I need advice on the best, longest lasting paint / coating for a common carrier 28ft aluminum PUP trailer. The landing and wheel gear is removed, sitting on bolcks and using them as a base for a strorage barn.
Being of 1987 vintage, the aluminum surface is corroded and needs cleaning with an acid cleaner of some sort then primed and painted. It also has a company logo that needs to painted over too.
Need suggestions. I believe the common latex is not a good idea and unsure about oil based paints. Planned color is a light yellow tan to match house trim.
FCAMX from NC
Replies
Why not stop at the local 'general aviation' airport and ask who paints planes?
I painted my old Cessna 150, about thirty years ago. You'll need to etch the corrosion off with acid and some elbow grease. It will probably take numerous applications of both to get down to a clean surface. If you don't do a good job of etching, the paint won't stick very well.
Next you'll have to use another chemical, alodine I believe, to seal the aluminum from corroding and to offer a good bond for the primer and paint.
It's a lot of hand work, A LOT, all that preparation. If I learned one thing from re-painting that airplane it was that I'd never do it again.
The best paint, meaning the longest lasting is a two part expoy based stuff (dangerous to inhale) made by Dupont and others like Sikkens. If you Google: Dupont Imron you'll find lots of imformation.
This is not the kind of paint that can be shot with common paint mask. It requires a full suit and a respirator, to protect the skin and the lungs from absorbing any of the chemicals.
Edit: Used as a storage trailer, you might be better off to just scrub it down, roll on some rustoleum and forget it. But buy a proper painter's mask and wear laxtex gloves. It's all nasty stuff for the lungs and skin.
Edited 9/29/2009 4:58 pm by Hudson Valley Carpenter
That is not an epoxy.I believe that it is urethane based, but not sure.But it is a 2 part mix. And outdoors the fume would not be THAT BAD, but you still need some precautions.And way overkill for something like this.And I would suggest an auto finish. But it sounds like he wants some that will blend in with a house.I would suggest a low luster latex.But the trick is the right primer. And proper pretreatment of the AL.Probably needs an acid passivation coating..
William the Geezer, the sequel to Billy the Kid - Shoe
You're right, now that you remind me, it's urathane, not epoxy.
It's been so long that I bunched all those two-part paints together in my memory under epoxy.
Nonetheless, it's nasty stuff to breathe and have contact with the skin. It all ends up running through the blood and the vital organs. Not conducive to long life.
It's probably illegal to shoot urathane without a full recovery system, in most states.
You say that urathane is overkill for his project. I'll agree that it's expensive but, after all the prep work that's required to do a long term job, most people choose to spend the extra bucks on the top quality paint.
Probably needs an acid passivation coating.
That's why I edited my first post, to suggest Rustoleum. I suspect that they make a primer that will neutralize surface corrosion, without etching it first. That's probably not a good long term solution but it would make the job a lot less time consuming.
Edited 9/29/2009 5:25 pm by Hudson Valley Carpenter
Well, the OP did ask for 'the best.'
Whatever paint he uses, a pro shop ought to be able to match both the color and sheen of his house. I've been amazed what the pros - and I don't mean the kid at the box store -can do.
Have had good results with both BMS10-23 and Polane B&T.
Zinc chromate primer
Powder coat if you can get your whole trailer into an autoclave <G>
Edited 9/29/2009 7:19 pm ET by junkhound
Where can you get zinc chromate primer? None of the paint strores around here carry it.
will TSP wash off the coorosion and prep for prime?
I painted my pontoon boat in 1998 and I could get zinc chromate but I couldn't get it in 2005 when I painted it again. The auto paint store did have an etching primer that did a good job and I found a 1 part urethane enamel that worked great. The trick is preparation. I hit the whole thing with a D/A and 1 150 grit pad to knock down the oxidized spots and then shot on the primer. Two coats of the urethane enamel and I was good to go. This is a boat that runs 400+ hours a year in salt water and always swings a few feet above the water on davits when it isn't in the water. Like the other guys say. These are all nasty chemicals so be sure you use a good respirator and other PPE. A tyvek suit is not unreasonable.
Look at the primers and washes here.http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Primers%20Sealers%20Undercoats&categoryId=37&refine=1&page=GRIDhttp://www.aircraftspruce.com/search/search.php use primerhttp://www.airsuppliers.com/shop/search.asp use primer.
William the Geezer, the sequel to Billy the Kid - Shoe
Where can you get zinc chromate primer? None of the paint strores around here carry it.
Here's a page on primers and other prep products from the old standby for DIYer's in aviation, Aircraft Spruce and Specialty. Check the second item from the top.
http://www.aircraftspruce.com/menus/cs/primers.html
We use a self-etching primer on all of our aluminum barrier parts. I'll try to find the name of it.
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No, I didn't vote for him; but he IS my president. I pray for the his safety, and the safety of his family every day. And I pray that he makes wise decisions.
thanks. what about washing with TSP before priming?
In another life I was involved with painting large aluminum items. Aluminum can be painted easily and durably with proper preparation. As I used to say, "The paint will stick just fine to the dirt. Unfortunately the dirt does not stick to the metal!"
FIRST: The aluminum must be clean. All dirt and grease removed. Use your favorite cleaner, with a detergent in it. Low sudsing recommended. TSP is not the answer.
SECOND: Rinse. Rinse. Rinse. Rinse. (Do you detect a pattern here). The detergent (or tsp for that matter) can cause adhesion problems.
THIRD: Get a water-based aluminum treatment. It will help clean off the final unrinsed residue, and any aluminum oxide corrosion products.
The Alodine folks are one source. But keep in mind that these days Alodine is a corporation. Initially Alodine was a chromate-based product typically applied by dipping. As mentioned above, aviation folks are probably the best source for the general market. READ THE INSTRUCTIONS!! Sometimes the final coating must be applied within days, sometimes hours after application. Delaying too long can actually cause the paint film to fail.
FOURTH: Paint. By this time almost any paint will work. After pretreating the aluminum we used the cheapest alkyd paint available. I used to see products that had been used near the ocean (like on a boat). Paint would be worn off in places, but I never saw paint film failure. Again, check with the treatment people: THEY can tell you what will stick to their treatment. DO NOT depend on the paint people.
Edited 9/30/2009 12:37 pm by JohnD1
you are correct about the alodine chromate conversion. from my research, the cost appears to be prohibitive for my project, about $600 for the stuff.
great advice, thanks
Glenn
aluminum starts to oxidize in 15 minutes. you need to mechanically remove it, clean and prime as quickly as possible. If you do this[prime in sections] it will last very well
That is what an etching primer is all about. It cuts the oxidation and provides a membrane to prevent further oxidation until you get the paint on.