New Boat Part 6

In the last installment of the construction of our Penny Fee, we were rough-shaping the keelson. Before the garboards can be attached the keelson needs to be checked and final adjustments made. What this involves is the time consuming process of clamping a garboard in place to see how it fits to the keelson (the “hog” as the British builder calls it—on this side of the Atlantic “hog” is a large motorcycle), with the garboard clamped in place, it is possible to see how well, or how poorly the two surfaces mate and to correct for the areas where the fit is poor. If you look carefully you can see the carefully cut curve that transitions down the length of the keelson.

Shaping the Keelson

still some shaping to do

Dry fitting the garboards

At some point the gains must be cut on the planks. Gains are basically a long gradual rabbet scarf in the top edge, bow end of the plank. The purpose of the gain is to allow the lapped planking of the hull to come together in a flush seam at either side of the stem. Some builders recommend cutting the gains before the plank is glued in, others feel that the process of twisting the plank into place is too likely to break the gain. I like to rough the gain in partway before the plank is glued in then finish the gain off when it is glued into place using the next plank as a guide to finalize the cut. This way the gain gets started easily on the bench and is finished on the boat making a close fit. There are a number of methods that will work well to cut the gains; we used a Stanley #78 rabbet/bull-nose plane with a batten tacked in place as a guide.

Cutting the first part of the gains on the bench

The gains are finished up with the plank glued in place

With the gains cut and the keelson shaped it is time to glue and clamp the garboards in place. The twist of these planks is substantial, but with two people working from the center of the boat towards the ends, it worked out pretty well. Having clamped the planks in place and removed them several times while checking the keelson was good practice for when the gluing session finally started.

The garboards glued in place

If I can point one thing out to anyone who is starting a boat project like this for the first time; no matter how professionally the molds are made, the key to a beautiful boat is to have a fair twist and bend to the planks. That said, there will be times where trying to make the plank meet the mold exactly will not result in as sweet a line as letting the natural bend in the plank determine the curve of the boat.

If you are unfamiliar with glued lapstrake construction, I should also mention that the gluing of the planks has two steps. The first step is to coat both surfaces to be joined with raw epoxy. While that soaks in, epoxy thickened with filleting compounds is mixed up. The thickened epoxy is now spread on the still wet raw epoxy, on both surfaces to be joined, then the surfaces are mated, aligned, and clamped into place. There should be some epoxy that squeezes out of the joint as it is clamped (squeeze-out), which is scraped away before the epoxy has a chance to harden too much. The thickened epoxy fills any voids between the two mated surfaces and the raw epoxy ensures that the wood does not soak the epoxy out of the thickened epoxy which could potentially weaken the joint.

Next time the first strake….

If you would like to read all the posts related to this project together, go to the category at the right called “Penny Fee” and click on it. It will pull all the posts on the penny fee onto one page for you.

Advertisements

Tags: , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: