Building the Scarab 10 foot trimaran

This boat has gone through many changes as the build continued. It started with sliding tubes but then new ideas blossumed. This made the build much slower and more of a challenge. I changed the beams and made it a folding trimaran. The plans will be available soon. The boat shown in the photos uses beams similar to the some of the other Scarabs. The plans will show a design that has sliding tubes instead of the folding beams. This boat was built using foam sandwich but the plans allow for a plywood version with chines made using Stitch and glue construction.

Main Hull

A building frame was made out MDF. Two longitudinals were notched at the station positions. These longitudinals can be used for the main hull and the floats and the positions are the same. The bulkheads were also notched and fixed to the longitudinals. This makes the frame strong and square. The panels made from Laminated foam panels or plywood panels scarfed together were attached to the bulkheads. The permanent bulkheads were drawn using the building frame bulkheads as a template. If you draw around the bulkheads on the inside of the panel as you attached the panels then it will not be necessary to level the hull or floats as the permanent bulkheads are in the same position as the temporary ones.

Scarab 10

All the panels were attached to the building frame. I wanted a round bilge so I strip planked the bilge panel. In the plans the main hull and floats have chines and are not rounded. This will make it much easier and quicker to build.

Scarab 10

The joints on the main hull were taped and the hull filled ready for paint.

Scarab 10

The main hull was primed with epoxy high build filler and painted with Jotun Imperite. Non skid was applied on the side deck and floor of the hull.

Scarab 10

The beams were moulded then painted with high build primer and Jotun Imperite. Tramps were made similar to catamaran tramps.

Scarab 10

Floats

Floats were built on the building frame. The bulkheads were slotted on the same stations as the main hull. Temporary bulkhead were used to draw the permanent bulkheads (with a few adjustments). The position of the bulkheads was marked as the panels were attached.

Scarab 10

Bulkheads were taped in and the deck was added. Floats were painted. The beams shown will not be included in the plans. The boat will have sliding aluminium tubes.

Scarab 10

Picture of the main hull almost finished with beams and tramps attached.

Scarab 10

Testing the rig. Fully battened mainsail.

Scarab 10