Structural Filleting, Part 1

Been a while since I updated this site.  Had some family issues that kept me from doing much for the last 3 weeks.  But I'm back to work now.

When I left off I had masked the area between bulkhead 8 and the transom for filleting.  Got those done and they turned out pretty nice.

I filleted the center section under the footwell with one big fillet instead of two smaller ones.  It was work to get it right but it turned out nice.

Moving forward I did the next bay.  Since the center area is wider here I used two smaller fillets on the keelson-hull joint

I've masked the area between bulkhead 1 and 2 and removed the stitches in preparation for filleting.

Next up:  Continuing the process of structural filleting.

Hours this session: 8
Hours total: 118
Hours remaining: 284

Masking the Water Tight Bulkhead Area for Filleting

I finished the tack weld step.  Gotta be kinda a contortionist to get to all the places.  I've got aches in places I forgot I had.

In preparation for the final filleting I masked off the area behind the watertight bulkhead.  This was done by:
1.  Removing the stitches in this area.
1.  Deciding what radius I wanted to use on a specific seam.
2.  Inscribing the radius on the seam using a compass.
3.  Taping to the radius lines.

The idea behind this is that it makes the fillets much more even, reduces sanding and overflow cleanup.  I've done this before on other boats I've built and I think it is well worth the time.

Notice that the vertical corners of the transom have not been taped off.  I ran out of tape!  So time to take a break.

Hours this session: 4
Hours total: 110
Hours remaining: 292

First Tack Welds

The two steps that I tackled today was to glue bulkhead #7 and floor support #4 to the centerboard trunk and to create the tack-welds.

Bulkhead #7 was no problem since I hadn't stitched it in completely to allow for the temporary screws.  I masked off the edge of the trunk and the mating edges of the bulkhead to keep squeeze out to a minimum.  That part worked perfectly.  I then finished the stitches and all went easy.

Floor support #4 was another manner.  It was lightly stitched in and wouldn't pull out very far which made it difficult to get epoxy behind it.  In the end I prevailed and while I was there I created the fillets for this floor board on the C/B trunk.

Now that everything in the lower hull is in final place I started to do the "tack weld" step.  The idea behind this is to run thickened epoxy between all the stitches.  This glues everything together so that most of the stitches can be removed (crap... I just got them all in!!!).  These tack welds must be made small enough that they will be completely covered by the final structural fillet.

My first attempt at the "pastry bag" method was a minor disaster.  I cut the corner too deeply and thickened epoxy gushed out much too quickly to create the small fillets.  When I realized this, I immediately transferred the unused epoxy to a new zip lock bag and cut a much smaller hole.  This time it worked perfectly and created fairly nice tack welds.  I smoothed out and cleaned up the areas where I didn't get it quite right.

I repeated this process and did about 1/3 of the boat before I had to stop and take the wife to dinner.

I'll let this dry and get on it again for the next session.

Hours this session: 6
Hours total: 106
Hours remaining: 296

A Little Problem

If you check out this link it'll explain the problem that I found.

http://www.pocketship.net/phpbb/viewtopic.php?f=3&t=207

Basically all but the floor support at bulkhead #2 line up perfectly.  However, the pre-glued support at bulkhead #2 is about 1/2" too high.

It doesn't seem like I've made any measurement or assembly mistakes.  I have an idea of how I can remedy this situation, but I'd sure like to know what went wrong.

Bulkhead and Floor Support Stitching

In theory the rest of the stitching of bulkheads and floor supports should go quickly.  In practice there is a lot of tweaking and adjusting to get everything just right.  After a tough battled I prevailed.

Getting the transom just right required a lot of messing around.  The misfires have given me a few screw holes that I will have to fill in later.  In the end I was able to get it to fit almost perfect.

As the manual states the front will require the use of some home made alignment "tools".  I will tackle this in the next session.

Rechecked the alignment and everything seemed right.  The only issue being floor supports #5 not fitting as snugly against the trunk as I would like.  I'm going to readjust those during the next session.

I'm very impressed with the way things have turned out so far.  It hasn't been easy but nothing a normal guy couldn't deal with.

Hours this session: 6
Hours total: 100
Hours remaining: 302

Side Panels

The side panels seemed a little long and awkward working for moving around by myself.  So I had my son come over and give me a hand.  We wrestled the port side in first and I placed the ties while he came behind me and tightened them.

The only problem we had is that he wanted to tighten the ties down too tight.  I will probably have to remove some of them so that I can get the correct inner-edge to inner-edge final placement.  I've learned from my other two builds that it's easier to tighten the stitches just enough to hold everything together and then go back and incrementally adjust them tighter while adjusting the panels for a correct fit.  That's a minor complaint though because it only took about 90 min to accomplish what might have taken me 4-5 hours alone.  Thanks Sean!

After the side panels I stitched in bulkhead #4.  This thing really locks in nicely to the notch in the keelson and the recess in the front of the center board trunk.  Bulkhead #7 was also located at the rear of the center board trunk.  At this point I checked to make sure that everything was square and that the distance between the tip of the bow and the rear corners of the transom were the same.  It is a minor miracle how nicely everything goes together with the precut pieces.

The only problem is near the bow.  The manual tells you how to take care of this problem but It'll wait until after the other floor supports and bulkheads are stitched in.

The bow is the tightest fit of all.  Getting the lower ones to mate up requires much work.

Next up will be fitting the transom and the rest of the internals.

Hours this session: 3
Hours total: 94
Hours remaining: 308

 

Cradle Construction and Initial Stitching

The day has finally come to start putting all these pieces together.  Assembly of the cradle was very straight forward.  The only thing I did different was instead of using the particle board cradle cross pieces I used 2X4 cut to the same length.  This created a very strong base.

Getting the keel into the correct location in the cradle took some work.  The stern cradle was very snug around the keel and made sliding it to the correct location impossible.  I had to pick it up and put it down several times to get it to the right place.  And that keel is heavy!

Couldn't find any 18 GA steel wire, so I got 19 instead.  Just have to be a little more careful not to break them.  The stitching of the bottom panels is a little awkward since you have to lay down to tighten the steel stitches.  Only broke a couple.

If you look at the bow pictures you'll notice that it's a little weird looking.  The manual cautions that the stitching near the bow is trouble.  It is.  I still haven't gotten it right yet.  I'm gonna build a jig tomorrow to help keep the panels from sliding over each other.

An quick check of the alignment shows that everything is squaring up correctly.  So far so good.  Pressing on!

Hours this session: 7
Hours total: 91
Hours remaining: 311