Fun with dynel

I've spent the last few weeks fairing the hull, ruminating about whether to fasten the sheerstrake before or after the hull is turned over (no decision as yet), and getting ready for the new adventure of applying dynel fabric to the bottom.

Iain Oughtred, and other folks who seem to know whereof they speak, advise using dynel below the waterline to protect the hull from scrapes which might expose the plywood directly to water.  I had considered kevlar fabric, but determined that, while that might make the hull more bulletproof, it would offer no more -- and perhaps less -- abrasion resistance.  That and the fivefold difference in price, convinced me to go with dynel.

The preparation for the dynel that Oughtred recommends is to round over the edge of the strakes to be covered, and then to apply a shaped fillet to make the strake edges curve as gently as possible without diminishing the clinker look.

Strake edge planed round and filleted

That process took me a surprising number of hours to get it right.  Ultimately, the look seems pretty good, and I take comfort in the knowledge that anyone looking at these particular strakes once Lagniappe is in the water will have more important issues on his mind.

The next step is to fit and cut the dynel.  I ordered 7 yards of 54 inch fabric from my reliable supplier, Jamestown Distributors in Rhode Island.  (JD is great, by the way.  They have just about anything you could need, they ship the same day, and their prices are reasonable.  Being on the US east coast helps me, because if I order on Monday, my stuff will arrive on Wednesday.  Makes "just-in-time" ordering a practical practice.)

Dynel laid out, and cut to cover bottom 3 strakes

I solicited the assistance of my long-suffering wife to lay the fabric on the hull.  Like making a bed, it goes much easier if two are involved.  First, I drew a line down the middle of the dynel, lengthwise.  Then, we laid the dynel along the hull with the drawn line along the centerline on the keelson.  We slit the fabric for about six feet along the centerline at the stem and stern, and pulled the port and starboard sides in toward the keel to smooth out the folds in the fabric. After cutting out the excess at both ends of the hull, we were ready for the next step.

Dynel folded over out of the way to allow wetting the hull

 After folding the dynel over onto itself on the starboard side, I wetted down the port surface with unthickened epoxy.  My wife ably assisted by mixing batches of resin and hardener in the basement workshop and running them out to me in the garage. That way, I could use small batches and get them spread before they started to kick. As always, I used West System 105 with 206 slow hardener.  Next the dynel is flipped back and pressed into the wetted surface.  Finally, a coat of resin/hardener is rollered on to the surface of the dynel, which is thoroughly soaked, smoothed carefully, checked for saturation and rechecked.

Dynel soaked in resin, and undergoing final smoothing

 This is slow, messy work, but much like fiberglassing, the more carefully you work (i.e., thorough saturation, no bubbles, smooth all creases) the better the job turns out.  The next step will be to repeat the process on the starboard side, and then to add two or three additional coats of epoxy on top.

In the meanwhile, I can continue my ruminations regarding the installation of the sheerstrake.