Refinish AC undressed fibreglass cover

[red67]

I have a 1967 Camaro with AC and the underhood AC box that contains the evaporator sat in the California sun for awhile and the finish on the top is weak. I'd like to refinish the box. Looks like the box is fibreglass and has gel coat on it from the factory. Anyone have any experience with refinishing these or have any ideas.

[Charley Lillard]

Try a spray can of satin clear in a spot and see how you like it.

[Unreal]

Look at an original one. It's sort of gray with light fiberglass whiskers. Not easy to duplicate. If the original look is what you are after, clear a spot, as Charlie suggests, or try to wet sand ai inconspicuous spot, to see if you can remove the oxidation.

[resto4u]

Do you mean the hood was off and exposed to the sun? If that is what happened, it dried out the resin and you can see thru the fiberglass. If really bad,it gets thin and brittle. I would suggest spraying on a resin,but it will really soak it up like a sponge. It would help if you had some pics. Thanks,roger

[SS427]

If it is not badly sunbaked I have had really good luck using plastic media or glass media at a low pressure. As Roger says, if it is really bad respraying the resin will really help. Here are some before and after shots of a case that was not horribly bad to begin with. I light media blasting followed by a satin clear really spruced it up. Fiberglass heater boxes are the same and are usually in much better condition to begin with.
Rick

[ORIGLS6]

Satin Clear is a good choice. I also had good results using oil based polyurethane a few years ago. (The spare tire carrier on a Corvette.)

I hit the worst areas with 0000 steel wool, then rubbed the matte/satin polyurethane on with a cloth. It soaked in quite a bit in some areas but I went back over those until they were saturated.

Gotta be careful with the steel wool. Those fibers can poke through the wool and put some nasty holes in your fingers!

[red67]

Thanks to all of you who responded. I really appreciate it. Some really good ideas from experienced people. Although I don't post here very often I do look at the material here quite often and find the posts and comments excellent.

SS427: The work you did on the air box and under dash parts is really impressive. Very nice work. If I could get mine to look like that I would be really happy. Thanks for the photos. A picture truly is worth a thousand words. I would appreciate it if I can ask you a few questions about restoring the other air conditioning parts. I have a few spare parts that I've collected over the years from 1967 -69 Camaros and Novas that I could select from. All years seem to be slightly different. I do have an unmolested complete 1969 Nova under hood assembly that I can use to experiment with. Unfortunately it also sat in the sun with the front end off the car and is actually in worse finish condition than my 1967 one. The gel coat has just turned gray but the fibreglass looks good.

The air box on my car sat in the California sun (San Diego) for some time without the hood on. The top part is faded to the point that the gel coat looks to have vanished. The actual fibreglass is still intact and in good condition and is quite different than the under dash parts which are in very good condition. The under dash parts look to be made of a different material that is denser in fibreglass strands than the under hood parts. The bottom of my under hood part is in very good condition. I can't remember it very well when I first got it as it was in the mid 1980s and I cleaned it before installing it back on the car for a mock up with the fender on. It could be that the lower part had under hood debris such as an oil film that protected it. I'm finally getting at putting the car back together and will be taking the mockup with the fender apart in the next few weeks. Not sure exactly sure when but I'll try and post some pictures when I get it off. If I can get some good photos as on the car I'll try and post them.

[red67]

Here are some photos of the AC box.

http://www.yenko.net/ubbthreads/pics/usergals/2016/02/full-11162-39547-img_1339r.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2016/02/full-11162-39548-img_1340r.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2016/02/full-11162-39549-img_1345r.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2016/02/full-11162-39550-img_1346r.jpg

The rear part of the passenger side and the top has lost the shiny gel coat finish and the bracket for the POA valve has lost the phosphate finish. The bracket below the POA valve bracket used for the expansion valve is in very nice condition. The driver side of the box is not bad.

Should I try a new application of gel coat or just refinish with clear either directly or after a light media blast? Any specific suggestions for a brand of gel coat? Will I need to clear coat with a spray gun or could I use a spray can product? Any specific suggestions for products?

I would like to refinish the POA valve bracket. However to do this I'll have to remove it by removing and replacing the rivets. Any suggestions on how to do this?

[olredalert]

----Maybe its just me but what you have pictured isn't bad enough to gel-coat. Clear it!.....Bill S

[Charley Lillard]

Safest rust remover will probably save the poa bracket finish.

[resto4u]

That is way better than i was expecting. I would say it just needs clear coat, scuff with a grey scuff pad. Do not use sand paper. And if you don't want to use a spray gun, you can get 1k or 2k clear in spray cans from your local body shop jobber. I would not remove the bracket unless u are doing a frame off restoration. Clean the bracket and paint with a phosphate spray can.

[njsteve]

I concur on the safest rust remover, and it wont hurt the fiberglass either. But remember it will remove cad plating (but since there is none left on that part it isn't an issue here).

[MosportGreen66]

Shine that thing up with Bully Dog adhesive promoter. It acts as a fiberglass polish

[red67]

I've heard of safest rust remover here on other post but what exactly is it and where can I buy it?

[red67]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: resto4u</div><div class="ubbcode-body">That is way better than i was expecting. I would say it just needs clear coat, scuff with a grey scuff pad. Do not use sand paper. And if you don't want to use a spray gun, you can get 1k or 2k clear in spray cans from your local body shop jobber. I would not remove the bracket unless u are doing a frame off restoration. Clean the bracket and paint with a phosphate spray can. </div></div>

Thanks for your suggestions. I feel you are right about the condition and from what I've seen and heard it looks like clear coat will do the job rather than more gel coat. Although the car is a driver rather than a frame off restoration I think I'm just too fussy about finishes too fussy about finishes to paint the bracket. I'll likely have the box off in the next few days and I'll try a few things on it to see how it goes.

[red67]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MosportGreen66</div><div class="ubbcode-body">Shine that thing up with Bully Dog adhesive promoter. It acts as a fiberglass polish </div></div>

I've tried a few polishes on the box without any success. What exactly is Bully Dog adhesive promoter and where would i buy it?

[Charley Lillard]

http://safestrustremover.com/

[njsteve]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Charley Lillard</div><div class="ubbcode-body">http://safestrustremover.com/ </div></div>

Evaporust does the same thing as well and I think it is available at most autoparts stores. I use both.

[MosportGreen66]

CLICK HERE FOR BULLYDOG (http://www.amazon.com/Kleanstrip-ETPO123B-Bulldog-Adhesion-Promoter%252c/dp/B005IUBMS6/ref=sr_1_sc_1?ie=UTF8&amp;qid=1456323555&amp;sr=8-1-spell&amp;keywords=bullydog+promoter)

[SuperNovaSS]

I use evaporust as well simply because it can be purchased on Amazon prime with free shipping. I believe is $90 and change for a 5 gallon bucket.

Jason

[red67]

Thanks for all the replies. When I get the box off I'll try a few products. In the meantime I'll see if I can find the products suggested here locally and then go further if necessary. I'm in Canada so shipping some of the products across the border if they do not have environmental approval can be tricky. Since I'm quite close to the border I can drive down and pick products up at a mail drop but sometimes you get hassles at the border.

[red67]

Thanks. Checked the link for safestrustremover and luckily there is a distributor in Vancouver. I'll check with them and see what I can find out.

[njsteve]

I recently bought four gallons of the evaporust at advanceautoparts. I used one of the online coupons and knocked a ton off the price. And, if you use one coupon per gallon you can really increase the savings instead of just making one purchase for all four. (I had to buy them at seveeral stores since they ususally only have one gallon at a time at the local store)