I'm looking to redneck engineer an aftercooler for my newly replaced air compressor. I need something like a transmission cooler that will handle 150 psi reliably and is a square foot or two. Ideally, it'd have 3/8 or 1/2" connectors on it. Something like this:

http://www.summitracing.com/parts/flx-45321

would be perfect, but I don't want to spend $125. Any ideas?

Transmission cooler circuits are typically low pressure, less than 50 psi. Don't know if a trans cooler would be reliable at 150 psi. You could always pull one from a wrecking yard and test it's burst pressure.

You might look at AC condensers it can handle the pressures and old R12 units have larger fitting.

Some of the aftermarket trans coolers are advertised as tested to 200 psi, but I share the concern about using one. Horse, I'll look into that. Might be a good option.

Run your line through a tray of water?

Thought about that, but don't want to maintain it.

Convert your line to copper, buy a small copper coil, drop that into the 5-gal bucket with a lid and cut holes in the lid as necessary and hang the bucket from the ceiling or something. Maintenance would only be re-filling and possibly draining in the winter? Trouble would be getting a larger size tube to coil that tight and supply the needed volume. So maybe a galvanized tub would be better. Then it becomes cumbersome. Ok, I've pretty much talked myself out of that idea.

Liquid Nitrogen?

Liquid nitrogen would be awesome! Aftercooler and home cryo in one! The other issue with the water/coil method is that there isn't any way to easily get the condensation out of the lines. With an air cooler I can mount it above the compressor and let gravity drain the water into a water trap.

You don't need a compressor. You need a big CO2 tank.

Why do you want to cool the air? Spraying ?

Spraying is part of it. Cooler, drier air will also make a difference for my plasma consumables. People are seeing a 100-150 degree difference in the temp of the air entering the tank, and collecting a noticeable amount of water out of the system. It also means that slightly more air can be held in the tank since cooler air is more dense.

Ok, I was just wondering. I know that keeping water out of the lines is important, just hadn't heard about cooling the air. You must be running the compressor continuously creating heat build up from the pump, maks sense.

Been doing some more reading. It looks like the Derale coolers are rated to 300psi, but my best bet may be a AC condenser. Anyone have a spare laying around? In a perfect world it'd have 3/8" or 1/2" connections, but I can braze different ones on if needed. Automotive is good, but I'm equally happy to take apart your broken refrigerator or AC unit.