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George · 09-27-2004, 09:42 AM

Andy,
I need some advice, help, or maybe just Reassurance.

I'm in the process of painting my 24' Argosy M.H.
I have taken your advice on painting as Gospel, as nothing beats experance!!
The problem that I have is that the paint manufacturers strongly recommend that aluminum must be prepped with acid etch or etch primer.
I explained to any and all who would listen, the concern with rivets and corrosion, they say that it isn't a problem.
WELL---- You say it can be a problem, and I totally AGREE!!
the acid will stay in the cracks and crevices/rivets etc.
It just makes good sense and your experence backs this up.

I have posed the question many times on internet body shop forums such as our forum here, they say the paint will not adhear to the alu. properly if not chemically eched one way or another.
I explained that I have stripped with aircraft stripper and will SAND thourghly
with 150-180 grit then apply epoxy primer then topcoat,
their feeling is do what you want, but be fore warned that it may not bond well and "peel" if not chemically cleaned.
Their help is and experance is well appreciated.

SOOO, where does that leave me?
I have stopped work till I get some sense of direction.

I ALSO have the galvenized end cap to deal with, do I etch it only??
I don't believe this has been addressed in your procedure.
Please HELP

Some how, California seems to be getting closer to Michigan as these problems arise

gaylejoe · 10-22-2006, 09:55 PM

Very interesting thread. Our 77 Argosy paint has faded and I have been thinking of having it painted. The paint is faded and not peeling from the trailer. I wonder if it would be possible to just sand and paint over the existing paint. I know that will work with an airplane.

Does anyone know of paint shop in the San Antonio area that will paint a trailer? Better yet, I would like to locate some one in Central Texas who restores Argosy's.

bhayden · 10-22-2006, 10:05 PM

If your original paint is just faded then thats the best base you can get for repainting.

I had to repaint a horse trailer once that was galvanize. It required a special acid etch. Been too long to remember but I think it was phosporic acid. Acid in cracks or riviets shouldn't be a problem as long as you neutralize after the acid wash. Prep is 90% of a good paint job.

The airplane folks are good ones to take lessons from.

-Bernie

3Ms75Argosy · 10-22-2006, 10:10 PM

I believe Bob Thompsen had an awesome tread on painting his Excella.
No acid prep done, but he did address this issue.
Marc

Bob Thompson · 10-22-2006, 10:30 PM

Yes, I did paint my Excella and the related thread is here:
http://www.airforums.com/forum...5-a-10522.html

One minor correction to what Marc said above. I used Alumiprep on the aluminum after sanding it. Here's the key.....aluminum starts to oxidize quickly right after it has been sanded or cleaned with an etch like Alumiprep so it must be sealed with epoxy primer within hours. Paint doesn't bond very well to oxidized aluminum. If you decide to sand then prime, sand with 120 grit paper and coat with epoxy primer within 6 hours. If you decide to use Alumiprep, you must use a two step process. First Alumiprep to remove oxidation, then alodine to convert the surface to a more corrosion resistant surface then coat with epoxy primer. DO NOT USE SELF ETCHING PRIMERS. Again, from starting Alumiprep to finish epoxy primer should not exceed 8 hours. This is the key to durability of the paint bond.

Once the epoxy primer is on, oxygen is kept away from the surface of the aluminum and corrosion is halted.

Once the epoxy primer is on, it can be a couple days before the finish system must be applied. The finish system can follow 1 of 3 paths. You can use a 2-phase system with paint followed by clearcoat like I did. You can use a non-clearcoat system like Imron 5000, or you can use an aeronautical system where the clearcoat rises to the surface after being sprayed on.

The steel encaps get sanded then primed with epoxy primer, then painted with the rest of the trailer.

Inland RV Center, In · 10-23-2006, 04:43 PM

Just saw your post. I was out of town for a while.
The post I made on 4-7-2004 really covers it all.
Sand, sand and sand some more. Then clean the entire coach "quickly" and then apply epoxy primers.
Let the epoxy primer 'out gas" at least two days before you continue.
Acid, "in any form" is a huge no no.
You can never completely remove all of the acid, and in time, you will find out the hard way, where is still remained.

Andy

rmpray · 12-19-2006, 07:38 PM

I repainted one of my riveted aluminum boats two years back with great success. Had her sand blasted and used Glovit epox folllowed with high gloss latex. Rather keep my AS polished, but if one is going to paint, this seals and paints and after sand blasting adhears nicely. Hey, the old boat was my traler for twenty five years

Happycampers · 12-20-2006, 03:41 AM

George, I painted our 75 Argosy a couple years ago and used Dupont DTM (direct to metal) it worked great, Go by a auto paint store that has Dupont paint and they will giive you a information sheet on it. Marvin

scottanlily · 12-23-2006, 05:38 PM

The best primer used on aluminum would be zinc chromate .It is industrial
and is specifically for aluminum .airline manafacturers and the folks that refit airliners use zinc chromate for corrosion protection .Zinc chromate is that green primer ,has a green/yellow kinda look to it .I once was into restoring old outboard motors and zinc chromate was the choice of primer at the marine store I went to .works extremely well .

Scott

Aerowood · 12-23-2006, 08:04 PM

I don't like dissagreeing with members here, but the aviation industry has not used zinc chromate primer for many years. Polyurethanes and epoxys are what the industry has used for the last several years. Water based polys are the current choices now do to the VOC's of the original polys and epoxys.

Kip

Inland RV Center, In · 12-25-2006, 01:13 PM

We have used "flexible epoxy" primer for many years.
It does a superior job over chromate primer, any day.
It also provides much more hiding power for the little scratches etc, that the shell may have.

Andy

kenny2 · 12-25-2006, 04:06 PM

I am going to paint my 1977 Minuet. I did a dent repair on one of the rear panels but still have a few irregularities in the panel (it is an aluminum panel). Can one repair the remainder of the dent with some sort of body filler?

I was wondering if the expansion/contraction of the panels would prevent this type of repair. Any ideas??

Janets Husband · 12-25-2006, 06:36 PM

Aluminum panels can be fixed with filler. That being said here's the kicker, no more than 1/4" thick the thinner the better. You must be sure there is no dirt, grease or oil on the spot to be repaired. Rough the spot up with 80 grit paper then wash with lacquer thinner. Immediately apply your filler. A
light-weight filler is best. Check with your local auto paint store best filler for use on aluminum. Detail, Detail, Detail...