best outdoor varnish? decoupage glue? polyurethane? for a chair

topic posted Thu, June 19, 2008 - 11:47 PM by  Tiger
so i got these two fiberglass chairs see which someone had painted a kind of nauseating turquoise (NOT spraypainted mind you, so it ends up the paint is flecking off anyway) and underneath is an equally unlikeable plastic rust color. So I wanna funky decoupage it up (mostly types of paper and pictures i think). What do you guys think is the best, least toxic most durable longest lasting non-yellowing not so expensive material to weather the outdoor ages, as a finish sealant? Thanks if you got any suggestions or tips if you tried something similar...
posted by:
Los Angeles
  • Unsu...
    Strip the old paint and abrade the fiberglass a bit. Wash with bleach and rinse with water. .

    It'll take any exterior Alkyd paint.

    If you want a long lasting clear resin to use for decoupage get a two component resin like a catalyzing urethane or epoxy. both will adhere well to pretty much anything especially fiberglass.

    Whatever you use make sure it's rated to full sun exposure of the UV will wreck it.
    • To clear up a misconception, ( maybe a pun...maybe not ) clear top coats, even if UV rated , do not protect what is under them ( IE. your decoupage) A lot of the UV passes through the clear. That UV rating means that the clear it's self is more restant to breaking down. The inks on the paper will fade quickly if exposed to strong UV.
      Marine spar varnish, is the most, of the best, for the least. I wouldn't spend the $$ on 2 part stuff.
      • thank you both, you both cleared up some questions i wondered about and didn't directly ask so marine spar varnish will help to spare inks on paper from UV light?
        • Um no the spar varnish will react with most of the inks. Most printer's inks are oiul based. Marine spar is a petrochemical suspension. Follow the dots. Oil soluble ink. Oil suspension. Guess where the ink wants to go. This is aside from the lack of bondability with fiberglass. varnishes use their penetrative capacity to bond. Otherwise they flake. Lacquers bond to themselves and create their own matrix. They respond and bond to the tooth of the surface. Ok I am going way too technical here. In short Spar varnish will not be the coat rack you thought you were or something like that.

          • Most printer's inks are oiul based<<
            Not so , most printers inks are Soy based.
            And unless you prime the F. glass you will have trouble with adheasion. you can use water base latex to prime and paint, white glue to decup. and top coat with M.S. varnish. It will seal the latex, making it water proof, but won't protect the ink color .
            As to the Lacquer, it sounds like you're suggesting that Fiberglass is a lacquer base, it is not. You can put lacq. on F.G. but it must be primed first
            >>In short Spar varnish will not be the coat rack you thought you were or something like that<<
            HUH ? Who thinks he's a coat rack ?
            • Yes they now are soy oil based. Still an oil suspension and still reactive to other oil based and or solvent suspensions. As to the Lacquer and fiberglass. I was not implying that fiberglass is lacquer based but rather the manner in which lacquer creates it's matrix will work with fiberglass. Big reason they use it on cars, thought automotive lacquer has a bunch of additives that allow for flexibility and bondability, but the surface has to have some tooth. The primer will create that as will previous coats or sanding between coats.

              The last statement was a twisted reference to a butchers quote from the Movie Dune. Not really germane to the discussion.

              • Thanks, now I'll have to watch Dune again to figure out what the hell you're talking about ;-)
                Not Soy oil....Soy period.
                NOTHING soaks into to creat a Matrix. It is all a mater of coheasive effect. The liquid sinkes into the scratches, dries, and you have a bond. Primers have linear matrix, better for adheasion, Most top coats have non linear matrix's, better durabilty.
                So you prime partly to give the top coat something to soak into, or "attack" to use pro verbage.
                And they hav'nt used Lacquer paint on cars in 20 years ! And that is Acrilic Lacquer, as opposed to Cellulos base ( used on wood).
                Inks will NOT run, bleed, float to the surface , or rise up and call you Nancy, when coated with Petro chems. If you had ever tried it you would know that . The only exception to that is some inks that are on enamled ( shinny) paper. And that's a good thing, since ALL clear top coats have petro chems in them.
                Befor dispencing advice that " sounds right", you should check your facts, You never know when you'll run into some who has been in the industry for 35 years.
                • well Dan being I was in the printing industry for years you should take your own advise. But if you think I might be bullshiting here is a link with an overview of Veg including Soy based ink

                  I didn't say Lacquer soaked into Fiberglass. The "Matrix" I was indicating is based on its ability to lock onto a roughness or tooth of a surface. That is to say if the surface is scratched or has a coating with a significant tooth like a primer.

                  If it makes you feel any better I will pick up some lacquer and do it again since i haven't run it over printed papers for probably 15 some years but I did make the mistake on a fairly large collage quite a while ago fucking up numerous hours of working.



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