Keel: Truth and Theory

I cleaned up the edges of the keel, sanding & chiseling away the excess epoxy, to get a better look at the fitting of the laminated pieces. It'll work. There are some things I need to fix. There are some things I wish I'd done differently:

I wish I had cut ALL sides of each board with the table saw. Never assume the lumberyard edge is straight. There were some parts that were narrower than the rest of the board. Now, those places have caused uneven sides in the laminated section, and those spots need to be filled.

I wish I had planed the boards more. I needed the thickness of my laminated keel to be one inch. I also wanted to leave myself a little room for error. That's why I started getting nervous when the planed boards got as thin as 5/8". Unfortunately, leaving them at that thickness also meant that the surfaces didn't get planed as flat as they could have been. It turns out that, at 5/8" there was still plenty of thickness for me to plane them just a little more so that the surfaces would have been at least somewhat better. After lamination, the combined thickness is 1-1/2 inches. I was shooting for 1-1/4. So, I could have taken another 1/16" off each board, easily. The surface irregularities, though seemingly minor to the naked eye, left noticeable gaps when the pieces were combined. I knew that would happen, anyway.... but it could have been better.

For the very same reasons mentioned above, I wish I had taken the time to sand the surfaces of the boards after I'd planed them. I don't have a thickness planer. I have a general-purpose planer/jointer. It "gets the job done," but it's a lot to ask for one guy to get a nearly 10-foot board planed perfectly flat with one of these things. Just a little surface sanding would have knocked down some high spots, and improved the fitting.

Those are some lessons learned.

In most places, the fitting is fairly decent.

In some places, the fitting is better than in others.

This area on the starboard aft is definitely getting shimmed.

In some places, the fitting is not pretty. This gap in the seam will get filled with some more thickened epoxy. I'm also going to shim the gap seen at the bottom part of the photo.

This little gap on the side will get a shim, also. Is that a hairline crack I see?

The Slow Saga of Zip Frame #4 — part nine

I wanted to make all of the major cutouts in the dash beam long before the hull is built and flipped. It seems to me that it would be easier to do this work now, when I can lay the beam flat on a work bench, than when it's a vertical fixture in the hull.

And, since my dash has the 10 degree angle "built in" to the frame, I felt it would be easier to make these cutouts before attaching the dash beam to the rest of the frame.

Now, all those cutouts have been made.

3-1/4" cutout for the helm, plus marking the placement for a rocker switch.

I made the initial cuts for the rocker switch hole with a drill and a coping saw.

I enlarged the hole with my jig saw, and finished it with a wood file.

After some tedious and meticulous work with the file, the switch fits. I'll file it just a little more to accommodate a layer or two of epoxy.

The next steps for Frame #4 will be to sand away my placement markings and attach the dash beam to the rest of the frame.

Happy Monday to you! (Yes, it's a Monday, but we can make it a good one if we choose to.)

This is the day the Lord has made; let us rejoice and be glad in it.

— Psalm 118:24

3/4 of a keel

Lamination work on the keel has begun.

I started with the big 4" wide chunk of mahogany, mentioned in the last post. It was 4" wide, 2" thick, and 9' 10" long.

The plan was to re-saw this board into 3 smaller boards, each approximately 1/2" thick. I would then (a) cut a short 3' section off of one of these boards, and butt-join it to one of the longer ones. I'd then (b) take the longer leftover cut, and use it to back the butt joint.

This would leave me 3/4 of a keel, with the thicker section on the aft portion. Since the forward section would temporarily be thinner, it should (c) be easier to bend, as needed, into the keel notch of the breasthook when attaching the keel to the frames.

Once this is accomplished, I would (d) laminate the remaining needed thickness onto the forward section of the keel.

My re-saw job on that big chunk of mahogany was less than perfect. I set my rip fence to cut a 3/4" wide strip. I knew I'd have to plane some surface irregularities from there, and I did. Two of the finished pieces were 5/8" thick when I deemed them "usable." In retrospect, I wish I'd planed them down a little further in an attempt at better fitting.

The remaining, "leftover" board is closer to 1/2" thick... or maybe even a little less. 

Due to some width irregularities, I shortened the 9' 10" length down to 9 feet. The Zip plans call for a 4" wide x 1" thick x 12' long keel.

So, where are we now? As you might have guessed from the title, we're at the point of having 3/4 of a keel. Let's take a look:

Sometimes, you just don't have enough clamps.

Somewhere in the middle of all that is the butt joint.

Butt joint and backing plate.

I used System Three Silvertip epoxy, thickened heavily with mahogany wood dust. I knew the fitting between the laminations would be less than perfect, so I wanted a good thick mixture to fill in any gaps. 

After the epoxy cured and I pulled the clamps off, I saw that some of those gaps had been bigger than I thought. Since the thickness of the laminated keel is now at almost 1-1/2" inches, I realize now that I could have safely planed away more surface irregularities and still made my goal of 1" combined thickness.

At the time, I stopped planing at "usable" because I feared the wood was getting too thin. 

Live and learn.

Ah well, epoxy-filled gaps or not, this is the keel, and I'm moving forward with it.

Christmas in February

With a hectic work schedule this time of year, there was virtually zero progress on the Zip during January. February and March don't look to be much better, but there is good news.

Cupid, who has otherwise proven himself useless over the last few years, has delivered quite a few gifts to my little boat shop.

There was the massive 2" thick x 8" wide, and roughly 9' 6" long board of mahogany. This is destined to be the keel and a few other parts.

There's the NFB rotary helm and bezel, as well as a Faria Euro Beige fuel gauge, to add to the dash hardware.

And, in order to make something of that huge mahogany board, there's the new table saw.

Faria Euro Beige fuel gauge, NFB Safe-T II rotary helm, and 90° bezel.

Look at this mess. Seriously... I just bought this yesterday. Yes, I DID use the proper blade guards. Here, they are removed in preparation for re-sawing the 4" wide keel.

The big chunk on the left is the current state of the keel... still a full 2" thick. The 2 stacked pieces on the right are 2-1/4" x 1" floor battens. The leftover piece in the middle is waiting to serve a purpose.

So far, I have ripped the 8" wide board into 2 4" wide sections. One of these sections will become the keel. The Zip requires a 12' long x 1" thick keel, and this board is only 9' 6" long. My plan is to re-saw it into 3 strips, and butt-join & laminate pieces cut from that in order to obtain the full 12 feet.

The second 4" wide section had some problem areas along one edge, so I ripped that again into a 2-1/4" wide section + the leftover side. Then I re-sawed the 2-1/4" wide x 2" thick section into two 1" thick strips. These will be 2 of the 6 planned floor battens.