Fixing and painting fiberglass coated boat -How?

Discussion in 'Wooden Boat Building and Restoration' started by louischallies, Nov 30, 2013.

  1. louischallies
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    louischallies Junior Member

    Hi all,

    My experience with boating doesn't extend much beyond the odd fishing trip, and my experience with boat restoration is non. But I figured the best way to learn is to do it. I am purchasing an old wooden boat with a trailer and it needs some work doing on it. The boat is wooden but has a shiny coating. There is a hole in this thin coating and I can see strands leading me to think this is fiberglass sheathing, would I be correct? The diameter of the hole is around 20cm. Anyway, would I be able to fix this area using epoxy and then fiberglass cloth? Also, how would I paint the rest of the boat? Would it have a gelcoat or not?

    Basically, I want to fix the hole and if necessary, repaint the boat. Your help would be much appreciated.

    Regards,

    Louis
     
  2. PAR
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    PAR Yacht Designer/Builder

    Welcome to the forum Louis.

    Yep, it's very likely the boat was skinned or sheathed with 'glass and a plastic resin of some sort. Lets hope it was epoxy and not polyester. Posting some pictures would help, but more importantly would be to grind down some of this 'glass sheathing to see it's color, which will give a good indication of which resin was used. A greenish/blue color indicates polyester, while a yellowing color suggests epoxy. The smell of the sanding process is often the real giveaway, but you've never smelled the two, so . . .

    There are many previous threads about these types of repairs, so spend a few hours reading up on the techniques, materials and processes.
     
  3. louischallies
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    louischallies Junior Member

    Thanks for that :)

    I'll have a look around the forums. I will get a pic up asap.

    What's the deal with painting this stuff?
     
  4. PAR
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    PAR Yacht Designer/Builder

    Painting these surfaces is all about prep and how much durability you want to pay for. Real tough paint starts in the few hundred a gallon range. Most don't spring for these paint in a driveway job, so this leaves the single part polyurethanes, modified alkyds and acrylics as the descending list of durability. The prep techniques will all be similar with some products requiring a really good primer, while other none at all.
     
  5. louischallies
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    louischallies Junior Member

    Ok thank you.

    Very last question, since I wouldn't be using the boat a lot (I really doubt more than once a month) would I be okay to use normal acrylic housepaint over a primer? Would some type of sealant over this be necessary. Many thanks for you help
     
  6. PAR
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    PAR Yacht Designer/Builder

    No sealant is necessary and lots of folks use house paint, though Porch and Deck enamel is tougher than regular house paint. Also gloss is tougher then flat (by a lot).
     
  7. michael pierzga
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    michael pierzga Senior Member

    Best to use epoxy primer under water , then a paint system of your choice for the hull and components.

    If the boat will be in the water for a week or two this epoxy Copper coat stuff for underwater surfaces is just fantastic..it lasts for years and gives a good antifoul for trailer sailers or part time boats afoat.

    Coppercoat is a trade name..check in your region for similar

    It goes on as a bright copper colour then ages into a greenish copper colour

    http://coppercoat.com/
     
  8. djaus
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    djaus Salted Nut!

    Hi Louise.

    I'm no expert but here's what I suggest, get some expert advice on what type of resin was used, maybe take a small sample from the damaged area to a shipwright or marine engineer or similar shop.

    Depending on where the hole is & if the hole is in a spot that would be visible from inside the boat my approach would be to use sheet ply (as broad a sheet as possible) to place on the inner hull to cover the hole, glue it down & resin/fibreglass over it.
    Then cut another sheet to the size of the hole & glue it to the new inner sheet, from the outside. This will give you the ability to make the patch a flush finish with the exterior of the hull. Coat with glass matting & resin to finish the outer layer, sand it flush & coat with resin again if needed.

    If you can't flip your boat upside down to perform repairs then I would use a sheet of ply (larger than the hole) to cover the hole (from the outer side) & perhaps use temporary screws to hold it tight against the hull. Make sure you place some heavy duty plastic between the ply & hull so resin doesn't stick to it.
    Once this is done apply the same procedure as I mentioned before but do it in reverse. ie: cut a plywood patch the same size as the hole & resin & glass it in place from the inside.
    Preferably while the resin is still wet repeat the process but with a larger sheet of ply on the inside, resin coat both sides (between patch & inner larger sheet). Then once it's all hardened remove the outer sheet of ply, glass & resin over the patch, & the screw holes. If your dealing with curved surfaces I would just add more matting & resin from inside to bolster it & add strength instead of using another larger sheet of ply, you don't want air trapped between the 2 surfaces.

    The most important thing to remember with fibreglassing is to apply the resin with a small roller to eliminate ALL air bubbles under the glass matting & resin. Thanks to PAR I was made aware of "Bloom", this is a slimy coating which is left on the surface of the hardened resin. Wash it off with warm soapy water before sanding & painting.

    I started the "Hartley Flareline 16" thread here in the wooden boat section & had to perform a similar task to re-inforce some previously repaired damage on the hull. See here for the first of 3 videos I uploaded to YouTube regarding the patch job http://youtu.be/3fBfH5s1Z3U

    What type of boat are you fixing? We all love pictures here.
    My thread might be helpful plus there's an excellent fibreglass section here on boat design in the boat building section.

    When I paint my Hartley I plan to use oil based super enamel on the hull & an acrylic semi gloss for the deck & cabin. (to cut down on reflective glare & cost's!). Texture deck coat or grip tape would be advisable too.
     
  9. louischallies
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    louischallies Junior Member

    Thanks for the responses. I'm sure you could tell me exactly what I need to do if you had a photo so I'll get one up soon. djaus, the hole I'm talking about is only in the (thin) fiberglass sheathing rather than right through the boat, I'm guessing the repair would be similar to how you said but just put some patches of fiberglass over the hole and then epoxy and sand over that. Nice video by the way.

    For painting of been looking at some acrylic 'Solarmax exterior house paint' which is meant to be really tough. Its also self priming. Sound ok? I'm guessing I'd sand before painting so the new paint sticks right?
     
  10. michael pierzga
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    michael pierzga Senior Member

    Hmm

    Primer.....

    The reason you use primer before top coat is to give an easy to sand base.

    A typical routine would be one or two thin coats of primer...sand and patrol for surface imperfections....fix them, prime again....sand lightly, then topcoat ..

    As for fixing your hole...hard to visualize but epoxy is your friend. If the glass sheathing is damaged , remove the section. If the sheathing was in a high wear zone, replace the sheathing..

    Always prime bare wood with epoxy...fill the hole with epoxy filler...sand flush and then you are in painting mode.

    Housepaints are durable...nothing wrong with them

    Many of the cheaper two component marine paints are worth considering.

    Two component dries very fast. As a result you can rapidly build coats day after day and the job goes faster.

    Your choice..they both will get the job done and be durable
     
  11. SukiSolo
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    SukiSolo Senior Member

    Check the timber under the glass reinforcement is sound and DRY. Make sure it is dry, patch and feather in (new glass) and seal with resin, epoxy is best. Paint should in my opinion be a marine one pack polyurethane as it will sit on any substrate paint without a problem (very rare to get reaction) whilst other systems can react with each other. If you know what type of paint is already on her you have an advantage.

    None of the household paints here in the UK are good enough for marine use.
     
  12. djaus
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    djaus Salted Nut!

    Sounds like both our boats had the same problem. Mine didn't have a hole (probably was in the past just not my doing), it was just a section of fibreglass had separated from the resined hull plywood skin.
    I scraped away the loose matting, sanded flush to get rid of all the lifted edges, then resin, matting & more resin. If I run my hand over the patch I can feel a slight "bulge" but i'm not fussed. It's on the under side & besides so long as it's strong enough to withstand severe hull slap when planing....which it does.
    I've come of a few waves & landed flat in the trough & so far no new damage.
     
  13. louischallies
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    louischallies Junior Member

    Yeah had a look through your video's and had just heard you talking about what you mention here. Looks like mines the same. Sounds like a relatively straight forward repair job. There's a rim that runs around the outside of the boat that is just wood, it seems to have a few cracks in it and am worried water will get in and damage the wood. Would you suggest I go ahead and fiberglass the rim while I'm at it? Real nice boat you got there mate. Hoping to be out on the water myself soon.
     
  14. PAR
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    PAR Yacht Designer/Builder

    The "rim" as you call it is a rub rail and by their nature, is considered a sacrificial element, to be replaced when it gets torn up. For this reason, you don't 'glass it in. It's likely the finish has been "exposed" to the weather for too long and is showing signs of this. Also, if they sheathed this boat, without removing the rail first, it's very probable that moisture has gotten behind the sheathing at this interface and you have more delamination issues than you realize. Post a picture of this area as well.
     

  15. djaus
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    djaus Salted Nut!

    PAR also made me aware of the issues surrounding rub strips. Certainly don't want to glass over those. The rub strips on my boat sure do get a work out at my local pontoon/ramp, mainly the upper one on the outer edge of the gunwale.

    I plan on fitting a length of rubber or PVC to these so in future it doesn't matter if they "rub" anything.

    With my lower rub strips I plan to just run a bead of glue (liquid nails in my case) along the edge where they join the hull. In theory this will keep water out but ensure they're easy to remove if I ever need to. On my boat the rub strips are attached to a section of hull that has a stringer on the inner hull so I imagine it would take some time to get water into the hull timbers...maybe.

    The person that built mine glassed the hull before fitting rib strips but then chose to fit them with screws that go through the glass, that's a no no!
    So I just need to keep an eye on them in regard to deterioration.
     
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