PAINTING QUESTION

[EDMO 1078]

I ended up getting 6061uncoated and 2024Alclad sheets for my flaps and ailerons - Forget which goes where -

Question:  Should I use Alumaprep and Alodine on both kinds before painting, or just a self-etching primer? 

Should I paint inside surface of 6061?

I thought about just leaving the Alclad as is, without painting, but I don't like to polish planes.

EdMO

Edited 10 Jul 2015 by Ed In Missouri

[KFfan 151]

Assuming you are referring to 6061 tubing, I've seen postings that it is difficult to get good coverage on the tubing, unless you have some asterbised device to apply the paint?

[EDMO 1078]

Not tubing - just the sheets of aluminum for flaps and ailerons - sort of like flaperons, except separate controls.

I don't know what an "asterbised" thingy is, but you can paint tubing with a spraygun or rattlecan just fine.

EdMO

Edited 10 Jul 2015 by Ed In Missouri

[Luked 71]

Hey Ed,

 

I'm no paint expert. I do read quite a bit on Vansairforce.net since we make products for their airplanes. As you can imagine, the topic of painting aluminum comes up a lot over there since that's what their planes are made of. They actually have a whole section of the forum just for primer:

 

http://www.vansairforce.com/community/forumdisplay.php?s=&f=54&page=1&pp=53&sort=lastpost&order=desc&daysprune=-1

 

There are also a lot of opinions about it, so they refer to this topic as "Primer Wars".

 

From what I've read about it, I think the concensus is something like this:

 

Spray can self etching primers are okay for most stuff where you just need to protect against corrosion. It won't hold up well in areas with high wear (cockpit, etc.). It's recommended that you scuff with scotchbrite first. Some recommend heating parts before painting.

 

Alodine plus some kind of primer is better than just self etching primer. Alodine, and then apply any type of primer you like.

 

Epoxy primer is best. AKZO seems to be the prefered brand. Of course you have to clean up your spray system after every use.

 

I'm not sure you need to do much to alclad. It probably depends on your preference, and the area you are operating the plane in. I would definitely prime any "bare" aluminum though.

 

Here's a link to a guy who compared spray can self etching primers. Pretty interesting reading:

 

http://www.vansairforce.com/community/showthread.php?t=96070&highlight=primer

 

Also, for some entertainment, here's a past thread that relates to the topic  :

 

http://www.vansairforce.com/community/showthread.php?t=98446

 

Luke D.

[KFfan 151]

Not tubing - just the sheets of aluminum for flaps and ailerons - sort of like flaperons, except separate controls.

I don't know what an "asterbised" thingy is, but you can paint tubing with a spraygun or rattlecan just fine.

EdMO

Sorry, thought you were referring to painting the inside of tubes.

Discount my $.02

Edited 10 Jul 2015 by KFfan

[EDMO 1078]

Thanks for the info Luke,

      I worked in a prop shop in Anchorage, and one of my jobs was to blast clean, inspect, prep with scotchbrite and citric acid (something like alumaprep) and alodine props and blades.  Another guy did the epoxy painting.

      My Ercoupe wings got metalized - alumaprep and alodined the whole plane before painting with Ford Truck Paint - Looked good, and never had a paint problem with it in 10 years.

      I will be prepping and alodining my skins, inside and outside - Just haven't decided on what paint to use yet.

We used Stewarts primer and topcoat on some sheet metal parts for the J3 - a month later we couldn't scratch the paint at all with thumbnails.  Tried a knife edge, not point, on it and it was hard as a rock.

EdMO

Still don't know if I am going to paint the inside of the 6061 flaps or ailerons, but think it would be best....

After Bryce posted that "science lesson" I forgot what my original question was! 

I think that was about "fuel tanks and gravity"?  Better watch it again!

Edited 11 Jul 2015 by Ed In Missouri

[Flyhighbigsky 4]

Hey Ed, did you have all your paint questions answered? I paint professionally and use Stewart Systems almost exclusively On all substrates. Let me know if I may be of assistance.