Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Sunday, September 7, 2014

More Fairing And Struggling For Material

One of the challenges of writing a blog is finding enough material to write about. I believe this problem occurs for all forms of writing. For me it also manifests itself in my lack of participation in the Glen L builder's forum.

When working on my boat, I always have something I need to or want to do, but much of what is being done right now is not "photogenic" or "good copy material". Rather, it is session after session of  sanding, planing, chipping, and more sanding. So weeks might pass before I feel like I have anything remotely like enough subject matter to put in an article. With the builder's forum, I always feel like I should only post if I actually have something to contribute or if I've made some significant progress.

So it's been like this for the last two weeks. From my perspective, I've made fairly good progress with fairing. I'll cover that in a minute. But the actual work involved is not the most exciting thing to write about. However, the pressure is still there in my mind that I should try and put up another posting. So I am attempting to do that today.

As I have mentioned in previous articles, fairing the front of the boat is by far the most challenging part of the process. So many different angles to consider and hardly anything is on a straight line. Probably the one constant that I can count on is that the mating surfaces need to be flat in at least one plane. Having the concept of a fair curve is also very useful as it helps define the curves that need to be maintained as material is removed. A fair curve will insure that I have a fighting chance of getting the plywood to lay down over the length of the boat.

Each session gains a little more ground in the fairing process. If I try and think of all the different aspects of fairing, I begin to get depressed and lose enthusiasm for continuing. But if I focus on the next task at hand, mundane or otherwise, I get a little closer to the end and the next step often is easier to visualize or accomplish.

Another challenge I face personally is worrying if I do something that will be difficult to fix. This is a particularly vexing problem for me because I end up spending a lot of time just looking at the boat and delaying what needs to be done. I have to mentally prepare myself to make some of the riskier cuts.

All of this manifests itself in small portions of the structure getting faired individually and then eventually "connecting the dots". The last two weeks has been exactly like this. In my last article I mentioned how I was using the long stick to get angles on the chine and on the stem parallel to each other. It appeared at the time that the angles would be too deep and I mentioned that I didn't think I was going to use that approach.

I tested the angles by laying the scrap plywood on the structure and clamping it into position. It was quite obvious that the plywood was trying to bend around the edges of the chine and the stem. Some material was going to have to be removed in order for the plywood to lie down properly. But, how much? As best I could tell, on the chine, the angles indicated by the long stick would be the correct angles, or nearly so. After a lot of hemming and hawing, I finally decided to just make the cuts and give it a go.

I started cutting the notches in the port side chine forward of frame 5. Each notch going aft was a bit deeper than the one before it. The finally notch just before frame 5 appeared to line up with the aft side of frame 5 where it joined with the chine. This is what I would have wanted to occur because it would mean that the curve from frame 5 moving forward would be a fair curve with no dips or bumps. More than anything else, this convinced me that the notches were correct or at least close.

As I got closer to frame 5, I realized that the chine was actually too deep into frame five and the curve of the chine was not quite fair at this point. The angle coming down off of frame 5 would have ended up in thin air over the center line of the chine. The gap was not great, only 3/16", but it was enough that I felt I needed to correct it.

Using a long batten clamped in place down the length of the chine and straddling frame 5, I could see that the a fair curve was indeed about 3/16" out from the actual chine. I cut a shim this thickness and about 12 inches long and glued it into position on the chine. This shim was then blended into the chine to make the fair curve.

Now the reason I added this shim was because I wanted the notches in this area to be the correct depth inboard. Most of this shim was actually removed later but I was able to insure that the notches on the chine were not too deep. The same process was repeated on the starboard side.

Once all the notches were cut, it was a matter of blending them together. I used a sander to accomplish this but could have used a plane or some other method. The sander raises a lot of dust, but is the quickest way to get this done, given the tools I have. The biggest thing to watch for when using the sander is to go slower and with lighter touches as you get close to where the final cut should be. I finish it with a block sander and 50 grit sand paper.

The angles on the stem were cut the same way I cut them them when I was working forward of frame 6, by using a long stick lined up on six inch marks on the stem and chine. A short straightedge clamped parallel to the stick and extending up to the stem showed how deep down the sides the notches needed to be. The center line of the stem was the other extent of the cut.

Then a series of close slits were cut until the saw reached both extents. The wood in the slit areas was chipped out and filed smooth forming a notch. These notches were blended together using the sander. Here is the results.

Finally, the acid test. I laid the scrap plywood in place, clamped it into position and saw that I was successful in my cuts.. The angles were close enough that I could correct minor discrepancies with the block sander. Remember when looking at the lower mating surface, that the plywood skin for the bottom will only extend to the center line of the chine, about where the plywood angles away from the chine.

The next step in the fairing process was to complete the keel fairing and the remaining portion of the
stem by the keel. The stem was finished in the same way just described previously. The keel was planed using a hand plane. I had previously drawn a fair curve on the sides of the keel connecting the two notches at frames 4 and 5. I simply planed down to the fair curve on the sides and then finished with the block sander.

At this point, what I have remaining to fair is the chine between frames 4 and 5, the edges of the frames (to match the angle of the skin as it progresses forward from the transom), and some touch up work. There are also a few divots (a polite way of saying screw ups) where I will have to fix the wood and sand it smooth.

I am not yet sure how I am going to fair the frame edges, but I think it will probably involve getting the lower surface battens into position and using these as a guide to get the angles correct. That means that the notches that the batten lie in will have to be cut to the correct angles as well so that the battens don't have to bend over a sharp edge as they progress to the ends of the boat. I'll cover that process next time. I'm still hoping to complete the fairing by the end of September.

Until next time, take care.

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