Saturday, January 13, 2018

3D, at long last!

Finished some more prep work on the bulkheads and transom hardware, also a bit more shaping on the leading edge of the rudder.

After cleaning the shop a bit, my father came over to offer an extra set of hands for a 3D dry run.  All went smooth with only small "crack" heard from the bow.  After the dry run, the following night everything was glued in place.

My main helper, installing hardware on the transom.

Using a stainless steel rod from Duckworks, bent a 90° on one end, filed a flat face and drilled a hole for a clevis ring on the other end.  A 24" section of rod was plenty to make 2 of these.

Slow work on the rudder, only on my first edge.

Limber holes cut using Simon Lew's plywood holesaw guide trick, (planingaround.blogspot.com).  Cut limber holes prior to 3D in case of any surprises, also much easier to manage individual bulkheads.

3D BEGINS!!  
Here is the dry run.  We sanded the chinelogs carefully so they would contact one another and not split/ pull away from the ply.  We drilled one side of the stem at a time.  2 people is almost a requirement for 3D.

Also 2 ratchet straps are almost a requirement.

Despite our best efforts, we heard a "crack" ring out from the stem.  We both froze, and cringed...what we were both dreading.  We seemed to fair better than some builders.  The ply split on the right hand side of the photo below.

Finally all together.  Bulkhead 1 is in fact the hardest to put in, both dry run and glueing.  It gets easier from there moving towards the stern.  

Proud Goat owner.

Bulkhead 4 is the only joint I can boast about...the other bevels are not as tight and bulkhead 1 seems to have too much bevel angle on the bottom; will need to plane and epoxy a shim.  Everything else will be filled easily enough with epoxy/ silica.  

Bulkhead 1, moved aft a bit and bevel angle off...close enough.

Glueing begins.  Starting at the stem, one side at a time.  The boat disassembles one part at a time easier than you might expect.  Most movement can be controlled with 2 clamps clamped to opposite chinelogs and pulled together with a ratchet strap; here at the stem, it was not even necessary.

Checking straightness after glueing, only off center by about 2mm.  Clamped gunwales temporarily in place while checking squareness/ straightness and made sure saw horses were level and parallel.  So far, boat is almost dead-on square from multiple diagonal measurements...a very good feeling!

I have been using Raka epoxy and have been very happy, specifically 127 Resin with 606 "Slow" hardener & 610 "Fast" hardener.  The "Fast" hardener works down to 50°.  Outdoor temps have been in the teens and single digits and I can only keep the workshop warm to about 40-45°.  Therefore I have been using SystemThree SilverTip epoxy with a "Fast" hardener, which is rated down to 35°!  So far, so good!





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