Aluminum Panels (not VW)

karmannghia60 Karmann Ghia Sucker

1,459 posts · joined Aug 2002 · 24 Jun 2003, 9:33 pm

#60050

I was checking a car on the weekend, bonnet, boot & doors had this weird bubbling all over and I mean all over. Looked like the rust bubbling you would get around normal door bottoms or sills but simply everywhere. The owner said those panels were aluminum and weren't prepaired properly but its not rust. Just chemical reaction which causes the paint to bubble. Is this true? Any damage to the panels or simply they just need stripping and repainting properly?
Cheers
Raf

his@hervw Casual Dubber

49 posts · joined Apr 2003 · 25 Jun 2003, 8:38 am

#60228

Steel Rusts,,,, Ali oxidizes. Its lost its protective coating. Happens when air gets to the metal. Big job,looks like a white powder, and will brush off with your hand. If you put a brass coin or screw on the metal it will eat through in no time......

Never Rushed

his@hervw Casual Dubber

49 posts · joined Apr 2003 · 25 Jun 2003, 8:38 am

#60229

Steel Rusts,,,, Ali oxidizes. Its lost its protective coating. Happens when air gets to the metal. Big job,looks like a white powder, and will brush off with your hand. If you put a brass coin or screw on the metal it will eat through in no time......

Never Rushed

karmannghia60 Karmann Ghia Sucker

1,459 posts · joined Aug 2002 · 25 Jun 2003, 9:49 am

#60248

So panels need stripping, protection then re-spraying? Why do you say its a big job? Would the panels be damaged?

helbus Administrator Mad fabricator, paint and body

7,386 posts · joined Sep 2002 · 25 Jun 2003, 7:32 pm

#60476

Steel Rusts,,,, Ali oxidizes.

Rust is oxidisation - iron-oxide

The bubbles on the panels may be humidity blisters which is not necessarily reaction to the aluminium, but humidity that was trapped either between the metal ant the primer, or between the primer and topcoat. If the vehicle was puttied, this adds another possible layer.
If the bubbles are under the primer, then it is possible the aluminium has corroded.

The only fix in any of these cases is to fully remove all traces of the defective products.

EJ22 into Bay Microbus - Finished project build thread- click on this spot here for info

his@hervw Casual Dubber

49 posts · joined Apr 2003 · 25 Jun 2003, 8:00 pm

#60484

Yep,,,, sorry,, Another thing is if the panels are attached wrong they will fail, because of two disimiliar metals in contact with each other, to far apart on the galvanic scale. The metal will pit deeply, where a rusted part has protection in a small way from the rust itself, the ali won,t. think that's right.....2c worth anyway:bounce

Never Rushed