Loading ...
Sorry, an error occurred while loading the content.
 

Re: [Michalak] Re: Bad fiber butt joint

Expand Messages
  • Andre Basso
    Thank you Brian. Nice procedure. I m following Payson s method and did fine for all but this one. My fault as I didn t wet the fiberglass properly and should
    Message 1 of 6 , Mar 6, 2013
      Thank you Brian. Nice procedure.

      I'm following Payson's method and did fine for all but this one. My
      fault as I didn't wet the fiberglass properly and should have chosen a
      heavier weight.

      I decided to sand it off and redo one side of the joint. Better to step
      backwards now instead of discovering a failure in the future.

      Blog updated: http://umveleirosimples.blogspot.com.br

      Regards,

      Andre.

      On 05-03-2013 14:02, owwin@... wrote:
      >
      >
      >
      > (Damn I had that formatted nice before responding via email)
      >
      > Probably depends on how close the "white" areas are to the seam
      > between the panels; the closer to the seam the more stress the joint
      > will receive. I have found this procedure to be very effective for
      > glassing a butt joint in plywood panels:
      >
      > Do a dry run of the procedure before mixing the epoxy. I hate finding
      > problems after the wood is wet.
      > Glue one side at a time!
      >
      > Use a flat surface big enough to work around both panels (concrete
      > garage floor in my case)
      >
      > Align the panels on the floor with a heavy sheet of poly under the
      > seam to prevent gluing the panels to the floor.
      >
      > Imobilize the panels so they won't move during the glueing operation.
      > I use bags of rock salt and have even parked a garden tractor on a panel.
      >
      > Measure and cut your fiberglass strips for the joint.
      > Mix your epoxy.
      >
      > Apply epoxy to the area of the panels that where the glass will lay.
      >
      > Make sure you get the edges where the panels actually touch - don't
      > trap any air in there.
      >
      > Lay up the glass tape over the seam per typical fiberglass butt-joint
      > instructions - parallel to the seam and stagger the layers.
      >
      > Saturate the glass tape with epoxy. Work it in with a brush and don't
      > worry about excess - we'll flatten it good and remove any excess
      > before it sets.
      >
      > Place another sheet of poly over the joint.
      >
      > Put something flat and heavy on top of the poly-protected joint,
      > making sure it's protected by the poly and doesn't get glued to the
      > panels. I use deep cycle batteries.
      >
      > The weight(s) on top will have a tendancy to "float" a bit as they
      > squeeze the joint and push excess epoxy away from the seam. Readjust
      > as necessary for the first few minutes.
      >
      > When the weights have settled you will notice excess epoxy around the
      > edges of the weights (hopefully protected by the poly).
      >
      > Use a squeegee or wide plastic putty knife to pull the excess out from
      > under the poly and off your panels.
      >
      > Let the epoxy cure completely.
      >
      > Remove the weights and poly and flip the panels to do the other
      > side.Be very very very careful when flipping. A one-sided fiberglass
      > butt joint is very weak against "folding" forces.
      >
      > Before doing the other side, sand the panels to remove any cured
      > expoxy that may have oozed down through the seam.
      >
      > Repeat procedure for the other side.
      >
      > When boths sides are cured hard I use a sabre saw to remove the ragged
      > glass edges that extend beyond the panels and sand everything smooth.
      >
      > You will now have a strong, flat joint.
      >
      >



      [Non-text portions of this message have been removed]
    • Mike
      Andre, I had a few of those but not on the actual joint itself. I sanded down and redid the expoxy in those areas and then feathered it out. After that I used
      Message 2 of 6 , Mar 7, 2013
        Andre,
        I had a few of those but not on the actual joint itself. I sanded down and redid the expoxy in those areas and then feathered it out. After that I used a thin plastic spreader to flatten out expoxy when I put it on so that it would release any airbubbles that were trapped. I notice some people use a ribbed roller to minimize air bubbles in the expoy but I haven't tried it myself.

        Regards,
        Mike

        --- In Michalak@yahoogroups.com, Andre <basso.asb@...> wrote:
        >
        > Yesterday I inspected the fiberglass butt joint I made to join bottom panels together. Noticed white areas where the fiber clearly wasnt epoxy filled. I would guess 15% or less.
        > What to do? just fill it with another epoxy coat?
        > Andre
        >
        > prairiedog2332 <nelsarv@...> escreveu:
        >
        > >I have Trilars plans.
        > >Twister meets my criteria regarding size and weight (16x16 350 lbs.)
        > >simplicity to build and trailerabilty. Can sleep two under cover
        > >snuggled up if built with the extended bridge deck which one has been
        > >built. The pram bow and flat bottom aft gives more interior space than a
        > >multi-chine with pointy bow the same length. Yet the warped V entry
        > >makes for less pounding in a chop over a flat bottomed pram. Flat
        > >bottom in the aft section "might" get some semi-planing flotation going
        > >over a multi-chine hull? My thinking is a bit straighter run in the aft
        > >section might just give more semi-planing ability than the aft rocker
        > >shown on the plans. At the cost of some sailing efficiency if the stern
        > >drags at the corners when heeled under sail.
        > >
        > >I also want the ability to venture into backwaters and creeks for
        > >shelter overnight as well as trying a yuloh and even poling to do that.
        > >But mainly my post was to share what other folks may be looking at as a
        > >versatile design. Sort of a hybrid design option over just a sail boat?
        > >
        > >Nels
        > >
        > >
        > >--- In Michalak@yahoogroups.com, tom s <tdsoren@> wrote:
        > >>
        > >> you might want to consider researching some kind of catamaran or
        > >outrigger. much higher displacement speed, less heeling under sail.
        > >Malcolm Tennant has some great articles regarding this.
        > >>
        > >> Sent from my iPad
        > >>
        > >
        > >
        > >
        > >
        > >[Non-text portions of this message have been removed]
        > >
        >
      Your message has been successfully submitted and would be delivered to recipients shortly.