Building the Clark Fork Drifter,
Session 3
September 28-29, 2012
Whenlast we left our Clark Fork
Drifter build, we'd only had a short, one-day session and only
got the fiberglass down on the sides. This week was the Big Session,
where we go from flat planks to 3D
Everything starts, as it always does, with a view of our resident
Great Blue Heron, Waldo. We decided to call him Waldo because we
figured most people would call him "Harry" or "Harvey"
and we wanted him to be unique. Also, we'll be able to ask "Where's
Waldo?" a joke that will never get old.
Step 1 was to trim up the edges. Epoxy-soaked fiberglass is damn
sharp, so we went around all the pieces, trimming off any excess,
and smoothing out any rough spots.
While Curt and I worked on the big pieces, Bob handled the fiddy
bits.
After trimming, we went over everything with the random orbital
sanders to get the surface roughed up and ready for the next layers
of epoxy.
This is a Stitch-n-Glue build, where we use zip-ties to 'stitch'
the parts into place, then hold them there with epoxy fillets. We
clamped the two sides together and drilled holes for the zip-ties.
We then loosely stitched the bow together and also loosely stitched
on the transom.
Lift up the sides and place them on the bottom.
The trick is to them spread the sides out until they hook over
the bottom and are held in place pretty much by friction. At this
time, I pulled the bow zip-ties together tightly.
Starting at the bow and working back, we stitched the boat together
. . .
. . . .until we got to the transom, trued it all up, and zipped
that together, too.
The final step for the evening was to tack the seams down with
a small bead of thickened epoxy. We have lots of silica filler a
the Boathouse, but I decided to use wood flour as the filler. The
wood flour comes from our own sanders from pervious projects - we
have gallons of the stuff.
Bob mixed the epoxy, I laid it down, and Curt smoothed it. Great
team work. We finished a little after 6pm and headed over to Pig
Feathers for a beer and dinner.
After the epoxy cures, you can either slice off the exterior parts
of the zip-ties and leave the little bit on the inside, OR you can
remove all of the zip-tie. The first method requires 2 cuts, one
for each 'leg' of the tie. The second method requires just one cut,
but then . . .
. . . you have
to pull the zip-tie through. I've found using channel locks or pliers
and rotating the tie out is by far the fastest and easiest way to
do it.
I was working alone that morning and surprise surprise, Joe and
his daughter, Katherina, came for a visit. Joe had wanted to watch
how I did fillets, and since I really didn't know how to do fillets,
I encouraged them to go on a rowboat ride while I tried to figure
it out.
I ended up making very thick batches of epoxy - well thickened
with wood flour. Joe commented that my fillets were a little on
the thin side, so I made them even thicker. Peanut butter consistency
for sure. I made a couple paddles for spreading the fillets into
nice, uniform shapes. On the bow I used a 2" dia paddle and
on the sides I used a 4" dia paddle.
I finished up the fillets by covering them with a 6" wide
strip of epoxy-soaked, 6oz fiberglass. The book doesn't say to do
this but for some reason, I felt compelled. The 'glass came from
the excess from glassing the bottom, so it didn't cost anything
- except weight and more epoxy.
So there she is - flotable in her current state, but unusable without
seats, gunnels, and all the other stuff that makes a boat a boat.
We've used roughly:
- 1.5 sheets of 6mm ply (bottom and transom)
- 2 sheets of 4mm ply (sides)
- 4 yards of 6oz fiberglass cloth (bottom interior with excess
width used for fillets and Payson butt-joints)
- 10 yards of 3.25oz fiberglass cloth (sheathing the sides and
the fiddy bits)
- 2 gallons of epoxy
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