Building the Mast Trunk for SCAMP Sailboat ARGO
The "Mast Trunk" for the scamp is a vertical wooden box, open at the top, that the bottom of the mast slides into in order to secure the mast in the boat. There is a drain hole at the the bottom of the mast trunk to allow water to drain out. The aft side of the mast trunk is a bulkhead, and in the bulkhead is a long opening through which the mast can be seen and the mast trunk inspected.
- I opted to do the initial assembly of the mast trunk outside the boat on a set of saw horses. This allowed me better access to lay down two of the internal fillets, and it was just nice and open to assemble with plenty of space.
- I dry fit and screwed the entire mast trunk into the boat, then disassembled it, then glued (thickened epoxy)and screwed the bottom, sides, and ramp together, then filleted everything on the mast trunk that I could while it was outside the boat, then I fiberglassed the outside corners.
- When it had set up, I screwed it in place in the boat.
- Some tips: used a file to widen the slot in the mast trunk "Y piece". Also, I used screws to pull the mast trunk assembly into the dados in the bulkhead; to easily locate where to drill the holes, I first drilled pilot/locating holes from the dado side through the bulk head, this was a very easy way to get nicely located screw holes. I used 4 screws up each side of the mast trunk through th bulkhead.
I installed the mast trunk at the same time as deck and cabin top beams so they could all be clamped together. This view is from above into the must trunk. To the left of the trunk opening is the ramp that aids in stepping the mast into the trunk. When I applied pressure to the clamp (not too much pressure with epoxy!) , I got good fill of the joint with thickened epoxy.
-Next I will fiberglass the parts of the mast trunk that are above the cabin-top, but I will do that later after the cabin top is installed, so done for now with the mast trunk.