler pipe is usually galvanized or aluminized. That will have to go before the steel will.