Cradles for our floats

 Now that both floats are assembled, the next steps involve finishing a few interior details like tapping the keel seam, adding a compression member in the bow, and closing the bow and stern.  These steps are easiest to do with the float in the upright orientation.  So we made two sets of cradles to support them.  The cushioning is just foam pipe insulation split around the form edge.  At about $1.25 per 6-foot section, this was a very economical solution, and seems to work well.

 We reused the old form frames to make the cradles (hopefully we won't decide that we need the forms again!)  I traced out the shape of the hull at the two beam bulkheads using the pattern for the bulkheads.  I added some margin for the hull thickness and for some cushioning.  I also made sure I left at least a couple inches at the bottom of the forms so they don't split when handling.  The difference in height of the two sides in the photo is a result of reusing the old forms which already had cutouts. It took a little thought to get the vertical placement of the aft form correct so the float deck is level.

 At times, I will want to support the floats on their side, such as when we fair and glass them.  So I kept the forms that were positioned directly under the beam bulkheads (forms 5 and 11).  I then recut the two adjacent forms (4 and 12) to match these so I have two sets, one for each float.  Most importantly, I wrote "Keep" in large letters on these  pieces so I don't accidently reuse them for some other purpose.

Here is the cradle structure without the forms installed.  Since I wanted to be able to change orientation of the floats depending on the task, but didn't want to make a dozen cradles, I made the forms interchangeable.  Note the slots (dado) cut into the two vertical supports.  The forms simply slide into the two slots.  No fasteners are needed to hold the forms in place.  In case you want to do something similar, here are a few key dimensions:
Verticals: 24" long with 3/4x25/32 dado
Horizontal: 41.5" long (dependent on width of your forms)
Legs: 24" long
Vertical support gussets: 10" x 10"
Leg support gussets: 16" x 16"

Floats in the winter

 Winter has arrived at the boat house.  This is the second big snowfall we have had this year.  This time, however, the forecast is for cold temperatures, which will put a damper on the float building progress.  Hopefully it will be warmer than the meteorologists expect so I can get back to it.

 Nonetheless, there was notable progress prior to the snow storm.  We now have two whole floats and the form frame is history.  Hurray!  Here is the starboard float sitting upright for the first time in cradles.  See the next post for more about the cradles.

Here is a view from the rear.  The floats are taller than they seemed while laying on their sides.  Setting the cradles on the strongback makes them a little higher than I would prefer.  I considered dismantling the strongback since I don't really need it until we start the main hull, but I hate to take on the extra effort if I don't have to.  So given the available space, putting the cradles on the strongback was the best option for now.

Boat building art work

 Building a glass-reinforced plastic boat requires a lot of supplies.  Through the past six months of building, we have gone through boxes of brushes, stacks of tray liners, reams of rollers, and gloves galore.  And we always seem to have some left over epoxy that is kicking to fast to use.  In an attempt to make productive use of this detritus (or occasionally by accident), Dawna and I have started making boat building art!  No doubt the global demand for this high art will inspire absurd bidding at elite auction houses such as Christie's.  Here are a couple of our finer pieces.

The first piece is a great example of modern art of the "found object" genre.  No doubt Rauschenberg aficionados will find this piece true to the spirit of the mid-century pop culturalists!  You will surely appreciate the juxtaposition of the practical nature of the modern boatsmith's tools and the way these discarded tools express the desire of the boat builder to drift away in a steady breeze.

The second piece expresses the sense of severe pain that a boat builder feels in his back when he is twisted into a pretzel while trying to work inside the float of an F-82R trimaran.  Note the weaving of the brushes into the form of a deformed spine.

Let the bidding begin!

Taping the inside deck seam

The weather continues to cooperate thanks to El Nino (or is it La Nina?).  So we are continuing to take advantage of the not-exactly-warm, but warm enough weather to work on the second float.  Here you can see the inside of the bow end of the float.  On the right is the deck seam that we just finished taping.  Note the mirrors we used to see what we were doing while we applied the tape.  This shot is looking in through the open bow.  It isn't really as spacious as it appears, I just stuck the camera inside to take the shot.  But it does have a somewhat sci-fi look, like inside the underwater alien ship in The Abyss.

Now I will remove the million drywall screws holding the hull to the form frame.  Then we can pop the hull free and take down the form frame.  Then we start on taping the interior keel seam in the upright position.  Hopefully we will be done with interior work for both floats before the New Year.  Happy Holidays!

Tape and gussets

At last, we finished taping the bulkheads into the starboard float.  We also made a new set of gussets and used foam filets to form the transition between hull, gussets, and bulkhead.  This time we tried wetting out the tape before putting it in place, then laying in the wet tape.  This saved some effort working the epoxy into the tape through small access ports.  I think this is a better way to do it, though in either case the tape was fully wetted and strong.  In this photo you can see the finished product.  The other side of this bulkhead was taped via a 6" diameter access port, as shown before.  I'm pretty happy to be done with this task, though we still have several tasks remaining that have to be done through the access ports.  Next we will tape the deck seam, then we will remove the float from the forms.

Progress taping bulkheads

 The weather cooperated this weekend, so we were able to make some more progress on taping the bulkheads inside the starboard float.  I'm sure the skiers would have a different evaluation of this weather.  Here is a shot of the shroud bulkhead after we filleted and taped it.  This side is easy to tape thanks to the large access hatch.  As we showed in earlier posts, most of this work is done through 6" diameter inspection ports with a mirror.

 Although the mid-day temperature in the boathouse is getting into the upper 70's, as soon as the sun goes away the temperatures plummet.  So I am running a small heater inside the float to allow the epoxy to cure.  In this view the lower half of the access hatch is reinstalled as I close up the hull to insulate it from the cold night.  We keep the heater set on low power and set the thermostat on 65 F to minimize the heater operation.  We just want enough heat to keep the epoxy chemistry cooking.  I also set the heater on a scrap of 2x6 so it isn't in direct contact with the epoxy and foam hull.  I really don't want to look outside and see the warm glow of our boathouse burning down!

 And here is the starboard hull with all of the access ports closed up and the ends covered with towels.  Its cozy warm inside, while the boathouse drops below freezing.

We should finish up the bulkheads and deck seam next weekend.  I had to make a new set of gussets to finish the bulkheads since the original pair fell victim to the sawz-all a couple months ago.  Here you see the new gussets in the vacuum press.  I'd like to add a heating pad to the inventory of tools to keep vacuumed parts warm.  For now, I'll settle for a slow cure until the boathouse warms up tomorrow.

Second float together ... finally!

 I know its been awhile since our last update.  Between vacations in the caribbean and the arrival of winter temperatures, progress has been slow.  Nonetheless, we found a warm weather window to finish mating the two halves of the second float together.  If you recall, we had finished laminating the interior surface of the last (fifth) float half just before we went on vacation.  After a day of additional prep (actually a couple hours, which is all I can take when it is 40 degrees in the boat house), we were ready to put the halves together to form the starboard float.  Here is a picture of the two halves in place and opened like a clam shell.

Here is the same view after we glued the seam of the halves together.  Note the plethora of clamps, straps, and plates to hold the keel seam together while the epoxy sets.

And here is the view from the deck side.  If you look closely, you will note that I put the access port cut outs back in the holes, and closed off the ends with a couple old tyvek suits.  There is a power cord running inside the float for a thermostat controlled heater.  Hopefully the heater will keep the float warm enough the allow the epoxy to cure in a normal time although the boat house temperature is in the 40's and falling.  I also built a heated box to cover the resin and hardener drums so they are more usable as temperatures drop.

In spite of our efforts to keep things warm for continued progress, we will likely move on to the beam construction for most of the winter.  That way we can move our work space to a smaller heated space.

In case you think I forgot, here's a Big Tip #3 that I figured out while laminating the last float half:

   The stiffening stringer has a trapezoidal profile, and on the previous four halves we kept the sharp corners and then fought with the glass to make the bend around the corners.  This time, while sanding the foam in prep for glassing, I decided to round the corners on the stiffener.  It took about two minutes to make a nice curved corner.  And the payoff was the glass just conformed to the curves and I didn't have to babysit it for two hours while it cured.  So the big tip is to soften outside corners when possible to allow easier laminating.  Even light weight glass fabric needs a radius greater than zero to make a bend comfortably.

A blanket for a float

It's getting chilly at night now, which is not entirely compatible with slow cure epoxy.  So we cranked up a couple small electric heaters under the float half in the frame, wrapped the entire form frame in a sheet of plastic, tucked under the corners, and let it simmer over night (with an occasional glance outside to make sure the boat house wasn't burning down!)  It worked well and the epoxy putty filler cured nicely in spite of the exterior temperatures in the 30's.  Of course, once the sun starts shining, the temperature quickly rises and the inside temps get into the 80's and 90's.

We actually completed the glass laminating this past weekend.  No pictures yet since we are rushing to get ready for a trip to a toasty warm island in the Caribbean.  I'll post some shots of the final product when we get back, including Big Tip #3!

Fifth of four float hull halves

We got a good start on the fifth float half.  Okay, I am starting to get a little tired of building float halves ... but this should be the last one until the next boat (keeping our fingers crossed).  Notice the fourth half sitting on the rack previously occupied by the first half.  I still haven't had the heart to take the remnants of the first half to the landfill.  Maybe I can make a planter out of it!

We reversed the form frame back to the original configuration fairly quickly.  To make it easier we labeled each batten with its location in the form so all we had to do upon reassembly was put the batten back where it came from.  With the form reversed, a couple battens had odd curvature and had to be slightly repositioned, but all in all it worked well.  The whole task only took a few hours.  Then I spent the rest of the day prepping foam for planking the fifth half.  Today I got to work on forming and gluing the planks.  As you can see, I got about half way.  We should have it finished by the end of the week and hope to glass it next weekend.  It's starting to get cold at night, so the sooner we get this half glassed and joined the better.  This may be the last big task we do with epoxy in the boat house until spring.

Recycled bulkheads for a greener boat!

 So after cleaning up the extracted bulkheads, we spent a few hours taping them into the "last" hull half.  Reusing these bulkheads saved us at least a day.  With the temperatures dropping, and a goal to finish the float fabrication by the end of October, every day saved helps.  Unfortunately, I don't think we will meet our goal given the need to build yet another float half, so we will probably shoot for November now.

One plus of scraping the first half was we got to use our new talent of producing perfect filets.  It's amazing how easy it is when you find the right tool.  In this case, the right tool is a 1-1/4" pvc pipe about 3 inches long.  Just pack in the putty along the seam, take a couple passes with the pipe, and clean up the excess putty.  We let it start to cure so it is firm, and then add the tape.

We also used the foam filets on the gussets like we did in the port hull.  In this view you can see how the fillets form a column in the bulkhead.  I also tried vac bagging the gussets ahead of time and reinforcing the edge with a layer of tape.  It came out nice, but it was quite a bit of detail work getting the tape to lay flat.  I may go back to preglassing with the fabric lapped over the edge for reinforcement since we will be installing inside a closed hull.

Of course, the cooler temperatures (40's at night, 60-70 during day) makes the cure take quite a long time.  If you recall, we are using MAS epoxy with slow hardener.  If we finish applying the epoxy in late afternoon, it is generally still slightly soft in the morning.  The boat house is unheated but the sun warms it pretty quickly, so the cure hardens the following day.  We will probably need to relocate our epoxy work when winter sets in, and we are discussing the possibility of getting the medium set hardener as well.

Dude, Is that your boat?!

Behold the remains of a dear, departed friend.  This is what's left of the first hull half that I built.  We were preparing to bond it to the last half when I found some issues with the lamination on the stiffener.  After thinking it over for a night, reexamining the stiffener the next morning, talking to Dawna about the options, and considering the quality of our later versions relative to the first, we concluded the best solution was to scrap it and build yet another float half.  I also inspected the other three halves to confirm we didn't have a similar issue on the other hulls.  The other three are very well bonded.  If your keeping score, Dawna started helping (leading) me on the laminating work on the second half, so once again she proves to have superior talent when it comes to epoxy application.

Once we made the decision, out came the sawz-all and 15 minutes later the bulkheads were removed for reuse and the rest of the hulk was ready for the landfill.  It was not a pleasant experience, given the time and effort that went in to its construction.  But it was a learning experience, and we prefer to maintain a good level of quality in a boat that may take us miles from shore.  So back to the form frame (which now needs to be switched back to the previous orientation).

Fast finish for final float fabrication

I made quick work of the last float half.  Working alone, I found I could comfortably complete the foam on a float half in two days.  I had hoped to do it in one, but two days isn't bad.  Here you can see the final product all cleaned up and trimmed to size.

Here's a shot of the soon to be merged pair of halves.  We are looking forward to being done with the inside taping work.  Then we can get on to the exterior fairing and glass work.

And on the other side of the shop is the port float awaiting detail work.  On the work bench, the foam for the stiffener is being glued together and clamped.  You can never have enough clamps.

Next week we will glass the interior of the last half, then we will finally join the first half to it to complete the structure of the starboard float.

Here we go again ...

At last, the first float (port side) is together and removed from the form frame.  It looks pretty good.  The third half (bottom in this photo) was the best yet, with almost no scalloping and very fair.  The float almost looks boat-like!  Once again, Dawna took care of the frustrating inside work by taping the rest of the deck seam.  There are still many details to finish:
- tape keel seam,
- add high density inserts for later hardware installation,
- install bow compression brace,
- cut out beam access holes,
- seal bow,
- seal stern,
- seal forward access port,
- fabricate large hatch structure and reinforcement,
- reinforce round inspection ports,
- initial fairing of foam core,
- exterior lamination,
- fabricate and install bow,
- glass bow,
- final fairing of exterior,
- paint,
- install hardware,
- build rest of boat,
- sail.

I'm sure we can finish these tasks in a weekend ... okay maybe two.  But for now, my priority is to complete the work with the form frame.  This means we are back to foam install for the forth (and final !!) float half.  This half will be joined with the first half to make the starboard float (which is definitely better than making the starboard sink, sorry couldn't resist ...).

You can see I started cutting the foam at the bow end.  I already cut all of the 4", 6", and 8" wide strips of foam, so all I have to do is cut to length.  I am using the same layout as the third half, and most of the tape on the frame is still in place, so I am hoping this will go pretty fast.  My goal is to finish the foam by Saturday, and maybe glass on Sunday.  Then another weekend to join the halves together.  So here goes ...

The first machined parts

Now that we are getting the float hulls joined up and focussing on details, we needed to start thinking about the chainplates.  I decided to go with the carbon fiber chainplates.  These require a custom thimble to wrap the carbon fiber over and a custom clevis to hold the turnbuckles.  So I drew up some drawings based on the details provided in the plans and went to Hand Precision Machining.  Robert Hand did a great job of machining these parts from 316 stainless.  For reference, the thimble is 2.75 inches long, so not too big. Of course machinists are not cheap, but Robert always seems to give a good break on pricing for personal jobs, so we were able to feed Catherine another day.  I know this is a chemical imbalance somewhat unique to engineering types like myself, but I really love the look and feel of nicely machined parts.  Hopefully Dawna won't mind if I put these pieces under my pillow tonight!  I'll post more updates when we start assembling the chainplates.

Bulkheads complete

As planned, Dawna and I finished taping the bulkheads in the port float.  You can see we also added the lower gussets on the forward bulkhead.  As discussed in the previous installment, we used our super-sophisticated filleting tool (1-1/4" pvc pipe) to make nearly perfect fillets with absolutely no talent or skill.  I am not sure if you can tell, but the fillets made through small holes with the pvc pipe are actually slightly nicer than those we struggled with in the open.

For the gussets, we tried using some foam fillets to make the process of working through small holes semi-blind a little easier.  In this photo, the foam has been added to the pre-glassed gussets.  We then glued the gussets and fillets to the bulkhead and stiffener with a thick epoxy putty.  We also used some putty to fill in the gap in the corner where the bulkhead, gusset, and stiffener all meet.  Then we taped the gusset to the bulkhead and stiffener on both sides.

And here is a closer shot of the final result.  Dawna did all of the taping on both the visible side and the blind back side.  She was having so much fun, I went to pick up Catherine from school while Dawna continued taping.  And she finished just as we got home ... Jackpot!  It looks fantastic, and it is very stiff.  This was a lot of effort to get the tape on both sides neat and fully doped with epoxy.  And on top of all of this, we also started taping the deck seam at the stern with left over epoxy.

  Here is the view Dawna  (and I) had to use to work on the areas that we couldn't see directly.  I can't seem to get my hand to move in the correct direction when working from a view in a mirror, but Dawna did it like a pro.  Both the gusset and bulkhead taping turned out at least as good as the tape work done in the open.  The biggest difference is we are now hobbling around like old timers from contorting our bodies trying to reach all the nooks and crannies.  I can honestly say that this was hard to do well and generally not very pleasant.  The good news is there are only two floats to build.  The bad news is this was only the first.  And we still have lots of details to finish, plus the fairing and laminating of the exterior surface.

Stay tuned for shots of the port hull free from the form frame ...

Like building a bottle in a ship ...

Dawna and I spent some time today taping the bulkheads to the third half.  Recall we already taped the bulkheads to the second half (upper half) while it was still in the frame.  Now we had to do all the same steps working through small holes in the deck of the float.  This included forming perfect fillets of putty, which was somewhat frustrating when everything was wide open.  I did start the day by cutting the lower half of each opening and removing some of the frame stringers to give us better access.

This is a view looking in from the stern at the aft bulkhead.  You can see the access hole that Dawna is working through.  Generally the options are 1) look through the hole at what you are working on, or 2) put your hand through the hole and do something, but you can't really do both things at the same time.  We did use mirrors to view the tape work on the gunwale and deck (seam along the same side as the hole).  But once you stick your hand in to do something, your arm tends to block the view.

At least the forward side of the shroud bulkhead and the aft side of the forward bulkhead are accessible through the large hatch.  Here Dawna is working on taping the shroud bulkhead.  Catherine was wondering if this is her room.

Even after a hard day of work, Dawna makes Tyvek look sexy!  I know I'm pretty excited.  Grrr, epoxy ...  By the end of the day, we completed 1.5 bulkheads out of a total of three.  We didn't start until the afternoon, so it wasn't as bad as it sounds, but it is certainly slower than working in an open hull.  We will probably finish this task next Friday, as well as taping the inside deck seam.  Then we will be ready to pull it out of the frame for finish work.

In this view of the shroud bulkhead, you can see the nice fillet and tape job.  The filleting started out a serious problem, but then we tried using a 4" long piece of 1-1/4" pvc pipe as the forming tool.  By keeping the length of the pipe at a slight angle to the seam, the pipe surface squeezed the excess putty into the seam and left a perfect fillet.  It only took a couple passes to fill all of the seam.  Then we just cleaned up the extra putty the tool pushed out of the way, and voila, a perfect fillet working through a small hole.  We were very excited about this discovery, truly the holy grail of filleting tools.  I just wish we tried it earlier.

Joining two halves

At last, we joined the second and third float hull halves together today.  Here I am next to my magnum opus.  Looks like I used too much glue and got my hand stuck to the hull.  No that would never really happen ... really!  Actually, the joining process went pretty smoothly.  Here you can see a few spring clamps and ply squares with screws holding the stern keel seam together.

The aft keel seam from a slightly different angle.  We didn't really clamp the seam together except on the extreme forward and aft ends.  Most of the length of the keel, the ply squares just keep the seam aligned with the frame.  That way any variations in the seam prep can fill in with the epoxy filler mix and keep the overall shape more true to the design.  The seam lines up nicely once the squares are in place to counter the springy-ness of the hull half.

Here's a broader view of the keel viewed from the bow end.  And there's the ever lovely Catherine.  Again you can see we used about a thousand wood ply squares and screws to hold the keel seam together while the epoxy cured.  The temperature is about perfect in the 70's (F not C!)  So the epoxy on the seams took a few hours to kick, which gave us time to apply the epoxy and secure the seams.  Dawna and I spent about two hours gluing the halves together.  Dawna used a zip-lock bag with a clipped corner to apply a bead of epoxy and filler along the seam, like decorating a very crunchy cake.  She wetted the seam on top and bottom with straight epoxy first to ensure good adhesion with the filler.

The deck seam was made even by installing wood bumpers along the edge of the seam prior to gluing.  The top half tends to spring out, so the bumpers hold it in line with the lower half.  I used packing tape to epoxy proof the bumpers prior to gluing, which worked well.  The straps are mostly being used to pull the deck seam in line at the bulkheads, rather than clamping the halves together.  You probably noticed we cut the deck openings prior to gluing, at least the upper half of each opening.  The forward and aft most openings will be filled after completing interior joins, but the big hole in the middle and three round holes are for access ports in the finished hull.

Catherine is checking out the interior space and admiring her parents' handy work.  We now have to do all of the interior joins along the keel and deck seams, as well as the bulkhead joins to the lower half through these holes.  I will cut out the lower half of the openings after the seams cure to give us a little more room for access.  Nonetheless, trying to make a perfect fillet through a 6 inch diameter hole is bound to be a challenge.  More fun to come ...

Pre-fitting float halves

At last, we have two float halves arranged as a whole float hull.  This is a view from the stern looking forward of the second and third halves in preparation for bonding.  The initial fit is good, accounting for the natural springy-ness of the hull out of the frame.  We will need to use some blocks and screws to hold the halves together at the seams when we apply the epoxy putty.

Here's a view inside the aft end showing the aft bulkhead.  I had pre-trimmed the bulkheads on the second half so putting these halves together will be easier.  I will have to trim the bulkheads on the first half we built (still on the storage rack) prior to joining to the fourth half (yet to be built).  You can see the fit of this bulkhead is very close to perfect with no extra trimming.  The forward bulkhead needs a little additional trimming, but not much.  I think the shroud bulkhead (in the middle) is pretty close also, but I can't see it very well.  We will spend some time cutting out the access holes in the deck (to the right in these photos) so we can fillet and tape the bulkheads, keel, and deck seam.  Should be fun trying to work through 6" diameter holes.

Prep for glass works

Once again, it's time to glass the inside of a float half, this being the third half.  We prepped the foam core by trimming the edges, grating off all glue overflow from the seams, patching all screw holes and any other imperfections with epoxy putty, and sanding the entire surface.  It is very fair, no doubt thanks to Catherine's skilled effort.  We also marked the surface with the placement of the stiffener and the trim pattern of the stern.

Then we were ready to cut all of the glass fabric to size.  Here you can see all of the pieces of glass neatly laid out on the workbench. I mark the pieces with sticky notes to help avoid confusion when we are trying to race the epoxy kick time.  On the first hull half I marked the pieces with a marker, but the ink bleeds in the epoxy and makes a mess.  Sticky notes help keep things neat (assuming I remember to take them off before applying epoxy).  I write out the order that we apply each piece of glass to allow sections to start to cure before applying additional reinforcing, and to keep track of what layer goes on top of the others.  The result is a neat and shimmery glass job with minimal curses.  You can also see my respirator mask for mixing microballoons.  Definitely a requirement for working with microscopic glass balloons that tend to spontaneously evaporate like a cup of dry ice.

Here's a picture of Catherine explaining how the halves will be combined in to a whole float hull.  Either that or she saw a cool bug walking around up there ...

Dawna had to help a friend, so I only had her expert help for the first half of the glass work today (the nice half you see here).  I did alright though, after carefully studying her technique, not that I'm going to show you.  Trust me, my part looks almost as good as her half.

Actually, it all turned out very nice, though my epoxy decided to kick half way through the fifth section, which required some quick mixing and extra effort working in the new batch.

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.