Anyone have any luck welding up an aluminum heat exchanger

[brushwolf]

If you have any experience welding up a heat exchanger. Please let me know the method and results/recommendations. Thanks in advance

 

[Devilmanak]

I tried for hours to fix a Firecat heat exchanger that I broke the tube off of. Every time I thought I had it, it had a pinhole leak. I was tigging it, and I am a decent welder, but aluminum kicks my butt. Has to be SUPER clean and uncontaminated, I finally gave up and paid the $200 for a new one. Learning experience, not to try to straighten a slightly bent heat exchanger tube, lol.
Chris

 

[LRD]

A long time ago when I was doing long tracking of Yami Exciters from 121 to 136
for a friends dealership.
I cut the rear heat exchangers completely in half and then welded them back together straight. Stock they had a 45 degree bend in them from top of tunnel down snow flap area. Clean them really well, preheat in a oven to try boil off anti freeze out of pores and I think I also used some aluminum acid cleaning liquid. Also made up hoses so I could pressure test them and mark the leak or leaks. Problem I always saw was when you stopped the weld the ark would make a tiny hole. Never did fully figure that out.

Good Luck

 

[mtnjunkie]

My brother welded one up for me a few years ago. Has to be clean for sure. Then checked for holes, had a tiny pinhole. Welded that up and it lasted for years afterwards with no probs. Get someone who knows how to weld aluminum and it's a cheap, long lasting fix.

 

[mikew5945]

Mig welded one for a buddy last year. Worked great. I weld aluminum all the time though. Take it to someone. If they are worth anything they wont charge you until it is right. Took me longer to pressure test it then to weld.

 

[opel]

I use a low temp aluminum welding rod alot like brazing. I use it alot when out in the field doing A/C repair on condensors, radiators,air coolers,evaporators,heater cores etc. Does not have to be cleaned. Has a special separate powder flux that cleans and lets the aluminum flow real nice. The flux HAS to be kept dry and refrigerated if not in use. You can use mapp gas or acetylene/oxygen to do it. Have even fixed some aluminum A/C lines in tough spots with it. Its is called Super alloy 5. I get it through Muggy Weld. 30,000 psi and is easy to use with a little practice.

 

[john800]

Getting it clean enough is the hard part, we blew it off with air, cleaned it with iso then heated it with mapp gas to burn everything off then wiped it with iso again, then it was easy.

 

[jas123]

you can do it on the sled,drain the coolant down so that there is none in the heat exchanger and pull a hose so it won't build pressure. Any good welder can easily fix it up for you. My dad has probably done 100's them in the past 30 years. some of you midwest guys my recognize the name in my JAS in my signiture JAS Pro Cool. If you had a polaris nose cone radiator, he most likley built it. If your into Formula 1 or Formula 3 oval sled racing in the 90's you ran are stuff.

 

[skyman]

The material needs to be clean for sure to weld if there is anything that might boil up into the weld it will contaminate it but welding aluminum isn't that hard and as far as the pin hole at the end of a weld it's because the heat and amperage needs to be tapered off(while still moving) slowly to avoid this stainless steel will do the same thing.

Some tig welders have a option called crater fill that does this for you.

I have done lots of them with no problems.

 

[Howitzer]

Dented/torn front heat exchanger

I have to repair a considerably large dent/tear in my front heat exchanger (2000 Arctic Cat Powder Special 600). The front heat exchanger is welded to the rest of the chassis (odd design)... I can/will post pics and get some of you guy's opinions on the repair. I am leaning towards cutting out the torn/dented aluminum and rebuilding the area. The dent/tear is along the bottom flange of the exchanger and thankfully is not leaking any coolant (but the steering post is affected considerably by this tear/dent). Comments anyone?

 

[mattymac]

Dont weld over the ribs grind them down flat clean with a stainless wire brush heat with a mapp gas torch for cleaning and heat soak.

I bought a natural gas home leak pressure guage at a hardware store that has a 15 lb guage 3/4" outlet and a schrader valve to pressure up just plug off the other end of the cooler. Use soapy water to find leaks

 

[Howitzer]

some more info...