Don, The Aluma Prep and clear Alodine (not the green Alodine) is the standard way aluminum is prepared for a finish to adhere to it. [The green Alodine is used when the aluminum is to be painted, vs. clearcoated.] I have not tried this, so I have no direct experience, though I have done a lot of painting and other finishing on a variety of substrates. The Alclad aluminum used on the Airstream may or may not cause a problem. As most of you know, the aluminum exterior of the Airstream is an aluminum alloy panel with a thin pure aluminum exterior surface coating. If you go through the pure aluminum exterior surface, all bets are off. [ The color and reaction to cleaners and polishes will be different for the alloy substrate as opposed to the pure aluminum surface.] The way the Aluma Prep is supposed to work is to dissolve the aluminum oxide coating (caused by weathering, etc.) leaving the clean aluminum metal. The Alodine is a conversion coating which is supposed to cause a thin clear oxidizing of the surface which will not further corrode (oxidize) very fast, and provide a tooth for the clear coat, thus enhancing the adhesion of the finish.[The Aluma Prep also etches the surface to improve adhesion] The big question is, "will the Clear Alodine provide the look we are after?" The Urethane clears are slick, high gloss, catalyzed finishes which are used to protect metals and as a clearcoat over a base coat / color coat finish (Typically used on most cars and trucks these days with metallic colors). They also have a UV filter (some much better than others) incorporated into the finish to reduce the damaging effect of sunlight. The effectiveness of the UV filter will play a major role as to how long the finish will hold up when exposed to the elements. [Clear finishes tend to break down from within, on exposure to ultraviolet light. Pigmented finishes (paint) are opaque and are much less affected by UV.] If the Aluma Prep works, it should be a lot faster and easier way to remove the oxidation than polishing (or as a precursor to polishing). Polishing dull oxidized aluminum really scares me, since the oxide is very very very hard (they make grind stones and abrasives out of aluminum oxide - it's hardness approaches that of a diamond!) and the plain aluminum is very soft. Because of this marked difference in hardness, you run into a tendency to abrade more of the exposed aluminum than the adjacent dull oxidized surface when polishing with abrasive polishing compounds (unless, of course, they contain chemicals to cut the oxide). To get a uniform satin finish, it might be necessary to 1) cut the oxide with the Aluma prep, 2) polish to a high gloss, and then 3) kill the gloss with a chemical etch (Aluma prep and Alodine). This sounds like an awful lot of work. Hopefully the chemical treatment will do the job the first time. Has anyone tried this? Note: Aluma prep and Alodine are (or used to be) made by the Nelson Chemical Co. in Detroit. They are distributed by PPG/Ditzler autobody paint dealers. DuPont autobody supply dealers sell similar products made by DuPont. Oliver Filippi ----- Original Message ----- From: "Don Hardman" <[EMAIL PROTECTED]> To: "Multiple recipients of VACList" <[EMAIL PROTECTED]> Sent: Friday, February 23, 2001 4:36 PM Subject: [VAC] Re: Satin polish and clear coating > Sounds like you have the same thoughts as me. I have a 76 31" Airstream and > the clearcoat is coming in off all over. I would rather have the satin look > that is on the newer Airstreams as well. Wallbernize has a product for > Airstreams that do not have a clearcoat finish. www.wallbernize.com > If the products you mentioned work that would be great. Let us know if you > find out anything from another source other than the VAC list. > > ---- Original Message ----- > From: Carol and Oliver Filippi <[EMAIL PROTECTED]> > To: Multiple recipients of VACList <[EMAIL PROTECTED]> > Sent: Friday, February 23, 2001 1:16 PM > Subject: [VAC] Satin polish and clear coating > > > > Does anyone have experience or thoughts on how to refinish the exterior of > > an Airstream to duplicate (more or less) the satin aluminum finish of a > new > > trailer? [Instead of the mirror finish of the buffed and polished > techniques > > discussed on this site]. Would a phosphoric acid etch work (such as Aluma > > Prep, and the clear conversion treatment Alodine)? > > > > Also, are there any clearcoats that hold up. The Plasticote Airstream > uses > > (or used to use) is a lacquer base product. I have heard of Airstreams > > being coated with Ditzler (PPG Automotive finish) clear urethane, also the > > comparable DuPont product. I have no idea exactly which products were > used > > nor how well they adhere (and the proper surface preparation) or hold up > > (especially in the sunny Southwest) vs. the Plasticoat product. I live > in > > southern California. > > > > Or is it better to simply wash the trailer and periodically apply some > sort > > of antioxidant coating with a rag? > > > > Oliver Filippi > > '76 Tradewind > > > > > > > > > > > > > > To unsubscribe or to change to a daily Digest, please go to > > http://www.airstream.net/vaclist/listoffice.html > > > > If replying back to this message, please delete all the unnecessary > original > > text from your reply. > > > > > > > > > > > To unsubscribe or to change to a daily Digest, please go to > http://www.airstream.net/vaclist/listoffice.html > > If replying back to this message, please delete all the unnecessary original > text from your reply. > > > To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
