Spots on my Aluminum Skin...!

[mrbill]

Went to the Oregon Coast, came back with spots on the roof where tree sap and salt water sat on the skin. I have tried wax, rubbing compounds, acetone, mineral spirits, paint thinner, solvent, WD40, and just about everything else i have on the shelf. The skin is smooth to the touch, but the stains / spots are still there and very visible.

ANY IDEAS??

Thanks, Mr Bill

[madjack]

Mr. Bill, about the only thing left is an acid wash...you can get a cleaner for UNSEALED aluminum wheels and it should take the spots out...you can also goto a 18wheelr truck wash and have them doit...one problem...it will change the appearance of the AL, giving it a kinda bright white look...it is not a bad look, in fact it is not bad at all but you should do a test piece first and see if you like it...after the acid wash you can wax and seal or polish back to a mirror shine...once you get it like you want it, you may want to consider using sharkhide metal protectant ...I have not used this product myself but it seems highly thought of on aluminum boat forums...they also have an acid wash and other products for your AL...as always with any such things...YMMV...............
madjack

[Darren]

I recently decided to get rid of the stains on my house gutters. Took forever to find anything that would work at all. Ended up that some non scratching kitchen cleaner with bleech did the trick. Might be worth a try but do try it on a not so visible spot first.

[Monk]

i know i'm the new guy but i do know something about this one. this is a ongoing problem with airstream restoration. i've been researching this to start the multi-man hour project of polishing my dad's 63' overlander. madjack had a good idea about the truck stop, they polish alum daily(i.e. the shiny fuel tanks and trim on big rigs). also, check any number of web sites on airstreams about polishing. the problem is it takes a lot of time and multiple passes with different products and a power polisher. you can't just do one spot, you must do the whole thing, because it shines up like chrome. you must start with a heavy cutting compound and move to lighter grit then finally polish. even a small tear would take 40-50 man hours. also, the heavy professional compounds should be handled with care as prolonged contact cause cancer, so gloves and repirator are a must. the other option is an airstream restoration place that charge 100-175$ per foot to polish.

[asianflava]

I used to care what my metal looked like but with so many blemishes on my tear, I decided to embrace them. I keep them as "War Wounds" I just have to remember what story goes with which one. I'm talking about the scratches, dents, etc.

That's just me though.

[Dean_A]

I know this doesn't address the OP,but is there something you can put on your mill-finish AL skin as soon as you install it in order to prevent the spots (water, etc.) from showing up in the first place? Would regular automobile wax do the trick?

[Monk]

I know this doesn't address the OP,but is there something you can put on your mill-finish AL skin as soon as you install it in order to prevent the spots (water, etc.) from showing up in the first place? Would regular automobile wax do the trick?

Clear coat, spray on clear coat. it's the difference between a vintage airstream that's been polished and looks like chrome or a brand new one that has the dull mill finish. airstream offered clear coat as an option until about 74' or so then it became standard. remember nothing is a fix all and even clear coat must be washed every once and a while to keep tree sap and the like from staining. again lots of good products for alum through airstream places, afterall they've been using alum skins since 36'. just something we can use from our big round brothers.

[madjack]

I know this doesn't address the OP,but is there something you can put on your mill-finish AL skin as soon as you install it in order to prevent the spots (water, etc.) from showing up in the first place? Would regular automobile wax do the trick?

Dean, did you see my link above about the SharkHide...that is what it is for...goto some aluminum boat forums, they like it...if using a clearcoat, you need to shoot it with something like "Bulldog", a clear, paint adhesion promoter that should be available from an auto paint supply store.....
madjack

[Dean_A]

I know this doesn't address the OP,but is there something you can put on your mill-finish AL skin as soon as you install it in order to prevent the spots (water, etc.) from showing up in the first place? Would regular automobile wax do the trick?

Dean, did you see my link above about the SharkHide...that is what it is for...goto some aluminum boat forums, they like it...if using a clearcoat, you need to shoot it with something like "Bulldog", a clear, paint adhesion promoter that should be available from an auto paint supply store.....
madjack

MJ: Thanks, I just checked it out. It looks like it may do the trick. A little on the pricey side, but I've heard enough horror stories on this forum about damaged mill finish aluminum that I'm willing to try it out. Have you ever used it?

[madjack]

No Dean I haven't, my recommendation comes from what I have read on a couple of aluminum fishing boat forums...they really seem to like it, it apparently has a several year lifespan on boats being used in salt water enviorments.....
madjack

[Dean_A]

Good enough for me! I'll be the official guinea pig.
I'll let you all know how it turns out.

[madjack]

Dean, I think that would be great...to help ya out, here is a link to an aluminum boat forum, where the discussion is about Sharkhide...there is a factory rep(t_birder) involved in the discussions and a lot of good info...3 pages worth...makes for some informative reading....
http://www.ifish.net/board/showthread.php?t=96978
madjack

[Dean_A]

MJ: Wow, lot of great info here! It seems like it's really easy to use. My only concern is that they say it works much better if you apply it in cold weather. Not much of that around here until October.

[mrbill]

While i'm tempted to go with Bullshipper, I would like to clean it up to the way it was. I am going to sell it soon, and would like it to look good for the new owner. I have at my disposal the acid truck wash used by trucking companies and semi-truck washes. I wanted to steer away from that as Madjack says, it does change the color of the AL. I appreciate the post by Monk as well and while i also possess the needed buffers and polishers to perform a full on mirror finish, I dont really relich the idea of spending that much time on the skin.
I am curious, has anyone else seen this website?

http://www.metalwax.com/METAL%20CLEANER.htm

I sent them an e-mail with no response and plan to call them this coming week. Looks like a decent product.

I appreciate all the responses and I will keep you all posted as to the fix I use, if any, as the second tear is in the design process.

HAPPY CAMPING!!

MrBill

[Dean_A]

OK, it's time to follow up on this post. I went ahead and bought a can of the Sharkhide protectant and used it on my tear as soon as I was done with the construction. So far, I have only good things to say about it. As long as you follow the instructions (thanks for the link MJ) it turns out really nice.

Basically you just saturate a cloth with the sharkhide (a cloth diaper works best), then wipe the finish on with long smooth strokes. It's best to do it when it's on the cooler side so it has more chance to flow out before the solvent evaporates. One can was enough to do 2 coats on my tear, and additional coats can be added at any time if you want additional protection. One coat is supposed to last years, so it's not something I should have to do often (maybe once a decade), especially since I keep it garaged.

The only (very minor) flaws in the finish were my own fault where I let the cloth get a little dry and you see a bit of streaking. But they're the kind of thing you stress about for an hour then never notice again!

I've towed the tear through the rain and mud, and no problems with staining of any kind. I just wash the tear like I would my car and it comes out spotless every time.

It's only been 6 months so far, but I'm very happy with the results. It's nice not to have to worry about my finish when I take it out.