Kindly Old Dr. K’s Hydrosphere

I should have waited another day or so, but I couldn’t stand the suspense.  Popping a part out of the mold poses two big questions:

1)  Did the mold release work?  (Did I avoid total disaster?)

2) How does the part look?

As it turns out both answers are good.  The hull had been curing for about 24 hours and was hard to the touch, although it still needs more curing.  It was very gratifying to get the part to slide out of an ancient, long-dormant mold with only a minor struggle.

For us old school builders the term “gel-coat” is kind of a bad word.  We just paint a layer on the mold with the same resin we’re using for construction.  I didn’t do a clear layer as I’ve seen in the past that un-pigmented structural resin turns brown after a while exposed to the elements.  So, I took a chance and sprinkled metalflake in the purple outer resin coat.  I wasn’t sure it would work, but I just popped the hull out of the mold and it worked great.  I’ve got an opaque outer resin layer and the metalflakes shine through.

The deck is going to be tricker.  We’ll see.

Here are a couple of pics of the brand new hull.

Tyler Kirby inspects the new hull.  The blems you see in the surface are actually in the plastic mold release, still stuck to the hull.  The mold release washes off with water.

The bow area.  It’s difficult to see in the photo, but the silver metalflake is shining through nicely.

The hull is the biggest single piece of the project, and arguably the most important part of the boat.  For this project I’m using a four-layer hull: 2 layers of 6-oz. s-glass on the outside and 2 layers of 5-oz. kevlar on the inside.  In addition, there are multiple layers of extra kevlar in the bow and stern and under the seat, as well as strips of additional kevlar to serve as longitudinal ribs for extra stiffness.  Finally, in the foot area there is an additional pad of diolen to protect the kevlar from abrasion from the paddlers shoes.

Kayak in a Can.  It may not look like it, but there’s a whitewater boat hidden in these cans, waiting to be released.

The boat-building process is 90% preparation.  Epoxy is a very good glue, so the first responsibility of the boat-builder is to make sure that, when the layup is complete, the hardened boat part and the mold separate cleanly.  So, after the cleaning the mold the next crucial step is waxing.  Five coats of hand -rubbed carnauba wax seals pinholes and rough areas in the mold and forms the foundation for the mold release, a liquid plastic film that is painted onto the mold after the waxing is finished.  It may seem like over-kill at times, but this is a critical steps, as a stuck part means both the part and the mold are trashed, and thousands of dollars are down the drain.

Cutting the cloth.  The layers that go in to the boat must be carefully planned, with an eye toward constructability, strength, weight, and cost.  Each layer is cut to fit the mold before any resin is mixed.  Kevlar is fun to work with, as it’s soft, pliant, and one of the few ingredients of the entire boat-building process that isn’t toxic, carcinogenic, allergenic, or something.

The first layers are laid up.  For this boat I’m using a purple pigment with silver metal flake accents.  The purple contrasts strongly with the yellow kevlar.  Note that the layers are carefully trimmed along the edge as they are laid up.  This saves a dreadful chore of trying to trim a fully cured kevlar and glass part.  This stuff is tough, and will ruin saws and knives quickly.

The hull is finished.  The stern rib reinforcements are seen in the foreground, the seat reinforcement in the middle and the diolen foot pad in the distance.  The white fabric along the edges is peel-ply, a material that can be peeled off the part after the resin has hardened, leaving a surface ready for application of the inside seam without the extensive sanding that is usually required.

It doesn’t look glamorous from this angle, but the exterior will be beautiful when we pop it out of the mold in a couple of days.  I hope.

The last couple years I’ve been learning how to playboat and how to handle modern short boats in general.  It’s been a tremendous learning experience and loads of fun.  For all the advances in modern boats, though, there’s one thing they just don’t have, and can’t have, based on simple physics: SPEED.  A fast boat means a long boat, and a long plastic boat means a heavy boat, which defeats the whole purpose of having a long boat in the first place. Fast, light boats are simply not available in the marketplace except for highly specialized craft like squirt boats or slalom boats.  Great at what they do, but they come with heavy trade-offs in terms of comfort, safety, and cost.

When I started paddling in the early 70s almost everyone built their own boats for the simple reason that good whitewater boats were unavailable any other way.  The few commercially made boats were so inferior that they couldn’t be expected to last more than a few river trips without major repairs.  The modern paddler who wants a high performance river boat is presented, ironically, with the identical dilemma, i.e. the boat he or she wants isn’t made or sold anywhere.

Luckily, the old boat-building culture hasn’t disappeared completely.  Stashed in workshops and under decks across the country are untold numbers of boat molds awaiting the attention of the discriminating paddler.  My favorite long boat of all time was the Prijon Olympia 400, aka Augsburg, designed by Toni Prijon for the 1972 Olympics in Germany.  This boat is a contemporary of the Hahn C-1 that is still popular with C boaters in some areas of the country.  I’ve always felt the handling characteristics and aesthetics of the Prijon were superb and I still have the old one I built ca. 1973, although UV degradation has made it unpaddleable.

I casually inquired around the DC area for quite a while before I discovered that Carter Hearn (father of paddling legends David and Cathy Hearn) still had an original Augsburg mold.  This mold was made by Ted Waddell, one of the best local custom builders throughout the 70s.  Carter agreed to let me use the mold.  Carter’s son Davey and his wife Jennifer operate Sweet Composites, a complete source for all boat-building materials and equipment.  After quite a bit of dithering, I finally committed to the project, bought the materials and picked up the mold from Carter.  So, for the first time in at least 20 years I’m building a boat.  Here’s how it starts.

Carter helped me load the 80+ lb mold onto my car.

It may have been decades since this mold was opened.  It was amazingly clean and ready to go.  Ted Waddell built outstanding molds and boats.

This is the deck portion of the mold.  A little cleaning with water, get the cobwebs off and it’s about ready to go.  Note that the cockpit hole has been covered up; this indicates this mold was intended for vacuum bagging.  I’m sticking to old fashioned hand layup for this project, keeping it simple after a long layoff from the trade.

Here the mold halves are hanging in the shop, the hull below to be worked on first, the deck hanging above out of the way.  They will take some more cleaning, waxing, and covering with mold release before we’re ready to start laying glass.

More to come as the project develops.