A start on the hull proper

We cut the moulds for the hull almost two years ago, and erected them onto the strongback a few months ago – and while that looks like progress, you are always aware that nothing you have done is actually going to be a part of the finished boat…. So I was looking forward to getting on with some construction proper.

The moulds erected on the strongback

The moulds erected on the strongback

Starting Point

The first process is to construct the “backbone” of the hull, which is the internal structure (Stem (bow), Hog (inner keel), Transom, Clamp (inner gunwale), Bilge-Stringers and Floors (which are the transverse members that support the Sole (floor – confused yet?).

All of this (with the exception of the Transom, which is inch-thick ply) is constructed from Douglas Fir. Most of this is constructed as epoxy-timber laminations. So I ordered a substantial stack (about 40 4m lengths) of 6-inch boards (three-quarter and one inch thick) from Barry at cedarstrip.co.uk…

A couple of hours with a friend’s table saw transformed these planks into the rough-sawn stock for the stem,hog,clamp and bilge stringers. Then some work with the planer-thicknesser produced really nice timber to begin laminating.

Epoxy: a revelation!

A lot of the construction of the boat relies on Epoxy Resin – it’s used to clad the finished hull in glass cloth, it’s used as an adhesive and as structural component in fillets etc. While at first glance it seems like the resin you would use in traditional glassfibre, it has several nice features – most notably it does not stink!

You can add material to the raw resin to produce composite materials with differing properties. So adding microfibers turns it into a very strong adhesive and filleting material. Whereas to produce an easy-to-work filler you add “microballoons” or add sand for a non-slip varnish or graphite for a bearing surface etc…..

Construction Begins

So the first thing was to laminate seven boards to produce the timber baulks for the stem Below you can see the lower part of the inner stem being laminated on the bench and the vertical part after laminating and planing to size (6″ by 4″)…

laminating inner stem

seven 20mm laminations clamped (lightly) to bond

Part of Inner Stem

Laminated and planed to size

 

 

 

 

 

Clamptastic 2

We made the (triangular) inner knee from 4 laminations of inch ply, and were then ready to fit the two stem components and the first lamination of the hog onto the moulds, and then fit the knee.

As noted in the last post this required a deal of head-scratching, but in the end a few minutes with a saw and plane resulted in an assembly that was ready to go together – the pictures below show how this was achieved, and also the merits of buying your clamps in bulk!

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