Houseboat roof paint questions

Discussion in 'Materials' started by nopeda, Oct 24, 2018.

  1. nopeda
    Joined: Aug 2013
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    Location: GA

    nopeda Junior Member

    Right now after the things people have said here and other places I'm thinking to clean the amine blush first with water and a scrub pad. Then rough it up with 60 grit sandpaper. Then sweep off the dust and wash with acetone. Then use a primer, rated for wet bathroom type conditions? Or outdoor? Then use a deck paint like Behr. Or Olympic... does it matter? Rustoleum? Can it be water cleanup paint? Also for the additional coats does it need more washing or acetone or sanding or priming or... between coats, or can you just apply the additional coats after you've primed it for the first coat?

    Thank you folks for all your help, and your patience with my ignorance!
     
  2. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    No need for primer between coats, some may not require primer all, but every paint will have slightly different requirements, so read the can.

    There are some water clean up options, but most don’t hold up as long.

    The easiest is Rust-Oleum with hardener, easy to find, cheap to buy, with better than average results
     
    Last edited: Oct 28, 2018
  3. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    David,

    Everything Ondarvr just said beers repeating.

    What is the surface finish of the unrepaired portions of roof?

    Rust-Oleum is oil based and therefore cleans up with mineral spirit.

    There is a tremendous drop in cosmetic appearance and longevity associated with water bourne paints. Are you willing to accept a short lived less beautiful finish for the convince of water clean up?

    If so, I recommend:
    • Adding sudds (dish soap, Simple Green or citrus cleanser) to first wash.
    • Zinsser 123 as primer.
    • Three or four coats of Behr PnD
    • No adhesive need to sand or wash between coats applied with in a week of prior coat.
    • Ok to sand application errors away (runs, drips, roller tracks) or wash off bird droppings or other fresh dirt.
    If you want a roof that looks better longer, and are willing to work with mildly toxic solvents. Then substitute Rust-Oleum for the 123 and PnD.
     
  4. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Paints depend on climate, as to choices, I know where I live (27 degrees south), 100% acrylic house paint will beat the pants off any alkyd (enamel) house paint on any external surface that is prone to flex or movement, and especially a horizontal surface.
     
  5. nopeda
    Joined: Aug 2013
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    nopeda Junior Member

    Went to Lowe's and then Home Depot today. Those guys know a lot less than you people and I told them now that I know what specifically is available I'd ask the forum people and see what they suggest. The location is about 40 miles north of Atlanta, GA.

    Lowe's has Zinsser 1-2-3 water based primer and sealer. The guy said it should be good enough if covered with an oil based paint. Also Valspar porch and floor anti-skid latex (with sand stuff mixed in) $40/gallon. Or Rustoleum flat oil based 7590 $10/qt, said the flat finish will make it not too slippery. Probably about like what was up there originally.

    Home Depot has Zinsser 1-2-3 Bulls Eye water based primer $22/gallon. Also Behr low-lustre enamel 6050-N $30/gallon. Or Rustoleum protective enamel oil based flat white 7790 $8.37/qt.

    I tried to stick with oil based paints that were intended to be walked on, so even with so many selections of different paints available at the store it came down to pretty much those few. Would any of those paints not need a primer? Or would it always be better to use a primer regardless? Is it true that the water based primer would be okay if covered with an oil based paint? Is mineral spirits all I need to have to clean up, or would acetone (I've learned to love acetone) do better? Will it clean the brushes, or would it do as well or better to just replace the brush after every coat, since Dollar Tree sells the 3" brushes I've been using to apply the fiberglass resin for $1 each? I don't think there's enough open area to make using a roller and pan etc worthwhile.
     
  6. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I have never seen flat or semi-gloss alkyd enamels specified for external painting.
     
  7. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    My opinion of store clerks is that they know what isle an item is on; but not how to use it.

    Primers are designed to do certain jobs better than paint. The three traits you are most liKelly looking for are; sandability, greater adhesion and substrate sealing. You have not given me the impression that you are after a flawless finish, so I don't think you need a high build sanding primer. Which is good because 123 doesn't have a reputation for easy clog free sanding. Oil paints have greater adhesion than water bourne, including 123 primer. 123 must be used under a water paint, but is usually detrimental under oil! You haven't said what the unrepaired portion is, I'm assuming gelcoated fiberglass. If so, the difference in porosity is insignificant and won't affect appearance if two or more coats are applied.

    You mentioned non-skid. The paint on the top of the raised particles wears off quickly, and the particles soon come loose. Often in less than a year. Make sure there is lots of paint beneath them. And only put them in final coat. An old fisherman's trick is to use rock or coarse salt. It makes next year's sanding for repaint much easier. What ever is used, non-skid is always harder to keep clean.

    Low sheen paint is good for not highlighting surface flaws. That is why it is used on walls. It is always less durable and harder to keep clean than its higher sheen counterparts. I RECUMEND USING HIGH GLOSS RUSTOLIUM.

    Acetone cleans oil paint out of brushes. Sometimes it even cleans the bristles out too. It will curdle the paint, so don't use it as a reducer of thinner.
     
  8. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    I have used dead flat oils on several exterior applications. They are a birch to keep clean. Especially as the cleaning process usually buffs the sheen up.
     
  9. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Don't use Zinser - its a special undercoat for marked or fire damaged walls. It might work, but its too expensive for no real benefit to you.

    Like I said, good quality sealer undercoat for wet areas like bathrooms seems to work well.

    I know its a pain for cleaning, but non water based paints are far superior to any water based if you are going to walk on it. If you want to save your brushes, after you give them a good rinse out with Turps, leave them to soak in a Washing Machine Powder/Water mix ( about the same as you would use for clothes) in a container for a few days, and they will return soft and ready for re-use after a good final rinse

    Do NOT use crushed rock or salt in the top coat. You wouldn't put 80 grit sandpaper down on a floor in case you fell over and gave yourself gravel rash, so don't create your own 80 grit paper on the deck.

    I just tried to ring a guy who knows, but he used some sort of plastic particles especially designed for deck grip.

    Edit : Peter used a special decking compound that you trowel on, and gives you a stippled, rubbery finish.
    His friend on another boat used crumbled cork, but that still leaves little hard paint spots when they get knocked off. Its better than sand and other hard stuff.

    Another great hint, when you apply the top textured layer, do it in a "hopscotch" pattern, and mask areas of with tape in alternating squares. Then you have somewhere to stand without getting stuck as you apply the final, textured coat. It means you have to do it in two stages to allow the first lot to dry, but it will be a better result.
     
    Last edited: Oct 31, 2018
  10. pauloman
    Joined: Jun 2010
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    Location: New Hampshire

    pauloman Epoxy Vendor

    google aluthane - an aluminum filled mcu coating that will reflect heat and look sort of light gray. unaffected by UV and sunlight
     

  11. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Aluthane ( MCU ) Aluminum Paint, Anti Corrosive, Rust Sealer, Primer and Top Coat

    Yeah, but how is it for anti-skid, non gravel rash applications ?

     
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