Epoxy Method and Protection of Epoxy

Discussion in 'Boatbuilding' started by tontoOx, Apr 25, 2021.

  1. tontoOx
    Joined: Feb 2021
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    Location: Australia

    tontoOx Junior Member

    Thanks. So would I wet out the cloth on the wood, wait say a day for partial curing and then do a second coat with the silica in it? Is this the scratchproofing? Silica is hard but what purpose would micro-baloons be (baloons are hollow aren't they)?


    To kerosene: Thanks, so one layer inside bottom, two layers external bottom.
     
  2. latestarter
    Joined: Jul 2010
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    Location: N.W. England

    latestarter Senior Member

    An inexpensive alternative which I have found invaluable is a Stanley Surform Shaver. The the epoxy comes off as shavings, no noticeable dust.
    https://www.totaltools.com.au/65299-surform-shaver-tool-521115
     
    Blueknarr likes this.
  3. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Neat (little to no additives) wood.
    Let set.
    Second neat coat lay glass on wet then wet out glass with more resin.
    Peel-ply (ask supplier) at edge of any future overlaps.
    Silica is a thickener. You can add a little to keep the resin from running, or add a lot to make a hole filling paste. Make it harder to sand.

    Micro-baloons are hollow. They thicken the resin but it still will be runny. Makes it easier to sand smooth.
    Thicker (heavier) glass is the protection against dragging for kilometers. This is why kerosene suggests two layers on exterior
     

  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Light woven glass does not form over square edges. All edges must be radiuses, minimum 1/4". For a planing hull, the transom, at a minimum is returned to square with fairing.

    Fumed silica is a bear to sand and is only used where sanding is not needed or a very hard edge is desired. Like a transom edge rebuild to square or fillets between panels where you tape immediately after filleting.

    For those woven fabrics, they can be wetted down through the fabric which has been laying on the boat overnite allowing gravity to shape a bit.

    The typical next day procedure is to neat coat to fill the weave. A neat coat is mixed epoxy applied at about 2 oz per yard. Use a 1/4" or 6mm nap or less roller. Something about 3-6" wide is nice to work with. The epoxy must not be applied to thick or it'll run. Two neat coats typically fill the weave pretty well, bit for a pristine finish, you may decide to sand high spots and the entire boat and do a third.

    A block plane is typically not used for ligjt sanding of wovens, but for humps or drips. I rarely use a chisel or plane and mask when sanding or facing a viral pandemic.

    ps-do not use silica in your finish coats; it is not for amateurs to experiment with...I have messed with it and do not enjoy the associated work..you want a hard and smooth surface with the correct mechanical key for paint and will have that with epoxy alone...if you are planning a lot of beaches or oyster beds a bottom alternative is graphite in epoxy..
     
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