Eastport Pram Build: Wireless Connectivity is Flipping Awesome!

So, I'm a bit behind on my blog, but at least that doesn't mean I haven't been making forward progress!  Here's a catch-up blog for the last month:

First, here's the tool you'll definitely need for the "stitch" part of Stitch & Glue™, a wire nipper.  It allows you to cut the stitches without damaging the plywood because it cuts flush.  I first stumbled on this tool while stringing barbed wire fencing around an entire ranch during a summer in college...

I have a confession to make, I jumped the gun a bit on the woodworking and made a pretty serious mistake.  I cut out the handle holes into the transoms and immediately busted out the router to ease the edges.  Only afterwards did I remember that the transom doublers have to be installed before the edges are eased, so worse case scenario, I have to mix up some wood flour thickened epoxy and fill the slight groove the eased edges I created on the handles and top of the forward transom.  Good news is that at least I thought about it before I eased the aft transom.  I was so bothered by this that I actually seriously thought about remaking another forward transom, then I realized that I'm going to beat this thing up a bit by using the heck out of it, it's not a museum piece, so I'm not going to agonize over a bunch of silly details.  After all, I'm the only one that will know.  This is a constant theme for all of my woodworking...

Okay, so I finished the contours on the center bulkhead and fitted the transoms back.  Only this time, I was so jazzed to put the damn thing together that I didn't remove any of the glue squeeze-out.  FYI:  the directions call for using epoxy on everything.  I used a waterproof glue (Titebond II) to laminate the panels that are more than 6mm (1/4").  Since everything will be encapsulated in epoxy anyway, it shouldn't matter as long as the lamination is structural, which it definitely is.

So, I wanted to go into a little more detail about the stitching technique since it caused me such a quandry.  Below are examples of a stitch that I managed to pull together since I'm doing this by myself on my lunch breaks, and one that I replaced once the panels were all together and twisted correctly since it's neighbor stitches were holding it together while I did the intermediate stitch properly.  It's amazing how the rabbets and a properly twisted wire pull the hull together.  Remember, twist the properly located wire just enough to snug it up against the wood fibers.  A partial twist more will cause the wire to cut into the thin plywood edge.

Improperly twisted...

Properly twisted...

Oh, at this point I removed the transoms and scraped the glue squeeze-out from the lamination and reattached the transoms.  With a little help from a friend, I was actually able to get the transoms stitched super-tight onto the hull, which was really gratifying.  Then, I tweaked every stitch on the boat just shy of damaging wood fibers.  This stiffened the hull noticeably.  At this point, I felt that it was prudent to flip the hull.  I squared the sawhorses (including diagonals) and made marks on the shop floor.  The hull flipped easily because it's so light and gently rested back on the sawhorses.  It's a major milestone in the build that the hull is structural enough to flip, which now means it's time to mix up some epoxy for the first time!

Flipped!

 After tweaking each stitch, I thought it prudent to nip each one off to reduce the wires sticking out and possibly (read probably) interfering with the upcoming steps, which involve epoxy, which one can't afford to eff up...

Stitches tightened and nipped off...

 After reading a ton of other blogs (thanks guys!), I determined to deviate from the instruction manual slightly and "tack" the laps between the stitches.  I think that this should be explicitly recommended in the instructions because if you get globs of thickened epoxy onto the stitches, then you've got a pretty serious issue to address once it's hardened.  It's not smooth or fair and the only way I was able to deal with the few boogers I created was with a Dremel tool and a small burr.  This was done by squirting the silica-thickened epoxy with a syringe with the idea in mind that I would come back with a larger radius fillet once the tacks had cured.  It worked amazingly well.  The hull was amazingly stiffer once the tacks cured.

The second pass of silica-thickened epoxy created the exact same fillet as shown in the manual.  It left the thin plywood rabbeted edge and tangentially intersected its adjacent panel.  This creates a lot of surface area contact, which creates a lot of structural hull integrity, which is kind of the point.  I was successfully able to use the denatured alcohol trick to smooth 75% of the laps.  Unfortunately, due to time constraints and the laws of thermodynamics (it didn't get as warm in the shop as I'd anticipated), I had to leave two laps un-smoothed.  The next morning after the epoxy had fully cured, there was a noticeable difference between the glassy smooth joints and the lumpy, non-skid joints.  A few minutes of hand sanding the offending laps got them within striking distance, aesthetically-speaking, of the smoothed ones.  Not perfect, but acceptable, considering I'm going for a working boat, not a museum piece...

Panels overlap transoms in anticipation of a flush-cut saw to establish a smooth, flat face.
Notice the nice, tight gaps...

First pass, laps tacked together between the stitches.
Second pass, long, smooth fillet after stitches are removed...

Now that the laps were structural, it was now time to start thinking about filleting the interior.  Since I'm using the tabbing technique, I wanted a smaller radius for the tabs.  Then I'll cover the tabs with a larger radius, continuous fillet.  This meant two different filleting tools.  System Three spreaders have a nice 3/4" radius on them from the factory, so I took one and laid out a 1" radius.  The tabs were filleted using the factory spreader and the long, continuous, smooth fillet was made with the modified one.  An added bonus to using a spreader is that once you're done making the fillet, you can use it to scrape up the excess that squeezes out.  One thing that first time epoxy users might not know about plastic spreaders and mixing cups is that once the epoxy cures, you can usually peel/pop the epoxy off the slick plastic surface and it's like new!

Original and modified filleting tools...

Tabs in place.  Transoms are rock solid.  Wires are easily removable...

I deviated from the directions again by fiberglassing the bottom of the boat first.  I agonized over this step for several reasons.  First, it's much easier to do the bottom.  It's one panel and it's convex shaped.  The interior is concave and three panels.  It's actually a huge difference in the wetting out process.  I'd recommend considering this option.  Of course the trade off is that if you glass the interior first, you can still make sure that the boat is square by using winding sticks or just a visual.  There's no way to tell if the boat's square if it's upside down with both ends drooping over the sawhorses.  Plus, I had no idea how stiff glassing the bottom would make the boat, so I didn't want to build a permanent twist into it.  What I did to address the issue was place the boat right side up on the sawhorses and shim it square.  Then I flipped the boat upside down and put the equivalent shims under it to compensate.  Theoretically, this should make the boat square.

Protective tape in place on first lap.  Rolling out 6oz clothe...

Luckily, my shimming trick worked!  I squeegeed all of the excess resin out of the cloth, leaving the glass weave showing.  You know when the cloth is properly saturated because it get's completely dark.  No white cloth showing, only nice dark wood grain.

Boat bottom shrouded in 6oz cloth and hand smoothed...

Bottom wetted out...

I made a pretty serious deviation from the directions here, which really ended up biting me on the butt when I did the interior.  Because I got some epoxy drips outside of the target zone, I was concerned that it would fuse the glass in the wrong spots, so I ran a razor knife along the silica thickened fillet on the first lap, severing all of the glass fibers.  This allowed me to remove the excess dry cloth without disturbing the bottom panel.  This actually worked too well, because it lulled me into a false sense of security when glassing the interior...

Excess cloth trimmed and tape removed...

Properly wetted cloth still shows the weave...

To Be Continued...

Captain Skully out...