Cleaning Heat Exchangers

[Irish911]

This may be a dumb question but I have no previous experience with bead blasting. Is it OK to bead blast the heat exchangers to clean them prior to painting? I can just see all those beads ending up inside the exchangers and hope they can be removed. Should I be using a particular medium? So before I do something possibly stupid I thought I would ask the question.

Also does anyone know what temp the heat exchangers get up to?

Thanks for your invaluable help.

[Irish911]

So I take it no one has bead or sand blasted their heat exchangers?

[edmayo]

We bead blast them all the time, just use an air nozzle to blow out the beads. Occasionally when diagnosing engine problems I'll use an infra-red gun to measure pipe temps, I'll see up to 350 (F) or so at idle.

[Irish911]

Thanks Ed, really appreciate the response.

I was talking to a gentleman that has a large powder coat operation and he said they have finishes (powder coat) now that are good up to 1000F. If that is the case would it be possible to powder coat the heat exchangers? I had always thought they would get too hot since regular powder coating uses curing temps around 400F. Has anyone done this or heard of it?

[edmayo]

I have never powder coated heat exchangers, just used some type of hi-temp paint suitable for exhausts. It seems I may have heard that powder coated exhaust may emit some fumes you don't want to breathe, like when the heater is on! Any one else know more about this?

[M_deJong]

I've always used VHT on manifolds and heat exchangers with good results.

[gsjohnson]

Ceramic coating is the way to go...and it lasts...A little pricey though.

[CidTito]

I've never done this.. nor have I thought of anything like it. My guess is it would really get hard to get in those seam grooves, but I assume if you work at it long enough, you could get them spanking cleaned up. I guess you can duct tape any holes in the heat exchangers before putting them in bead blaster.

[Irish911]

Yes, they plug all the main holes but I know there are still gaps. Being able to blow out the glass beads as Ed mentioned makes sense. I'll just use the VHT paint I used on the muffler to finish it off. Maybe powder coat in the distant future if it turns out to be a viable and safe option.

[4SFED]

Would it be a good idea to run the heat exchangers through a parts washer first to get any residue (oil, carbon, etc) out of them while they are off the car?