Sunday, April 29, 2007

More float lamination plus bubble trouble

(FYI: I will be not be working on the boat for M-Thu this week, due to some extensive work committments. I do have Friday off and will get back to work then.)

The starboard float side that I laminated on Friday turned out reasonably well - only a handful of small bubbles in the laminate; I circled them and left them for later repair. My son helped me to swap the port float for the starboard one, on the float frames. After placing and trimming the glass...

...I went ahead and laminated it:

It was a pretty warm day and I had high hopes that the the laminate would cure quickly without any bubbles. Sadly, this did not happen. This morning I was quite disappointed to find a ton of bubbles all over the new laminate.

Here's a picture of the float with the bubbles circled:

And another:

(You can actually see some of the bubbles in the pics above. No, each circle is not an entire bubble -- I merely circled groups of bubbles to make it easy to locate them, is all. Most bubbles were circular in shape - about 1-2" square. A few were "ripple" bubbles where there would 3-6" long of a raised bubble area.)

I'll be honest, getting all of these bubbles is really, really depressing. Progress is going to be slow if every laminate I do needs major sanding and patching to remove bubbles. Could the glass be at fault? (Ok, I doubt it too.) Really sucks - I wish I knew what I was doing wrong. I do my best to get the glass to lay naturally, and I don't think I'm over-squeegeeing the fabric either. I don't think it's outgassing, because this is foam, not wood (and I haven't even laminated over my wood inserts yet, either). Any tips from anyone out there? I guess I will shoot System Three an email about this as well.

After sanding out the bubbles, I placed new laminate over all of them...

...and wetted them all out. And that was about all I had time for today. To sum up the current state of affairs: I have two floats each at 33% lamination complete. And one has probably five extra pounds of fabric and resin for bubble patching. Argh - can't wait to fair that one.

Well, enough doom-n-gloom for today. Stuff happens, I guess. :)

Friday, April 27, 2007

Starboard float exterior lamination begins

Yesterday after work I worked on preparing the form frames to help laminate the float hull sides. My approach was to first cut off a portion of the upper sections of frames #5 and #9:

(Little bit of a mess under that strongback. But this is an advantage of building outside: I don't feel compelled to clean all that crap up all the time.)

Then they were mounted in the usual locations on the strongback:

Then I padded them with some towels, and my son helped me lift the starboard float into position:

I was a little worried that the float would be too bow-heavy in this position, but that turned out to be a non-issue. I will leave the form frames like this for laminating the starboard float hull sides, then I'll flip them around and do the same for the port hull sides. The working height of the float hull surface is near perfect, and there's plenty of room to work on the bottom edge of the laminate as it is wrapped around the keel. Well anyway, none of this is rocket science but it was definitely quick and easy to put together.

Tonight after work I laminated the starboard side of the starboard float (seen above). Obviously you've got to lay out the glass first:

There's something really cool and fun about unrolling a ~21 ' length of glass out onto the float, then trimming it to fit. Having a single long piece also makes it very easy to work with. The downside is that you end up with a lot of long, narrow, trim scraps that may not be good for anything. I thought about laying the glass in vertical strips and having an overlap every 50" (the width of my glass rolls), but decided against it. I wonder what other builders do about this? And how small does a scrap have to be before it's not worth saving? (Comments, suggestions welcome...) If you really wanted to conserve on glass costs, you could laminate every scrap you had back onto the boat somewhere. I don't think I want to go that far though.

Lamination then began. Nothing too remarkable about this, but allow me to make two comments: first, the 18oz cloth doesn't wet out so easy - you have to work at it a bit more; and second, I can see why Ian didn't give these float hulls a knife-edge keel: it's much, much easier to wrap the glass around the gentle-curved keels -- I didn't even need to cut darts except at the bow and transom. Well, this might be one reason why Ian designed it this way, but it seems plausible given his "easy-to-build" design goal.

Here's a shot from early in the process:

And another, from a distance:

And here it is all done:

I was hoping to have time to laminate the deck of the port float, but doing the starboard float took took too long and I had to get cleaned up for dinner. I did check it over very carefully for bubbles before calling it a night, and things were looking good. I'm just hoping the Bubble Gremlin doesn't attack in the middle of the night.

P.S. My bow cap laminations turned out good...phew.

Wednesday, April 25, 2007

Bow caps laminated (and vacuum bag debacle)

After work today I was very motivated to get my bow caps laminated. At that point I still had not decided on whether to vacuum bag the float hulls or not, but figured that it would be a good idea to at least bag the bow caps, since they have lots of tricky curves.

First thing was to cut rebates for the bow cap glass. Based on some quicky testing and guesstimation, one or even two layers of 12oz glass do not require much of a rebate. So while I did cut rebates behind the bow cap on my starboard float... is a very light rebate and you can hardly tell it is there. To be honest, I quickly started doubting the benefit of doing rebates for such a thin cloth and decided to skip this step on the port float.

After that, I started wrapping both bow caps with two layers of B cloth. This is quite the fun job; all I can say is thank you, thank you, for Raptor staples. Without those, and my wife lending some extra hands, I don't think you could wrap these bow caps in one step - you'd want to laminate one side at a time, e.g. with the float on its side. Here is the first layer on the starboard float:

Looking pretty sharp, eh? Well, reserve final judgement until you see the back side:I kept going like this until both float caps had two full layers of B cloth, with this being the final result at that stage:

The cloth is pulled especially taut around the leading edges, but in looking at this picture some of the other areas could have used a bit more tightening.

Next I mixed up some epoxy and started wetting out the cloth. While I was doing it I did things the old-fashioned way: pour a little resin on the squeegee, and then apply it to the cloth. You get a lot of drips and wasted epoxy this way (lay down a drop cloth or some plastic! - I forgot at first) and I now wonder if using a sponge roller would be more effective. Regardless though, I did make steady progress. Here is the port float all wetted-out:

Another view of the port float:

And one of the starboard float from the underside:

At that point, I should have wrapped it all up with peel ply and called it a night. Unfortunately I kept going and tried to vacuum bag both bow caps simultaneously, but it didn't turn out very well due to leaks. Read on for the gory details.

Earlier in the afternoon I had run a vacuum tube from the garage out to my boat tent, and I also had a "T" tube-fitting and some extra tubing, so that was all ready to go. But even with my wife helping me, I really underestimated how long it would take to get both bow caps all wrapped up in peel-ply+release film+breather+bag film (lots of odd shapes and corners to deal with), and I really underestimated how hard it would be to get a decent seal against the foam. Or I underestimated how hard it would be to get the bag pleats sealed - if anyone else tries this, I suggest making and testing your bag before you begin laminating. Anyway, here's what the setup looked like, when everything was all put together:

When I started the pump it quickly became clear that I was far, far, from having a decent seal, and I never ever got more than 5 inches of vacuum. After futzing around for twenty minutes trying to find the leaks, I finally gave up and left it there for the night (with the vac pump off - there was no point leaving it on :). On the bright side I should have two fairly well laminated bow caps underneath all of that bag stuff -- I just need to go and dig them out tomorrow.

I might be giving up too easy, but I think this experience has helped me decide: I'm not going to vacuum bag much else on this boat, except for critical or easy-to-bag parts. Bagging can be fun but it also takes a lot of time and work and I just want to get this boat done and go sailing.

By the way, when people ask me when I'll be done, I always say "in the water by Summer 2008". If they haven't seen the boat tent and the floats yet, they think that's a long way off and ask me if I'm sure it will take that long.. Once they see the floats, then they think I'm being optimistic. Go figure :).

Monday, April 23, 2007

More float fairing

Yesterday I worked some more on the float decks. Eventually I figured out that rather than just eye-balling the deck to see where the high-lows were, it was much more efficient to use a long straight edge. I have a good quality 6' level with a machined flat edge that was perfect for this task -- it got rid of the guess work and made me feel much better about the job. (I can hear the experienced builders out there laughing -- sorry, I'm fairly new at this fairing business.) It turned out after checking things all over with the level, that each float deck had roughly the same profile: a high spot over the two beam bulkheads, and a low spot forward of the transom. I guess I can understand the bulkhead high spots (no "give" under that part), but I'm not sure how the last foot or so near the transoms ended up low. Anyway: I sanded down the deck areas over the beam bulkheads until the level lay flat over them, and called it good. The deck areas near the transom, I left alone -- I'll build them up with fairing putty later as needed.

A note on tools: I am using a 3' longboard. Not being the inventive type, on my last project I spent the cash for the fiberglass\foam boards made by 3M (I have both the flexible and the rigid ones) with the Hookit sandpaper-stick system. The 3M-brand paper is a bit expensive, but lasts a long time. The 36-grit with the rigid board worked especially well on smoothing down the deck high spots.

After being satisfied with the deck fairing, next up was rounding over the deck edges. I chose to form a 1 1/2" radius (see my last post for a picture of the PVC pipe I used to make a sanding tool) on the edges; partly this was to avoid taking off too much material, partly because I'm lazy. However now that I'm all done with this part of the job, I think that the floats might look even better with the 2" radius that Ian allows for. Hand-sanding cured putty edges is not much fun though, so I'm stopping here.

Here is a picture of the starboard float edge getting rounded over, in the fwd beam bulkhead area:

See the gap there between the planks and the deck? This particular float half is the one where I made the mistake of trimming the planks too short at the top. On both floats I had small gaps in many places between the deck and planks. I had decided to finish rounding over the edges before filling those gaps:

(The port float in the background has already had its deck-to-plank gaps filled, and is nearly ready for laminate.) Here's a closeup of the putty on top of the bow cap:

(It's hard to tell in the above pictures, but I ended the 1 1/2" radius about 8-10" back from the bow cap front. From that point forward I hand-formed a decreasing-radius edge up to the bow cap. I thought the full radius would be too much if carried all the way up.)

Here's a picture of the transoms, all sanded down:

See that blob of putty on the port-side of the starboard float transom? That was to fix an small boo-boo from the jigsaw back from when I was cutting off the excess hull from the float half. :)

Overall I am getting excited since the floats are looking pretty darn good -- rounding over the deck edges really gives them a nice, finished look. The only things left to do before beginning the main lamination are round off the transom edges, and laminate over the chainplate. I am still on the fence about whether I should vacuum bag or not.

The weather has finally been warming up - go-go gadget-summer! Today was great, got up close to 70 deg F. I have noticed that the warmer it gets, the more my boat tent begins to feel sauna-like. (Notice in the picture above that I've opened the back flap for more ventilation.) But I'm not going to complain too much after suffering through the winter dorking around with heat lamps and such. I'm looking forward to laminating a part and having it cured in the same day.

Saturday, April 21, 2007

Bow cap shaping and float fairing

A short post to bring things up to date. I lost most of last weekend due to family events so progress mostly been made in short stints after work, plus today. The main focus has been on shaping the bow caps and on fairing the floats.

I am reasonably pleased with my choice of bow cap construction technique. As seen in my last post, I started with a huge hunk of foam on the end of each float. I started initially just trying to sand this into shape, but that would have taken forever. So I borrowed a neighbor's reciprocating saw and did some rough cutting of the excess foam:

After that, I mainly used the sander to get it close, with intermittent sessions with the longboard to true things up (I was a bit afraid of going too far with the sander). Obviously I turned a lot of expensive 3/4" Corecell foam into useless scraps and dust. However, because I used such thick foam, there were very few fairing lines to contend with and they were not a big deal to handle. Here's a couple pictures of one of the final formed bow edges:


It looks better in person that it does in this picture, IMO. The leading edge is a bit under 1/4" thick, and I rounded it over with hand-sanding. I'm hoping that's enough - -- any thinner and I think it would be difficult to get the laminate to bend around it. I emailed Ian a question today to double-check that though.

Another thing I've been doing is puttying all of the screw holes, cracks between the foam planks, and other blemishes on the floats:

Another view:

Puttying holes was tedious work -- I feel like I've been way too personal with every darn screw hole on these floats. But it's 99% done now (every so often I'll notice a hole that I missed), and both floats have been "good enough" faired on all surfaces, except for the decks. I don't want to try to fair the foam to perfection for a couple of reasons. First, the plans don't call for it, and second, I'd be worried about fairing the foam to death and ending up with 1/8" foam instead of the 3/8" I started with. I'm exaggerating but you know what I mean.

The decks though are one area that have me a bit worried. I'd like them to be as flat as possible, but I unfortunately ended up with many highs and lows. Not easy to see with a casual glance, but I can definitely tell. I don't think I should do the deck-edge rounding until I'm satisfied with the deck fairing. So tomorrow I'll be back out there, sanding away. Don't want to go too far, but it needs to be better than it is (sorry, I don't have a good picture here).

However, I did buy some 3" PVC pipe to use as a sanding tool for the float deck edges. Here I'm getting ready to glue some sandpaper into the cut pipe pieces:

I used super-glue for this which worked well. After doing some testing, I ended up cutting the 1/2-circle pieces you see above into much narrower chunks, like about 1/4-circle sections. Otherwise the edges of the pipe will dig into the foam too much -- during testing, I accidentally cut some grooves that I'll need to fill in. Based on my quick test though, rounding the deck edges won't be difficult once I'm finally satisfied with the deck fairing.

All in all, decent progress has been made. I feel I'm getting close enough to start thinking about the lamination.

Ian sent out a builder's email update earlier this week with tons of updates and new plan sheets. Lots of new information to look at, and he also announced that the beam mounts are now available for ordering. I should be ordering mine within a month or so. Then they can sit in my office and silently motivate me to get the rest of this thing done so I can install them.

[Edit: here is Ian's response to my question regarding the bow cap thickness:

> How thick should the leading edge of the bow caps be?

It is personal preference - knife edge is too easy to damage while a large radius has more drag. I would not go less than 1/4" - production boats have around 1" as less than that can't be molded very well.


Wednesday, April 11, 2007

Bullnose floats

Work is getting busy on me, but I did duck out this afternoon to glue my bow caps on.

First a quick jigsaw cut and some sanding to get rid of the vestigial portion of the deck that was sticking out:

Then a straightforward putty job:

I was worried about how to hold the bow caps in place until the putty started to set, but this ended up a non-issue: the surface tension\suction was almost enough by itself to hold them. I did screw a single screw down through the top of the each bow cap into the rest of the float, and that locked things in place quite nicely:

My starboard float deck looks pretty good too:

Finally, if anyone were to even think about robbing the place, please note that we have a vicious attack dog who maims intruders on command:

(Sorry -- I promise I won't let the blog degenerate into maudlin personal stuff. Couldn't resist that one though. :))

I think that today's work just about caps it (punny) for the easy work for awhile. Starting tomorrow I need to get busy on fairing.

Monday, April 9, 2007

Considering float hardware

I had not been putting much thought into which brand of float hardware I would be getting; up until today, it was a bit of a tossup between Beckson and Tempress. I even ordered one of Tempress' 6" deck plates and it looked basically fine, although not much different than the Beckson ones I can see down at the local Fisheries Supply. Then today I saw on the Yahoo F-boat forum, that Ian recently posted a comment that he considered the Ronstan PNP40 to be a good design, because the screw-in part has a overlapping lid that covers up the threads and screw holes. Who am I to argue -- so I'm going to order enough of those for both floats. The wide lip also has the advantage that it hides the screws -- I had mild esthetic concerns about those being visible all the time.

For the large float deck hatches, I am considering this Tempress model. It also has a wide lip that hides the screws when closed.

I am still looking for a vent cover for the transom pressure relief hole, although I am also wondering why there isn't some wiz-bang pressure relief valve for that application, that would also keep out water. Of course, a simple hole has the advantage that it is low-tech, and not much can go wrong (I wonder how loud of a sound does an over-pressured float make when it blows up in the sun? :).

Lastly I need to think about which screws to use. I know they are "just" screws, but I'd like to get decent ones that will not go all rusty after one season -- am I being naiive? McMaster has a wide selection of screws in 316 stainless steel, which is one of the variants Ian recommends in the building manual. And I can get them in my favorite square-head drive configuration. Anyone know of a better option?

Starboard float deck attached

After work today I went out to the tent and removed all of the heavy items from the port float deck. (I was partly worried I'd come home to find that the float had cracked into two pieces from the weight - thankfully that didn't happen.) Overall the glue job on the port deck looks pretty good. Here is a side shot that gives you a pretty good idea of how it turned out:

You can certainly see some raised areas where we didn't get the deck pushed down all the way. Also, about the gap you see between the top of the side planks and the deck: for some reason, on all of my float halves, the top of the deck flange did not quite come out flush with the top of the planks, even when I had the planks shoved up hard against the deck flange mold plate -- weird. On both floats the deck flanges combined to create a true level platform across the float top. So I didn't artificially force the edges of the decks down to close that gap, instead I tried to let the putty squeeze-out to fill it. In the places where that didn't happen, I'll be filling it in with extra putty after the corner radius is done. But I don't see any daylight underneath the deck anywhere, so I'm going to claim success for the moment.

After that, there wasn't any other prep work to be done for the starboard float deck so I went ahead and jumped directly into the Goop Zone:

My lovely wife was again outside helping me spread the putty out into an even coat. Well, fairly even anyway:

(Just kidding honey, it looks great.)

I also decided to use the strap-ratchets to help tighten this float deck down. I have eight strap-ratchets, and even with spreading the clamping pressure using boards, it was not enough to pull the deck down 100% everywhere. So I had to go back to using some of the heavy objects:

I'm confident that this approach will work, but I'm now thinking that it might have been better to go buy more strap-ratchets - Those things really pull the deck down good. I just hope I haven't created lots of high and low areas to deal with.

Sunday, April 8, 2007

Port float deck attached

Today I woke up all motivated to get my decks glued on. The weather was pretty decent (low 60's deg F) too. But thankfully I have a habit of doing a last-chance review of the plans before I do anything final, and realized that I had forgotten to glue in the tapping plates for the bow eyes. I had chosen to do my tapping plates in 6061 aluminum as recommended by Ian and already had the metal on hand (small quantities can easily be purchased from Online Metals). I traced out a shape that would work, and started to work cutting. Woof -- it turns out that 6061 aluminum is some pretty tough stuff! I was expecting an easy job, but the basic metal blade on my jigsaw was going nowhere. Then I switched over to a manual hacksaw which was a little bit better, but it was still going to take me a lot of time to get done. Rather than waste the entire day on these small pieces of metal, I decided it was time to call in someone with better tools than me: my neighbor "Bubba" (not his real name :) cut the pieces out for me on his bandsaw:

He also smoothed up the edges so they wouldn't tear at the glass:

In retrospect, I should have taped these plates in place at the same time I was doing the bulkhead flanges. The floats were upside down then so that's obviously the most convienent time. I tried to tape these plates in place with the floats right side up, but that didn't work -- the aluminum was too heavy to be held up by the wet glass alone. With the epoxy already mixed and glass wet-out, I hurriedly called my son outside and we flipped the floats upside down onto sawhorses so I could do the taping on the downhill. That worked much better, but unfortunately it meant that I had to wait for things to cure before continuing on with deck fitting; I ended up taking a break here.

After the tape had cured enough to hold by itself, my son helped me flip the floats back over and I got back to work on the decks. There was only one minor task left to do before gluing the decks on, and that was to make a hole for the chainplates to poke through:

Yeah I know I cut the hole too bit on one side; no biggie, some putty will fill it in in just fine.

To get ready for gluing on my first float deck, I went and collected heavy "stuff" to pile on top of the deck. Unfortunately we didn't seem to have many heavy things suitable for such a task, and I was bit worried about this after having read Ed's account of his deck joining. I ended up using many of the walking paver stones from the yard, along with a few other things you'll see below.

Once the heavy items were collected, I started mixing putty and spreading it on around the flanges. The weather had cooled off a bit, but I was really worried that the putty would start to kick before we had gotten the deck on. My wife was helping me by going around behind me with a spreader and evening out the mix. Here's what it looked like after ten minutes of fast work:

Then we laid the deck in place and started piling stuff on to weight it down. I had worked hard at dry-fitting the deck, but it just didn't seem to be weighing down enough. Also, once you're in the moment you get worried and want to make as sure as possible:

The big round thing near the back is a heavy ceramic pickling vat I inherited from my parents. It hasn't held pickles since I got it, but today I was glad I've been saving it all these years.

(I'm a little worried about all of that weight sitting on top of the decks. I hope my float doesn't start to hog.)

After an hour or so had gone by, I went back outside and removed the 3/8" fiberglass dowels from their holes in the float. I didn't want them to be in the way when I start to longboard the deck, or when I rebate the beam attachment areas for the extra reinforcement that the plans call for there.

That is where I left things for today. I decided that the starboard float would have to wait, since we had run out of heavy things. But I am now wondering if my strap-ratchets would be a better way to clamp the the decks down while they are gluing. I have a bunch of them to use, although I would want to put strips of wood both on the deck and under the keel to distribute the load. I may consider this for the starboard float.

Chainplates laminated

Friday evening I laminated some glass around the upper portion of the chainplates. Reviewed the results on Saturday morning and it was clear it did not turn out so good; I had relied on peel ply to hold things in place and apparently didn't wrap things tight enough - lots of bubbles resulted. (The job Tor did on his chainplates looked great. Anyone else notice that how cool looking his Christmas-color-theme carbon\fiberglass is? His boat will be stunning even before he paints it. :) I ended up sanding down much of the glass on the chainplates to remove bubbles but decided to move ahead with laminating them into the floats, since this was a key step that needed to be done before the float decks could be glued on, and I'll be adding more glass later anyway.

So Saturday was the day for gluing the chainplates into the floats. First my son helped me get both floats on their sides:

I had already done prep-sanding on the existing laminate, so next was making sure the flange holes were big enough and marking the location of the chainplate:

(The plans call for the chainplate to be installed at a 84 degree angle. This is tricky to measure even when you're just doing a dry-run, and it's the last thing you want to mess with when you've got epoxy mixed and you're under the gun. I did my best to get the angle right while marking the location of the chainplates. I hope that if I am a degree or two off, it won't cause a critical failure. Makes me feel lame to even say that -- such are the pathetic hopes of an amateur boatbuilder. :) )

Finally, it was putty and laminate time:

The weather was warm enough that when the fillet putty started to kick, I got lots of fumes and heat coming from the fillets. Tried to capture some of that in a picture, but none turned out.

Keel foam shaping

I spent some time Friday evening and Saturday shaping the keel foam on both floats. This was more tricky than I thought it would be -- it's easy enough to sand the keel down to the supplied template shapes, but that only tells you what three spots (form frames #2, 7, and 11) should look like. Making the rest of the keel nice, smooth, and uniform with those three spots is all your (my) responsibility. My new sander worked great, by quickly taking down all of the rough stuff. Once you're down close to the right shape though, it seemed difficult to me to really tell how you're doing. I really hope I did not take too much off anywhere -- we'll see. There's also the usual issue with the putty between the planks being much harder to sand than the surrounding foam -- if you lean in hard with the sander to take down some cured putty, you almost always end up digging out more foam than you wanted to. This is frustrating but I don't know a good way to avoid the problem. On a flat surface a good planer might work but on these curved keels, no way.

I started off with the keels looking like this:

Here is a mid-way progress shot:

And another:

And a picture from underneath the transoms (the one on the left looks pretty good; the right one needs more curvature):

By the time I decided it was good enough to stop (on Saturday morning), things were looking like this:

I don't think I'm 100% done shaping the keels, but I decided to save the final fine-tuning for after the decks are attached and I'm pre-fairing the entire hull. And I'm done with using the sander on the keels - next time will be all longboard (I'm afraid of going too far, as I mentioned).

By the way, I don't want to give the impression that I spent sixteen hours on this task -- it was more like three to four hours total, and a lot of that was on careful sanding of problem areas. It seems clear to me that Ian designed the building procedure this way (vertical keel plank\batten combined with post-float-join shaping) in order to avoid any tricky tight thermoforming around the keel area. If that was his goal then he succeeded, but I'm not yet sure if the new method is any better - but I'll tell you in a year when the boat is done :). (And I wonder why he designed the F22 float keels with less of a knife-edge that his other trimarans seem to have?)

Lastly, the resonance of the sander on the hulls makes a curious thrumming sound. My wife says it sounds like there's a full-scale light saber war going on outside. No sightings of any storm troopers, thankfully.