Aluminum Radiator repair

Just when I thought I was making progress on the coupe...another set-back!

anyone know what filler rod should be used to solder tubes in a new aluminum radiator?

As usual, I`d like to fix it myself...I just hate to pay high shop rates if I can do it myself.

I know aluminum doesn`t turn red when it`s hot enough to solder like bronze when brazing...so it will be easy to get too much heat on the cut tube...

I`m guessing some type of silver solder ...but what alloy?

any Aluminum radiator fixers out there?

Tom

 

Epoxy ....

 

My advise is, if you have little or no experience welding aluminum, your 'spensive alloy radiator is the worst place to learn. Take it to a pro and suck up the cost. You will kill that rad in a heartbeat if the metal goes short and fall on the floor.

 

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http://durafix.com/



Works great...

 

Ditto. And they will pressure check it to make sure it's all ok, too. Gary

 

Hey Tom- I'm an engineer for a company that manufactures most Nascar/IRL aluminum radiators used today. It is next to impossible to weld the tubes to the header. Aluminum radiator cores are brazed in temperature controlled brazing furnaces specially designed for this application. The tubes and headers are coated in flux prior to being brazed and there is a very small temperature window (less than 10 deg) in which the flux, tubes, and headers become liquidous and flow together. Most aluminum radiator tubes are around 0.010-0.015" thick, thus requiring them to be brazed rather than welded. Hope this helps.

 

We ussually fix small pin holes in radiators by applying a slight vacuum on the core and flowing some hi-temp epoxy into the core while applying heat with a heat gun. The vacuum helps in sucking the epoxy in all the voids.

 

We ussually fix small pin holes in radiators by applying a slight vacuum on the core and flowing some hi-temp epoxy into the core while applying heat with a heat gun. The vacuum helps in sucking the epoxy in all the voids.

 

Aluminum radiators are basically not repairable. They are made from brazing sheet which is made up of two different alloys that are bonded together during the rolling process. The outside of the sheet is a lower temperature melting alloy that is resistant to corrosion. Between the outer layers is a different alloy for strength. The brazing sheet is formed to the desired shape and then the pieces are stacked together and clamped to form the tubes for the radiator. The clamped stack is then put into a vacuum furnace and heated up just enough to allow the outer layers of the sheet to melt and flow together, this is called vacuum brazing.

As said in an earlier post, epoxy is your best bet in trying to repair a leak.

 

Thanks for all the input, guys!!!

I`ll check tomorrow with the local Rad shop; I`ll see what his opinon is.

I cut 4 tubes with the new mechanical fan...I changed from an electric puller to a mechanical flex fan... the overflow tube was dangling down and got caught by the new fan...guess what...yep It tweeked the fan blades enough to make me think I`ll regret it if I don`t replace it.

Thanks for your help!

Tom

 

Hah! I did the exact same thing with the overflow hose on the 37 Chevy pickup i built. Cored my brand new copper/brass rad. My rad guy says "well, I can see you got the fan nicely centered!"
Ralph

 

Glad to know i`m not the only one!