The case was glued and screwed to the chine and gunwale at the position shown on the plan. The outside of the case and the inner face of the outside skin were both given coats of epoxy, undercoat and topcoat prior to attaching the ply to the frame. As I had decided to construct the mini keel only one centre board case was required. . I added a shaped piece of cedar between the chine and gunwale on the other hull about halfway between frame 3 and frame 4. This ensured that the curvature of the outside skin was maintained.
When the outside skin was attached the front shelf join was completed to this skin similar to the inside skin. The chine edges of the skins were then planed back to the chine ready for the chine to keel planking. The only thing to watch here was that the inside of the ply skin needed to be painted in the front shelf area. Indeed the interior of this compartment needed to be completely sealed with epoxy-TPRDA mix.

Once the chines and keels had been beveled it was time to start adding the plywood skin. I started with the stem inside sheet. I used a full sheet here - I have seen pictures of construction that show this sheet only going to frame 1. The plywood sheet was trimmed to a rough size and then offered up to the hull frame. The position of the chine and stringers was marked on the sheet and the sheet then cut to slightly oversize. Holes were also drilled for the attaching screws. The sheet was then glued and screwed with stainless steel screws to the frame.
 
Masking tape was used on the down side of the forward shelf join and an epoxy fillet formed between the shelf and the ply skin. Once the epoxy had set it was smoothed and fibre glass tape added to the join to strengthen it.
 
The forward bridge deck beam was shaped at this stage and glued and screwed to the rim pieces.
 
I filleted joins in this front area as I went to ensure that I had the maximum working space I could get.
 
The inside skins were completed from stem to transom on both hulls. Butt joins were made between sheets. These were glued and screwed with 10mm countersunk head stainless steel screws. These protruded into the inside of the hull and needed to be filed and sanded off later.
 
Whilst the glue was setting on the various planking sheets I made the centre board case as shown on the plan. This needed to be finished and installed before the outside skin was attached to the hull. The case has a layer of fibre glass cloth on its inside followed by two coats of epoxy high build undercoat and a finish polyurethane paint.

Planking or Skinning