Technical A Copper Pipe Question- Yes It Is Car Related

To get coolant from the radiator outlet back to the engine I had a very small space and needed a couple of tight bends, so I soldered together a couple or 1.5" wrot copper "L"s (plumbing fittings). It works, but there is a spot on the outside radius of one of the bends where I could use 3/8" more clearance.

My question is: Can I just give it a couple of whacks with the ball peen, or is this kind of copper going to react badly to that? I know copper work hardens, but is a coupla whacks ok?

 

While I can appreciate your innovative approach to solve a problem, I'm a bit concerned not only about whacking the copper pipe for clearance but for the solder joints holding up to vibrations and hardening of the copper over time. I've seen the results of dumping hot coolant under a car at speed from a failure of a hose (actually it was one of those "street roddy" chrome coiled hoses) and it's not a pretty sight. Just my opinion, but I would hope that you can find another solution.

 

Copper sweat fittings are plenty soft, put a dent in it if you want. Shouldn't be a problem.

I wouldn't be concerned about solder joints. Until the modern generation of high tech, high priced aluminum radiators and (gasp) plastic ones, every radiator was soldered together.

Let's have some photos.

 

I wouldnt think it would get work hardened with hose on both ends,insulating it from vibrations and jolts.Any way to make your dents before soldering?

 

I have been testing a similar installation in a 31 Chevy. 45 years and 117,000 miles and still working fine.

 

I'd be more worried about electrolytic action eating the copper from the inside out. Use some sort of a zinc piece in your cooling system to do away with this worry. Check the zinc piece every year. When it's almost eaten away, replace it.

If lead solder is a concern, make another piece using silver solder. The navy uses lots of copper & copper nickle plumbing, and all is silver soldered. Fit up your pieces, and knock the clearance into them before soldering.

 

A couple of swats with a hammer is not going to work harden it, heat it first to anneal it. I used to have to clearance hard copper tubing all the time when I was working commercial refrigeration.

 

Thanks for the responses.

I've done copper fittings in similar situations before without incident- they allow tighter turns than any molded (or flexible) hose can make. I do use a short piece of rubber hose on each end to isolate from vibration.

The issue I'm dealing with is putting a Mopar 383 into a '38 Chrysler. I got the engine in and have been running it hoodless for a couple of years. It was a very tight squeeze. I decided I wanted to put the hood back on, and thats when I found I needed to scoot the whole grill/radiator assembly back 1/2 inch. And thats why I find myself needing that extra bit of clearance.

I haven't annealed copper before. Will a propane torch do it, or is oxy/ace required?

 

I have used two copper 90 degree fittings soldered together to form a tight bend on my lower radiator outlet for years (55K) with out any issues. Remember that before you "whack" it with a ball peen, that during the forming process the outside radius stretches and is thinner than the rest of the fitting. When copper pipes freeze thats where it usually splits.

 

Get it red hot, let cool.

 

Actually it will anneal @ about 800 degrees so just prior to red hot, map gas will do it but propane will not get it hot enough, copper dissipates heat really fast.

 

annealing copper is backwards of annealing steel , you get it red hot then quench with water , then its softened .

 

Agreed ......
Propane alone probably not hot enough, Propane with Oxygen mite work....
LW

 

Actually, copper anneals either way. Quench it or let it cool in the air. Same results. Problem is, he will compromise the solder joints at the temperature needed to soften the copper

 

can reflux and redo joints after the annealing

 

While we are on the subject, do you need a bead around the end of the pipe to keep the hose from blowing off?

 

^^^ Yes. I've had good luck using a strand of 12 ga. copper (ground wire from 12-2 Romex), and soldering it onto the tubing. I've done radiator hoses, and gas tank filler tubes with copper. My '36 (my avatar) had copper lines all the way to the rear of the car to a second radiator under the floor. Never any problems. Just to be sure, I'd sweat the joints again AFTER you whack away at with a hammer.

 

FYI, propane burns plenty hot to anneal copper, at just shy of 2000 degrees. Copper anneal at about 800 degrees.

 

Probably a better way to do your bends, post a pic so we can see what you are up against.

 

If you have soldered the fittings, you have annealed them. Guys you all are way over thinking this, just whack the son-of-a-bitch with a hammer and move on.

 

these copper fittings have been on the road since about 1990

 

Just make a new one!

 

Make a spare and keep it in the trunk! Honestly, I'd do it and not worry about it.

 

For sure put beads on the ends of fittings.
On any hose fitting you need a bead or you are looking for a problem.

Ago

 

If you have enough room for copper you should have enough room for a rubber radiator hose.

Regardless of how you proceed with the idea how about posting a photo of what your doing. HRP

 

Think I'd consider add a 1/2" to the length of the hood, or whack the tubing. You guys are making this way more complex then it needs to be. Gene

 

Hit and forgit it. Pipes like that carry boiling hot water and steam in apartment house heating systems and last 100 years. Then they tear down the house.

 

The spot I'm working in is impossible to get a good picture of, and whoever said there must be room for a hose: Well, no, you can't bend hose this tight. This is involves two pairs of soldered-together L's joined with a very short piece of hose to make a kind of offset "S", which in turn has short pieces of hose connecting to the w/p and radiator. PHEW, it is even exhausting to explain.
You can see a glimpse of copper in this photo below the water pump & P/S pump.

At any rate, remember this has all been in and working fine for a couple of years, I just asked about denting the pipe for clearance. And I have now done that, so back to your previously scheduled programming.

FWIW I like the idea of soldering a wire around the tube to make a lip/barb-ish thing for the hose. I hadn't heard of that when I did this, so I put several small pop rivets through the edge of each pipe to serve the same purpose. It worked fine and the whole business was a bitch to get apart : )

 

I heat copper head gaskets with a propane torch until they just turn color and let them air cool to anneal them. It makes them dead soft to reuse again and again. Should work the same here. Whack it! lol

 

"FWIW I like the idea of soldering a wire around the tube to make a lip/barb-ish thing for the hose."

Another thing you can do is slightly upset or bulge the end of a tube if you have a suitable flaring tool. This works best for fuel lines etc. that you can do with a brake flaring tool.