Restoring Evaporator Box

[71CHEVYSHORTBED402]

Some questions about restoring an evap. box.

The box took some over-spray long ago with black aerosol. So first order is to remove it. I know a guy who can blast it, not sure what material he uses (black something), but it's much finer than sand. Is there a better way considering these are plastic?

I know some people remove the rivets for the bracket, but I think I can away without doing that. A finish guy and I agree that he paints what's black first, then clear coat the entire unit. I think these had a satin sheen, does that sound right for a restoration?

Is there a way to remove the door flapper on these without damaging it? The flapper is still good. If he needs to paint around it OK, but I'd rather remove it cleanly if possible. Unless I'm missing something I don't think it can be removed, similar the A/C diverted flapper. Makes me wonder how they assembled them to begin with.

Thanks!

Thank you

[BobbyK]

I disassembled the whole thing and powder coated all the metal parts.




After the rebuild




Here's a link to my rebuild of my A/C/Heater

https://public.fotki.com/blazbk/blaz...e/?view=roll#1


.

[71CHEVYSHORTBED402]

Looks nice. How did you finish the container?

[BobbyK]

Sprayed it with clear-coat (aerosol)

[71CHEVYSHORTBED402]

Here's some pictures of the original finish. Pretty sure these were clear coated, however, there might be another option: http://www.67-72chevytrucks.com/vboa...d.php?t=268199

Seems to me once blasted and polished they're back to their former glory, pending a clear finish. EDIT: Just dawned on me aircraft paint remover might be a good option to take the paint off prior to blasting the unit, it
s pretty thick in places. Thought it might damage the plastic, but why would it? Think I've read oven cleaner removes paint from plastic, but don't quote me on it.

[FirstOwner69]

When new, the box was not clear coated or painted. It appears to be a rather fibrous fiberglass type material, so I think blasting it would alter the texture. All I did with mine is clean it thoroughly and apply ArmorAll, and it looks new. I believe I first used ArmorAll on it in the 70s and only once or twice since.

[71CHEVYSHORTBED402]

Originally Posted by FirstOwner69

When new, the box was not clear coated or painted. It appears to be a rather fibrous fiberglass type material, so I think blasting it would alter the texture. All I did with mine is clean it thoroughly and apply ArmorAll, and it looks new. I believe I first used ArmorAll on it in the 70s and only once or twice since.

Thanks Jim, I think you nailed it, fiberglass type material. I think I'll skip the aircraft paint remover. Your point about blasting is why I'd like to remove the paint first. I can see how this comes apart for painting the rest - not doin' it

Some research shows the best method for removing paint off fiberglass is soda blasting.

Then again, there's this. I've already tried lacquer thinner. Slow, but doesn't harm. I read acetone destroys fiberglass. https://www.youtube.com/watch?v=ckW0b-x-y1A

[71CHEVYSHORTBED402]

Think I'll give aircraft paint remover a thumbs down for these. Doesn't eat it up say, but it will etch the surface. I put a fat glob on this, left it on there 5-6 minutes, which is plenty. Oil following makes no difference. I may be able to get away with it because the paint should come off quickly - but think I'll pass. A lot of paint on the RH side.

Flapper is in real nice shape, no rust anywhere. My excuse for not dismantling it

[BigBird05]

If memory serves me correctly they started out with a flexible sheet of plastic on both sides and some kind of fibrous material in the middle. When put in the mold or press it was heated up for short time and came out looking like that. It just needed to have some of the flashing trimmed away. If you look at the edges you can see where they are rough and not shiny.

[71CHEVYSHORTBED402]

Did some work on these today, one done, the other partially. A lot of paint on these. I remember it's not spray bomb, I used an automotive paint on it in 93 when my buddy and I R&Rd the engine. I sprayed everything in a COLD winter outdoors surprisingly it stuck well, just looked like half a job

Rubbing alcohol is good for cleaning these, but lacquer thinner is the cat's meow. I tried oven cleaner to remove the paint. 25 minutes in it may etch slightly, so I left it on short that & no harm done. Can't swear it helped though, because none came off with the hose. Once in a lacquer thinner bath however some flaked off immediately. End of the day I found lacquer thinner is the only method I know for removing paint on these, assuming you desire to save the original surface. Takes a long while, nylon brush, and light brushing with a brass where it's 2-3 coats in places.

Glad you chimed in Jim, I was taking the wrong route, these won't be blasted or clear coat.

Originally Posted by BigBird05

If memory serves me correctly they started out with a flexible sheet of plastic on both sides and some kind of fibrous material in the middle. When put in the mold or press it was heated up for short time and came out looking like that. It just needed to have some of the flashing trimmed away. If you look at the edges you can see where they are rough and not shiny.

Pretty sure it's one piece fiberglass of some sort. All edges appear the same as the rest. Could be some variances.

[Already Gone]

I have a new heater core waiting to go in my truck and am thinking I should pull the whole works out at the same time. Long Cold Winter home project. I'm procrastinating taking it out cause never done it but have procrastinated on doing things to my truck before and finally just going for it did it and things worked out fine.

[FirstOwner69]

Originally Posted by Already Gone

I have a new heater core waiting to go in my truck and am thinking I should pull the whole works out at the same time. Long Cold Winter home project. I'm procrastinating taking it out cause never done it but have procrastinated on doing things to my truck before and finally just going for it did it and things worked out fine.

I just finished doing this on my factory A/C equipped '69 and found these instructions very helpful.
http://67-72chevytrucks.com/vboard/s...9&postcount=23

Suggestion... don't wait until it leaks like I did.

[71CHEVYSHORTBED402]

Few seconds of carelessness in my youth turned out to be 4-5 hours to clean-up. That was a job, but I got the paint off the fiberglass.

Nearly the entire RH side was painted, and real heavy in places. Pretty sure the oven cleaner helped somewhat. Other than that lacquer thinner and patience. Still have to prep the metal yet, but it will come easy. They're good without a painted finish. I ordered ROLITE FIBERGLASS POLISH. Expensive - hopefully it's the ticket.