Stitch and tape - how many layers?

[Blindblake]

Hi. I'm building a John Welsford Navigator and am at the stage of finishing the outside of the hull. The inside the bottom panel is stitched and taped to the first plank. I did this using a big fillet of thickened epoxy and one layer of 100mm (4 inch) fibreglass tape. On the outside of the hull I have fibre glassed the entire bottom up to the second plank – this covers the outside of this joint.
Is this enough fibreglass to reinforce a stitch and tape joint or should I put another layer of tape on the outside over the joint to further reinforce it? I’ve done a lot of reading on this and get various opinions. I would like to avoid putting this extra tape on as I’m almost ready to paint and I also fear it will show up in the final finish. I don’t know what it is but first-time builder paranoia has suddenly set in!

[wizbang 13]

I do not use any tape. Large 403 filets only. Junky, weak fillers, need tape.

[JimConlin]

What does the designer recommend?

[ssor]

Nothin too strong ever broke. You can always fair and sand.

[Blindblake]

I do not use any tape. Large 403 filets only. Junky, weak fillers, need tape.

My fillets are "substantial" and I used tape plus glassed the outside so I guess I'll be alright.

[Lewisboater]

You're good...the reason for the tape is to spread the stresses on the joint well into the ply panels (over fillets which start the job) and external glassing of the joint reinforces this. It also assists in sealing the joint properly. If the hull or part thereof is glassed it is normally for abrasion resistance and a bit of stiffening along with providing a good matrix for sealing the surface and preventing checking of the wood ( should it be a species that does this).

[Thorne]

John W. will often answer questions via email directly, plus there is a Welsford Builders group on Yahoo -- both worth using as resources for your build. Subscribe: jwbuilders-subscribe@yahoogroups.com

Best of luck!

[Boatsmith]

you can make test panels and destruct. It doesn't take much fiberglass and filetting to be stronger than 1/4" or 3/8" ply. Once the ply breaks instead of the joint ,then any more is just addin'heavy. David