AC condenser repair

Have your hvac tech friend put a small pressure in the condenser (1-2 psi-where goggles) and heat. It may push out the slump. Then you can remove pressure and braze again. You can bypass any line in a condenser provided you look closely an verify all other passes are in the loop. However you will not have as much condenser as you once had. This may mean you clean the condenser or filter more often or it don't cool as well. If it is copper you can buy fittings to fabricate a 180 degree bend if you have room for it. The idea is to salvage as much condenser as possible. I have messed up many condensers trying to repair them and most of the time have been able to remove the slump of solder and try again. If copper........try dynaflow (available hvac/r distributors) it fills nicely. I have filled 1/4" holes by filling in around the hole........letting it cool ......fill some more etc until it is fixed. Blow compressed air or something thru, when you are finished to verify you did not plug it. Good Luck Lyndell

The Surplus Center often has them, At the moment it appears they only have one size in stock, probably not large enough:

The braze you used probably had too high a melting point. You should use a phoscop or similar brazing rod that has a lower melting point than copper. Silver solder would work too. There are also epoxy compounds that are used but I have no experience with them. I do only industrial chillers and coolers on machine tools. I fixed a leak in a condenser the other week after a refrigeration guy couldn't find it. When you braze the leak you should purge the system with dry nitrogen to get all the freon gas out of the system or you will make hydrofloric acid when it breaks down from the heat of the brazing. The acid will cause premature failure of the system. Most guys don't take the trouble to do the job right. It also gets them more work in the future.

John

I forgot, where abouts are you located........there are farms here in southern IN. :-) Contact me off list if you are not too far away. Lyndell

HVAC condensers are not magic. You can replace the whole core if necessary, so long as the new core is the same size (heat transfer fin area) or perhaps a little bigger that the original, and the tubing size is a reasonable match.

I assume that the tubes are copper. The usual braze filler is phosphorus copper, which is self fluxing on copper.

Probably the best source of a core is the automobile aftermarket. Do the research in the junkyard, then buy a new core for installation.

Joe Gwinn

The easy way is to make a repair sleeve out of the same material and slide it into place then silver solder it in place by sweating the joints.Just like doing copper pipe joins.

Since it's the outer tube I would probably do it even easier. Take a Dremel type tool and cut out one side of the tube where the braze slumped. Remove ONLY the slumped area and clean the tube up good. Make a patch that will cover the hole with a slight overlap. Clamp the patch in place and flow the solder around it.

I think now would be a good time to repost the r.c.m. map someone made a coupla years ago.

Anyone remember who it was? Got a link?

technomaNge

I did one. It was December 2009.

I'm 50 miles west of the Twin Cities in central Minnesota.

Karl

Just cut into the core right at the bad spot (lucky it is the top run) and clear away the fins for an inch or so each side. Clean the tubing very carefully, then find tubing that will fit tightly to the existing tube. Now, braze carefully with low-temp brazing rod (sil-phos).

Jon

Check with the big tractor junk yards. Like Worthington.

Ah, a little far for me to come help with it. I will try to watch the thread for a few days to lend moral support if nothing else. Like all refrigeration people we are swamped right now. I will check in the evenings. Lyndell

You usually find solutions, but keep me in mind here, Karl. I'm pretty good with a O/A torch. I'd bring my torch and silver brazing materials.

...

Thanks for the kind offer. I'm taking you up. You got mail.

Karl

Where "the system" == your hide, oh yes....

It's like "low-ball" - to give the least possible bid that you think your client will accept, therefore sometimes shooting oneself in the foot, as the fee doesn't cover the cost of doing the job.

This is particularly annoying when one finds that the client would have been happy to pay twice as much for a quality job!

Hope This Helps! Rich