Catherine the shipwright

Here's Catherine hard at work on the third float half.  She planked the entire half in just one weekend.  And it looks great.  I think each half gets better.

But don't get in her way when she is on a roll, she is a woman on a mission ...

Catherine has a critical eye for quality control.  She inspected each plank to ensure it conformed to the form frame, per the designers specs.

A job well done makes you feel good inside.  Catherine will finish removing the clamping squares at the ends during the week.  Then we can clean the seams, patch the million screw holes with epoxy putty, and trim the edges.  Next weekend we will glass this half.  Then we will be ready to join the two halves together.  At last, a new task.

That's a nice rack ...

As planned, we removed the port side float hull from the form frame.  It looked very good in general.  Planking was very fair, except for some areas at the aft end in the tight bend from side to deck.  I have some ideas for improving the quality of the bend that I will try on the next half.  In any case, it will be a very nice hull with minimal fairing required.

Here you can see the port hull in storage on a new set of racks I built on Friday.  I attached these racks to the table and toaster oven, so it was quite easy and quick to finish.  The boat house is starting to fill up, maybe I should have gone for the 22' wide building instead of the 18'.

We spent some time looking at the quality of both hulls and finally decided not to rebuild the first half.  Although not quite as fair as the second half, it is still quite good and I don't think it will take too much filler to make it fair.  And I think both halves have very good structural integrity.  The only thing I am particularly disappointed with in the first half is some sloppy lay up on the gussets at the forward bulkhead.  We also weighed each hull and found they were within a pound or two, at about 40 lbs each.  So that was something of a relief, and we won't have to worry about heeling to starboard.

So, with that decision made, we are moving on to the next step in the float construction.  Namely, we reversed the form frame so we can start the other two halves.  I know, looks a lot like the previous form frame.  In any case, I was afraid it would take several days to finish putting the frame back together, but it went much quicker.  I was able to finish it in a day, and I even added a few extra battens to the form.  So now we can start planking the third half.  The schedule is to have the third half planked by next weekend, and glassed the following weekend.  Then we will be ready to mate the first two halves into something that almost looks boat-like.  So exciting times soon to come.

Gussied up gussets

After the fillets set for about an hour, they were stiff but still not fully cured, as desired for a stronger bond.  So we got to taping the bulkheads in permanently.  Here you can see the result.  Dawna did one side while I did the other, so we made good time.  Of course, the temperature in the boat house got into the high 90s, so in spite of the "slow" epoxy, we still had to race to keep up with the cure time.  We tended to finish a bulkhead, but then the left over epoxy would kick and we would have to make a new batch for the next bulkhead.  By the end of the day, we had big thunderstorms move through which dropped the temperature about 20 deg.  As a result, the last batch is still slightly tacky many hours later.  Notice that we remembered to make this a port-side float, as determined by the direction of the beam cutouts.

The real challenge for the day was installation of these gussets on the forward beam bulkhead.  You've seen them before, but these turned out much nicer than my earlier attempt.  Again, the "Epoxy Maestro" applied her touch and the results are a very high quality installation.  Actually, even the maestro was getting a bit frustrated on these evil reinforcing elements.  The filleting was very frustrating do to the lack of a solid support for the gussets.  A jig may be needed next time.  And the glass work is much more complex than any of the other components so far.

Nonetheless, we took as much time as the temperatures would allow and worked it all smooth.  The result is pretty good.  Glass strands are nicely aligned (mostly in the desired directions), excess epoxy was kept to a reasonable level, and the gussets are generally square and aligned.  As noted above, the last batch of epoxy was applied after temperatures dropped a good 20 deg. while glassing the gussets.  As a result, the gussets are still a little tacky five hours later.  They should harden overnight and the return of high temps tomorrow should make the boat house a nice post curing oven.

Only thing left to do is to clean up the excess glass at the ends of the seams and in the beam cutouts.  Then we can pop this half out of the frame, clean up the outer surface, and make a final determination if we should rebuild the first starboard float hull half.  This should be done in the next day or two, depending on how I feel after I get back to the day job.  All in all, we finished this half in two weeks (actually three weekends), which was my goal.  This rate should put us on schedule to finish the float hulls by the end of October ... trick or treat!

Fillet or filet?

We are now preparing to install the three bulkheads.  We vacuum bagged the fitted bulkheads to make a very high quality lamination.

Here you can see the fillets made from a putty of epoxy and microballoons.  If you recall the last time we attempted this, I did the filleting with mixed success.  This time I handed over the task to the "Epoxy Master."  And sure enough, she's a natural at this.  This time we started by filleting all three bulkheads in place and then let the epoxy start to set before taping with 4" biaxial glass.  This made the process go much smoother.

A good mix for putty that does not sag is 1/4 cup balloons for every 25 ml epoxy mix.  You have to add the balloons slowly to mix smoothly and avoid turning the balloons into a dust storm.  Don't even think about doing this without a decent dust mask or respirator.  The balloons tend to get electrically charged and are very small (hence the name "micro" balloons).  The slightest disturbance tends to send them airborne.  In any case, this mix makes a very dry putty that can be molded by hand and doesn't slump.

Here you can see one of the jigs I made to hold the bulkhead in position during installation.  It is critical that the cutout for the beam be positioned correctly.  The reference marks in the top photo are only barely visible, so trust me, I very carefully laid out the jigs so I could attach the bulkhead in the correct position to within a millimeter.  We'll see if I met the goal in a few months when we install the beams.  I made a jig for each bulkhead.  We  leave the jig on until the first layer of glass tape is applied.  Note the cuts in the jig to allow access around the entire join.

Ahh, shimmery ...

This weekend we finished glassing the inner surface of the latest hull half.  It turned out spectacular, as you can see in this photo.  Notice how shimmery it is.  Dawna did all of the work of applying the glass while I assisted by mixing batches of epoxy and squeegee-ing off the excess from the previous sections of glass.  Dawna is really good at this, so I was more than happy to stand back and watch the master at work.  The surface is completely uniform, with basically no excess epoxy.  And the very fair foam planks help too.  All glass strands are properly aligned, with no glass spaghetti, and the edges blend together cleanly at the overlaps.

You will note the satiny stiffening stringer structure (say that 10 times fast) in the middle of the forward nine feet of hull.  It is particularly tedious to get the multiple layers of glass to lay tight and fully bonded with no voids.  Dawna and I worked together for a good hour going back and forth on the stringer repeatedly pressing the layers back down until it all kicked and solidified.  The first time I did this on the previous hull it came out pretty good. This time, with Dawna applying her magic touch, the result was much cleaner and I have not found any voids or bubbles.

So guess who gets to do all of the glass work in the future?

Here's a bug eye view, okay maybe a mouse eye view, of the glassed surface with the stringer running down the right hand side.  Notice how the glass warps (bundles of glass strands) line up uniformly.  Maybe it is just me, but I find this very exhilarating.

So now we will get ready to install bulkheads next weekend.  I bet Dawna will be a natural at that too!

Ready for glass

We finished planking the second float hull half and prepped it for the inner glass lamination.  I didn't quite finish the planking last Sunday, but by the end of Friday it was ready to go.  This hull half seems to be much, much fairer than the first half.  There were several things we did differently this time:
- I used the heat gun to only heat the foam in the tight bend from hull side to deck, rather than heat the whole plank in the toaster oven.  This process ensured that most of the plank was perfectly flat, and minimized distortion in the bend.  There is almost no scalloping of the planks, and what little there is is only in the tight bend where heat was applied.
- We used much less urethane glue so it wouldn't make such large overflow beads along the seams.  The seams required minimal cleanup on the inner surface after the glue cured.  The seams still had full coverage with the glue, I just didn't load it up with lots of excess.
- To clean the seams we used cheese-grater style planes, which did an excellent job of cutting the urethane while only scratching the foam so long as we kept a light hand.  We will do a light overall sanding to remove any residue prior to lamination.  As a result, there was no gouging or excessive removal of core material.
- I used the screws and wood squares to clamp the planks liberally to ensure they closely followed the curve of the forms.  I had no gaps between planks and forms.  The only concern I have is the planks bent a little too sharply in some areas between battens, so I had to soften the curve.  I am still thinking of ways to better control the strong bend, perhaps with some type of mandrels to roll them around.
- I used narrower planks at the ends.  In general, the last five feet at the bow and stern were formed with 4" wide planks.  I used 8" and 6" wide planks in the middle sections.  When the gap in the seem between planks exceeded about 1/16", I switched to a narrower plank.  The narrower planks formed more easily, and required essentially no trimming of the edges to make a tight seam.  As a result, the planking took about the same amount of time as the first hull, even though there are about 50% more planks.  And the seams were all very tight.

We will make a final evaluation when we remove the hull from the form, but I think this hull will be in a totally different class from the first half.  If it comes out as fair as I am anticipating, we will likely scrap the first half and build a new one using these techniques.  Although it will cost us some material and initial time, I think it will be a small price given the overall quality of the boat we are trying to build.  And it should only take a couple weeks to replace.  We will let you know what we decide in about a week.

In the meantime, we prepped everything today to do the inner glass tomorrow.  All of the fabric is cut to size, numbered, and laid out on the work table so we can efficiently apply it.  In the background you can see the stringer being pressed on the table.  I'll cut it to size in the morning prior to starting the glass work.  We also filled all of the screw holes and some very small gaps.  I found a mixture of 150 mL resin epoxy mix combined with 1.5 cups of microballoons makes a very stiff and light filler with no run on vertical surfaces.  Of course Murphy is alive and well, so we came up a bit short and still have to finish about 5 square feet of filling at the stern.  Dawna will do that in the morning while I start to wet out the glass at the bow.  That way we won't waste a whole batch of filler for such a small area.  And Mother Nature seems to be cooperating with cooler temperatures expected for tomorrow, so we won't be quite so rushed with each batch of epoxy.  So now we are ready for sticky fingers!