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JEM Spacer Stitching Method - Perfect panel spacing
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Author:  jem [ Sat Sep 18, 2004 10:40 pm ]
Post subject:  JEM Spacer Stitching Method - Perfect panel spacing

With stitch and glue plans, you never want a hard spot or a "wood-on-wood" contact spot in your seams.

The reason is that filleting material (epoxy and woodflour) works better with fiberglass to evenly distribute any sudden loads placed on the seam.

Maintaining a consistent seam gap is also easier to build and fair. We've always recommended a spacer to maintain a consistent gap. The problem is that just putting a spacer or shim in the seam isn't always easy because the spacers twist or fall out.

Well here's a way to solve that:

1) Get some tongue depressors (craft sticks). I like using the wide ones because they are only about 3mm thick. Drill 2 holes about 1/2" apart, then one in the middle to make a slot.
Image

2) Stitch the hull with the stitches going right through the slots.
Image

3) Adjust the spacers so you have a consistent gap. What's also nice about this is you can pull the stitches tight.
Image

Author:  zoobricke [ Wed Sep 27, 2006 10:17 pm ]
Post subject:  Spacing for stich & Glue

Great idea, but the 21 garvey plans say that after you stich you should glue from the outside first. does that mean that you need to but some kind of tape on the inside because the epoxy will run out if there is no backer. Will paper tape do the trick? After you glue the outside do you then remove the stich and glue all the other spots then grind evenly before fiberglassing all the seams and turning the hull? :?:

Author:  jem [ Wed Sep 27, 2006 10:28 pm ]
Post subject: 

some masking tape between the spacers would work.

If you thicken the tack weld material so it's a little thicke, but not beginning to dry out, you can force it into the seam a little and it will stay there until cured.

You might get some running but not much. I'd do a small section to see how it works.

Also, you're doing a larger boat. I haven't tried this method with a larger boat and thicker plywood. I'm guessing you might need some strong spacers.

Author:  Jason [ Sun Nov 12, 2006 8:07 pm ]
Post subject: 

That is a very good tip. As a beginner, I was wondering the same thing. How would I use spacers when laying large sheets of plywood on the frames though? Also, could I use small dowels through the panals and into the end of the frames? Or is that just wasted effort?

Author:  jem [ Sun Nov 12, 2006 9:56 pm ]
Post subject: 

on small boats, spacers are not needed on frames. Bigger power boats, it becomes more important not to have "hard spots" (wood on wood seams).

Dowel trick could work as well.

That's the benefit of playing with a smaller hull first.

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