polished aluminum clearcoat?

Joe Casey · Post by **Joe Casey** » Wed Feb 27, 2008 8:02 pm

Does anyone have any experience trying to clearcoat polished aluminum? I have often wondered, in this day of "killer urethanes" and "moisture catalyzed" paints if there is something that would stick, and maintain the reflectivity? Any experiences?

cjensen · Post by **cjensen** » Wed Feb 27, 2008 9:06 pm

I do plan to polish my 7, but I've always been told NOT to even think about clear coating polished AL. Two reasons...one is that is just won't stick in the long run. There may be some high performance, high price stuff out there that would last a while, but not as long as paint over a rough surface. Two...paint and or clear coat will crack. There's no way to stop it from happening. AL moves with temperature, it flexes when you move it, whether starting the engine, or flying thru the bumps. It will crack...then what?

Again, these are things I've been told by those that do polish, and I intend to follow suit...polish once a year or so.

weezbad · Post by **weezbad** » Wed Feb 27, 2008 10:47 pm

i agree with chad mostly. as far as cracking goes however most good urethanes hold up well when flexed or folded. in the ppg paint school they have you paint a sheet of alu in the following order etch, epoxy, sealer, base then clear...after it cures in a baking booth they fold it all kinds of ways. it dont crack. ive painted camaros for years and only once used the elastomeric additive...thes cars have plenty of drooping flexing plastic on them they never crack ...the one i used elastomeric additive on did crack..

thats why i never used it again... i have seen imron (duponts trade name for polyurethane) chip off in the size of silver dollars. that was in 1986 however. amny of your new cars such as cadillac's have aluminum body parts. many of them have alu hoods. the bottom line i suppose is that alu doesnt relly like to be painted but if you do it right it shouldnt be a problem. the polished look is really cool esp the colored nose and invasion stripes on the 8's beware the glare off of the wing though

captain_john · Post by **captain_john** » Thu Feb 28, 2008 6:36 pm

Yup, I have heard pretty much the same thing.

A polished surface lacks the adhesion profile and the polish pretty much is the worst way of prepping a surface for a coating.

The Airstream trailer guys have a method that seems to work, but I wouldn't use it on a plane.

I am just gonna polish it too, that is the parts that aren't painted.

CJ

P.S. Paint the outboard sections of the wings! They are SUPER REFLECTIVE and it hits you right in the eyes with the dihedral!

cjensen · Post by **cjensen** » Thu Feb 28, 2008 6:53 pm

captain_john wrote:P.S. Paint the outboard sections of the wings! They are SUPER REFLECTIVE and it hits you right in the eyes with the dihedral!

This seems to be another "he said, she said" kinda thing. They are very reflective...but not ALL the time. The only time this would be somewhat bothersome, is when flying a the angle to the rays where it does bounce them to you. The guys I've talked to about this tell me that it's not as often as one would think...but it does happen.

captain_john · Post by **captain_john** » Thu Feb 28, 2008 8:35 pm

Ummm, yah...

They are only reflective when the sun is out!

CJ

cjensen · Post by **cjensen** » Thu Feb 28, 2008 8:47 pm

Not really what I meant, but that is true...