painting the flaperons

[Jerrytex]

I am ready to paint my brand new flaperons. I already have the wings painted so I am focused soley on the flaperons. I am thinking about using single stage urethane (car paint) so I can match the color of the wings and also use it on the fiberglass with a flex additive. I am wondering what kind of prep is necessary on the aluminum flaperons to get the paint to stick? I don't have much experience with painting aluminum and neither does the paint store since there are not alot of aluminum cars on the road. I goggle this and as you can imagine, I get everything from etching to alodining, to scuff and paint. Just wondering what worked for other people. Not going for a showroom finish... just want to make sure the paint doesn't blow off during flight.

[cap01]

i used the poly fiber products and since my flaperons were bright , clean and not corroided , i just etched them . after etching they have to be well cleaned and dryed . i used polyfiber epoxy primer and poly tone finish . its reccomended to shoot the finish on the primer before it sets up . almost need two guns to do that . worked well for me and hasnt blown off yet .

[Dorsal]

I did the same as Cap, paint seems to be holding.

[Av8r3400]

Mine were painted with poly tone. I don't know what kind of prep or primer was used, but they are pealing badly now. When I repaint them, it will be in a complimenting color, rather than matching, and will be with an automotive primer/paint system that will be assured to stick...

[jtpitkin06]

Aluminum has its own problems when it comes to painting with automotive paints. If the surface oxidizes it sloughs off the paint in a short time.

Make sure your paints are all the same brand and type. This helps with compatibility.


Painting aluminum is a three step process.

First is preparation and etching. Just clean the surface a Scotchbrite pad and wipe clean with denatured alcohol. Immediately spray the clean aluminum surface with self etching primer, the green stuff. Do not wait to spray on the etching primer as oxidation begins immediately. Let the etching dry for overnight. Do not sand. This step stops the oxidation on the surface.


Second, spray the etched primer surface with gray or white painting primer. White primer is better for light colors, gray for deep rich colors. For example: a bright red will look almost candy apple with a white primer and deep blood red with a gray primer.

Never use dark gray primer under white or yellow top coat. It will look dirty or dull.

Let your gray or white primer dry and sand lightly to smooth off any gritty bumps. Add a second coat and sand again, if necessary.

Third, spray on your finish color. The first passes should just fog the surface. Let dry for a few minutes. This provides an adhesion layer and partial coverage without runs or drips. The second passes improve the coverage. Just fog the surface again. Immediately start your final passes. The final passes should be just heavy enough to make the paint flow. Do not expect to see a glossy look while spraying. It should look smooth, but not necessarily shiny. New automotive paints develop the high gloss after the paint starts to dry.

It’s an easy process and the paint will really stick to aluminum if you use this three step process.


There are also special two part polyurethane paints just for aluminum like Alumigrip. They are good enough to paint jets, and have a jet price tag attached.




John Pitkin
Greenville, TX

[Jerrytex]

Thanks for the Info. This forum is a great resource. I googled the etching primer. I guess I'll go on the hunt for it tommorrow. Don't guess anyone knows if it's available at the big retailers? i.e. Lowes, Home Depot, etc.

[jtpitkin06]

O'Reilly's Autoparts has Duplicolor Self Etching primer in 12 Oz aerosol cans.

http://www.oreillyauto.com/site/c/de...etching+primer

[cap01]

there has been some discussion about a napa 7220 etching primer on both this site and the vans site . seems there has been some good results using it on aluminum

Hi guys:

I have used 7220 extensively for years with extremely good results on aluminum and steel parts of my RV-4. Here is my application process:

1. Clean the component with PPG Wax and Grease Remover or Dupont 3812S reducer.

2. Lightly scothbrite the component.

3. Clean again with PPG or Dupont.

4. Spray with 7220.

I have used 7220 entirely on the internal aluminum parts of the RV-4 (now flying 5 years and 500 hours). After about a week it sets up very hard. I have topcoated it with AlumaGrip polyurethane with excellent adhesion results on the interior parts of my RV-4. I have also topcoated it with PPG acrylic urethane with good results also (however acrylic urethane is much more brittle than polyurethane).

I am using 7220 again on the internal components of my RV-7 under construction. The downside is that the price is now $9.95 a can in the local area.
__________________
Doug Weiler

Hudson, WI
pres, MN Wing, Van's AirForce
RV-4, sold (now N160NS)
RV-7 under construction, N722DW

[jonbakerok]

Oreily's also carries Nason self-etching primer, which is much better than rattle cans for painting large areas. It's a two part primer and is much more durable and clings to the aluminum much better. It might even be cheaper than the number of rattle cans you'll need to cover the flaperons.

All O-Reily's carry the rattle cans but to get Nason you have to call around and find the one in your area that carries pro painting supplies.

[Jerrytex]

Thanks for all the suggestions and help. I opted for the Duplicolor etching primer from Oriley's. I also bought the light gray primer since I am painting white. Now all that's left to do is watch the Epoxy filler dry on the flaperon tips. (kind of like watching grass grow) Once I finish the flaperons and get them installed...a little paint on the cowling and some minor adjustments and then it's off to the airport for some slow taxiing. Hurray!