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Anodized vs. Polished vs. Painted Aluminum

PostPosted: Mon Apr 23, 2007 10:23 pm
by Trackstriper
I could use some real-world feedback about the advantages and disadvantages of the various aluminum finishes that are out there. I have been playing with the following AL samples:

White painted sign-grade aluminum
mirror finish clear anodized
satin finish clear anodized

1) The mirror finish anodized was the clear winner in terms of not picking up heat in the sun, being highly reflective. The white painted and satin finish anodized were about the same, with some minor heat gain. I live in the South so this could be an issue, even with insulation. Maybe it's not a big deal?

2) What are the issues regarding durability with weather exposure between the above mentioned systems? I see that some build with mill finish aluminum and either leave it alone or polish it. I don't think I have the energy to do that much polishing, but polished aluminum can always be re-polished. Do the anodized finishes eventually go bad? If so, is there a way to renew the finish or be able to paint over it in the future with a proper primer? Are any of the finish types more prone to damage/chipping from the inevitable stones?

3) Are there problems towing a highly polished trailer (like RWJ's Serenity in the Hall of Fame) in traffic? Does there seem to be any problems for other drivers with a) sun glint, or b) the effect of driving next to a mirror on multi-lane highways?

I'm leaning toward an anodized finish. Sure could use your experience and insight on any of these questions.

JB

PostPosted: Mon Apr 23, 2007 11:26 pm
by fatehunter1972
JB,

untreated anodized alclad (that is aluminum alloy coated with pure aluminum a few molecules thick) does need attention.

Contrary to some opinion Aluminum does rust, only it is not red. Some experience with airplane wings that were neglected for only a few years resulted in having to acid wash and paint them.

A good way to go is to get a really nice shiny surface and then absolutely wax the **** out of them. And then keep it up.

Anyways i'm kindof a low-maintenance guy so don't listen to me.

I'd say clear coat it with something just don't leave it bare aluminum unless you don't mind lots of polishing.

PostPosted: Tue Apr 24, 2007 1:51 pm
by madjack
...painted or anodized finishes certainly have some maintenance advatages...Steve (sonnetpro) beach camps and has done his tear in anodized to resisit the salt environment ...on the other hand, Doug sprays with BullDog(a paint adhesion promoter) and auto clear, to give a finish that you can wash and wax like a car...another product I have looked at is http://sharkhide.com/ ...it is a wipe on protectant that would seal a mill finish and keep it fresh looking for several years...have read up on it on the boat forums and they like it A LOT...i
madjack 8)

Re: Anodized vs. Polished vs. Painted Aluminum

PostPosted: Tue Apr 24, 2007 2:08 pm
by Leon
Trackstriper wrote:Are there problems towing a highly polished trailer (like RWJ's Serenity in the Hall of Fame) in traffic? Does there seem to be any problems for other drivers with a) sun glint, or b) the effect of driving next to a mirror on multi-lane highways?

No worse than driving around any other shiny vehicle. I've see tankers, and flat sided trucks with polished sides and it hasn't been a problem.

PostPosted: Wed Apr 25, 2007 7:37 pm
by robert johnson
JB, other than the high maintenance of polishing the dern thing, I've heard no complaints. and there's plenty of polished airstreams out there too. But the trailer (Serenity) has melted a plastic trash bag from the sun's reflection. That was a suprise!
Bob

PostPosted: Wed Apr 25, 2007 9:49 pm
by Trackstriper
Thanks all. Madjack, I'll have to look into that clearcoat idea over polished aluminum. I was looking over some new Airstreams several months ago and it seemed like their standard finish was a clearcoat over a lightly brushed aluminum.

Bob, I guess you have to watch where you set up the band lest you sunburn the back of you legs. Melts bag...hmmmm...suppose a tear had a parabolic shape on one side with perhaps a 10' focal length....could you cook both breakfast and an early dinner in the summer? :thinking:

As I think about it, there are some shiny tankers out there on the byways and some semis have that shiny "quilted" look on the back doors. Guess there's no big problem.

JB

PostPosted: Wed Apr 25, 2007 10:10 pm
by Podunkfla
madjack wrote:...painted or anodized finishes certainly have some maintenance advatages...Steve (sonnetpro) beach camps and has done his tear in anodized to resisit the salt environment ...on the other hand, Doug sprays with BullDog(a paint adhesion promoter) and auto clear, to give a finish that you can wash and wax like a car...another product I have looked at is http://sharkhide.com/ ...it is a wipe on protectant that would seal a mill finish and keep it fresh looking for several years...have read up on it on the boat forums and they like it A LOT...i
madjack 8)

Madjack... I ran across this on another forum:
Hi Bob, Thanks for your interest. Although SHARKHIDE has been around a long time in the clear form, I'm just now starting to experiment with the tinted colors as well as pearls. It's funny you mentioned blue tints. That's one of the colors we're doing now. I also sent two different shades of PPG blue pearls to the lab as well. I hope to have these back by the end of the month. If interested, you can purchase SHARKHIDE directly from me at this time. My number is 618-624-4091, or e-mail me at [email protected]. As far as corrosion resistance goes, I just received an e-mail from a gentleman tonight that has been testing SHARKHIDE for me in a salt spray booth. So far it's at 1700+ hours of exposure with no visible signs of breakdown. Hope I've answered your questions, and look forward to hearing from you. Clint Bland
I'd love to try the stuff... But, at $65. a quart it is kinda spendy! :o