The bottom shell panel of the scow is made from 9 ply.

As the bottom is longer than 2440mm (8'), it is necessary to join two pieces of plywood. As shown in the drawing, the join is arranged to be in between the stern and mid seats/tanks.

As with the side shell panels, I am of the opinion that it is better to join two rough-cut pieces of ply and then do the final cutting. So start with two rectangular pieces of 9 ply, one complete sheet and one sheet cut to 1100 long.

I had the luxury of getting my boss (an experienced wood boat builder) to cut scarphs in the end of these panels - with an epoxy/microfibre 'glue' the result is superb, but I would not attempt it myself! The two alternatives are:

- a butt strap on the inside of the panel - this should be between 150 and 175mm wide and fixed with epoxy/microfibre 'glue' and nails;

- a laminated joint using glass cloth on either side of the panel - some people reckon these are only suitable for thinner ply, but I can see no reason why this is true.

In the case of the bottom shell panel, a butt strap is ideal - the panel does not have to bend round a tight curve and the extra strength of the butt strap in bending will be welcome.

When the ply is joined, mark and cut out the panel as shown.

The shape of the finished panel is shown in the drawing. It is not easy to fit a 3.6m long panel very accurately so I recommend that you leave about 10mm of extra width on the panel which can be cut off later, but mark the correct width on what will be the top side of the panel to assist in lining it up during assembly. Leave all the extra length on the panel that is shown in the drawing - this is useful during assembly to pull the panel down into position.

Mark all the dotted lines shown in the drawing on the top side plywood with pencil - DO NOT leave this to do later as it will be very difficult. It can be helpful to mark both sides of the thickness of the internal structure, so that you do not try to assemble them out of position.

Mark the centreline of the panel on what will be its bottom side - it is much easier to do this now rather than later.