Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Saturday, November 2, 2013

Work Continues On The Keel And Battens

Since the last posting, I have also purchased the plywood for the transom and have begun fitting all the battens as well as the remaining keel part. There's actually quite a bit that has occurred since last Saturday. Even before last Saturday, I managed to get in some checking of the structure

So I will start with that. Since this structure is made from many individual parts, one of the challenges has been getting all of them to be in the correct position in relation to each other. Certain positioning elements are controlled by the size of the frames. These measurements were accomplished earlier this year when I was manufacturing and assembling the frames. So when I positioned the frames on the building form, I could get some some of the position of the frame very close. This includes the vertical position of frames 1 through 5. The horizontal positions were likewise controlled by their placement on the building form. And centering the frames on the form was accomplished at that time as well.

But he correct position of the frames is only part of the process. There is always some margin for error in these designs and this needs to be worked out as you get further into the build. For example, the notches for the battens were not cut when I originally built the frames because I wasn't confident that their positions would be correct after the frames were mounted. This turned out to be a correct assumption. When I began laying out the positions of the notches, using the battens as a guide, I could see my original marks were off somewhat. I'll go over this more in a minute.

One of the processes I went through was to recheck the alignment of the frame sides and bottom edges by using a temporary wood strip. I wanted to insure that when I eventually add the actual structural members in place, that they will follow a natural curve without any dips or bumps. The following series of photos illustrate this process.





One thing to notice in the third photo is how the wood clamped in position is slightly high from the corner of the frame closest to the viewer. This particular frame is the transom frame and this offset is significant as I will get into a bit later. But as you can see in the photos, the temporary wood strip follows a nice curve around the various places it was clamped. This tells me that in general, I have the frames in the correct position side to side (athwartship).

After I got the mahogany board last Saturday, I cut the remaining keel part from it and fitted it into the keel notch on the frames. I had already spent quite a bit of time on the fit of the keel which I have covered in previous articles. The key point is that the keel needs to be straight from frame 4 aft. Not level, but straight, so that a straightedge set on the keel will show no gaps. This will also come into play a bit further into this article.



There was enough mahogany to cut two 16 foot battens for the bottom of the boat. I will eventually need more material to make the other battens, but I could use these existing parts to set the notch locations for all the battens. The transom frame already had notches cut when I made the part earlier this year. I had measured similar distances on each frame when I was assembling them. But I did not cut the notches for the reasons mentioned earlier.

I laid the batten in potion on the frames and used blue tap to mark the locations for the notches. As mentioned previously, these positions were slightly different from the measured marks.




I started cutting the first series of notches for one batten. This was accomplished using the router and the same tooling I used to cut the keel notches. After I cut the initial notches, I placed one of the battens into position to see how it fit.





This is were I ran into some issues. The battens, like the keel, need to be straight in the aft end of the boat. I checked the batten for straightness using a straightedge and found that there was a significant bow in the batten as it went from frame 1 to the transom frame.

This concerned me quite a bit and I spent several days trying to figure out what was wrong. The keel seemed to come into the transom frame perfectly flat, but the battens did not. This made me wonder if the frame was shaped wrong on the bottom. I measured various elements of the frame, and double checked it's position based upon measurements given on the plans. Everything seemed to be in order. So what was the problem?

If the keel would have been bowed as well, then I could have moved the transom frame up a bit and this would have corrected the battens. But this didn't seem to be the problem. This was mistake number one. I didn't actually attempt to move the frame up to see what would happen. I simply assumed that moving it up would throw the keel off.

I will digress for a moment to talk about my trip to Houston yesterday. I needed to get plywood for the transom skin and after considering all my options, decided to get it in Houston. But before I left yesterday morning, I took another look at the alignment of the keel in relation to the transom frame. I found that if I raised the transom frame 1/8" and added a 1/16" shim in the keel notch at frame 1, that the keel was still flat. Yes!!

So I went to Houston, a very long drive, and purchased my plywood. By the time I got back, I was too tired to do anything on the boat.



But today, I went out and looked at the transom frame again. I saw that I could indeed move the frame up 1/8" and it would correct the issues with the battens at the same time. If you look at the transom frame in the area of the notches, you can see an approximate 1/8" gap in every notch. All of the battens in the photo as well as the keel are straight . The gap shows how far up the pieces must be raised in order to get them to be straight. I also sighted along the notch edge of the frames, lining up the edges of frames 3 through frame 0 and I could see that frame 0 was low. Remember the third picture at the beginning of the article where the wood strip didn't quite line up with the corner of the transom frame. That is further proof that the frame was too low.


So I am satisfied that my concerns about straightness have been resolved. I spent some time today cutting more batten notches. I still have some more work to do on these and hope to finish up this task tomorrow. But here are some photos showing the results on one side. Remember that the wood shown in the notches are not the final battens (since I don't have the material for them yet). One of the pieces shown is too short and doesn't reach the last notch.




After I complete the notches, I will be making mock ups of the chine and sheer parts so I can cut the notches for them in the transom frame. This is because I will be removing the transom from the building form and adding the skin using the plywood I just purchased. I will also take the opportunity to raise the position of the frame when I eventually re-install it on the building form. Since the notches on the transom frame will be covered on one side by the plywood, I need to have them cut out before I add the plywood. I will be covering that whole process at a future date.

I still need to save up enough money to purchase the bronze screws to connect all these parts together, but I have enough work for now to keep me busy for a few weeks. By then I can order the hardware and begin putting parts in place permanently.

So until next time.................

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  1. The build is looking REALLY good! I admire all the precision you're putting into this.

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    1. Thanks Mike! I get my inspiration from others like yourself. When I set out to do this, I saw how others were building theirs and I set a goal to do it to the best of my ability. I've made plenty of mistakes along the way and had to change course a few times, but I keep moving forward and that's the most important thing.

      Looking forward to seeing more work on your boats as well.

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