When a radiator shop repairs an aluminum radiator with epoxy, what product are they using? Thoughts?

Good question. I actually never heard of that type of repair. I have read rad manufacturers use epoxy, but it was not supposed to be a primary structural component, if I can believe what they shared. I spoke with a niche high performance epoxy manufacturer, and gave them my parameters for a solution on a radiator, <30psi pressure, <250F, and water/glycol long term exposure, constant pressure cycling. They were most concerned with the water/glycol exposure long term, seeping into the carbon fiber filament, which is not the case for a typical rad solution issue. Never got an answer that would not require testing, and that was beyond what I wanted to invest. Lets us know what you discover.

I have used JB weld for repair of copper/brass radiator tanks. It worked fine for short term repair... then I replaced the radiator. For aluminum I would try JB Aluminum weld based on the idea expansion with heat would be more similar to the radiator.

i repaired many motor cycle gas tanks with JB never a prob with longevity.my curent rad in my daily driver is repaired with JB,going on 15 years no leaks.SURFACE PREP.

My stock radiator on the 67 RT is dripping a tiny bit at a seam at the top of the tank and no one in DC metro repairs radiators. I was going to sand off the paint and try to solder. Would JB weld be a better option?

Per my experience JB sticks well to copper/brass... but not sure about lead. It may not stick so well to the solder already there.

You could try the JB... or re-solder. Either way it would be good to have a "plan B": send the radiator out to a specialist like Glen Ray or replace it.

Most epoxy will become soft when it gets hot. Although, I have used JB Weld on radiators with success. I would stick with JB Weld or Marine Tex. Any high quality epoxy should work. I use west system epoxy mixed with aluminum powder as a substitute for JB Weld. I try to stay away from the 5 minute epoxys too as they dont seem to get as hard as a slow cure epoxy.

i was at the local ace hardware recently, and i think i saw some high temp JB. i could be wrong [wouldn't be the first time, and certainly NOT the last .]

I think i saw that too.but mabey not ,i could of though.

JB it with clean prep and no coolant for at least 24 hours and don't do it outside with temps below 60

Whats the world coming to.... LOL

That is sad though, no joke..

That's why God gave us Stop Leak.

But.....

If it's the seam between the top tank and the core this may be a clue that your core is partially plugged. I had it happen once, it just kept opening up little by little. About 2/3 of the tubes were plugged (probably from Stop Leak!).

I guess I'm saying the epoxy might solve the symptom but not cure the disease. Solder would be my choice for a leaking seam.

R.

I wouldn't trust epoxy on a radiator, just solder it. It's not that dificult..

Paul is correct. I have repaired radiators both ways (solder & epoxy) and both work.
1. all epoxies will chemically resist antifreeze.
2. all epoxies will be OK with roughly 300F continuous temperature.
3. Slow cure epoxies are stronger, stick better & have better chemical resistance than 5-min. epoxies.
4. all epoxies stick very well to all metals that have proper SURFACE PREPARATION as another poster mentioned... including lead. For plastic, you need a 5-min.type epoxy designed for plastic (mercaptan based pt. B)

I JB Welded a fitting that I accidentally tore off. Never had a problem. You could clean it and solder it like you're supposed to.