How to bury yourself in wood dust

I'm "pleased to announce" 🙄 that the fairing process has begun in earnest.

"Fairing." The mere word conjures up the mental anguish of back pain, the ceaseless whir of my cheap belt sander, and enough wood dust to fulfill an old testament prophecy of plague and pestilence.

But, it has to be done.

"but we also glory in our sufferings, because we know that suffering produces perseverance; perseverance, character; and character, hope." 

— The Apostle Paul, in his letter to the Romans, chapter 5 verse 3. 

Or, to quote the classic Pink Floyd album, The Wall:

"The show must go on." 

So far, so good... but there's a LONG way to go.

(For an actual description of the fairing process, click here.)

Whatever floats your boat...

I hadn't expected to encounter rain on the way to the lake. 

That's why I left the drain plugs installed while towing. But rain, it did. And as my mom and I rode comfortably in dad's old pickup truck, the boat was filling with water — and I'd forgotten to switch on the bilge pump.

That sounds more dramatic than it actually was. (How else am I supposed to make this interesting?) 

We drove through a couple of small, intermittent summer rain showers. When we got to the lake, the weather was beautiful and dry. Sure, there was a little bit of water in the boat — just barely enough to justify pulling the plugs out to drain it. 

The drain tubes did their job, and let out all the water they could. There was a miniscule amount of water still left in the boat when I put the plugs back in. 

Thank God, it stayed that way. 

The boat didn't take on any additional water while we were out on the lake.

Good thing, since this was my mom's first trip out in the boat.

Photographic proof that it still floats.

Zip: Floor battens installed

Once the half-lap joints were reinforced, it was time to install the rest of the floor battens.

Then, of course, I needed to start trimming them.

Those builders of Glen-L Zips who choose the optional 3 battens per side arrangement all seem to go about it a little differently. The battens on my Zip are all 2-1/4 inches wide. The inner battens are on 7-inch centers from the keel. The battens themselves are all on 6-inch centers from one another.

That's one milestone reached on this project, but a long, long way to go.

Utility transom drains installed

I finished the interior touch-up paint around the new transom drains. Let's take a look at the before and after of this near-fiasco:

Before:

After:

Plenty of room behind the bilge pump for the starboard drain plug.

Let's just hope they're watertight.

Zip: Scarf Joints, Half-Lap Joints, and Floor Battens

When I went back to the lumber yard to buy more mahogany, they only had 8-foot boards available. So, I bought a couple.

When I got them home, my son helped me rip the wider boards into 2-1/4" widths to use as floor battens on the Zip.

The next challenge was to make 8-foot boards ten to twelve feet long.

The preferred method for this, without question, is to use a scarf joint to join two pieces together. The longer the scarf, the stronger the joint. A 1:12 ratio is optimal.

However....

To accurately make these cuts for a scarf joint on my table saw, I would need a lot of room to maneuver and support these 8-foot boards. In order to make that room, I would need to move quite a bit of stuff around, build a sled for the table saw, and enlist my kids' help in supporting the boards as I made the cut.

To me, it seemed so much easier to simply clamp the boards to my work bench, and cut away sections for a half-lap joint with my router.

The Case for Scarf Joints

Scarf joints are simply stronger than half-lap joints. In many places, I've seen them described as being almost as strong as solid stock. They have a particular advantage of withstanding bends better than half-lap joints, which will fracture much more easily.

The Argument for Half-Lap Joints

My thinking is: the joints in these floor battens will be located in the aft section of the hull, where there are NO bends. Not only that, but just because a scarf joint is stronger, does not mean the half-lap joint is weak. The question is, will it be strong enough to do the job?

In this particular case, I think it will be. As I said, there are no bends involved. Besides, part of my plan includes adding a strip of 1/4" plywood backing over the joint, just as with my laminated keel. The joint, therefore, will be sandwiched between 2 layers of plywood: the backing (or butt block), and the hull itself.

The Jury is Still Out

I decided to go ahead and try the half-lap joint. 

It was easy enough to do with my router and a 3/4" rabbeting bit. The boards themselves were rough-cut, 5/4 mahogany, so it took more than a 1/2" bit to do the job. 

I placed an 8-foot board and a 3-foot board lengthwise on my work bench, aligned & butted them up against each other, and clamped them firmly into place. After deciding on a 4" overlap, I clamped a stop guide for the router across the top of the boards. Then, it was simply a matter of cutting away with the router.

4" half-lap joint, after sanding away all the epoxy mess.

I glued the pieces together with thickened epoxy, and clamped them firmly together. Once the epoxy cured, I was honestly surprised at the strength of the joint. However, I still wanted it to be stronger than it felt, so I continued on with the plan to add plywood backing.

For the butt blocks, I used 1/4" Douglas Fir marine plywood. I've found that the Douglas Fir plywood is considerably more rigid than the Meranti, and in my opinion it's better suited to this type of application. The butt blocks are 23-1/4" long, centered over the joint.

Once these butt blocks were epoxied into place, I was very happy with the strength of the joint.

After re-reading the section on floor battens in Glen L. Witt's Boatbuilding With Plywood, I also came away with an idea for how to reinforce these joints even more. It depends on how I want to build the floor. I'm still considering my options. For now, it's time to move on to notching these battens into the frames.

And the rains came.

There is still painting to be done, particularly on the inside of the boat.

However, I did manage to stay ahead of the rain... barely. Everything is epoxy-coated and under a couple layers of paint.

And most importantly, now that the rain has started: functional. 

Testing the transom drains. During actual use, the plugs will be on the inside.

Redemption?

Progress is coming along nicely on the transom repair.

It looks like everything's going to be fine, but we won't know for sure until the boat is in the water. In the meantime, let me catch you up on the progress.

Here's where we left off:

I had cut a 1-1/4" diameter x 2" long plug of mahogany with a hole saw, filled the pilot hole with thickened epoxy, coated everything (heavily) with thickened epoxy, and tapped it into place with a hammer. 

Ugly. But solid.

The next day, I very carefully re-cut the starboard hole to where I wanted it to be.

Starboard hole re-drilled & sanded.

This put the top of the opening where I wanted it to be, but it also now created a gap at the bottom, as you can see in these next photos.

At first, I planned to simply fill this in with a lot of thickened epoxy. That probably would have worked fine, but another thought occurred to me.

The big 2" chunk of mahogany I'd cut the plug from was still sitting on my drill press, underneath the 1-1/4" hole saw. I realized that, if I aligned the hole saw slightly off-center from the hole, I could cut a 2" long crescent-shaped shim.

I then coated the shim in thickened epoxy, and pressed it into place.

This, of course, left another ugly mess once the epoxy had cured. So, I ran the hole saw back through the hole to clean up the inner diameter. Then, I spent some time sanding, filing, and chiseling away the excess in order to create a nice, flat surface for the drain tubes to mate to.

I regrettably don't have any "before" pictures of the drain tubes. I'll try to describe this part succinctly:

I used Moeller 1 x 3 tubes that I bought from Jamestown Distributors. These are made from thicker, heavier brass than the Seachoice tubes you might find at Academy Sports or Walmart. The Moeller tubes aren't as "pretty" (meaning shiny and polished), but they're definitely stronger.

The tubes come flared at one end. I placed the tubes in the holes, and marked approximately 1/8"  extended past the transom. To do this, I simply held a fine-tip sharpie flat against the transom, with the tip on the brass tube — and rotated the tube to create the mark.

I cut the tube off at this mark with a pipe & tubing cutter.

The installation

I mixed a batch of epoxy, and using double layers of latex gloves, I coated the inner diameter of each hole and all other exposed-wood surfaces in order to water-seal it.

Then, I added mahogany wood dust to the remaining epoxy and thickened it heavily. With this mixture, I coated everything — and I mean EVERYTHING — the inner diameter of the holes, the outer surface of the tubes, and any / every mis-cut that needed to be filled.

Then I inserted the tubes from the outside in, using a twisting motion to make sure as much epoxy as possible remained between the tube and the wood.

To flare the tubes, I used a flaring tool that I'd gotten from another boatbuilder (who actually launched his boat for the first time yesterday — congratulations!). I believe the flaring tool was a Seachoice or SeaSense brand. Plenty of boatbuilders say you don't really need one of these tools. I haven't tried their described methods, but they apparently do work. For my part, I was glad to have the flaring tool.

In the process, I got epoxy all over everything. I made a helluva mess, and it took forever to clean it up. But, in the end, I was left with this:

Starboard drain tube

Port drain tube

Obviously, this mess needs to be painted now. Stay tuned, and God Bless!