Advice on resins and fiber glass

Discussion in 'Fiberglass and Composite Boat Building' started by Outwith Jack, Aug 5, 2020.

  1. Outwith Jack
    Joined: Aug 2020
    Posts: 5
    Likes: 1, Points: 3
    Location: Ireland

    Outwith Jack Junior Member

    And so it begins, so many questions !
    Before I ask anything, I've looked at previous posts , as suggested. Some I don't understand the technical terms and some I don't think help me !
    I will add photo's to show how I started and later after some sanding of the hull. Ive not even started on the inside yet.
    My idea ! 1. Sand all the outside, getting rid of lumps of resin that was poured over gloss paint job. Also sand off all gloss paint back to original fiberglass or gel coat.
    2. Use epoxy resin mixed with silica to fill large holes and screw holes.
    3. Epoxy bottom of boat and add one layer of csm, then one layer of fiberglass cloth, then 2 more layers of csm. This will be to strengthen the hull which appears very thin.
    4. Under coat and top coat.
    My question ! 1. As i am not sure what type of resin was used before, Epoxy will go over other resins ? Polyester won't ?
    2. As I'm working outdoor in Ireland, its never hot and often wet. Is Epoxy the best in this weather ?
    Please be gentle with your answers !!!!
     

    Attached Files:

  2. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    A lot of questions there, and it is always a lot easier to assess such things, "on the ground". Firstly, I would say your boat is almost certainly made from Orthothalic Polyester, the cheapest way ! Fibreglass often gives the impression of being alarmingly thin, which it may be in some cases, but the flexibility (lack of stiffness) of it, goes a long way toward creating that impression. I'm not sure how "lumps of resin" ended up on the outside of paint. I would be looking for cracking in the bottom, if you don't find any, it is a sign that it is strong enough. At the moment, it requires you to survey the bottom thoroughly for signs of such stress, before thinking what to do next.
     
  3. Outwith Jack
    Joined: Aug 2020
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    Location: Ireland

    Outwith Jack Junior Member

    Thanks My Efficiency....... The boat, at some stage has had a gloss paint brushed on and I'm guessing after that some one has decided to do repairs with resin and in some places a little fiberglass added.... Most of the patches were lifting enough to get your finger nail under the edge, the larges being around 10 inch wide and a quarter inch proud of the surface of the boat. This patch, along with every other has been sanded down to find fine cracks or chips in the gel coat or original fiberglass. The layers were always the same. Gloss paint/ Resin/ Gloss paint/ Gel coat/ Original fiberglass.
    The attached photo's show the above patch before and after.
     

    Attached Files:

  4. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Stop immediately, your suggested plan is not the route you want go.

    I'll explain a bit more soon when I get time.
     
  5. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    You may need to be a forensic scientist, to work out what a succession of tinkerers have done to some old glass boats, this is made immeasurably more difficult if having been painted over, which of course the motive for, is often to hide the "multitude of sins", and worsened by the fact, that it is effective in doing just that ! In some cases, if inside access is available, and there are doubts about structural integrity, that is a lot easier place to add it, especially if the painter has not been at work inside.
     
  6. Rumars
    Joined: Mar 2013
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    Location: Germany

    Rumars Senior Member

    I think this is the right project for someone wanting to learn about sandblasting, gelplanes, and all the different sanders available on the market.
     
  7. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Be patient with ondarvr. He is a wise old owl on glass boats.
     
  8. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Your boat is made from cheap polyester resin, you could use epoxy to add more glass, but its not really going to make a difference. Polyester will do everything you need for this project.

    The amount of glass you wanted to add is over twice what's needed, and the wrong types.

    Doing it from the inside if possible is better, it takes lot of work to get the outside looking good again after adding multiple layers of glass.

    At most one layer of 1708 and one layer of CSM added to the inside will make an incredible difference.

    Don't grind all the way through anywhere before glassing, you can grind down to remove some of the damaged glass, but you want to retain the original shape.

    36 grit paper on a small grinder will be your friend for a while. Grind off all the paint, and most of the gel coat, don't stress over getting 100% of it off.
     
  9. Outwith Jack
    Joined: Aug 2020
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    Location: Ireland

    Outwith Jack Junior Member

    Thanks for your advice.
    I can glass the inside, no problem..
    The photo is the stage I'm at.
    I believe the top comes away from the bottom at the rubber fender.
    Thanks again.
     

    Attached Files:

  10. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Don't take the deck off!

    The deck is keeping the hull from drastically changing shape.

    It looks like it's possible but a bit tricky to add a layer of glass with the deck still in place.
    You can use smaller pieces of cloth. It doesn't have to be a single piece of cloth.

    As Ondrvr directs:
    Maintain shape and add rigidity will FG to the inside. Then repair any cracked original FG from the outside. Finally fair and paint.
     

  11. Outwith Jack
    Joined: Aug 2020
    Posts: 5
    Likes: 1, Points: 3
    Location: Ireland

    Outwith Jack Junior Member

    Thanks for the advice :)
     
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