Primer/ sealer for Aluminum

[muddog16]

I'm thinking about shooting a good primer sealer on Aluminum, should I use a primer etcher first and what is a good primer "filler" to use?  I'm not wanting to paint it yet, I'd like to run up and down the road a couple of times (1000 miles) to see how the body panels and Sika hold up, its not that I'm worried about the Sika but just my use of it!   The final paint will be a solid medium silver gold mist (no graphics unless the body is so ugly that I have to use them) with a clear coat.  What color of primer do I want?  As always thanks!   Yeah I did change my mind again.......no black after a summer like we've had I want to give the air conditioning units a chance to do their job!       

[rv_safetyman]

Pat, what you put on there now is really important.  There have been several threads on the same subject, but the most recent is:  http://www.busconversions.com/bbs/index.php?topic=16945.0

In that thread, I talk about PPG DP40LF.  I used the white version of that product on my bare aluminum and it has held up very well.  Kind of has a slight sheen to it, so it does not look like primer.  That is all you need to protect and cover the surface.  Later you can spray a build type primer for sanding.  However, none of those offer protection.  You are better off to spray the DP40LF (or equivalent product) or the Zinc Chromate and be done with it now.  If you use the DP40LF (different numbers for different colors) then you will have to scuff it and re-coat it again before you apply any other paint.

Jim

[Jeremy]

My standard primer for just about all applications is a product called Upoxy. It's an etch primer that is also high-build, and it seems to perform really well. Also - and I think this is more important than most people think - it's really easy to use. Other etch primers are more of a 'wash' than a conventional paint, being really thin - this makes it very difficult to ensure decent coverage without constantly getting runs etc. Even if you use multiple coats any edges or corners tend to end up with very little paint on them.

I don't know what the paint laws are like in the States, but here all paints sold for use on cars now have to be water-based. If you go to paint dealer and ask about primers he will naturally offer you water-based products as that is what he normally sells, and what he assumes you want. But the law says that commercial vehicles can use 'old-fashioned' solvent-based paints, which generally speaking are superior in all respects to water-based stuff. So I always tell the paint dealer that I'm painting a bus, even when I'm not.

Jeremy

[Don4107]

I think the hottest paint color I ever had was Chevy metallic silver.  Could have fired eggs on that thing.  You might want to do a test panel first. 

Hard to beat mostly white.  A stroll around a parking lot/RV lot in the sun with a infrared heat gun or the back of your hand can be very educational.

Good luck
Don4107

[eddiepotts]

One of the things you need to think about is when are you going to paint.  From what I have read is the epoxy primers get really hard and does not take paint well if left to long before you coat it. The other thing is Primer is porous. If it is setting outside it will soak up water and hold it down to the aluminum. It will also soak down to any body filler that may be under it. When I was taking auto body in school they would suggest if we prime it we paint it with any cheap paint to seal it. So if we were doing major surgery on the back of the car but the fenders and doors were finished go ahead and spray it with paint then block sand the whole car when done. I don't think you want to to this to an entire bus but you may. When you use a different color than the primer it makes finding high lows easy. We would buy off color paint from the paint store for about $25 a gallon and just spay it on for a true sealer. Just think about all this before you primer it and plan to wait until next spring to paint it with it sitting out side in the snow.

[muddog16]

Don this Summer made me a believer, I gave up the idea of black......with a white top, plenty of insulation, three heat pumps.......awings  and a case of beer I'll chance the med grey metallic w/clearcoat!

Eddie that's something to think about.......thanks!

[bottomacher]

Lacquer primer is porous, but not epoxy, so coating for weather protection is not needed. The stuff I'm using (PPG aircraft)allows paint coating after 4 hours and before 24 without sanding. With six million rivets to sand around, I'm going to paint it in 16 hours! (tomorrow, actually- the humidity in Georgia is finally going to drop today)

[Chaz]

This is what I use:
http://www.southernpolyurethanes.com/homepage.htm
I would HIGHLY suggest looking into it and if you have ANY questions, call them. You cn even talk with the owner!!!
Bottomacher is right, epoxy is non-porous therefore the best primer for several reasons. Plus, it accepts any body filler as good or better than the steel. Mainly because you have less chance of having undesirable stuff under the filler popping it up. It really is outstanding stuff. And I'm serious about calling them. They are top notch at helping you and are extremely knowledgable in all sorts of paints. Even if you don't go with them, they will let you know what to expect with other paints and primers. They are a company that cares about you. You don't find that very often.

Chaz

[crown]

 i was told you had to use wash primer first when working with bare aluminum than a primer sealer john

[Dreamscape]

This is what I use:
http://www.southernpolyurethanes.com/homepage.htm
I would HIGHLY suggest looking into it and if you have ANY questions, call them. You cn even talk with the owner!!!
Bottomacher is right, epoxy is non-porous therefore the best primer for several reasons. Plus, it accepts any body filler as good or better than the steel. Mainly because you have less chance of having undesirable stuff under the filler popping it up. It really is outstanding stuff. And I'm serious about calling them. They are top notch at helping you and are extremely knowledgable in all sorts of paints. Even if you don't go with them, they will let you know what to expect with other paints and primers. They are a company that cares about you. You don't find that very often.

Chaz

I agree with Chaz. When I was searching for what to use, they are very helpful. I think they have a forum, not sure though. I did not use their product, looking back I wish I would have.

[muddog16]

Paul, I liked Chaz's comments and recommendations too!  Reading their stuff right now, its a good place to start lots of information!   Thanks Chaz!

[Chaz]

Glad to be of help guys. I am by no means any kind of expert but Barry, the owner, is. His seminar was awesome and all the guys there were impressed and got lots of good tips, tricks and info. The primer is super good and I am hoping to have my bus in it this fall or next summer. I have my hot rods in it now.

Maybe I can get Barry to come aboard so we can get some good info here. (?)

Later.....
   Chaz

[Zeroclearance]

Pat, when you asked about your cap to roof seams I mentioned the PPG  DP 40 epoxy primer.

I have used it since the early 80's..   I recommend using it as your first base coat/sealer.   As others have mentioned, you can top coat with Bondo or a heavy primer.    It is better to Scotch Brite and re-apply and re-apply prior to painting.   Basically it will BITE hard into the previous base coat, and seal up your primer.

Cheers...

[muddog16]

You have to love a forum where you get all of this information!  Thanks everyone!  I'm reading, and reading and reading!  I have to tell this on myself bare with me here;   I had a dream where I took my first bus trip (great dream huh?) going down the highway.....each panel I installed pealed away and blew off .......   :'(and I left a trail of aluminum panels all the way across the US!     Talk about nitemares!

[Dreamscape]

Thank goodness it was just a dream!

You'll be fine, with the quality work you have shown I'm sure they will be still on a hundred years from now!

Paul