Loose Puzzle Joints - how to align panels?

Just starting the build on my Wood Duck 12 and I'm working on the 2 side panels.  I've done a dry assembly and noticed that I can move one end of each side a good inch because of play in the joint.  I did this by clamping the bow piece to the table and can then move the stern piece by about an inch.

How do I ensure that both panels are correctly aligned?  Seems if the port side is assembled with the play up and the port side with the play down, this thing will never assemble!

I was wondering if I should assemble them one atop the other - then I could be assured of them being symetrical.

8 replies:

« Previous Post       List of Posts       Next Post »

RE: Loose Puzzle Joints - how to align panels?

you definitely want them symetrical and you should build them on top of one another to ensure that.  if there is play in the arrangement, the plans typically have a reference line and an offset measurement that you can use for final placement that can be used to ensure they are built per plans. 

RE: Loose Puzzle Joints - how to align panels?

   Thanks for the info.  Where can I find the data on the reference line and offset measurements?  I'm not seeing it in the build manual that came with my kit.

RE: Loose Puzzle Joints - how to align panels?

Call CLC when they've opened today. You ought to get what you need to know from them.

Plans can be pretty simple, basically patterns for cutting parts, or more complex if the design merits having the details. Assembling panel sections with port/starboard paired in stacks is recommended but having some idea of what the true, designed shape ought to be before one starts is important for confidence as well as success!

RE: Loose Puzzle Joints - how to align panels?

Definitely follow spclarks advice if it is not part of the plans/manual. 

prior to puzzle joints (yes, these kits did not always have puzzle joints), there were scarf joints and you needed that reference line/offset to have any chance of doing it right.

it's possible that with puzzle joints, clc no longer provides that information as they don't view that there is enough play in the joint to worry about getting it right....but symmetry is still important :)



RE: Loose Puzzle Joints - how to align panels?

   When laying them on top of each other I recommend putting some wax paper between the areas glued. 

It will save you quite a bit of pain.

I found one of my joints on my Skerry to have some play and one other had no play whatsoever. I used the one without much play as a guide for the other.

Another thing that might be an issue is a cold shop. While I do not know much about this particular plywood in cold vs hot shop things do tend to shrink in cold temps and this might be the small difference that is bigger. Plus you want to warm the shop for the epoxy as well.

RE: Loose Puzzle Joints - how to align panels?

   i'd not done any puzzle joints in a few years and i thought what the hell no harm to check the forum for any tips, whatnot, on same, and whadyaknow some bright fellow here (hspira) has suggested definitely laying both sides of the hull on top of each other, before gluing the puzzle joints, first, for hull symmetry, which makes incredibly good sense, and of course, this brilliant step was Not a thing i'd had in mind to do... till now. Thanks to hspira!

RE: Loose Puzzle Joints - how to align panels?

   Ditto all of the above on alignment, etc: Just thought I'd add a couple of more tips on puzzle joints.  Concentrate on keeping each side of the joint flush with the other, while minimizing epoxy squeeze-out on each side of the joint.  Keeping flush- especially if you're going to stack the panels, means having a good, solid, stiff, flat base extending seveveral feet from the joint (a nice flat shop floor?), and the same on top of the joint (a solid flat board?), plus a good amount of pressure/weight placed on top (a tool box full of tools?).  Saran wrap, thick plastic (like thick garbage bag mil thickness) or wax paper all work between layers and bottom/top surfaces.  Be SURE that no expoxy can get far enough away from the joint to glue layers together.  Saran wrap tends to develop wrinkles. Wax paper requires care to sand/alcohol away all wax residue. I always have the thick roll of plastic available that I use to cover work surfaces, so that is my prefered anti-bonding interleave, just use scissors to cut out something like 1 ft squares. 

I think the biggest tip is to use less epoxy than you might otherwise think you need.  Excessive squeeze-out results in much exta sanding work, which usually means a non-flat surface develops on either side of the joint.  Use just enough epoxy to avoid any dry contact surfaces down in the joint seam, and you can avoid this by lightly "painting" both sides of the joint EDGES prior to assembly - but not the panel surfaces on either side of the joint. Even if you get an occasional area of a joint that isn't flush-filled after sanding, easier to add a bit a extra fill to this rear occurance the next time you mix a batch of epoxy than it is to sand away a lot of epoxy that squeezed out many lumpy inches on each side of all of your many joints. The joints become more than strong enough when subsequently coated with glass and/or epoxy in subsequent steps of the build.

RE: Loose Puzzle Joints - how to align panels?

   That is absolutely hilarious. I should've given it a try.

« Previous Post     List of Posts     Next Post »

Please login or register to post a reply.