Best Epoxy for *Hand* Layup??

Discussion in 'Materials' started by CatBuilder, Nov 25, 2010.

  1. sabahcat
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    sabahcat Senior Member

    The sheathing on this style of strip plank actually holds it all together
    No real strength without the glass

    For abrasion, it gets several more layers of glass
     
  2. CatBuilder

    CatBuilder Previous Member

    Some more... in red.

     
  3. PAR
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    PAR Yacht Designer/Builder

    There are about a dozen (actually more) distinctly different strip plank methods Sabahcat. most have a balance of laminate and wood core, though there a a number that are more narrow carvel with light sheathings, then true wood core or composite build methods.
     
  4. sabahcat
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    sabahcat Senior Member

    I realize that
    But for Lightweight construction
    Using lightweight core
    I, and many many other multihull builders and designers would suggest that it needs the glass for actual strength, not just abrasion resistance.

    Do you have any links to light multihulls that have been strip planked without the use of glass for strength?
     
  5. sabahcat
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    sabahcat Senior Member

    Fair enough, my mistake taken from your comment here
    Lets just say that I had two hulls planked and glassed in less than the 9 months you have spent so far on your ply ones.
    And I did it all myself, apart from the roll over
     
  6. Steve W
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    Steve W Senior Member

    Sabah, as i recall you built your cat in the very common Kiwi/Aussie strip plank composite method which has no internal framing (apart from bulkheads and furniture etc of course) and uses structual glass inside and out,much more akin to any other core boat than traditional strip planked boats.Would you mind sharing the layup with the members of the forum, i seem to remember 16mm kirri core?
    Steve.
     
  7. waikikin
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    waikikin Senior Member

    Catbuilder, dont be afraid of going full length, the fabric roll is generally 50" or 1270mm wide, it's not that hard, cut your lengths say 1-2 foot overlength, (this probably wont work with pre wetting- exotherm!) & roll onto a length of pvc pipe, support the roll on a "carraige or such- crane etc -hang vertically with a swivel- with an oversize endplate of plywood on the bottom to support the roll & work along the length of the hull- backwetting the core & manually wetting out 1-3 feet of fabric at a time depending on your speed & consolidate as you go- match your resin batch size to your rate of progress, maybe only 1.5-3 kgs at a time.
    Do yourself a small time & motion study- invest a few bucks in resin & microballooons/primer/polyU -on cd ply say a meter or two long x the roll width- do a layup & then fair & paint through to gloss, this WILL be easier than the boat itself but will give an idea of layup speed & also very importantly what it takes to take a raw laminate thru to a gloss "finish"- this later part is tougher than the laminating although the level of finish required varies greatly with what You are happy with- get an idea of the square meters of vessel this will apply to- in that the square meters relate to each other in a fair sense with some extra F factor for overlaps & internal corners etc.
    All the best from Jeff.
     
  8. CatBuilder

    CatBuilder Previous Member

    Jeff: This sounds like a plan. I'll create a sort of thing that can hold the roll in place while I do the longitudinal layups. I'll do you like you said and test it out ahead of time on some cheap insulation type foam from the hardware store, attached to some plywood. Nice idea.

    Now, I have to get to work reducing my core costs a bit. I can't (or shouldn't) try to afford Core Cell for the entire boat.

    Possibly, I can use balsa on the deck (easier to bed things anyway) and on the deckhouse and keep the hulls as Core Cell. I think Core Cell is the only foam that will work well with the male mold building technique. It is rigid enough.

    The one hitch is I will have to be fast or work many hours a day. I have to do two lower layers of 50", then one upper layer, or 3 full length, 50" layups in a shot to avoid sanding in between layers.
     
  9. Landlubber
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    Landlubber Senior Member

    CatBuilder, don't try to do it on your own mate, just get some help for the time it takes to do the job, the poor man pays twice remember, so don't waste materials and time trying on your own, too big an area to do it alone.
     
  10. CatBuilder

    CatBuilder Previous Member

    Thanks, Landlubber. I'll be careful. With the roll holder, I should be able to get away with only hiring one guy, which is a lot better than a huge team. The easier I can make it so that I could *almost* do it myself, the better for unskilled helpers, I think.
     
  11. Landlubber
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    Landlubber Senior Member

    ...yep, good one mate, even just one fellas will do the job, correct, on your own, you cannot ever get the scissors that you left on the table.......
     
  12. Landlubber
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    Landlubber Senior Member

    ...you will be wearing those thin gloves won't you...and did you know that you can wash your hands with white vinegar if (when) you get epoxy on them.....much cheaper than solvents and lots less trouble with the skin.
     
  13. CatBuilder

    CatBuilder Previous Member

    Yes to all! :D

    I used vinegar when I made the last hulls and it worked very well. I have no solvents in the shop, only vinegar.

    I am quite careful about the exposure. I used a respirator, goggles and gloves and did not track any epoxy (or especially hardener!) back into my living area from the shop.

    I figure an epoxy allergy would be the biggest disaster that could befall this project other than hurricanes or tornados.

    I seemed to get epoxy on my wrists most. It is the hardener that really bothered me when I got some on my skin. it itches like crazy! Until you scrub some vinegar on it.
     
  14. waikikin
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    waikikin Senior Member

    It is pretty tough shorthanded or on your own although quite possible, valid point Landlubber, also for personal safety/ resin splash etc.
    Catbuilder, Before a big layup you have to "empty out" or suffer the consequences! Having good prep & every thing to hand is essential, when you consider the value of glass & resin & core your applying to, a bit of labour is insignificant. The heavier triax fabrics take some work to wet & consolidate nicely, so do a trial, especially on fairing- finishing "one off" foam boats beats a lot of people & they end up paying others to do it. All the best from Jeff.
     

  15. War Whoop
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    War Whoop Senior Member

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