Tuesday, January 24, 2017

The Slow Saga of Zip Frame #4 — part five

In part four of this "Slow Saga," we left off with a pretty substantial gap in the first glued lap joint.

The gap, as of the last post.

Yesterday, I filled the gap with thickened epoxy, then forced the gap closed with some substantial clamp pressure.

The lap joint clamped back together, as the epoxy cures. I used scrap plywood to protect the wood from the strong clamp pressure.

After leaving it to cure for 24 hours, I removed the clamps. Thankfully, the closed gap held.

Clamps removed.

I wanted to drive a second screw through the lap joint, so I drilled a pilot hole, then countersunk it with a larger drill bit.

My attempt at countersinking the 1-3/4" #10 screw wasn't that great. The second attempt, on the other side of the frame was better.

Unable to leave well enough alone, I removed the screw from the first side, re-drilled the hole with a slightly larger bit, and drove a new screw through it. Much better.

Sunday, January 22, 2017

The Slow Saga of Zip Frame #4 — part four

Sometimes, the damnedest things go wrong.

I had decided to attach one of the side ribs to the floor beam, using thickened epoxy and screws. Seems simple enough, right?

Epoxy and screw the rib to the gusset: Done. 

Epoxy and screw the rib and gusset to the floor beam: Done. 

Drive one two-inch screw all the way through the lap joint. Well now, that's where we developed a problem. The screw actually pushed the rib away from the gusset some, rather than pull the whole thing together.

In hindsight, the simple thing to do would have been to remove the screw, and re-drive it. However, that's not what I did. I put nine clamps on the joint, and drove the screw as tightly as possible... until it broke.

No problem, I thought. I had more than enough clamps on there to do the trick. Or, so I thought.

You'd think this would be enough clamps. It wasn't.

Once the epoxy cured, and I removed all the clamps, however... I realized that reality was a bit different from my expectations. 


that's a big enough gap, you can see daylight through it.

The reality was that there was a substantial gap between the frame rib and the gusset. This is, of course, unacceptable. It must be fixed.

Fortunately, it looks like the gap can be pushed together, if I apply enough clamp pressure in the right place. So, my plan as of now is to fill the gap with more epoxy, and clamp it together forcefully.

Fortunately, enough pressure from the right kind of clamp will close the gap.

All this helped me to realize the weakness in my approach to the lap joint: Using only one screw through all the parts. I won't repeat that mistake on the other side. In addition to the one 2" #10 screw that's already in place, I will add one or two additional 1-3/4" screws that I bought recently. 

Here's part of the problem: only one 2" screw through the lap joint. I'll add one or two screws to this side, to avoid the same mistake. The best thing may have actually been to use carriage bolts. I used what I had, however.

Sunday, January 15, 2017

The Tedious Tale of Zip Frame #2 — part three

Attaching The Shims.

The shims were cut from some scrap mahogany.

I used epoxy, thickened with mahogany wood dust, to glue them on.

Held them in place with a lot of clamps for a day.

Waxed paper kept me from gluing the floor beam to my work surface.

Clamps removed.

A few passes across the planer/jointer to smooth the sides.

Next step will be to shape the bottom of the floor beam to its proper dimensions.

Monday, January 9, 2017

New year. Old trailer.

Happy New Year!

In the last post, we left off with the holes I drilled in the transom as preparation for bolting the motor to the boat.

However, before I can bolt the motor to the boat, there are a few other things I need to do. One is to seal the inner diameter of the holes with epoxy in order to water seal them and protect the wood. Also, I wanted to do some work on the trailer. This work would require lifting the boat. Obviously, that is more easily accomplished without the added weight of the motor.

New bunks for the trailer

I have never been fully satisfied with the bunks I built for the trailer, back in July 2015. At 4 feet long, they are longer than the bunks that came on the trailer when I bought it. However, after building and installing them, I still felt they were too short to sufficiently support the boat. In time, I also began to dislike the way they only supported the boat on the narrow end of the boards.

I decided that I wanted longer bunks that were also wider. 

The first set of bunks I built for the trailer back in 2015.

So, my kids helped me raise the boat and prop it up on a 2x4. I removed the old bunks, and tore the carpet off of them... and decided that I could reuse it all.

The boat lifted up onto a 2x4

The new 5' 7" bunks in position

I cut some new 2x4's to a length of 5' 7" to use as the new bunks. I used the old bunks as supports, since they were in perfectly usable condition. That's not to mention they're already measured and drilled for the brackets. I screwed the new bunks to the old ones in a "T" fashion, so that the wide end of the board would support the boat.

Between the repurposed carpet and the leftover I had from the original roll, there was enough to cover the full length of the new bunks. I stapled it on with stainless steel staples.

After re-attaching the bunks to the trailer brackets, I also replaced the center roller with a new one. The old roller had hardened and gotten rather grimy.

New center roller
The old roller had marked up the underside of the hull pretty badly.
Another of my goals for this work on the trailer was to lower all the supports enough so that the bow would fit into the "V" of the bow roller. Even with the roller's bracket raised as much as possible, the bow never actually rested on it.

So, after everything was installed, my son helped me lower the boat back onto the trailer. All that was left to do was to crawl underneath and tighten a few bolts. Everything seemed to go together pretty well. I'm definitely happy to have more support underneath the hull now.

With the boat resting on the new bunks, the bow fits into the bow roller.

The new bunks provide considerably more support to the boat.

New stainless steel bolts, waiting for the motor.