Homemade Dinghy

So, as broke college kids, we'll be spending a lot of time at anchor, instead of marinas. As such, we need a method of getting to shore and back with groceries, water, etc. As the inflatable canoe was deemed unacceptable for such matters, we needed a dinghy.

We had two options. Buy or build. After looking at various inflatables and hard dinghies, I decided they did not meet several of my major requirements; inexpensive,
lightweight, and low maintenance. The inflatables had a high initial purchase, questionable durability, and the added hassle of having to inflate it every time we wanted to use it. The hard dinghies were simply too expensive, not to mention the lightest one I found was almost 100 pounds. Just too heavy for Darcy and I to hoist over the side to lash it on deck. So, we build...

Acrux (or Alpha Crux, or Alpha Crucis, depending on who you ask) is a plywood dinghy of stitch and glue construction. This means she's simple plywood panels that are stitched together with wire ties during the initial construction, then later held structurally with epoxy resin. She's modeled after the D4 plans offered free from www.bateau.com, with some slight modifications. Anyway, here's the process of building a dinghy.

The first step: lofting. Here, we take two measurements from different sides, at a 90 degree angle to each other. At the intersection, you place a dot. After you have an entire panel lofted, to simply connect the dots, and cut the panels out. The second step: cutting out the panels, and drilling for stitches. This part is fairly straight forward. Cut along the lines you just drew in the lofting phase, then drill a hole every 6 inches on the sides being joined for your wire ties. Here we can see the frames and side panels ready for assembly and stitching. The third step: stitching it all together. Yet another relatively easy part. Simply align the panels and frame, match up the holes you just drilled, and wire tie them together. Her we have the bow and stern transoms in place, along with the center seat frame to give the boat some shape:
And here she's been flipped and the bottom panels stitched on: Now, on to making it a functional boat: laying epoxy fillets in the seams. This step provides part of the structural strength to the boat. Mix resin, hardener, and filler (in this case cabosil), and push it into all the internal seams. After this hardens, you can remove the stitching, and sand the outside smooth. Once that happens, you can lay out fiberglass tapes on the outside surfaces. These tapes hold resin against the wood, giving the joint its strength. If done properly, these joints are actually stronger than the wood itself. Sorry, no pics for these steps. I was in the process of moving the dinghy from my bedroom in New Bern to Moyock. And yes, up until this point, all construction took place in my bedroom in New Bern. Don't tell the landlord.

Step number five or six: taping the inside. Again, fiberglass tapes are used over the fillets to give the joints strength. After that, the entire thing is coated in resin to seal it. We opted to cover the entire bottom in fiberglass cloth, just for an added measure of strength, and to add some durability for dragging over beaches and the like. Steps twenty and twenty-seven: Finishing touches. Now that the structural parts are done, we have to 'glass and laminate the finishing touches. Rubrails, skeg, all that sort of stuff goes on.This process took several days. a lot of things needed epoxy laid on, then sanded down, more epoxy, then sanded. A whole boatload of fun...

Step one hundred forty seven: Flotation. We opted to fill all three seat compartments with chopped polystyrene (read as: old electronic and appliance packaging) for emergency flotation. You could break this dinghy in half now and she'd still float. And now, the big finale: PAINT. And lots of it, at that. Green, black, and blue. And fluorescent pink. Because who doesn't want a fluorescent pink boat? I lay no claim to the beautiful paint job seen in the following pictures. Caleb and Darcy cut out some stencils, and after the paint was purchased, I left the garage, Darcy, and Acrux to their fate.

Okay, here we go: the pictures... Step two thousand, four hundred and ninety seven: Sea trials. Only one thing left to do. Drop it in the water and see if it floats! Luckily, our first sea trials were not only successful from the floating aspect, but we even managed to stay dry! Up and down the canals, one person or two, we tested that Acrux does exactly what she was intended to do. Float, row, and transport us across the anchorage.
And last but not least, here she is resting on her preferred transport spot. Most of the time on the ICW we'll simply tow her behind, ready for quick deployment once we're at our anchorage for the night. But for crossing larger bodies of water, or just for extra security, this is where she'll rest.The aftermath:  a trip to Florida and back.

After putting a couple thousand miles under the keel, our homemade dinghy has definitely seen some sights.  And better days, I might add.  I would like to point out that just Sunday afternoon some grown women were screaming in admiration of my paint job, and they didn't even see it in its full magenta glory.

Maiden voyage - 1.20.2010

Home again - 7.20.2010

 Despite the strength of the epoxy, in rougher waves the docks still took quite a toll on "Dinghalicious" (I swear, Kyle came up with that.  To this day, we still refer to her affectionately as 'Liscious).  One thing that we considered when building the dinghy is adding a second sheet of plywood to the bow.  As you can see, it would have been extremely beneficial.  While we were in Oriental, the dinghy could just slip under the dock, then a few waves sent the brunt of the force to the middle of the bow.

We had even put some pool noodles on 'Liscious to combat the brutal dinghy dock in Oriental, but by the time we left, you can see the bow was still looking a little sad.  Right now all we have left is the stern noodle, and it disintegrates on whoever leans against it (usually me.  It took me quite a while to figure out why I had blue stuff all over my back and shorts whenever we were walking around town).

These are all pretty cosmetic, nothing substantially structure-related.  Our worst problem, by far and above, was oar locks.  If you are going with a rowboat, shell out the extra cash and get some good oarlocks.  If you have to row a half mile, crossing a busy channel at night, you don't want to risk shearing off an oarlock and having to row canoe-style the rest of the way to the boat.  We started out with clamp-on oarlocks.  Those twisted, which made rowing nearly impossible.  Next we tried U-style oarlocks, and those both sheared off right below the U (and this always happens where you're about halfway between the dock and the boat). 

The original oarlock sockets were on the brink of failure by the end of the trip, but they were still holding.  On one oar, we have half of each original clamp-on oarlock (almost too twisted to row with), and on the other we have a combination of hose clamps through which we put a ratchet extension.  We've been through a couple hose clamps on that too.

Oh, and also, we managed to accrue a few barnacles whilst sitting in Titusville for a couple weeks.

The dinghy is alive!

Finally, we've made some serious decisions about "next time."  Next time, we are building a sailing dinghy - too much fun, and only a little more work.  We actually saw the sailing version of our dinghy while we were in Titusville, FL.  It would be a lot of work to modify our current dinghy, plus she's a little beat up already so we would just build a new one.  And next time, we're bringing an outboard.  Maybe it will just be a little electric trolling motor, but dangit, we're going to have one.  Some of those anchorages are just too far from the dock to row.