Sunday, May 1, 2016

Keel and Skeg Stringers

It most conventionally built wooden boats, the frames refer to what you might think of as the "ribs" of the boat running across ways (thats "athwartship," to you, matey!).  In the Glen-L Waterlodge, the framing members run longitudinally and are called stringers.

So building the boat frame means assembling the individual stringers and then tying them together with various cross beams. 


There were five stringers total.  Two side stringers, one keel stringer in the middle, and two "skeg stringers" between the keel and the side stringers. While the plans are relatively straightforward about building the stringers, there are lots of pesky details to consider, notches for cross beams, plywood reinforcement, butt blocks to make sure the plywood on the side stringers didnt leak, and a subtle curve to the deck that will sit on top of the stringers.


The keel stringer used big pieces of plywood to structurally reinforce the member and did not have overlapping two-by pieces.  The skeg stringers did have overlapping two-by pieces but no reinforcing plywood. The result will be two big storage bulkheads under the decks on either side of the boat.

The side stringers of course had plywood that covered the outside surface of the boat and no overlapping two-by pieces.  Well talk about these and their butt blocks in the next build day entry.

The notches for the cross beams were easy, though we still forgot a few and had to cut them out of the already assembled stringers.  The porch deck beam notches were not really dimensioned properly on the plans and so we had to do a little improvisation later. 



We built the stringers on the asphalt floor of the barn.  It was flatish and shaded, so we didnt bake as we fretted over the details of our new stringers.

One challenge we faced was making sure that each member we built matched all the others. The plans suggested literally building them one on top of another.  This didnt seem that practical, so we hit on a solution:  Using the plywood already cut to shape for the side stringers as a pattern for our other stringers.  That way wed know that all the angles would be correct and all the pieces of each member would be in the right place.

We used what we called temporary butt blocks just to hold the side plywood in place while we were using it as a pattern.

So in these photos, you can see the side plywood under our stringers as a pattern. 

From left to right: keel stringer, starboard skeg stringer, and port skeg stringer.
So for each stringer, the process was more or less:  Lay out the pieces for fit on our plywood pattern; put wax paper under anything we didnt want to be permanently adhered to anything below, temporarily screw down, as necessary; apply a thin coat of epoxy to both surfaces of every joint; apply a thickened coat of epoxy to one side of every joint; and finally fasten together all joints with stainless steel screws.

 

After the epoxy on the stringers sets, we could put the stringers on the building form. 


Exciting!  It is looking more boat-like every day. These incremental changes are probably pretty minor looking to other folks, and the progress may seem pretty slow.  But for us, it is crazy.  Look we had a pile of lumber!  Now we have this boat(ish) thing!  Amazing!

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