Boat Advice Wanted !

Discussion in 'Fiberglass and Composite Boat Building' started by Captain Churl, Mar 25, 2016.

  1. Captain Churl
    Joined: Mar 2016
    Posts: 1
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: UK

    Captain Churl New Member

    Here's my fibreglass 9ft x 4ft boat. Yes, it's a mess, it's a long story.
    Has been used as a rowing boat, in freshwater, is kept on the shores of a lake.

    Condition of the vessel.
    Hull (exterior)
    Gel coat removed.
    It's been angle ground down to bare fibreglass on the hull.
    Its got Ultima (poly) filler on the port side of the hull, Starboard side is exposed fibreglass.
    Got some poly filler on the bow to reshape, the chunks missing, etc.
    Old Keel still needs cutting off (it's holding the boat rigid), resin removing, replacing with a new plank, resin into place with roving, etc.

    Deck needs laminating for strength, waterproofing, etc.
    It's had a few holes and slits (5-10cm) patched with poly resin / CFM/ cloth tape.
    Gunwales need levelling up. Trim fitting.
    Plywood transom fitting.

    Here's the materials I have to fix it.

    10m of Roving cloth (260g)
    50m of 3" Roving Tape
    10kg Epoxy Resin (don't have this yet)

    25m of CFM (300g)
    25m of surface tissue (30g)
    12 kg of Poly Resin

    8mm Marine Plywood (1.5m x 1m)

    Ultima Filer x 1 tin (poly)
    Hempel Epoxy Filler x 1-litre tin
    Hempel High Protect x 2 (750g tins)
    Hempel Light Primer x 2 (750g tins)
    Hempel Poly Gloss x 1 tin
    Hempel Thinners No 5 x 1 tin
    Hempel Thinners No 1 x 1 tin

    My plan
    Fill rest of hull with Epoxy or Poly Filler?
    Remove old Keel and resin remains, angle grind all smooth.
    Cover Keel area with roving cloth and epoxy.
    Put new Keel wood plank in, cover with roving and epoxy.
    Fill rest of hull with epoxy filler.
    Paint hull with Hempel products, to seal it all.

    Q1. Should I cover the whole Hull in Roving cloth and epoxy resin (is this overdoing it ? ) before finishing with Hempel products?

    Q2. Could I use Poly Resin and CFM to seal in new the Keel? Then start with Hempel products.

    Inside of the boat needs some work, and I'm thinking of laminating it with CFM, roving cloth, surface tissue, and poly resin. Sand it all down with 80 grit
    then paint over with epoxy Hempel paints as above.

    I've read on the forums that epoxy is superior poly resin etc., I don't have epoxy resin at the moment.
    I've also read that epoxy sticks ok to poly resin so that I could get away the above methods may be?
    Do I just buy the epoxy resin and use epoxy resin for everything? (the budget running low)

    Any tips / advice ?

    Attached Files:

  2. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 27, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    Personally if I was doing this, I'd stay all polyester for the main repair work - the boat has very little value. In fact I'd probaby roller flowcoat (gelcoat) over it, cut and polish. Alternatively polyester repair and seal then One Pack poly (gloss) the paint on, 2 maybe 3 coats. It's only worth undercoating any non gelcoated bits to get a fill in any little pores etc and get a better level. Just make sure any exposed fibres are resin sealed first.

    It's not worth using expensive epoxy or too much (expensive) paint, but that is my personal opinion. You'll also find that flowcoating it would actually be cheaper and likely more long lasting. If necessary practice on a small piece of scrap before doing the job and do NOT mix up too large a batch - polyesters cure quite fast. So you will have only 15-20 minutes to roller it on then start with a fresh batch. That's probably enough time to do half the outside of the hull btw, but you will need to work fast.

    One thing worth doing is making sure the hull really is dry before repair and/or coating.
  3. Jamie Kennedy
    Joined: Jun 2015
    Posts: 541
    Likes: 10, Points: 0, Legacy Rep: 117
    Location: Saint John New Brunswick

    Jamie Kennedy Senior Member

    I would also stick with polyester. It can be challenging, but once you go epoxy you can't really go back. Polyester can save some time also, as well as money, so it's good to work on those basic skills. I use epoxy too much, and so I am trying to do more with polyester.

    Q1. Should I cover the whole Hull in Roving cloth and epoxy resin (is this overdoing it ? ) before finishing with Hempel products?

    - I think this is overdoing it. I think you can get the stiffness and strength and durability you need with the skin that's basically there, repaired, plus maybe a little more thought into the keel. Maybe a keel-keelson combination where you have a piece of wood on the inside to correspond and fasten through the skin to each piece of wood on the outside. Rather than glass over the wood, perhaps epoxy and varnish. Besides looking nice it allows you to see the wood and keep an eye on it's condition. Maybe a strip of metal over the bottom of the wood as a rubbing strake. By having wood on both sides, besides supporting one another, they also serve the practical purpose of permanently clamping the fibreglass skin back into a straight flat panel so you don't have to rely on clamping it straight and hoping the glass over the wood keeps it straight. You would need inspection ports in order to install the backing to the outer rubbing strakes, but these will also give you some access for storage, and to bail out any water and to check for leaks. I am not sure you need all 5 runners. Maybe 3 will do. The other ones could be on the inside or the outside of those side take and help reinforce the joint there.

    Q2. Could I use Poly Resin and CFM to seal in new the Keel? Then start with Hempel products.
    - I would leave these as exposed wood, epoxied and spar varnished. I would screw down from the top strakes into the bottom strakes, I would predrill and the screw, and then remove the screws and epoxy and screw again. The epoxy might make it harder to remove the screws, but I think is necessary to seal the wood. I would use size up the screws so as to be able to remove them without them sheering. I'm not sure I would epoxy the wood to the fibreglass though. I think I would finish the boat flat bottomed, with whatever you are sealing and painting the bottom with. I would epoxy and varnish the wood on all sides even the sides going against the bottom, inside and out. Then when I put the wooden strakes on, after dry fitting and dry screwing, I would use something like 5200 between the varnished wood and the sealed and painted bottom, and epoxy in the screw holes.

    Someone might chime in on these ideas. There might be a better way to attach wooden keels and keelsons, and things like gunwales, onto fibreglass boats.

    p.s. So I looked at some videos on folks repairing or replacing wooden gunwales on fibreglass canoe. I am not sure they use any adhesive at all other than where the screws are. The reason I don't want to use epoxy is because I want to be able to remove them, so I seal and paint or varnish the wood and fibreglass independently and then screw them together, only sealing again where the screws are. I though there should still be something between the epoxied and varnished wood and the polyester resin and polyurethane painted or gelcoated hull. Even 5200 might be overkill, making them too hard to separate for eventual repair or replacement. I don't like the idea of using nothing, especially below the waterline, because water will get in their and do some damage over time even if both sides are well sealed. Not sure of best seal or adhesive that would still allow removal. Anyone?

    p.p.s. I think I found the answer and the answer is 4200. 4200 is ok below the waterline, in this case, and it allows the later disassembly of the parts. 5200 would not.
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