Heat Exchanger Repair

[whalechaser]

Hello,

My newly purchased rebuilt A4 came with the FWC kit. As I'm cleaning things up I've noticed one of the nipples has a hairline crack where it is soldered into the main stack.

Is this something that can be effectively repaired with solder etc.?

Thanks,

Chris

[joe_db]

Brazing is actually what you need, kind of soldering turned up to 11.

[Dave Neptune]

First I would wire brush it a bit to confirm if it is braised with brass or soldered. It does look like brass and if it is most any radiator or automotive welding shop should be able to braise it back to original integrity. A radiator shop or marine yard would also be able to "boil" it out so it is as efficient as new. Also an automotive radiator shop would probably be far cheaper as well.

Dave Neptune

[whalechaser]

Thanks, I sandblasted it and brought it to a metal fab shop, they brazed it for $50.

Cheers,

Chris

[hanleyclifford]

Yet another advantage of brazing over soldering is the reduced electrochemical action. Lead solder is the downfall of exchangers.