Sunday, January 7, 2018

26ft Sportfisherman Build Begins

The new 26ft sportfisherman of Kevin Agee is starting to take shape. This series of posts will follow the project one step at a time, starting with the building site. This is somewhat of a manual on how to build this boat, showing the way that Kevin has chosen to do it, sometimes under my guidance.

First step was to find a suitable build location. Those who live in a temperate climate can build out in the open or under a lean-to carport. I built all of my big boats in Cape Town in my garden, without protection from a roof. Here in Virginia the climate is not as kind, so frigid winter conditions make building outside very uncomfortable and cause big delays when work must stop.

The site chosen is a small industrial unit, large enough to contain the boat, the power tools and materials, with large enough spaces left over where full sheets of plywood can be laid out for cutting panels etc. There should also be enough space around the boat to allow standing back to view the hull as it develops, to judge fairness of curves of planking etc.

The foundation for a good build is to construct a solid bed (building stocks) on which the skeleton of the boat can be assembled. This bed has to be strong and stable so that the skeleton that is built off it remains accurate and true to the intended shape. There will be large loads applied to it through the weight of the materials that are added step-by-step and also the bending loads that result from forcing straight timbers into curved and/or twisted shapes. Clamping those timbers against the framing bends those timbers and sets up forces in the framing and beds, so they have to be strong enough to hold shape.
Basic shape of the building stocks, constructed but not yet anchored in the final position.
 If the build is over a concrete slab then the beds can be anchored directly to the concrete, with steel angles and anchor bolts. If the build is over natural ground then the beds must be elevated above ground to a height that the rails can be properly levelled, with the rails bolted to legs that are concreted into the ground for stability.

Most concrete slabs are not totally level, so the beds need to be levelled as much as practical when doing the anchoring. I say "as much as practical" because the rails may be straight when you buy them and not quite so straight when you make the beds a day or two later. Get them as level as you can, anchor them down, then add wedges or spacers where needed to level the individual frames when setting them up.
Steel angle and anchor bolts tie the rails to the slab.
Wedges under the rails shim them where needed to improve levels
A very important part of the building stocks is a wire strung above the centreline. This allows every frame to be set up using a plumb line hanging from the wire for reference. I will explain the use of this plumb line in the post about setting up the frames.
Plumb line hanging from an overhead wire that is accurately aligned with the centreline on the beds. 
Ahead of making the building stocks, Kevin had already assembled the frames so that their erection could be started as soon as the beds were ready. Some of the frames are temporary, cut from cheap plywood or MDF. Others are permanent, so cut from high quality marine plywood, with temporary bases and legs attached for fastening to the stocks.
One of the temporary frames being assembled on top of Mylar templates.
Frames and bulkheads ready to be set up on the stocks.
The transom on this boat is upright but it is radiused on plan. That means that it has to be laminated from plywood layers over a curved form to give it an accurate and stable shape. This one is two layers of transom and two layers of internal doubler.
The inner transom doubler layers are laminated first.
Then the outer transom layers are laminated onto the doublers
The next post will start with setting up the frames on the stocks.

This design is not yet complete, so is not on our pricelist. See our full range of designs on our main website or our mobile website.