Kindly Old Dr. K’s Hydrosphere

The boat is about as close to being done as any project like this ever is.  There are additional details to work out, but it’s paddleable now, so I declare victory.  I haven’t had it on the water yet due to some health issues, but it won’t be long now.

I see only one major mistake I made in designing the cockpit mods.  The rear of the cockpit rim is too high.  If you look at most boats the cockpit rim, especially the back, is down in some kind of well.  This is done to allow greater flexibility for the paddlers waist.  When I made a bigger cockpit hole in the deck this well area on the original Prijon was cut out of the boat.  I dithered on creating a new well in the location of my enlarged cockpit rim, but decided to stick with the simplicity of mounting the new rim right on the deck. This may turn out to be a major error.  Just sitting in the boat on dry ground my mobility while leaning back is seriously restricted.  It may be challenging to do a back deck roll, for instance.  One thing you learn from doing it yourself, though, is that there are very few things that can’t be fixed.  If I have to I could cut the cockpit a few inches of the rim-hull joint, move the whole thing down and re-glass it in place with the rim at or below the level of the deck.  We’ll see.

Here are some pics of the finished (sort of) boat.  In the tradition of other custom-modified factory boats like the Sweet Hahn and McKnight Hahn, maybe I’ll call this one the Kirbsburger.

It’s almost impossible to get seams to perfectly cover the very ends of the boat, so we seal the ends with plugs of solid resin, poured in from the middle.  We tilt the boat on end and mix up a batch of resin with some glass shavings or other way to keep the curing resin from cracking, in the same way aggregate is used in concrete.  It turns out the height of the workshop floor is perfect to align with the cockpit on a stood-up boat.

We use a cup with two strings on it to pour the end plugs: lower the cup holding the resin down into the boat with the top string, then dump it out by pulling the lower string.

Mini-cell walls are fitted, for strength and safety.

A simple foam seat, glued to the hull with 3M #77  (The cans are there to hold the seat down while the adhesive dries thoroughly).  I’ll stick a couple of self-adhesive velcro strips on this and attach a Jackson Sweet Cheeks to it.  Best thing since night baseball.  Similarly, a couple of smaller foam blocks form hip pads and some more velcro will allow adjustable hip pads to be fitted.  I haven’t decided on exactly what to do for foot braces yet.  Also, I’m playing with ideas for an adjustable backband.

Here’s the finished Kirbsburger with its great-uncle from 1972.

The view of the new boat that will seen by any rival Potomac attainers soon.  That is, the stern, leaving  them behind.

So, a couple of wrap-up notes on the project.

How long did it take?  about 7 weeks of calendar time.  It could be done much quicker.  I remember a grueling long weekend in Pittsburgh at Jack Wright’s shop wherein we mostly finished three boats in three days.  The actual labor for this boat was about 50 hours, including my cockpit mods.

How much did it cost?  The materials came to about $1000, and additional tools and disposables added about $300 to the total cost.  A well-outfitted shop would make some of that cost unnecessary.  I could have used cheaper materials and knocked a couple hundred off the material cost.  On the other hand, I could easily have doubled the cost if I’d gone for a foam-core vacuum bagged graphite construction.  Just depends on what you want.

How much does it weigh?  About 28 pounds, outfitted and ready to go.  Could have been lighter, but not bad.

So, how did it turn out?  Overall, I’d give it about a B.  There are some cosmetic issues, and the cockpit design isn’t fully worked out.  For the first boat I’ve built in decades, though, it’s not too shabby.

For any whitewater paddler who has any bits of do-it-yourselfer in them, this is an eminently doable project.  It doesn’t require any real art, just a bit of care in a few steps.  And there’s nothing like the satisfaction of paddling a boat you built yourself.  Go for it.