Cleaning/painting compressor assembly

[joesquid]

I want to sand and repaint my compressor and condensor.  They're in pretty typical shape for a 1950s machine, lots of surface rust, etc.  The system works very well and I don't want to shell out $500 just yet to have it professionally overhauled.  How can I clean it up and paint it without damaging the condensor?  What kind of paint should I use?

[Jim]

Eric,

I've always utilized a sand blaster for this type of work. Now, I know there are people out there probably cringing at the thought of this, but as long as you are VERY careful and know how to operate the sand blaster, the results are very good.

When blasting the actual condensor, cut the amount of sand flowing down to half so more air than sand is flowing and lower the operating pressure down below 100. Paying attention is the key here because some of these old units utilized copper lines through the condensor and you need to be careful.

Don't forget to blast and paint the bottom too!

Which reminds me about the recent topic about transporting machines laying down... Since you'll more than likey laying the condensing unit on its side to thoroughly paint all areas, remember to allow the unit to sit upright for a while before attempting to start the system.

As far as the paint is concerned, this is a matter of choice and have had good results from multiple coats, allowing to tack dry in between coats, of glossy black rust-oleum. This same technique was used on the fan motors to if they weren't replaced.

[joesquid]

Thanks Jim, I'll give it a try.  Worst thing that can happen is that I suddenly have a reason to send it off to global Compressors to be professionally overhauled!  Can't learn anything if you're not willing to try something!

[MoonDawg]

The worst thing that can happen, has already happened to me! The evaporator assembly needs to be handled carefully so as not to kink the copper tubing.                                                                         I built a small platform with 2 pieces of plywood and 4 short two by fours. The evaporator sits above the compressor again, and can be screwed down to be sure it doesn't fall off.
This also helps to measure out the new wiring. I set it on a 4 wheel dolly for easy handling.                                      After sandblasting, the compressor plate can be unbolted and pulled out from under the components. These plates are usually pretty rusted and look great when painted separately.        
                                                                         Glen

Make sure you take that fan motor off before you start! I don't believe it will work very well if you get sand inside...

Nate

[globalcompressors]

Ditto!!!


Eric '>

[joesquid]

I popped a couple of questions off-line to Jim concerning the type of spray paint to use on the compressor/condenser assembly (I was told once not to use glossy black because it wouldn't allow the compressor to "breathe") and the type/grit of sand to use to sandblast the compressor.  Here are his responses:

Hey Eric,

Using "glossy" paint doesn't allow the compressor to breathe...?  
You're right, that sounds rediculous!
As far as the sand is concerned, utilize silica sand and how fine the sand is, you'll have to ask; I can't remember (30F or 40F, I think) at the moment...

[globalcompressors]

Hey Bud,

  We use glass beads to blast with. If it's real heavy rust, use a carbon base media. As far as gloss or flat, no difference. The brand new condenser coils, we use, come with gloss finishes from the factory. Use a good quality paint, Rustoleum or Krylon. Good luck!

Eric