a pointless boat

Discussion in 'Boatbuilding' started by Tungsten, Jun 9, 2012.

  1. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    I have everthing i need now to build so i thought i'd keep a thread showing progress.
    I've cut the dovetails in the foam to extend the floor to 10'.Glued, clamped,scraped and sanded.
    [​IMG]
    [​IMG]

    i'd really like to glass the inside of the floor first before i stitch the sides.
    Unfortunately i didnt do a big enough test piece to see just how flexible the foam is with one side glassed so,do you guys think i could put 2 layers of 12oz on one side flat on a bench then be able to curve each end up slightly say 5-8"?
    or should i build a form supporting the foam up a little on each end then glass it?
    This is 1/2" foam and all the glass will be layed by hand with epoxy.

    just for demo purpose,

    [​IMG]

    the floor is longer then i need so screws can go threw the foam on each end to hold in place.Also each end will be cut to a curve to create rocker so screws can go there also to hold it all down.

    the form would be built with support underneath to hold the foam as i apply the glass.

    This is the only thing holding me back from progress so your help would be much appreciated
     
    2 people like this.
  2. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    dovetails are a waste of time mate, just butt join them... all the strength is in the glass skins, the foam core is only there to keep the skins apart, so the type of join in the core doesnt matter - sandwich panels are not like working with plywood or any other homogenous material.

    if you glass 1 side of the foam, you should be able to bend a 2D curve no problem. However, a 3D compound curve will be impossible, in which case you need to shape the foam first before glassing it.
     
  3. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    ok thanks groper,also i can just use a pencil to mark out the lines yes?then just sand them off before glassing.
     
  4. troy2000
    Joined: Nov 2009
    Posts: 1,743
    Likes: 170, Points: 63, Legacy Rep: 2078
    Location: California

    troy2000 Senior Member

    Always a pleasure to see another build thread starting. Looks like you're off to a good start; keep us posted.
     
  5. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    i actually use a pen to mark my foam.... or a chalk line for long straight lines... i dont bother trying to remove any of it before glassing, think about how much surface area is actually affected by a line...
     
  6. rwatson
    Joined: Aug 2007
    Posts: 5,852
    Likes: 290, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Yes, not much area, but if you have a 3 foot line, 1/8' wide that separates glass from the foam, it allows a film of water to lie there - and may gradually work itself larger.

    It may not happen, depending on its position and the glass strength, but it might.
     
  7. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    spent sometime building a bench with wheels today,this will make things handy being able to move it so i can park my truck.

    [​IMG]

    layed some plastic and finished getting the glass on the inside followed with some peelply.I'll mark out the lines after its cured and cut it out with my jigsaw.

    [​IMG]
    it was 62f when i layed the glass 2 of us got it done in 35 min.

    i could get the temp to 90F any benift in doing that? i have it at 70 right now.
     
  8. rwatson
    Joined: Aug 2007
    Posts: 5,852
    Likes: 290, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member


    Nothing wrong with leaving the high temp cure till the whole boat is done, but it may have benefits to do it during the build process.
     
  9. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    I just looked 83F right now on the bench.I think i'll leave it.Good thing gas is cheap.

    thanks,
     
  10. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    ok so the floor is easly bendable now that its cured,

    [​IMG]

    When i first started this build i built a 1/6 model,then i went full size with some 1/8 hardboard to see if its all right and looks good.So after the foam floor cured i played with the model again getting the floor shape right then traced it onto the foam and cut it out.the peelply works good for the pencil lines.

    So after the floor was cut i returned to the model pieaces stiched one side on and lined up my laser level to trace a line to create a flat sheer since this boat will be loaded onto my roof rack.

    [​IMG]

    cut the sides and put the model back together.
    [​IMG]

    [​IMG]

    didn't quite get the sheer flat but a little fine tuning and it will be good.so now i have full size templates and can cut out and glass the sides and end panals.
     
  11. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    So next up is stiching,with glass only on the inside the wires will start to pull threw the bare foam as i tighten them.i tried a little square of ply with a hole for the wire worked ok.is there a better way?
     
  12. rwatson
    Joined: Aug 2007
    Posts: 5,852
    Likes: 290, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Is there too much tension for hot-melt-glue ?
     
  13. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    One thing about the wires is it still gives a little play with the beam measurement so the side to floor angel has to be able to move a little.So no glue wont work.They'll be a lot of tension on the sides as well so more wires and i guess little pieces of wood as washers will have to do.
     
  14. rwatson
    Joined: Aug 2007
    Posts: 5,852
    Likes: 290, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Have you thought about just applying the foam to the outside of your mdf test model ( temporarily holding it place with wires etc ), applying glass to the outside, and then removing the mdf on the inside for glassing ?
     

  15. Tungsten
    Joined: Nov 2011
    Posts: 468
    Likes: 10, Points: 18, Legacy Rep: 75
    Location: Canada

    Tungsten Senior Member

    now thats a good idea,only a couple of problems.one ,i through out the model pieces already they're 1/8" hardboard and they omit a bit of a foul oder.two, they were so flimsy they wouldn't have supported much.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.