11 comments on “The Problem With Butt Joints

  1. I would get a Disk sander and dish the joint then lay in several layers of fiberglass/epoxy and then fair that in with a long-board sander before laying on the final fiberglass.

    • Chuck, thanks. Did the first two using a block plane and some 60-grit on a random orbital sander, waiting on fiber glassing the bottom – its been cold out there latterly.

  2. Looks great Steve,your movin on! I’m cutting bulkheads ,transom and bevel framing sticks.took your advice and read,read,page 151 .yep hard for me to visualize ,so I I better make a mock up on scrap before I start cutting up good expensive wood.Side panels went fine. This my first build so the learning curve is always always there !! Thanks for leading the way ,learning from your site helps.Jerry

    • Jerry –

      Glad to hear its going well for you. I’ve slowed down a bit, so I haven’t posted new material in a while. Busy life and cold weather holding me back a bit. But spring will soon be here, Lord willing . . .

      I did go ahead and planed down the joint in the post . . . then sanded the bottom w/ 60-grit. Its looking better now.


      Sent from Windows Mail

  3. Hi Steve,?? Does the top framing stick on the transom have the same bevel as the bottom framing stick??Plans show side and bottom view bevels,but not top ,the side view shows it beveled.What am I missing?

    • Jerry – I don’t have the book w/ me right now, but I think I cut the bevel from top of transom the same as the bottom. But if you are unsure about the angle, u could just glue the top framing stick onto the transom and then bevel that edge with a low angle plane following hull assembly, but before mounting the aft deck. I wouldn’t fret over a degree or two, the epoxy you’ll be using has some gap filling properties, or you can glue on a wedge if you miss-cut a bevel. Don’t ask me how I know this . . . Steve

  4. Steve,
    I am the point in my Mayfly 14 build where I am ready to install the bottom. Your post about the butt joint problem prompted me to carefully read what JM had to say in his book about the procedure. He specifically says that with Mayfly 14 bottom aft butt joint it should be made on a flat surface due to the severe rocker not allowing it to butt precisely when joined on the boat.
    I know it’s too late for you, but just want to thank you for posting your problem with it and prevent others from having the same issue.
    I hope your joint remedial process worked out OK.

  5. I corrected this problem by removing the solid wood backing plate (after the bottom was attached to the chine logs) and replaced the backing plate with 3/8″ plywood. I drilled several holes along both sides of the seam, glued the plywood plate down and then screwed decking screws from the bottom through the pre-drilled holes into the new backing plate. After the glue dries, remove the screws and fill in the screw holes.

    Removing the old backing plate required prybars, hammer, wood chisel, and a belt sander. Not fun, but the results of the effort was satisfactory.

  6. Steve, lots of good comments here to fix the butt joint. In the future you might clamp the joint using several thicknesses of wax paper to get a good seal between the bottom and the exterior chine log while preventing your clamp from becominga permanent part of your boat. 🙂 Len

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