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.

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.

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.

The Utility: Rough fitting the 1st forward panel

The aft port side panel is now attached. I followed exactly the same procedure as for the aft starboard panel, except this time I did remember the rag.

I decided to go ahead and rough-fit the forward panel on the starboard side. First, I marked and cut one of the Meranti panels in half lengthwise, giving me two 2' x 8' panels to use for the side planking.

Using one of these panels, I began to fit it to the starboard side. I had to go through several cycles of "Clamp, Mark, Remove, Cut, Repeat" in order to cut away extraneous material from the front of the panel. This was due to the low height of the construction form. For several attempts I could not bend the plywood all the way around to the bow without the floor getting in the way.

Finally, I got it roughly fit & it is now temporarily clamped into position. Once I'm satisfied with the fitting, I will check the starboard panel against the port side. If everything looks like a suitable fit, I will then use this panel as a template to mark and cut the second panel from the other 2' x 8' piece of plywood.

So far, I'm pretty pleased with the Meranti. It is a nicer-looking wood than I expected, and it seems to bend much easier than the Douglas Fir plywood.

Forward panel rough-fit & clamped into position on the starboard side.

The Utility: First planking panel attached

Over the weekend, I was finally able to attach the aft starboard side panel with epoxy and screws.

First, before I removed the panel from the boat’s framework, I traced the lines of the chines, sheers, and frame to the inner surface of the plywood. That way, I would have an easy visual reference for where to spread the epoxy. I also drew reference points on both the plywood and the chine to help align the panel when it was time to put it back on.

I removed the panel & set it aside, and staged all the items I’d need nearby: chip brush, extra latex gloves, awl, clamps, screwdriver, and the silicon bronze screws. I kept extra screws close at hand just in case I stripped any screw heads. This time, I put some old newspaper down on the floor to catch any drips of epoxy... right next to the earlier dried globs that I’m going to have to sand off of the concrete at some point.

Planking panel removed & waiting for epoxy.

Frame outlines made a great reference for spreading the epoxy.

Waiting for epoxy.

Some of my alignment was a bit off when I drilled into the sheer. I'll have to be more careful next time.

Same drilling alignment issue with the transom frame.

With everything ready to go, I mixed 6 oz of Silvertip Gel Magic epoxy. Gel Magic is a highly-viscous 2:1 mixture (2 parts resin to 1 part hardener). Its thickness makes it ideal for applying to vertical surfaces and for filling gaps. In this way it is very similar to Glen-L Poxy Grip.

The GelMagic components are color-coded.

Using the chip brush, I applied epoxy to both the plywood panel and the mating surfaces on the boat’s framework. At one point, I was concerned that 6 oz of epoxy would not be enough to do the job. Luckily, however, it was just about right, with a minimal amount of waste.

Wearing 2 layers of disposable latex gloves, I roughly aligned the panel with the reference marks I’d made earlier, and held it in place with one clamp. The Irwin spring clamps are great for this, as the springs in them are quite strong. Next, I used the awl to align the first holes, adjusting the clamp as necessary. I hand-threaded the first screw, then changed gloves to avoid getting too much epoxy onto my screwdriver.

After driving the first couple of screws, I clamped the rest of the panel into position. Hand-driving the screws went very smoothly. I found that using a ratcheting screwdriver with an oversized handle is just ideal for this task. I also found that I’d over-beveled some of the holes, as a few of the screw heads went slightly below the surface of the plywood. I’ll create less of a bevel next time.

With the panel fully “glued and screwed” into place, I used the putty knife to scrape away excess epoxy from the areas where I’ll need to join more wood: the chine and sheer where the forward planking panel will butt up against the aft panel; and the interior joints of the chine and sheer to the aft panel where the backing piece for the butt joint will be attached. I then used the putty knife to fill the screw holes with epoxy.

It was while using the putty knife that I realized the major component of this process that I’d forgotten: 

A rag. 

Thankfully, the laundry basket was nearby. 

There’s one less item I’ll have to wash, dry and fold. Hopefully, however, I will remember to get shop rags next time.

Alignment marks & filled screw holes along the chine.

Excess epoxy was scraped away from the chine so it won't interfere with fitting of the forward panel.

The small gap on the side of the transom is now filled.

Seam of cured epoxy against frame #1.

On the interior seams, I scraped away excess epoxy so it won't interfere with fitting of the backing block for the butt joint.

The Utility: Incremental progress on the planking

It has been a week of small, incremental progress on the Utility. Even when you can only spend 15 – 30 minutes a day on the project, each little step gets you further along, and can take much of the prep work out of the next major task.

So it has been for me over the last several days. One morning, I simply measured and marked the location for driving screws through the planking and into the chine. That evening, I “connected the dots” between these marks, giving me the line along which to drill the holes. The next day, I marked points along this line, spaced 3 inches apart. I drilled holes on a few of these points, and drove a few screws. The next day, I did a few more... and so on. 

Aft starboard side panel, dry-fit & screwed on.

Once the aft starboard side panel was screwed on, I trimmed the edges down some with a block plane. Then I went back and beveled the rims of the screw holes just enough so that I can drive the screw heads down flush with the plywood surface, while still achieving good compression of all the plywood layers beneath the screw heads.

Screws spaced 3" apart; Holes beveled for flush fit & layer compression.

At this point, the aft starboard side panel is screwed and fitted into place. I will have to wait until I have more free time to remove it, apply the epoxy, and then put it back on. In the meantime, I’ve resumed the fairing for the port side panel.

And, oh yes... Don’t think I’ve forgotten the Zip. I’ve assembled its breasthook & have been sanding the sides, as time permits.

Zip breasthook assembled & being sanded.

The Utility: Fitting the first planking panels

After a brief debate about whether to plank the transom first, or last, I eventually came to the conclusion that it’s a matter of individual preference. Other boatbuilders I trust kindly offered me their opinions, reasons, and techniques. I weighed all of their input before deciding on my own course of action.

I’m going to plank the sides first, and the transom second. That way, the aesthetics of the bright-finished transom should be consistent all the way out to the sides, with no end grain from the side planking visible.

Then I’m going to plank the bottom last. The reason for this basically boils down to ease of construction, regarding the transom. It seems to me that it will be easier to plank the transom while I can still access both inner and outer surfaces of it for clamping. I wouldn’t be able to do this after the bottom is planked. Since the lower edge of the transom will be underwater, then it won’t matter if the end grain is visible (whether or not it’s an aesthetic matter).

Planking
I started by cutting two 2’ x 4’ panels from a sheet of the Meranti. These will be the aft side panels. I clamped the first one into place on the starboard side. Then I roughly traced the trim line with a pencil, and removed the panel. I drew a second line 1” outside the trim line, so the panel would still be slightly oversized after I cut it. I cut it, and checked it against the port side. Since it looked good against the port side also, I used the cut piece as a template to trace out the second panel.

With both panels cut, I clamped them back into position. I’m very happy with the fitting on the starboard side. The port side still needs a little fairing, but it’s close.

Initial fitting of the aft starboard panel.

Aft starboard panel-to-transom fit. This gap will need to be filled in.

Aft starboard panel to frame #1 fit.

Aft starboard panel-to-transom inner fit.

Aft port panel-to-transom fit.

Aft port panel-to-sheer fit. This area needs a little more fairing.

Aft port panel-to-sheer fit, forward of frame #1. This area needs a little more fairing.