Friday, January 24, 2014

Sometimes it's the obvious things

I reserve the right to change my mind.

Yesterday, I'd decided to just leave the globs of cured epoxy sandwiched between the chines and stem as-is. They were hard to reach, and it seemed like it was going to take me forever to make any real progress on them. So, I thought I'd just write them off as large, malformed, out-of-control fillets.  

That was before I discovered the obvious: 

A chisel is very effective at removing cured bits of epoxy.

Certainly it will do it faster than sandpaper or files, which are of course still needed to smooth the surface. For what it's worth, I noticed that the epoxy I'd thickened with #2 silica is more brittle and breaks away easier than the epoxy I'd thickened with mahogany sawdust.

So, with chisel in hand, I once again attacked the biggest glob of epoxy, which is behind the starboard chine. After making a bit of progress with the chisel, I filed away aggressively with a coarse round file. A little more work, and I'll have it reduced to something more acceptable.

Sure, it will still be a large fillet. But it won't be so malformed and out-of-control.

So with that, I've made a blog post each day this week. I suppose it's a fairly representative week in the slow-but-steady progress I'm making on the Utility. God willing, I'll be able to put the little boat in the water this year.

Thursday, January 23, 2014

The Utility: More incremental progress

As predicted, progress on the boat over the last 24 hours has been small and incremental. Little things have to be done in preparation for the larger tasks. So it was yesterday evening. I sanded & filed away at some big globs of cured epoxy.

I should not have been so careless as to let these big globs cure in place unnecessarily. It only makes for more work to do after-the-fact. Of course, you can't always reach some places to scrape away extraneous epoxy.

Equally, sometimes you can't reach a dried glob of the stuff with a sanding block or a file, when the thin blade of a putty scraper would've gotten rid of it easily before it cured. Such is the case with those spots behind the chine at the sheer. I decided to just leave them. Technically, I suppose these spots are already "encapsulating" that small area of the wood. It's just not pretty. So be it. That part of the boat will only be visible with a flashlight, anyway.

Moving forward, I'll just have to strive to work more neatly with epoxy.

Wednesday, January 22, 2014

Preparing the stem for encapsulation

I should have encapsulated the stem a long time ago, before I ever attached it to the keel. I'm not sure why I didn't. Nonetheless, I did not. I won't repeat that mistake on the Zip.

In any case, it needs to be done now before the planking goes on. In preparation for encapsulating the stem, I need to sand away several dried globs of epoxy that have been stuck on it since earlier stages in construction. The worst of these are directly behind the chines, where they are attached to the stem.

I worked on that a little earlier this morning. As this is the middle of the week, and free time is quite limited, I'm expecting several more days of small, incremental progress in this task.

Tuesday, January 21, 2014

Success of a simple marking gauge

Just for fun, I thought I'd try to make a blog post each day this week. (I'm not making any promises, though...)

My Silvertip epoxy arrived yesterday. So, last night I took the next step & removed the forward starboard planking so that I can get to all parts of the stem.

I was happy to see that the marking gauge I'd made from a large spring clip worked very well. You may recall from an earlier post that I'd had some alignment issues when drilling through the planking and into the chine. 

The idea behind the marking gauge is to have a quick and simple method of marking where to drill through the planking so that the screw will go where you want it to in the chine, sheer, frame member... you get the idea.

With the spring clip, I simply placed the clip against the chine and extended one of the tabs. Then, I marked the alignment for the center of the chine with a piece of tape. With the plywood planking clamped into place, I just put the spring clamp over the edge of the plywood so that the clip touched the chine. Then, all I had to do was extend the tab and mark the line indicated by the tape. Worked like a charm.

Forward planking removed, revealing nicely aligned holes along the chine.

Here's the simple marking gauge. The silver duct tape on the other tab is for marking along another area.

Monday, January 20, 2014

Planking progress stalled by need to encapsulate stem

As January keeps winding on, it seems as though I’ve had a million things to juggle or deal with that keep interfering with my boatbuilding progress.

I am making progress, however.

I’ve gotten the forward starboard plank screwed into position. It is not epoxied on yet, however. The simple reason is the fact that I have not yet encapsulated the stem, which is still bare plywood all the way around. Once the planking is on, it will be very difficult to reach certain parts of the stem in order to coat it with epoxy, (or “encapsulate” it), as protection against moisture. So, I need to encapsulate the stem before I permanently attach the planking.

The forward plank on the starboard side is screwed into position.

Detail view at the stem
In this detail view, you can see the how the added chine strips got blended into the shape of the forward bend in the chine.

Unfortunately, I don’t have on-hand the proper type of epoxy for encapsulation. What I have on-hand is System Three Silvertip Gel Magic. VERY viscous stuff that is great to work with to glue parts together. However, I need something much thinner for encapsulation. I liked the Gel Magic enough that I decided I’d try another System Three product, so I ordered the regular Silvertip epoxy. It should be here early this week.

In the meantime, I have fitted, glued and screwed the butt block into position on the port side of the boat. 

Fitting the butt joint on the port side. Without the butt block in place, the forward plank does not match the curvature of the aft plank.

By comparison, here is the butt joint on the starboard side. The butt block allows the forward planking to match the curvature of the aft planking.

The port side butt block, before being epoxied into place.

The butt block epoxied into position against the aft planking on the port side.

The next step will be to encapsulate the stem & a few other parts with 2 or 3 layers of the Silvertip epoxy. Then, I can permanently attach the starboard planking. After that, the rest of the port side planking.

Thursday, January 2, 2014

Side planking? Well, almost...

Happy New Year to you! Last fall, I’d made it my goal to have at least one side of the Utility fully planked by the end of the year. I didn’t quite make that goal, but I’m close.

Over the Christmas holiday season, I made incremental progress on the boat. I trimmed off the aft ends of the side planks, where they extended past the transom. This was largely done sanding it by hand to avoid splintering the Meranti plywood... something Meranti is a little prone to doing, although not as badly as I’d thought. Now I’ve got a nice, flat surface on which to add a layer of the 1/4” Meranti on top of the 3/4” Douglas Fir plywood transom. The goal is to have matching, bright-finished transom and foredeck.

The transom; sanded & ready for a layer of 1/4” Meranti.

Starboard plank at the transom.

I also did enough rough fitting / shaping of the forward starboard side plank to use it as a template to mark and cut the plank for the port side. That plank is now temporarily clamped into position.

The next step was to fit the butt block on the starboard side, in preparation for attaching the forward plank.

I started by cutting a 9 x 19 inch piece of the 1/4” Meranti. The 9” width was to allow for a 4.5” overlap on either side of the butt joint of the planking. The 19” height was the general distance between the chine and sheer at the location of the butt joint. The problem is, the chine and sheer are not parallel, so my rectangular piece had to be trimmed to fit.

I marked and drew the centerline on the butt block, and held it in position with one hand. With the other, I marked the location of the chine and sheer onto the butt block. Then, drawing a line between these marks gave me the trim lines to cut in order to fit the butt block into position.

Next, I used one of the reversible Irwin clamps as a spreader bar to press the butt block into position, matching the curve of the aft plank. Then I marked and drilled two rows of offset holes, spaced approximately 2” apart, and screwed the butt block into position with 3/4” silicon bronze screws.

Fitting the butt block into position. Note the spreader bar pushing the butt block into the curvature of the aft plank.

Finally, on New Year’s Eve, I disassembled the butt block, coated the mating surfaces with epoxy, and put it back together. Cold temperatures led to a rather slow curing of the epoxy, which had me concerned as the last minutes of 2013 ticked away. However, I was happy to find the next morning that the epoxy had cured perfectly well.

NOW I can finally get around to attaching that forward starboard plank.

Butt block after being epoxied into position.

The 3/4” screws were a little longer than needed. I’ll have to sand all these ends off later.

Fitting the forward plank into the butt joint with the aft plank.