Make and Make Do  

By Rob Rohde-Szudy - Madison, Wisconsin - USA

 

Building Polepunt

Polepunt is a cheap and simple boat, and it might not seem worth a building article at all. But there are a few technical details where a short discussion might save the next builder some time. However, the reason I started writing this article is different.

Working with kids

At six years, my eldest daughter, Thalia, was ready to help dad with a project. She got interested in Polepunt when I pointed out that she could row it with kid-sized oars. She has always wanted to help with the rowing, but the oars in the light schooner are far from kid-sized. Polepunt is also the right size and complexity level that a kid can take a meaningful part in the project without losing all interest before it is complete.

Maybe this seems trivial, but I don’t think so. Once the boatbuilding bug bites you, you will need to find a way to get your family involved or you’ll never see them! (I exaggerate, but less than you might think.) The trouble is that most of us don’t know how to do shop work with a kid. Let me offer some ideas.

Drawing the lines

Thalia took great pride in striking the lines once dad lined up the straightedge. I showed her the numbers on the plans, then she would find the number on the tape so I could make the marks. She learned all about getting your body in the right place to make a good mark. And she also got to strike the curved lines while dad held the batten in place.

While she liked making the lines, she wanted to be far away while power tools were in use. Smart kid. I showed here the use of the hand saw and planning to a line, but she’ll need a bit more physical size to make these tools work right.

Of course they do get bored fast, and it’s hard to keep them occupied. Here they are destroying some Styrofoam. You can see why I seldom throw things away.

Driving nails

Kids love driving nails. It’s good to have lots of cheap little nails and some scrap wood for them to practice on. Thalia actually helped with the real nails on the wales and bulkheads. I’d start them and she’d get a few of them close to finished, then I’d drive them flush. She especially enjoyed clenching. There might be lapstrake in her future.

Painting

Kids really love painting. Even Rhea, the three-year-old could help paint. Make the most of it!

Going 3-D

This is a magical moment for any boat builder. A pile of parts becomes a boat. They mostly just handed fasteners to dad, but it is no less magical for kid boat builders.

Bending the Chines

OK, here begins the technical part. In the plans, Jim is not kidding about finding good bending stock for the chines. I broke the best I was willing to pay for, which was admittedly not very good. (I picked through the entire pile of cheap construction grade lumber.)

With this tight a bend and a 1.5” section, any grain runout will cause a break. 1.5” at this radius generates enough force to rip screws out of the edge of the plywood. I decided this was too much force on the fasteners and laminated the chines.

But I didn’t laminate the whole thing because that seemed like a waste of space and glue. Only the ends. I did it with three plies, but that was mostly because I had some thin scraps with the correct bevel already sawn. Two plies would probably work fine.

 

Actually, it was a lot easier to glue up with the bevel already sawn on one piece – this helped force at least one ply down against the plywood jig.. I used some blocks cut from the broken chine to make the laminating form, then painted on some melted candle wax to be sure no glue would stick. That bevel angle forces the first piece of the lamination flat against the base of the form. This tends to reduce any tendency of the lamination to creep upward. But be ready to clamp downward if you need to.

By the way, the curved cutout on the plywood is unnecessary. I just used the piece the side panel was cut from because it was convenient. And yes, I know you’re supposed to heat wax in a double boiler. Outside the frame is a bucket of sand for dealing with potentially spilled, burning wax.

Here is what the newly laminated chine pieces look like, along with one already dressed with a plane.

Scarphing

Once bent, I needed to cut scarph joints so the middle part of the chine could be fitted later. For this I made a scarph guide. Two pieces of 1x cut at an 8:1 angle, and a base board. It’s all glued and screwed together, and just wide enough for a cheap block plane to ride on. In use I kneel on it on the floor, so no need for clamping. The stock is rough cut to an approximate angle to reduce planing.

From here it is an easy matter to run a plane over it until it is flat. You’ll know you’re done because it stops cutting. And of course now I have the scarphing jig for next time I need it. (Probably soon, with as bad as cheap lumber seems to be getting.) I used Titebond III, but epoxy would let you get away with joints that are not fit as well. I would not use PL400 for this kind of joint – you want a stronger, harder-setting glue.

Nailing these chine ends to the side panels is just as simple as any other bit of nail and glue construction. But fitting the straight piece is slightly tricky, since it has to fit accurately to the scarph joints on both ends. This is not the place for “measure twice and cut once”. Better to make it deliberately oversized and shave it down bit by bit until it fits exactly.

I ended up with a straight part that wasn’t quite as wide as the laminated part. This was mostly because I didn’t feel like adding another ripping step to even them up. I asked Thalia whether we should try to even it up with a Dremel or call it good and move on. She thought it would look OK once it was painted. She was right. Smart kid.

Anyway, these chines might have been easier with good bending stock, but maybe not. With a scarph jig it was pretty easy. It just took a little longer because of more glue-drying steps. But that fits pretty well with fitting such a project around work and other commitments.

Hatch Covers

Tim Lehman came up with a great way of doing hatch covers. We’ll take a closer look at these in a future article, but here are some photos so you can see how it works.

The first cool thing about these was showing Thalia how to make trammel points from a piece of scrap cardboard. She was suitably impressed. Dads don’t have many years as a hero, so we have to make the most of it.

And yes, I do have a drawing compass…somewhere. I really never bother finding it because it is so easy to poke two holes in a scrap of something one radius apart.

Note that the holes for the tension knobs cannot be at the center of these semicircles. They must be closer to the centerline to allow space for the retainer bar to be withdrawn from the hatch. I figured it out by cutting the bars, then laying them on the hatch cover and drilling through the hole in the bar.

The next cool thing for Thalia to help with was clench nailing the parts of the cover together. I cut the oversize plywood piece and planed the edges. Together we clenched nails.

And finally, we added the stop blocks inside the compartments after the bottom was on. This might be easier to do before the bulkheads get installed, but maybe not, since you would have to trim them to fit the bottom.

But I’m getting ahead of myself…

Hardwood Pieces

There was a wrinkle in putting the hull together. The 3” framing sticks on the sides of the transoms have to restrain all the force of the bend in the chine and wale. I know most folks put the wale and chine on after assembly for this very reason, but it is a lot easier to nail things flat on the floor. You don’t need to pay for screws or worry about holding a backing iron.

But cheap construction grade pine couldn’t stand up to these screw forces. The transom side frames split as soon as I put the first screw in. I guess it is a lot to ask of a 3” piece of 1x2. But I had some scrap ¾” red oak flooring, so I replaced these “cheek” pieces on the transoms with the harder wood. When pre-drilled it held the screws just fine. For these four small pieces, the increase in weight is imperceptible.

A Transom Change?

That does raise another minor issue. Forming these transoms from two 1x2s on a 3” tall plywood panel leaves a tiny slot between the pieces of wood. This slot is very difficult to paint and clean. I think it would be easier to make this from a single 1x4 instead of two strips. This would also provide a better surface for mounting handles or other hardware, and at the expense of hardly any weight. I know it seems inelegant to glue a full width board to a plywood backing. Maybe one could skip the plywood except to use it as a gusset at each end, to fasten the cheek piece. Maybe an alternative would be to biscuit join the cheek pieces to the transom planks and skip the plywood. I guess it is pretty convenient to have the plywood there to serve as a template if nothing else.

A bevel mistake

Speaking of plywood templates, I ran into one other problem going 3-D. I’m absolutely certain this is my fault, too. After beveling and assembling, I wound up needing to add shim strips about ¼” thick to get the top of the bulkheads up to the same level as the sheer.

I’m pretty sure this means I somehow did the bevels with the line on the wrong side. This is easy to do. Let’s look at a transom as an example. The measured transom is supposed to coincide with the very end of the boat. But the framing sticks take up some of that space. So if you measure and cut the plywood to the recommended end-of-the-boat lines, you have to plane the framing smaller to get the bevels. Now your transom at the end of the boat is smaller than on the plans. This is why Jim provides not only transom angles, but also the additional measurement that should be added to the dimensions of the plywood transom. I figured out too late why he provided those measurements.

Of course this is a small difference and the boat still works fine.

Cartopping Tricks

I asked Jim about how to tie down camping gear and he suggested making some holes just below the gunwale. I was shocked at first, but he pointed out that the true effect on freeboard is slight. Water can’t come in that fast through several 1/2” holes, and at that point you’re likely to be taking more significant water over the gunwale anyhow. And anyway, this is not a sailboat that will be heeled over for hours on end.

The gunwale holes led me to a cool way of cartopping. With the cleats on the boat I didn’t need anything more than a factory roof rack and a bit of foam pipe insulation for padding. But a set of gunwale holes had to line up with rack. Each cartopping line runs from an eyebolt in the thwart frame, through the hole, under the roof rack, over the boat, under the roof rack on the other side, through the hole on the other side, and back to the cleat on the thwart frame. This lets the same line restrain the boat fore and aft as well as down.

I have five feet between racks, and five feet unsupported fore and aft. It seems I wouldn’t need a bow line with this system, but I did. The rack started ripping out of the roof of the Jeep at highway speed! I guess these racks don’t really resist upward loads too well. The rubber well nuts start to get chewed up. In any case, the final touch was to add screweyes to the stern to flag the overhanging load.

Parting Thoughts

The Polepunt is a LOT of boat for a cartopper under $200. In future articles we’ll have a look at some of the things it is good at.

Rob Rohde-Szudy
Madison, Wisconsin, USA
robrohdeszudy@yahoo.com

Click Here for Other Articles by Rob Rohde-Szudy


Power Caluker
SAILS

EPOXY

GEAR