Howdy folks. I work for a helicopter company on the Texas Gulf coast, so I'm pretty familiar with corrosion prevention and treatment. Here's how we treat corrosion, or prep metal for painting:

1. Remove old finish. I don't recommend sand blasting. You can get away with using plastic media, or even glass beads, but blasting creates alot of heat. Not good for airframes. We use a chemical stripper made by Turco. It make take a little longer, it's messy, and it burns like a SOB if you get it on you, but it will not damage the metal and it's water soluable. You just brush it on, wait a few minutes, and rinse it off. You can speed up the process by scrubbing it with a plastic brush after you apply it. It'll take a few applications to remove all the paint.

2. Treat the metal. For aluminum; scuff it with Scotch-brite, then etch it with Alumi-prep, rinse well, dry, then chemically treat it with Alodine. For steel I use Steel-prep after scuffing. Both procedures chemically convert the surface of the metal to provide better paint adhesion, and prevent corrosion.

3. Primer. Spend a little extra and get a good aviation grade primer. It will be well worth it and your paint job will last at least 2 or 3 times as long if not more. I use PRC Desoto Fluid Resistant Epoxy Primer. They even make a self etching primer so you can theoretically skip step 2. I don't trust it though. I always treat the metal. This primer is awesome. It dries fast, covers in 2 coats, and is extremely easy to shoot and work with.

4. Paint. Scuff the primer before you paint then wipe it about 50 times with MEK, Final Wash, acetone, or whatever. You cannot clean it too much. Prep and cleanliness is 90% of a good paint job. We use several different paints because when we buy a helicopter it's usually painted with some oddball brand and it's easier just to keep it original. Mainly we use Imron, RM, and PRC Desoto. Before shooting paint, get the tech sheets for whatever you're using. Most companies have a fax-back number you can call to get them within minutes.

Hope this helps. I guess you can tell, I'm pretty anal when it comes to aviation. It's mainly because I'm the one fixing someone else's crappy paint job when it bubbles or flakes after a couple of months because it wasn't done right. My work lasts for years, even operating offshore from Galveston, which is one of the harshest environments there is.

Take care,

Guy

--Eat one live toad first thing in the morning and nothing

worse will happen to you the rest of the day.

> >

> > Well, I'm back home in 90-degree, 90% humid Florida, and while I'm

> > feeling pretty good about it, Honey B is back to rusting. This was my

> > first airplane, and I thought I did a decent job of sandblasting the

> > cage and spraying it with epoxy primer, but there are thin areas where

> > faint rust is showing, and some scrapes and scratches that I have to

> > attend to. Some of these scrapes are down in the bottom of the cage and

> > I'd like to sand down to bare metal and prime with something more rust

> > preventive than the PolyFibre Epoxy (which doesn't seem to adhere well

> > unless the surface is darn near perfect), then cover the inside of the

> > cage frame with PolyFiber tape, PolyBrush, and PolyTone. This would

> > keep moisture away from the tubing and be easer to keep clean . Any

> > suggestions on cleaners, primers, etc., that would be compatible with

> > the PolyFiber products? Thanks, guys.

> >

Well, I'm back home in 90-degree, 90%

> > humid

> > Florida, and while I'm feeling pretty good about it, Honey B is back to

> > rusting. This was my first airplane, and I thought I did a decent

> > job of

> > sandblasting the cage and spraying it with epoxy primer, but there are

> > thin

> > areas where faint rust is showing, and some scrapes and scratches that I

> > have to

> > attend to. Some of these scrapes are down in the bottom of the

> > cage and

> > I'd like to sand down to bare metal and prime with something more rust

> > preventive than the PolyFibre Epoxy (which doesn't seem to adhere well

> > unless

> > the surface is darn near perfect), then cover the inside of the cage

> > frame with

> > PolyFiber tape, PolyBrush, and PolyTone. This would keep moisture

> > away

> > from the tubing and be easer to keep clean . Any suggestions on

> > cleaners,

> > primers, etc., that would be compatible with the PolyFiber

> > products? Thanks, guys.

> >

> ________________________________ Message 8 _____________________________________ Time: 12:19:16 PM PST US From: "Guy Morgan" Subject: Kolb-List: Re: Rust --> Kolb-List message posted by: "Guy Morgan"