Plumbing copper - will it work

[Gary Allan]

I figured that I'd post this here ..since it really isn't a cooling/antifreeze issue per se~ ..but more of a galvanic one.

Will plumbing grade copper handle engine coolant duty? I've got to do some fancy plumbing for some stuff and need to pull some longer straight runs and some 90° and 180° turns and I have a decent supply of 1.5" stock. It simplifies and cleans up a bit of a mess that flex hose alone can cause. Just trying to keep it tidy.

Any help? Now I'm fully prepared for some "you'll shoot your eye out kid!" comments

My gut feeling is that it should work fine. I use LOWTOX, a propylene glycol solution ..and this is used in exchanged systems for solar heating ..but you've got a lot of galanic chemistry going on there, so

I'm not worried about it wearing out. It can always be replaced and I dunno if this is going to be a long term (as in years) installation ..but it may end up being that. If so, then I'll buy the expensive stuff if need be ..but that's not in the budget NOW.

 

[b-man]

The copper pipe will work fine, as long as you're good at sweat-soldering the fittings in place.

I used quite a lot of 1-1/2" copper when I installed a water-cooled '64 225-cube Buick V6 into a '69 Type III VW Squareback, worked out great. I put a lot of miles on that freaky hot rod back in the late '70s/early '80s. Had 30' of radiator plumbing (engine in rear, radiator up front ala DeLorean) and only about 4' of exhaust pipe.

 

[Gary Allan]

Fabbing copper is "no sweat"

As long as it's dry, anyway. Cool. This will look better then common flex hose ..and I can't afford that convoluted stuff. Now I just need some straight sections and some clamps.

 

[XS650]

Support it well so it doesn't vibrate or it well work harden and eventually crack. Properly mounted, it should be good.

Mount it on the outside of your car and keep it polished.

 

[Al]

Speaking of soldering. I used to be able to solder with no problems. Since they changed solder about 20 years abo, my fittings frequently leak. What type of solder do you guys use. Whatt flux? I'm also thinking that I need a better propane outfit, other than just a regular tip and a propane torch. Anyone use mapp gas?

 

[TallPaul]

I don't know much at all about this topic, but FWIW they use flared connections for copper gas lines, like to a street lamp. Wonder if you could do the flare fittings. Or maybe flare only works on the smaller diameter pipe.

 

[andyd]

Quote:

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Speaking of soldering. I used to be able to solder with no problems. Since they changed solder about 20 years abo, my fittings frequently leak. What type of solder do you guys use. Whatt flux? I'm also thinking that I need a better propane outfit, other than just a regular tip and a propane torch. Anyone use mapp gas?

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Ive done a fair amount of plumbing around the house. It has all been with the new solder. When I first tried it, I think I had a bad torch out of the box. Since then, I got another torch and some tools. A tubing cutter, some brushes. and paste flux. Best results came when copper was cleaned and fluxed. I'm just using a low end torch. and Oatey solder and flux, Home Despot stuff.

 

[LAGA]

The ends of the pipes and the inside of the fittings should be cleaned by using fine grit sandpaper until copper is bright and shinny. This removes oxidation and and creates a rough surface for the solder to grip. The flux allows the solder to flow inside the fitting.

 

[XS650]

Quote:

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I don't know much at all about this topic, but FWIW they use flared connections for copper gas lines, like to a street lamp. Wonder if you could do the flare fittings. Or maybe flare only works on the smaller diameter pipe.

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If he can find flared fittings for 1.5 inch copper, they will be real bulky and expensive.

 

[Gary Allan]

Quote:

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Mount it on the outside of your car and keep it polished.

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I'll lacquer it up before installation. Remember, I'm lazy

This will have a few "flex joints" (just hose pieces) that should isolate the long runs and reduce any stress. You can buy chrome pieces that perform this very task. My buddy's customer (we're on a first name basis too) has a flathead roadster that uses them for plumbing the dual water pump setup that it uses. I'm just trying to get this thing done as cheap as possible without looking like something out of a grade "B" sci-fi.

You can see what I'm talking about on the righthand edge of this engine. It's the best shot that I had on hand.

As far as the lead free solder ..I've had pretty good results. I just use a compressed air tank to assure that the line is free of any residual water. It's much more effective then the "boiling it empty" technique

MAPP gas appears to work better then propane..but I haven't really timed either ..so..

This will all be fabbed off of the vehicle. I'll probably cushion it (some foam wrap) and zip tie it to either the engine or body with as much hose between them as possible where the stress would appear ..or where I think it will show up

This surely won't be plumbed in a manner that a pro-"dentist/surgeon" would. I'm not appearing on the next episode of Speed™. I'm trying to assemble all the interactive hardware on one "pallet" and hook up everything there on top of the intake plenum. I've improved my fastening technique with the purchase of 35' of velcro tape

McGyvering has has a shave and a haircut.

 

[wantin150]

A product called "Copper Bond" allows you to join copper pipes without solder. Verify the temp requirements but I believe it withstands some pretty high stuff. It is available at the Big Box Home Stores.

 

[JTK]

The only time I ever had problems with copper water lines was in my current home (circa 1958). I've had to replace several sections now due to pin hole leaks. Some of the original owners on my street have had the same problems and claim the corrosion was from the high sulfur content in the well water all these homes had prior to being supplied by municipal water 20yrs ago. Oh what a joy having to rip out a big section of the kitchen ceiling to replace a section of upstairs bathroom water line. !@#$ Needless to say, with a little help, I replaced ALL the upstairs stuff, clear down to the basement.

Joel

 

[Gary Allan]

Quote:

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A product called "Copper Bond" allows you to join copper pipes without solder. Verify the temp requirements but I believe it withstands some pretty high stuff. It is available at the Big Box Home Stores.

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Copper bond appears to be good from -40 to +275 ..but I don't know about a vibration environment with the frequencies that you can see in a vehicle. Water hammer shockwaves can surely be substantial ..but it isn't a constant thing. Copper epoxies also tend to be more expensive then soldering. Not a bad product

 

[Kestas]

Plumbing copper has just about the same composition as the core of a soldered copper radiator, so it should be no problem with your regular coolant.

I checked the chemistry of plumbing copper using SEM/EDS methods and find it is as close to commercially pure copper as you'll get. I had to do this check because I now use plumbing copper as stubs to hold my unknown samples for chemical (EDS) analysis of contaminant.

 

[beanoil]

Mapp, flux, scotchbrite, and since you aren't doing any drinking water stuff, regular ol' solder with the tin/lead mix is fine. Make sure the joints are clean, flux them, and join your fittings. Heat the joint, as solder flows toward heat, and when it begin to melt, remove the heat, and let the solder flow into the joint. Wipe it with a wet rag before it cools completely for smooth lines. No problem, Mapp gas is the secret...

 

[slalom44]

There will be no galvanic corrosion issues using copper tubing unless the surface of the copper is exposed to a dissimilar metal in an aqueous alkyl-halide environment (i.e. - exposed to a different metal in a wet environment with some salt). Since engine temps prevent these conditions from taking place, there's nothing to worry about. Besides - galvanic corrosion attacks the metal which is lower in the galvanic series, so copper would only get attacked if it was wet, salty and touching nickel, titanium, silver, gold, or a few high-temp stainless steels. Galvanic Series

If possible, use flared fittings with flexible copper tubing rather than sweated copper couplings. This is because tin-silver solder can "creep", or very gradually act like putty. I don't believe that a sweated copper fitting would fail at engine temps with conventional oil pressure, but I thought I'd mention it because creep is a very well known trait of tin under stress at elevated temps.

BTW: I'm a Metallurgical Engineer, so this is something I know about.

 

[Gary Allan]

This copper will only see engine coolant ..so it appears that I'm in good shape here. I'll probably buy a 3ft section of 1.75" reinforced hose for the expansion/flex joints (available at NAPA). I also think that I'll have a size change somewhere in there 1.5 copper of this schedule appears to need a 1.75" hose ..as does the Ford oil cooler ..but I think my outlet is 1.5" ..so I may be reducing down to 1.25" copper for at least one connection.

I'm going to attempt to make this look "clean" ..but I'm unsure of how well I can tame the octopus

..so don't laugh ....oh ..go ahead ..just understand I'm not an "artiste" at this stuff (I'm a neanderthal, not a surgeon

). The transition from concept to reality is sometimes not as tidy as we like.

Thanks for the authoritative replies

You've gotta love the information age. All this talent in one place.

 

[slalom44]

We want to see pictures when you're done, of course!

 

[Gary Allan]

Oh ..I'll do more than that. I'll give feature length commentaries to go along with them

 

[gedcruise]

Sweating pipe is one of the DIY joys of home ownership. How can something so simple actually work?
Anyway, I am embarassed to admit that I never thought of copper tubing in a vehicle aplication. Good idea!