Painting Lund aluminum boat

[manzi]

Hello all, I have not posted in awhile since selling my Wellcraft 18. And those posts were in the Force motor section. Didn't think I would be back into boat ownership, but went in on a Lund 20ft Alaskan, 2001 with my son. We are in the process of "restoring" it now. Would like some clarification on painting the aluminum. I don't mean using spray cans from home box stores. I have professionally painted before in the auto industry and plan to use professional products for painting. We have sanded the complete boat, going down to bare aluminum only where there was some minor surface corrosion and a couple of dent repairs that only needed some spot putty and no bondo. From what I know about aluminum, it needs to be etch primed or zinc chromated coated. I decided on the etch primer from a local autobody supply store. The product is made by Nason. I assumed that a surface primer would need to then be put over the etch primer, but that is one of my questions. So we purchased and acrylic primer from Roberlo. We were able to obtain the actual boat paint, Fall Marsh, from a Lund distributor. Just to see how the paint looked, we mixed it well and brushed it on a piece of bare aluminum. The paint was dry in less than 15 min and we could not scrape it off with a can opener. We were told that the paint should be used as is with no thinning and no catalyst. Could this paint be developed to use directly over bare aluminum? I don't think so but hope I don't have adhesion issues with the primers we plan to use. Also, since we are working on the boat only occasionally, the bare aluminum has been bare for 3-4 weeks. Are we ok to just do a light sanding on these areas prior to priming? Would appreciate any help you can offer. Thanks, Ken

 

[brunolund]

unfortunately i have no idea what type of paint that would be, but i just finished painting my tyee. i took it to bare aluminum completely, and sprayed it with epoxy primer immediately after sanding to clean aluminum.

an etch primer should be fine, although i’d still sand a bit just before spraying. the tech sheet for the etch primer you have should list the suitable topcoats, so check there. if you can’t find it, post the name and number of the primer you have. also do you know why type of paint they gave you? is it urethane? i would suggest, and also what i used, is to find the correct colour in a 2k urethane, then decide if you want single stage or base/clear. if you painted cars, everything is the same, other then the prep of the metal.

i went through the whole arguments about etch primer vs epoxy primer vs alumni rite and alodine coating. from what info i could gather, all are suitable, as long as each one is done correctly. the majority stated epoxy was the strongest though.

 

[brunolund]

i also found a supplier that had some sort of paint designed to go directly over aluminum, but was told to stay away from it. never asked why, cause i was skeptical of it too. should have got more info.

 

[gm280]

Odd the paint you are talking about isn't a catalyzed type. I have never used a quality paint that wasn't. I don't see how it will hold up to oils and fuels and such, not to mention scrapes and scratches from general usage.

I always use PPG paints for my boat and vehicles with great success. And I did completely rebuild an old 1976 Johnson 40 HP engine and uses zinc chromate. And the reason I used ZC was because that is what the government uses for their Air Craft. If it is good enough for their equipment, if is good enough for me too.

Then I used a high build primer on top of that and then top coat and clear coat. The engine looks amazing. You can click on the build project from the links below if you want to see it...

 

[manzi]

Thanks for the replies, folks. I plan on using the etch primer, (Nason 2k 491-17), then filler primer, (roberlo multifiller plus, Z4), sand, then paint. The only unkown at this point is the compatibility of the "Lund" paint on top of the primer. I don't think I can just use the etch primer alone as my understanding is these are thin products and probably will not cover feather-edged areas. I have no idea what type of paint Lund is using. I have never used a paint that doesn't get catalyzed or thinned/reduced. My understanding is that Lund was using paint from Delta? However, for the one color we have, Fall Marsh, you could only get that from Lund. I think I should be ok with what I have. I will spray a small area first and see if there is any immediate lifting/curdling. However, this is no indication of long term compatibility. Thanks again. Ken

 

[gm280]

Ken, one final note, you can easily get any color you can dream up at most any auto paint store like a PPG paint store. The color match isn't a problem. But that is only a suggestion if you want to use two part paints...