Sunday, June 24, 2018

First 2 floor battens attached

The time finally came to un-screw frames 2 and 4 from the construction form.

The frames had been attached to the construction form in order to prevent them from moving and thus causing misalignment problems. That's all fine and good. However, the way I attached them to the construction form created a bit of a dilemma concerning the floor battens.


Middle batten attached, clamped to levels in order to keep it flat.
So, my plan was to first attach the middle floor batten, because it is outside the attachment point / problem area. Then, I would unscrew the frames & remove the blocking. I figured that with the keel and one floor batten attached, the frames would be held in position securely.

After that, I'd attach the inner floor batten.


This photo shows how frame #2 is attached to the form: blocking is screwed to the spreader, and the frame is screwed to the blocking.

Same thing with frame #4.

This photo shows the dilemma. If I don't remove the blocking, I'll likely glue both the frame and the floor batten to it permanently.
Blocking removed; lines drawn on the batten showing where to apply epoxy.



Here, the inner batten is clamped to levels in order to keep it straight. The middle batten is already attached. Notches have not yet been cut for the outer batten.


Shim to improve fitting at the transom notch.

Inner batten attached. It's clamped into position as the epoxy cures.




Friday, June 15, 2018

Cutting notches for the floor battens

As you may have noticed from the photos up to this point, I did not pre-cut notches for the floor battens into the frames. That's because I planned to use the optional arrangement of 3 battens per side, rather than the standard 2 battens as drawn on the plans.

I wanted to wait until I could actually lay the battens on the frames, and place them as I wanted. What I've decided to do is to use 2-1/8" battens spaced 7 inches centerline-to-centerline from the keel, then 6 inches centerline-to-centerline from one another.

Here's how I went about cutting the notches for the floor battens:


The inner battens are on 7" centers from the keel.

The floor battens are on 6-inch centers from one another.
The battens, (or at least the two I have at the moment), are about the same thickness as my ruler. So, I will use the ruler as a guide to mark some reference lines.



At the aft end, I make sure to hold the ruler even with the underside of the batten, not flush against the 12° rake of the transom.



Using the underside of the ruler as a guide, I draw a line with a pencil to show how deeply to cut the notch. 

Then, I clamped the batten into place and made some initial cuts, using the sides of the batten as a guide.



I used a block of wood with a 12° rake as a guide, so that the horizontal cut would be level, not angled like the transom. This block of wood is actually the former tail-end of the keel.


Here, you can see that I goofed one of the vertical cuts. Fortunately, it didn't get very deep before I noticed my mistake. I'll fill this in later, but hopefully most of it will get faired away when I get to that phase.


Using this block as a guide, I held the multi-tool blade against it as I made the horizontal cut.




Here's the cut through the transom.

And the fitting of the batten into the notch. Not bad.
That completes the notch cut into the transom. Now let's move forward to Frame #2.

As before, I used my ruler as a guide to mark the depth of the cut, since it's about the same thickness as the batten. The ruler is aligned with the edge of the frame, so that the mark for the cut will be at the same angle. (Remember that the boat is upside-down on the form, so what's showing is actually the bottom edge of the frame.)


Ruler aligned with the bottom edge of Frame #2.

I'll mark the line with the scribe that is built-in to my sliding square.

Line marked for the horizontal cut.

Cutting guide and batten clamped into position.

The vertical cuts were made by aligning the side of the multi tool's cutting blade with the side of the batten.

The horizontal cut was made by aligning the bottom of the multi tool's cutting blade with the top of the cutting guide. I made minuscule finishing cuts with a coping saw.

The batten drops right into place.

Now, to repeat for Frame #4.


Cutting guides clamped into position.

Notch is cut.

That line next to the notch isn't a cut. It's the end of a shim I laminated onto the frame earlier.

Batten drops right in.
Now, for the Limbers. These are openings in the frame, alongside the floor battens, to allow any water in the bilge to flow to the back of the boat for removal.


I used this roll of Duck Tape as a guide to scribe the curved line. Seriously... it's called "Duck Tape."

Curved line scribed onto the frame.

Making the rough cut with a coping saw.

The rough cut is easily finished out with a Dremel tool fitted with a sanding drum.

et VoilĂ 

Working backward, repeat for Frame #2.
So there you have it. That's the procedure, or at least my version of it. Four more floor battens to go... but for the moment, I'm out of mahogany.

Wednesday, June 13, 2018

Keel, End-to-End

There are two main reasons why I chose to build a laminated keel.

The primary reason has to do with the upward bend that the keel makes at the forward end. A 1-inch thick mahogany board does not bend as easily as a board half that thickness. Not only that, but only the front part of the keel must bend... the rest of it has to remain perfectly flat.

Several Glen L. Witt designs use this technique. A common problem encountered by builders of Glen-L boats such as the Squirt and the Zip is that bending the forward end of the keel produces a bow in the aft section, where it is supposed to be flat.

My thinking was that, by having the aft section laminated to its full thickness of 1 inch, and leaving the forward section un-laminated at 5/8", the forward end would bend easily without disrupting the flatness of the aft end.

Simply put, it worked, and I'm glad I did it this way.

The other reason is that, by laminating, I could make a 14-foot keel out of shorter boards. While my execution of all this wasn't perfect, it does work.

So, on to the photos:


3-1/2" carriage bolts through 5/8" section of keel and the stem.

Holes drilled, test-fitting the transom knee.

I drilled the holes through the keel and transom by first clamping the transom knee into position firmly, then using the pre-drilled holes in the knee to drill from the inside of the knee outward. To do this, I used a 12" long, 1/4" diameter drill bit.

Transom knee temporarily bolted into position with 5" bronze carriage bolts.
Adding the final lamination to the keel. Note the forward holes to accommodate the carriage bolt heads that were already in place. The lamination was done with thickened epoxy and clamps only. No screws.

Transom knee epoxied and bolted into position.

Countersunk bolt holes, filled in with thickened epoxy.

Overhanging end of the keel cut off.
Epoxy fill sanded flush at the aft end.

Epoxy fill sanded flush, and a little pre-fairing at the aft end of the keel.

Epoxy fill sanded flush at the forward end.

Epoxy fill sanded flush at the forward end. 


The now fully-laminated keel. Note that I've started cutting notches for the floor battens.
Cutting limbers for the floor battens. More on that later.

So, the keel is on, and it's there to stay. Time to move on to the next step.