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This topic contains 9 replies, has 4 voices, and was last updated by Avatar of OCEANOPOLIS OCEANOPOLIS 2 years, 7 months ago.

Viewing 10 posts - 1 through 10 (of 10 total)
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  • #1616
    Avatar of elspru
    elspru
    Participant

    It’s time to paint the ferrocement boat concrete dinghy.

    The ferro-cement boat book I have recommends Chlorinated Rubber paints,

    however I’ve read that they have a large amount of VOC’s volotile-organic-compounds,

    Also they aren’t generally sold in north-america. So I’ve been looking at alternatives.

    Currently the only thing I’ve found in stores near me is some exterior waterproof latex paint and some semi-permeable acrylic paints.

    It seems to me that a waterproof paint would be the best, as it’s an extra boat-skin, helping keep interior dry. http://www.canadiantire.ca/AST/browse/3/HouseHome/PaintStains/SpecialtyPaints/PRD~0488389P/DryLok+Waterproof+Latex+Paint%2C+1+Gallon.jsp?locale=en

    If you have any knowledge or experience painting concrete or steel fittings please mention.

    #15244
    Avatar of shredder7753
    shredder7753
    Participant

    okay spru –

    i spent 1.5 yrs at school for ‘industrial coatings’ (in fact i think that’s me in the blue shirt) in addition to 7 years full time experience, and im running my own business with it right now (and tons of good references). also i just finished painting my own working seastead model.

    the drylok u linked to is exactly the product that i used on my berg. i put it in the water 2 days later for about 2 hours and it performed very well. i DO NOT recommend using anything expensive. for these projects we’re doin’, stick with cheap stuff, or at least under $30/gal.

    that drylok has a lot of sand in it and will give an even textured surface. i rolled it on with a mini-roller. u’ll want a cheap throwaway brush also – even if u clean it out u can really only use it for the drylok afterward.

    drylok extreme is supposed to be smooth, but for the dinghy thats not necessary (imho). theres also some rustoleum epoxy paints, and even roof coatings. keep in mind that if ur just gonna drag it around on top the rocks… it wont last too long. but thats why im saying dont spend 50-100 dollars on special stuff. if ur gonna leave it in the water a long time use this boat bottom paint. otherwise i recomment sticking to the basic drylok for ‘less-than-6-hour’ excursions.

    update:

    use the basic drylok. get 4 single gallons and do 2 coats. you can use a full size 9″ roller with a 3/4″ nap.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #15249
    Avatar of georgeberz
    georgeberz
    Participant

    You might also try garage (concrete) floor 2 part epoxy, that will give you a nice acrylic / epoxy shield.

    #15248
    Avatar of elspru
    elspru
    Participant

    shredder7753 wrote:

    okay spru –

    i spent 1.5 yrs at school for ‘industrial coatings’ (in fact i think that’s me in the blue shirt) in addition to 7 years full time experience, and im running my own business with it right now (and tons of good references). also i just finished painting my own working seastead model.

    the drylok u linked to is exactly the product that i used on my berg. i put it in the water 2 days later for about 2 hours and it performed very well. i DO NOT recommend using anything expensive. for these projects we’re doin’, stick with cheap stuff, or at least under $30/gal.

    that drylok has a lot of sand in it and will give an even textured surface. i rolled it on with a mini-roller. u’ll want a cheap throwaway brush also – even if u clean it out u can really only use it for the drylok afterward.

    drylok extreme is supposed to be smooth, but for the dinghy thats not necessary (imho). theres also some rustoleum epoxy paints, and even roof coatings. keep in mind that if ur just gonna drag it around on top the rocks… it wont last too long. but thats why im saying dont spend 50-100 dollars on special stuff. if ur gonna leave it in the water a long time use this boat bottom paint. otherwise i recomment sticking to the basic drylok for ‘less-than-6-hour’ excursions.

    update:

    use the basic drylok. get 4 single gallons and do 2 coats. you can use a full size 9″ roller with a 3/4″ nap.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    wow, awesome!

    hey, I couldn’t quite drag my boat out of the water,

    though next rainstorm the water level will rise,

    and anchor is set on the dry, so it’ll move over.

    I think I only have money to buy at most a single can of the stuff at the moment.

    Anyways, question is, can I apply the Drylok on wet concrete? or would I have to wait for it to dry some?

    I’m thinking of cutting up some scrap tires and using them as bumper-padding material.

    calm aware desire choice love express intuit move

    #15251
    Avatar of shredder7753
    shredder7753
    Participant

    i would choose something other than garage floor coatings. theres no advantage of using that over the ones i recommended. drylok will give u only 100 sq ft of coverage per gallon (1/4 of regular paint). if u only get one can – uh… just put it on the outside – for now.

    cutting scrap tires is easier said than done. them shits be radial. ie – they have steel wire inside the rubber. maybe some foam pipe insulation would be better – attach it with a waterproof masonry sealant (instead of adhesive). or just use no padding. what would it protect u against?

    i would give the concrete at least 12+ hours dry time between taking it out of the water and applying paint.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #15254
    Avatar of elspru
    elspru
    Participant

    shredder7753 wrote:

    i would choose something other than garage floor coatings. theres no advantage of using that over the ones i recommended. drylok will give u only 100 sq ft of coverage per gallon (1/4 of regular paint). if u only get one can – uh… just put it on the outside – for now.

    ya, the book I read, says to only paint boat once it’s cured for a long time, and then it’s best to do just the outside, as it’ll sweat on the inside for long time before can apply inner-coat.

    the surface area of a 6ftx4ftx2ft box is 88ft, so should suffice for the boat :-).

    cutting scrap tires is easier said than done. them shits be radial. ie – they have steel wire inside the rubber.

    hmm, maybe some bolt-cutters would do it?

    maybe some foam pipe insulation would be better – attach it with a waterproof masonry sealant (instead of adhesive).

    is there a particular you’d recommend?

    I saw a polyurethane tub-sealant in canadian-tire,

    seems to be one of the few waterproof ones,

    though I guess there is the one you used on your boat,

    you called this link the “adhesive” so I assume you mean a different one, http://www.homedepot.com/h_d1/N-5yc1v/R-202533510/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053 link.

    or just use no padding. what would it protect u against?

    I’m planning on taking it down the river, there are lots of rocks, and concrete dams I gotta get my dinghy over.

    i would give the concrete at least 12+ hours dry time between taking it out of the water and applying paint.

    okay assuming it rains wednesday, guess I’ll apply paint on thursday or friday.

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    calm aware desire choice love express intuit move

    #15256
    Avatar of shredder7753
    shredder7753
    Participant

    concrete normally takes about 30 days to cure. of course the hoover dam is so thick that the concrete is actually still not cured. but i only let my berg dry for like 5-6 days before putting 2 coats inside and out. so far, no problems. you will notice that it wont look completely white with just one coat.

    heres some sealant to use as an underwater ‘glue’. i havent tried that actually, but if i was in ur shoes i prob would. you DONT need $20/tube stuff – i didnt like the tube it came in, doesnt mix efficiently.

    dont forget ur racing stripes! lol

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #15259
    Avatar of OCEANOPOLIS
    OCEANOPOLIS
    Participant

    two types: bottom paint (for the bottom, bellow the waterline) and topside paint (above the waterline). Both tend to be expensive, specially if you buy from West Marine or Boat US :) So, see if there is a chandlery in your area and go shop for deals. It also depends if you are going to keep your dinghy in the water at all times or just once in a while, launch and use. For your dinghy bottom ( if you keep in the water) 1 gallon will do, maybe some cheap antifouling bottom paint. 2 coats, roll them thick, don’t spread it too much. If you don’t keep in the water at all times you don’t need bottom paint, just the same topside paint.

    For topsides, an epoxy based is the best. Also 2 coats over 1 coat of thick primer.

    The best sealant for marine use is 3M’s 1500. Damn expensive but it will cure underwater.

    PS. Should check the hull for cracks, leaks, etc and patch. Then sand it down to a smooth surface before painting using different sanding paper grids, from low to high. Then wash down, dry and then paint. If using bottom paint use a mask and don’t let it splash into your eyes, it’s highly toxic.

    #15260
    Avatar of shredder7753
    shredder7753
    Participant

    spru has a budget of $23

    ____________

    My Work II

    “Leadership and do-ership are not the same thing”

    #15261
    Avatar of OCEANOPOLIS
    OCEANOPOLIS
    Participant

    maybe a gallon of any cheap paint at Home Depot :) In fact, Spru doesn’t really have to paint that dinghy, it’s cement,…lol.

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