Forum Discussion

Deano56's avatar
Deano56
Explorer II
Apr 23, 2014

painting

I have started to take off my baggage doors (not basement type) so I can do a proper paint job on the bottom of our 1990 Champion Lasallle motorhome. The bottom sides are galvanized metal except where the wheels are, that area is fiberglass. I have to get someone to bend two panels that I am replacing due to rot. Have any of you heard that washing down the galvanized metal with vinegar will help the paint to adhere? I was told its almost like acid etching
Class A

8 Replies

  • rgatijnet1's avatar
    rgatijnet1
    Explorer III
    Apr 24, 2014
    badboy368 wrote:
    first it needs cleaned with a good wax/grease remover, the sanded real well, then sprayed with a self-etching primer then sanded again then painted. only way it will last.:)


    Sanding is OK for hot dipped galvanized plating but if the piece is electro-plated sanding could remove the thin coat of galvanized. Usually electro-plated sheets are smooth enough and just need to be cleaned to remove all oil and dirt before applying primer. The primer can be sanded IF it is sanding primer.
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 24, 2014
    I just used a product called Ospho to prime a galvanized steel trailer. I painted it with Rust Stop from ACE hardware. The paint is adhering and looks good.
  • badboy368's avatar
    badboy368
    Explorer
    Apr 24, 2014
    first it needs cleaned with a good wax/grease remover, the sanded real well, then sprayed with a self-etching primer then sanded again then painted. only way it will last.:)
  • Roman_Duck's avatar
    Roman_Duck
    Explorer
    Apr 23, 2014
    Vinegar is great in cleaning oxided galvanize metals, it will help in prolonging the paint applied, yes longer than when no vinegar at all. It was used back in its time as a wash to remove the oil residue that was on the surfaces
    Nowadays there are special primers available that would do better
  • Roman_Duck's avatar
    Roman_Duck
    Explorer
    Apr 23, 2014
    Vinegar is great in cleaning oxided galvanize metals, it will help in prolonging the paint applied, yes longer than when no vinegar at all. It was used back in its time as a wash to remove the oil residue that was on the surfaces
    Nowadays there are special primers available that would do better
  • rgatijnet1's avatar
    rgatijnet1
    Explorer III
    Apr 23, 2014
    They make primers specifically formulated to adhere to galvanized metal. CLEANING the metal of all dirt and oils is the most important and sometimes, after it is cleaned, allowing it to weather(dull) somewhat will also help the adhesion process.
    Since they have products designed to prime galvanized metal, I would not use vinegar as a substitute.
  • diazr2's avatar
    diazr2
    Explorer
    Apr 23, 2014
    I am not a painter but have dealt with galvanized quite a bit. I have found no paint that sticks to it very well. I think that's why most all galvanized boat trailers are not painted. I think powder coating might do it but even then on my wheel house in the boat I have a hatch that is galvanized it is powder coated black. The paint is just peeling off it. Still the hatch is in great condition no rust no corrosion but no paint as well.

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