JEM Watercraft

David (13-year-old-son) and I are getting ready to start gluing up the panels. I'd planned to use fiberglass tape for this. Some random questions:

1. In an email you mentioned butt blocks. Do you recommend these?

2. When mating the panel pieces, if I use 4-inch 9-ounce fiberglass tape can I get by with just a layer on the inside or do I wait for the epoxy to cure then put a layer on the outside too?

3. Since I'm going to cover the whole hull with a layer of 6-ounce glass, will I need to fair the selvage edges of the 9-ounce tape I'm using to avoid air pockets, or shoud it be OK? I've only used plywood butt blocks in the past, so this glass-on-glass thing is new to me.

4. Any problems with me running a layer or two of glass tape along the centerline of the boat OVER the glass cloth covering the whole outside? This is going to be a boy's boat in areas with lots of rocks. I am sure they are going to beach it by cruising in at full speed and I want a little abrasion resistanct on the impact points.

5. How long should the thwarts be for this boat, and where should I place them?

Thanks!

1. In an email you mentioned butt blocks. Do you recommend these?

The bottom panels span pretty wide like we talked about. You may, in fact I'm almost possitive, need some extra stiffening. Wooden butt blocks would provide that.

2. When mating the panel pieces, if I use 4-inch 9-ounce fiberglass tape can I get by with just a layer on the inside or do I wait for the epoxy to cure then put a layer on the outside too?

For fiberglass splicing instead of wooden butt blocks, you need to apply the tape to both sides of the panel, 8" wide (4" on each side of the seam).

3. Since I'm going to cover the whole hull with a layer of 6-ounce glass, will I need to fair the selvage edges of the 9-ounce tape I'm using to avoid air pockets, or shoud it be OK? I've only used plywood butt blocks in the past, so this glass-on-glass thing is new to me.

Knock the edge off. A wood scraper or the Sure-Form tool works well. You won't need to feather it perfectly smooth. Just get the edge even with the top of the tape.

4. Any problems with me running a layer or two of glass tape along the centerline of the boat OVER the glass cloth covering the whole outside? This is going to be a boy's boat in areas with lots of rocks. I am sure they are going to beach it by cruising in at full speed and I want a little abrasion resistanct on the impact points.

No issues there. Just be sure to be mindfull of amine blush issues. Take a look in the Tips and Tricks section and review the graphite trick. I've done this and it works well.

5. How long should the thwarts be for this boat, and where should I place them?

Long enough to reach the gunnels. 2 that space the hull length in thirds should do well.