Work hardened copper needs to be annealed. Under vibration I believe they work harden and eventually fail. Copper oil lines can create sludge (maybe minuscule amounts). That said I would not use copper line on my car ever again. Thanks for the tip on cunifer Hitchhicker, sound like the solution.
air brake copper is un seamed used in heavy truck for millions of miles with no problems, I have heard that the problem with some copper is the seam, I have used airbrake copper in the past with no issues for brake and fuel lines
Also this copper line is sold under the Bendix Westinghouse air brake brand so this must feel it is safe for large trucks
Thats a good question...I don't know that the wear can really be measured in mileage. I think its more of an hours thing. when I originally researched copper vs. Other materials Cunifer was way superior than regular copper. That being said.. I don't know that you will have a problem. But it seemed like a no brainer to me to me, just going off the superiority on paper. Posted using the Full Custom H.A.M.B. App!
Hitchhiker, I completely understand where you're coming from. I won't argue that cunifer is a superior product, but I'm not convinced that plain copper line is a safety concern. Based on the pictures of that airplane restoration where copper lines are everywhere I can't see why I should be worried. Once again, I won't argue about the fact that there are superior products, but I'm not convinced that heavy wall copper is unsafe. Posted using the Full Custom H.A.M.B. App!
I'm not convinced its a problem either. I think you'll be fine. Its not like 500 miles and copper will shit the bed if you do it right. Posted using the Full Custom H.A.M.B. App!
Another refrigeration guy here. Transport and container units are subjected to the most grueling and punishing vibrations you can think of. They are all entirely plumbed with copper. Copper is not a problem, won't be a problem and looks better (IMHO) than any other alternative. It can work harden, but we're talking years and years. I have replaced just as many cracked steel diesel fuel lines as I have cracked refrigeration lines. If it is bent and installed properly it will outlast you. A piece that breaks in someone's hands from bending has a lot more to do with the Brave than the Arrow.
I just read through this thread and got interested so did a little search and found the following interesting facts. Work hardening isn't an issue as it doesn't make the metal weaker only stiffer. Metal fatigue however is more of a factor as with copper subjected to a cyclic load there is NO minimum limit to the fatigue effect. See graph here http://en.m.wikipedia.org/wiki/File:S-N_curves.PNG What this shows is that after 10 million cycles copper's ultimate failure strength has dropped to a third of it's original level. Personally I'm running copper oil and fuel lines. I haven't calculated it but I'd guesstimate the loads on those lines are less than 5-10% of the ultimate so I'm looking at a million million cycles before it starts to even approach being an issue In the real world this would mean running my engine at 5000rpm for 38 years. So I'm not that worried ;-) M Posted using the Full Custom H.A.M.B. App!
I've added copper lines to diesel engines without issue. There were hydraulic return lines that John Deere originally made out of plastic (no pressure, but still a bad idea) and I replaced with copper over 20 years ago. Reading this thread, I probably should have anchored them better, but I haven't had any problems. Ditto for lines running to the oil pressure gauge. That being said, I would probably still recommend Cunifer for under the car due to the possibility of damage from debris depending on your driving style and location.
The early Ford V8s used copper plated steel. It is available 1/4" dia. at most early ford jobbers. Thats how this copper fuel line thing got started. Henry being frugal wouldn't go to the extra expense if it wasn't necessary.
Back when I was a kid we used copper on our cars everywhere. We didn't know any better and had no problems. Now I know better and the lines would probably split. Look at those coiled brake and fuel lines in some of the "Little pages."
The only way 'work hardening' would set in is if the copper pipe were literally bouncing up and down and flexing, not just from vibration. I've seen brake liness with 18" of unsupported copper pipe hanging off the frame, and THAT is where people will have problems with work hardening.
I have used copper for many years in my job as a Stationary Engineer and used as fuel and fuel return on all my builds . Million miles all projects tallied together . Not one issue . Best part of it is never gets corrosion on the inside from bad fuel resting in a low spot during the storage times . Good luck . Just pay attention to the OD when purchasing it . There are tubes made with OD and ID measurements produced . Most automotive tubing is OD measurement . Be safe Posted using the Full Custom H.A.M.B. App!
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