Tuesday, February 5, 2013

Chine logs

I decided to get going on the interior chine logs for the pram.  I cut the bevel to the greatest angle, consistently for the entire length of the chine, 30 degrees, and I plan to plane the chines to the needed angle after they are attached.  The angle at the ends is about 20 degrees.
The intent here is not to get the exact shape that the chines will eventually need to conform to, but rather to get them close enough so that the work of fastening them goes easy and nothing breaks!  I did this with my toe rails when i put new larger ones on my 27 foot cruiser.  I took the lengths of wood and tied them to the stanchions and over the course of about a month and a half I slowly drew them in with a spanish windlass.  Being that the boat was outside and uncovered the rain and sun all helped the process so that when I made the final attachment the wood was just about perfect.  This was especially good as I did not have the means to steam bend a 1-1/2"x2-1/2"x 30 foot length of wood.
Chines being "bent" by clamping and weights and letting the wood get used to the new shape.
In this case the chines wood is much stiffer than the plywood of the sides, so the preformed chines are important to get a good final shape, as well as a few station molds.

Once the chines have set for a while I will go ahead and flip the boat over and attach them to the sides.
The chines will give a good glueing surface and keeps me from making this a stitch and glue type of build.  I am not sure why I don't want to use epoxy for the chine, but there ya go!
a simple spanish windlass on each end pulls the chine logs together and helps to get the needed curve.   The chine logs are longer than needed right now, so they need to be bent out of their final position.
The water tightness of the boat will depend on how well I fit the chine log and how well I spread the waterproof glue that will work with fasteners to join the bottom to the sides.

Friday, February 1, 2013


Cold in the shop today, but the wood stove, and the occasional nip from the flask, kept things moving along.
Even with the wood stove going the shop is still only in the 40's.
While trying to get the transom on the bow to line up I decided to see what the boat would look like with a pointed bow.
Much more traditional looking
So I took the transom bow out and brought the side together.  I temporarily fastened the sides together
and flipped the boat over.
I like the angle of the bow, but don't think I couldn't keep it if I added length to the bottom.
The rocker brings the bow up pretty high, but I don't think too much so.  The concern I have with this is that I would loose the slightest bit of surface area on the bottom, even so, I probably need every bit of buoyancy that I can eek out of this single sheet of plywood.

temporary midship frame.

The beam is 2' at the bottom amidship, 3' at the gunwale.
I did like the more traditional look of the pointy stem.  I put a one and a half inch square piece in at the stem to check the angle the sides come into.  The 90 degree corner seemed to work just fine!  The only bevel needed would be where the stem meets the floor.  A 35 degree setting on the chop saw worked pretty well at a guess.

The stern is almost to vertical for my tastes, but I think it has just enough rake to keep it from looking just like a box
I suppose I could try the boat with this hull shape.  I could even lengthen the bottom a few inches, up to  a total length of 7'6" and still have enough left over for the transom.  The stem would be close to plumb and that might not look as nice.  I might try it.  At $13.99 for the sheet of plywood, why not?  All the other wood used for framing, gunwales, scrap.

with the transom bow I think the boat has a asian quality to it.
I put the transom bow back in, but with the angles to work out for the sides I am loosing about 2 or 3 inches in over all length.
looking at the stem, boat upside down, with this angle the boat will loose a few inches of LOA, but only 1/4 in of length on the bottom.
If I do try to build a pointy version I might try to make another chine in the bottom at the bows with a cut and twist into shape technique, so that the bow will cut thru the water easier.