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Good morning letterheads. I need to paint some mill finished aluminum panels & was wondering if I should prime it or paint it straight one shot.
Thanks always.
-------------------- Felix Marcano PuertoRicoSigns.Com Luquillo, PR
Work hard, party like a tourist! Posts: 2289 | From: Luquillo, Puerto Rico, USA | Registered: Nov 2000
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One way is to srub the aluminum with a Scotchbrite pad and Comet, then rinse with clean water and airdry. Then prime with zinc chromate primer.
The automotive people have several primers that acid etch the alum. in one step, and you can acid etch, wash, and then prime, but the Comet works just as good. Basically your goal is to get rid of any oxidation first, then prime.
-------------------- Jeff Ogden 8727 NE 68 Terr. Gainesville FL, 32609 Posts: 2138 | From: 8827 NE 68 Terr Gainesville Fl 32609 | Registered: Aug 2002
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Felix,call an auto paint jobber down there,PPG is the one most like to have it,and ask for a product called ALUMAPREP,it chemically treats the aluminum then you can prime it and paint it and its in the $25 and under range(i'm assuming you're talking about raw aluminum here and not powder coated stuff) then you can paint over it,or go down to the local house paint jobber and ask for exterior metal primer it will run you about the same thing more or less...tehn paint it...comet and a scotch brite pad should be your absolute last resort,if you're gonna try to cheat your luck and do it that way wash it with vinegar when you're done...but then if you want to do a quality job you should still use the etch primer over the aluminum,paint right on top of raw aluminum is never a good idea,unless its a WELCOME sign you want to last one day...other than that lotsa people will tell you how many years they've had panels done like that out there etc etc,but don't always cross your fingers and count on that. Cheaper in the long run to do one extra step in the beginning or spend $10 and be done than try to pinch a nickel and wind up redoing it later or even 11months later. Just my $.09
-------------------- Gavin Chachere Plotter in the garage,New Orleans La.
"Sgts Shugart and Gordon again request permission to rope down to crash site two" Posts: 1223 | From: new orleans.la. | Registered: Mar 2000
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I can tell you that Scotchbrit and Comet is not some home brewed concoction, but rather the recommended proceedure put out by the Matthews Paint Co. They have paint chemists on their staff and if they say its just as good as etching then I for one am not going to dispute the fact. They also recommend the zinc chromate primer.
The main reason I prefer this method is the health hazard issue using acid etch.And that acid etch/primer one step stuff they sell will really eat you up if you don't watch out.
-------------------- Jeff Ogden 8727 NE 68 Terr. Gainesville FL, 32609 Posts: 2138 | From: 8827 NE 68 Terr Gainesville Fl 32609 | Registered: Aug 2002
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Felix, hey compadre...I would use the scuff method like some of the fellows mentioned, but what I use is XIM 100. works GREAT! never had any problems with it. I've done box vans in large areas. I haven't used the other brands so I can't relpy on it. but it works just as good as described. On the down side, yes use it in an open area, it does has a smell, on the positive side it drys fast and can be used with 1-Shot or any other lettering enamel. I've even used it on repainting a tile sign.
-------------------- aka:Cisco the "Traveling Millennium Sign Artist" http://www.franciscovargas.com Fresno, CA 93703 559 252-0935 "to live life, is to love life, a sign of no life, is a sign of no love"...Cisco 12'98 Posts: 3576 | From: Fresno, Ca, the great USA | Registered: Dec 1998
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Never mind....i missed some of what Jeff posted b4...i had it in my head he was recommending scuff then painting bare aluminum......
And unrelated, someone else emailed me a couple of product specific questions,whoever it was hit me again i dumped the email b4 i could hit reply sorry.
Jeff.....I know what Matthews recommends...but they recomend the scotch brite routine to give the surface tooth only b4 you prime it,they dont suggest that you scuff it then paint it bare,no paint company does......aluminum oxidizeses,just like steel rusts,below the surface and unless you treat it and prime it it's going to come back...you're gonna have adhesion problems or worse. The point of what i posted was to recommend priming it,painting it bare is a crap shoot at best. I forgot about the XIM cisco mentioned but thats a good product too
-------------------- Gavin Chachere Plotter in the garage,New Orleans La.
"Sgts Shugart and Gordon again request permission to rope down to crash site two" Posts: 1223 | From: new orleans.la. | Registered: Mar 2000
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We paint bare aluminum on a daily basis, as a large share of our work is routed aluminum faces. After a lacquer thinner wash, we D-A sand with 150 grit, then spray with acid-etch primer by Matthews. All our topcoats are also Matthews.
Interesting: Matthews acrylic polyurethanes may need up to 72 hours cure time before applying vinyl, but by adding accelerator you can apply vinyl next day.
Brad in Kansas
-------------------- Brad Ferguson See More Signs 7931 Wornall Rd Kansas City, MO 64111 signbrad@yahoo.com 816-739-7316 Posts: 1230 | From: Kansas City, MO, USA | Registered: Nov 1998
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