View Full Version : Joining Plywood questions

04-05-2005, 06:54 PM
I am going to build Bolgers Micro Trawler, and am adding 4 feet to the aft. I had planned on joining the plywood with a joint if 3 inch and 6inch tape. I planned on cutting a 3 groove in the ply and taping them together, then feathering the groove out to 6 inches and putting the 6 inch tape on. My question is every one is talking scarfing, and I am wondering if the taped joint is as good, worse, or better? Also, would it be lots more work than it is worth?

Thanks, Stephen

04-05-2005, 08:46 PM
I do not think it is a good idea, scarfing it the way to go. If you want info on scarfing go to http://www.boatbuilder.org/godzilliscarfing.htm . Good luck with your project.

04-08-2005, 10:43 AM
I found it difficult to understand the description of what you were doing.

Butt block ing works well to extended paenl length. Generally, you have to have a butt-block as thick as the wood you're joining and about 12" total length. Hard to say exactly what you need with seeng the plans.

Fiberglassing splices work in many instances as well. You'll need double layers of biax on each side of the joint.

Contact the designer for input on the best way to do it.

04-09-2005, 04:30 AM
I was thinking about making a fiberglass splice, but am going to go with the scarf instead.
Next question though. Do I need to thicken the epoxy for the scarf joint? And what about joining two sheets together as in laminating them, should I thicken the epoxy there also? And if I need to thicken it, wilol wood flour be ok to use?
thanks again, Stephen

04-11-2005, 07:55 AM
Yes you should thicken it (I prefer wood flour) to about a ketchup-like consistency. That way it'll still fill in the little valleys but won't run out everywhere.

You don't need high clamping pressure. Only enough pressure to hold the pieces of wood together.

Fiberglass splices are nice for looks. But I often prefer wooden butt blocks on canoes and kayaks because you get the advantage of the extra stiffness.

Matt - JEM Watercraft

Andy M
05-21-2005, 02:58 PM
I skarfed the plywood on my daysailer and I applied 6" tape to both sides and epoxied. The joints sanded down nicely and are almost invisible. Good advice JEM and good luck Blacksmith.