Hi Dave & Derek,
On the matter of “attaching edges” as it relates to NUTMEG… The construction method for scarphing (joining two smaller plywood sheets to make one continuous longitudinal panel) for NUTMEG’s side planks and bottom is Tape & Epoxy. Dave Carnell explains the method and the steps to accomplish this task in the building instructions. This method is very strong, allows the side planks and bottom to bend to the boats shape and is a relatively simple procedure.
Securing the scarphed plywood bottom panel to the bottom of the scarphed plywood side planks is accomplished by using screws and glue. After the frames and the out outside chine is attached to the bottom of the edges of the side panels – transom to stem – then the bottom is laid down aligned to this perimeter or ‘shelf’ and screws are driven through the bottom panel into all facing surfaces around the boat. Clever and efficient.
Derek you bring up a good point on the ‘Stitch & Glue’ plywood construction method. No doubt this construction technique (first used on the Mirror Dinghy developed in England in the ‘60’s) has changed and made possible building small boats by amateurs. Dave Carnell mentions attaching the bottom panel to NUTMEG’s side panels could be accomplished using the ‘Stitch & Glue method. In this case the outside chine would NOT be installed and the adjoining edges would be drilled and pulled together using plastic wire ties or copper wire (the boat is upside down). Then the edges would be tacked with epoxy between the ties, the ties would be removed after the epoxy cured and fiberglass tape saturated in epoxy would be wrapped around the edges transom to stem. Then one needs to turn NUTMEG over and using a mix of epoxy and wood ‘flour’ lay in a thick radius fillet along the inside edge of the side and bottom panels; this will create an inside chine stiffening up the boat.
Derek, your comment on the use of epoxy is well taken. I hope to get an epoxy post started soon. Do note however, that NUTMEG as designed uses very little epoxy – 1 quart. Last edited on Wed May 10th, 2006 04:22 pm by Thom V |