Saturday, March 31, 2007

Bulkhead flanges done

I spent Thursday evening trimming and sanding the deck flanges back, doing prep-sanding for the bulkhead flanges, and finished up the rest of the keel taping on the port float (as mentioned, very easy to do in the upright position):

I do wish I had a smaller sander though -- its very hard to get mine into small spaces like down by the keel joint. That's why you see a layer of putty under the tape in the picture above; the putty smooths out irregularities that are too hard to sand out, but would make the tape lie non-flat if left alone.

For doing the bulkhead flanges, I had been thinking that I would setup the form frames (#'s 5, 7, & 9) back up on the strongback, and then add a mold plate to the top of them (other F22 builders have been doing it this way, can't claim this as my idea). Then I began thinking about what it would be like crawl around in the middle of my strongback while laminating -- did not like that idea. So instead, I did my flanges with the float halves sitting on sawhorses. Each bulkhead had its own mold plate of course, held in place with a strap & comealong.

On Friday evening, I prepared the horizontal mold plates:

...cutting them to a reasonable size and covering them with packing tape. You can't tell in the pictures, but they are cannibalized from a few float frames (just like the Indians and the buffalo - no part of the carcass goes unused). I also prepared the angled mold plates used for the deck flanges:

Today the first order of business was setting up the mold plates on the float:

I really liked the idea of being able to sit on the chair while working, but I didn't seem to have enough scrap lumber laying around to get the float high enough (the chair fit, but I still wouldn't have had room to sit under the float). Also, there's not much room toward the aft of the float -- I was moving that rear sawhorse forward and back all day, depending on which side of the aft beam bulkhead I was working on. So alas, no chair - instead, I spent the day on my knees (ouch).

There is a crapload of laminates to be cutout for this phase of the project. I recommend staying as organized as possible, otherwise it is easy to lose track of where you are.

In some cases, you have eight pieces of glass per bulkhead side. By keeping the glass for each bulkhead side in a pre-counted pile, I didn't have to worry about counting glass layers as I went. (It would be quite tragic to be in the middle of the layup, and start wondering "was that two or three layers on that last bulkhead?")

Here's a fwd bulkhead beam, with just the first two layers of "C" laminate in place:

The angled line on the left is there to guide me later when placing the angled mold plate. Note the scribbled-out angled line on the right - that's right, I almost screwed up and laminated the deck flange backwards. Thank goodness I was double-checking things today; it's easy to get confused (could be just me though).

The fwd and center bulkheads are pretty easy to work on. You want to be careful on the aft bulkhead though....if you were to jerk your head to the side without thinking, you could guillotine yourself on the deck flange. :)

Here I am using hot-glue to place one of the angled mold plates into position:

(Wow, look at the belly on that guy. Maybe he should be building a tugboat instead of an F-boat? :))

The hotglue gun trick works great by the way; I was worried that the glue would not be sufficient to hold the mold plates in position, but they never budged.

Here is an aft beam bulkhead with all glass in place:

One thing I found, was that on the aft bulkhead the 9" angled mold plate does not quite fit if placed in the specified position and angle -- it's too long, and will hit the side of the float. I had not seen any other builders mention this though, and wasn't sure what do (and wasn't willing to lose time by emailing Ian about it). Choices were to trim the length to fit, stand the 9" mold plate up at a steeper angle, or position the bottom of the mold plate closer to the centerline. I chose the first option -- it didn't need much trimming, I think I cut it down to about 7 1/2" before it fit.

Working the glass on the angled mold plates is not difficult, but does take time. There are six pieces of "A" laminate per bulkhead side, for the fwd and aft beam bulkheads. I wet out and placed each piece of glass individually, since on the first beam bulkhead I tried to work a triple-layer of "A" into place and found it to be a difficult task and gave up. Doing it one layer at a time like that, by myself, meant I was up and down a lot today -- I will sleep good, for sure.

Tuesday, March 27, 2007

Float cradles assembled

Just a brief post to cover putting the float cradles together.

I have seen some really nice looking float cradles on the web, that look CNC cut and robust enough to hold up the Titanic. For awhile I was thinking that I had to create some cradles that kept up the tradition, and this was slowing me down a bit. This evening after work I got exasperated with myself and said "just build something, dang it". So I did.

I did have one good idea (for me anyway) which was that I could use the form frames themselves (#5 and #9 of course) as patterns:

This let me avoid having to get the form frame full size patterns out. Of course, the form frame lines are 3/4" off from the real hull (battens). So I scribed a line 1/2" inside of the frame lines, to give a little wiggle room, then cut out those parts with a jig saw. I cut out two pieces per cradle, and screwed them together so the float had a nice thick base to sit on. The cutouts formed little half-moons which I then used as side-braces:

A little bit of work later, including smoothing over all the edges with the sander, and I had a little family of these guys:

You can tell I wasn't being too precise with my jigsaw work, so some of the lines are a bit rough. Not worried about that, but I am wondering if they will be stable enough when I start sanding the hulls and whatnot. We'll see, if not I can always add some long side braces. I'm still debating about what color stain to go with (joke).

Here's the port float sitting up on the cradles:

(that's my sixteen year old son in the background, sorry for blocking your head out Zach.)

I can tell already, that finishing the keel taping from the upright position is definitely the way to go; looks like even the bow bulkhead would be pretty accessible like this.

Here's an aft shot:

Obviously I have some deck flange and transom trimming left to do. I have to say though, it was pretty motivating to see that float sitting nice and upright!

Monday, March 26, 2007

Port float joined and unmolded

Didn't get as far as I had hoped this weekend. The weather did not cooperate at all and sometime around midday Sunday I just got tired of being outside in chilly, rainy weather. However, I did get some things done.

Friday evening I laminated the fourth float half:

I thought everything went pretty well, but on Saturday morning I found a few minor layup bubbles here and there, and some massive bubbles around the perimeter of the chainplate pad laminate. Very aggravating. When I started sanding these out, the small bubbles went quick; the laminate over the chainplate pad was still a bit green however and when all was said and done, I had stripped both layers of "C" laminate off of the pad. Not much fun, but I did get it super nice and clean for re-lamination:

Saturday afternoon I joined the third and fourth float halves. The fit was pretty good except for the front beam bulkhead, that required some trimming. The upper float half was the first one I did, i.e. it's the one where I made lots of plank-to-keel join mistakes: not too surprising then that it would need a little help. All bulkheads were taped in -- including the #($#&*@# bow bulkhead which ended up looking like this:

I feel bad saying this but it could have been much worse, believe me. I'm hoping that this is the worst taping job on the whole boat (but I won't be too surprised to be disappointed).

The transom tape is not much fun either, but I was proud of how this one turned out:

I decided not to do the keel tapes other than two small pieces between the fwd beam and center, and center and aft beam bulkheads. I need to be more patient at times: I was trying to mix enough putty (using Fast hardener) to do two bulkheads at a time, and ended up losing the race to get the second bulkhead taped in before the fillet putty kicked. Trust me, the fillet tapes look wayyyy better when you lay them in place wet-on-wet. :)

Sunday morning I unmolded the float, and it looked good from the outside:

(Yep that's me; the wife came out to the tent for a status report and I got her to take a picture. I also took some of her inspecting the work, but I'm promised an early, slow death if those pics show up here on the blog.)

I really should have done the keel taping then, but the weather was chilly and so instead I stalled by dismantling my form frames.

I did some contact cement experiments on some scrap foam, and was not impressed. Either I'm expecting too much from contact cement, or I'm way spoiled by the gripping power of epoxy. I'm sure it doesn't matter, since Ian wouldn't recommend it if it was non-worthy, but I think I am going to use epoxy putty for my bow caps regardless. I had bought one two many sheets of 3/4" A500 -- was previously planning to sell it, but now I think I'll put it to use for the bow caps, which will minimize the number of join lines.

I also worked on preparing the bow compression struts. I'll probably break my arm patting myself on the back here, but they turned out really good. First step was shaping the struts and rounding the edges off:

(they are intentionally too long to start with - I'll cut them to fit later.)

Then I used my Raptor composite staple gun to staple one end of the glass to the struts:

The Raptor gun and staples worked really well - this was my first chance to use them. I was worried that the cloth would just tear through the staples but that didn't even come close to happening. It is a nice tool.

Then I wet out the glass, rolled it up as tightly as I could get it, and wrapped it in peel ply to help keep it tight:

After peeling off the peel ply after work this evening, the struts look great and feel even stronger.

Thursday, March 22, 2007

Fourth float half ready for laminate

Here's a short update on progress this week so far, and plans through the weekend.

Tuesday night I planked the entire float half - it went quick, I just chugged through it.

Wednesday (last) night I dremel'ed between the planks and puttied everything together. I hadn't realized how low I was on micro and silica -- I used every last ounce I had to get the job done -- the last two deck flange corner pieces were glued on a bit sloppily (runny putty). I did have some wood dust left, but was trying to avoid using it (though I guess it wouldn't have mattered).

Tonight I sanded the float half down, shaped the chainplate pad, marked out the location of the stringer and the extra reinforcements, and pre-cut all of the glass except for the flange reinforcements (I'll cut those tomorrow from the offcuts from the main float laminate). I'm essentially prepped for laminate.

Tomorrow night after work (assuming the weather is at least half decent) I'll laminate this float half, and maybe also glue the bow caps together. I picked up some contact cement this afternoon for doing the bow caps; was thinking I'd use my A400 scraps for that job (figuring that A400 is more suited for a crush\crumple zone area).

Saturday I'll join the port float halves together, and maybe start working on the bow stringer cross-pieces, and also do something about constructing some cradles.

On Sunday I should be ready to set things up for doing the bulkhead flanges.

Here is the puttied and sanded float half:

Here's how I was setup for shaping (sanding) the chainplate pad; you can also see the markings on the float half for the extra reinforcements and the chainplate pad location:

Here's my garage "table" with all of the laminates cut and ready to go (the rolled up glass is of course the main laminate for the float half):

This is essentially how this corner of my garage looks every night, after I've cleaned up and put my car inside. Yes, it is a bit crowded. The benefit is that because I've got little room for leaving messes around, I tend to be somewhat anal about picking everything up. The garage so far has stayed decently clean throughout the project.

Monday, March 19, 2007

Starboard float unmolded

Didn't have as much time for boat work as I had hoped this evening, but I did manage to get the first (starboard) float unmolded. Wasn't quite as easy as the last time. (Builder tip: break the "seal" between the deck flange and and the deck flange mold plate before you place the matching float half on top of it. Otherwise it can be hard to get to.) Overall the float looked good, not that I'm an expert:

That darn bow bulkhead tape had a couple of small bubbles in it (only having a couple is actually a miracle in itself). I cringe at the thought of trying to grind them out in that small space - I may just live with it. The keel tapes actually turned out pretty good, but there are a couple spots I may patch with extra tape later on.

The keel pieces did not meet up 100% perfectly everywhere; not sure why, I thought I had that part nailed. I don't think this will be a major problem, I'll just have to sand it even before glassing it over.

After unmolding the float, I could not resist grabbing my sander and going to town on those stubby keel flanges. They're all gone now! :) I didn't go too far though , just enough to smooth them even. I guess I needed the motivation, to see something really smooth and boat-shaped (it's been a long winter).

After that, I stored the float away on saw horses; the tent is starting to feel more and more "full":

I sure envy those builders with nice big shops and plenty of places for storage.

I spent the rest of the time cleaning up the keel batten (it got gunked up with putty pretty good) and doing other prep work to get ready for the last float half. Tomorrow after work I'll be able to start planking right away.

Sunday, March 18, 2007

Starboard float half joined

(Back in college, I made brownie points with an English Lit professor by submitting for extra credit an "unpublished" canto from Dante's Inferno. The ne'r-do-wells who inhabited this new level of Hell were...Literature professors. The professor took it with a sense of humor; in retrospect, I was lucky.

I may have to add a new canto for whoever invented inside taping.)

It has been a busy week. I found time to plank most of the third float half on Tuesday and Thursday evenings. On Friday I finished up by puttying between the planks. Saturday was spent on laminating this float half. Pretty straightforward at this point.

Today though, I joined my first float; this one will be the starboard float. It was a very busy day and I didn't have time for a lot of pictures, unfortunately. The upper float half (my 2nd float half) fit the bottom one pretty well everywhere except for the transom - not sure why that area gives so much grief. Lots of fine trimming (and cussing) going on. (As usual I was working all by myself. Fortunately, I am big enough that manhandling a float half by myself is not too difficult -- wonder if I'll be able to say that with an entire float.) Eventually the fit was good enough and I went ahead with the joining.

I used Medium hardener for my putty, which was good because the temperature sneaked up to about 68 deg F today, a nice surprise. I had plenty of time though to putty all of the join lines before setting the upper float half in place. I used strap come-alongs to force the upper half down on the bottom one. (At first I tried bungee cords -- you might be able to get away with bungees if you have a perfect fit, but alas I needed the come-alongs. Plus I'm always a bit nervous around taut bungees.). I ran out of come-alongs, so had to use a field-expedient method:

After getting the top half located and locked down, I went around and started making fillets for the bulkheads, and smoothing out the excess putty at the keel line. The bulkhead fillets were not bad except for the bow bulkhead -- it's just darn near impossible to do a good job up there in that tiny space:

(this picture makes the space look bigger than it really is)

I ended up just sticking a blob of putty on the end of a brush that was screwed to a long stick, and shoving it up into the join line, then brushing the putty back and forth to try to form something that at least resembled a fillet. There's enough putty up there that it won't move after the putty and the tape cure, but it's not the prettiest job in the world. Hope that doesn't invalidate the warranty.

Doing the inside keel taping was also a pain in the rear. Last night I had pre-cut 50" tapes for the long keel sections. Unfortunately, working with a wet, 50" tape using a brush-on-a-stick is not the easiest chore in the world. I ended up cutting all of my tapes down to ~20" or so to make them easier to handle with the brush-on-a-stick technique. If anyone out there has some tips on better ways to do this inside taping, I'd love to hear them.

I'm now wondering what would be wrong, with joining the float halves but only taping the bulkheads and transom, and leaving the keel taping and bow bulkhead taping for later while the float half is upright. Maybe it's just slower? Anyway, tomorrow night I'll unmold this float, then move on the fourth and final float half. I also need to think about throwing together some cradles to hold the floats once done.

Monday, March 12, 2007

Second float half unmolded; form frames reversed

We unmolded the second float half this evening; it was a piece of cake. My daughter was even out there helping me loosen screws, and once that was all done we had it out of the mold in five minutes flat. Pretty exciting.

This float half looks good; not quite as fair on the outside foam as I was expecting, but quite acceptable. The float half is now nestled against its twin, both waiting for me to finish their mates:

After that was put away, I got busy dismantling the form frames. The tear down process went quite fast. I marked each of the battens so I could get them all back into their original places:

When I had a bare strongback again, I took some time to re-check the level. Remember that my strongback is built on top of pierblocks, which are sitting on a sand\gravel base inside of holes dug about a foot down into the ground. So I was curious to see how things have held up, now that six months of our rainy winter have almost passed (sigh - has it really been that long?). I think though, that this will work:

It looked that good everywhere; the strongback essentially hasn't moved at all. Considering it's a wooden strongback built outside on essentially a dirt base, I'm quite pleased.

Remounting the form frames went pretty fast. My form frames are made of 3/4" construction plywood, but it turned out that form frame #1 actually had some minor warpage. I think this is because it is the frame that is closest to the door of the tent, so when it rains it gets a lot of semi-direct moisture. The warpage wasn't that bad though, and I decided to keep using it. All of the other frames were fine. (Thank goodness the boat itself is not made out of wood -- if so, I would not be building it under these conditions.)

Some of the battens were another story. I was planning on reusing all of them...

...but some of them had suffered from warping. They didn't seem warped when I was doing the first two float halves, but when I was trying to put them back a few were quite uncooperative (a few of the screw holes got kind of tired too) -- maybe they waited to be unscrewed, then took their chance to warp and ran with it. After some thought, I think I will just replace them; I've got plenty of extra battens laying around. But the majority of the battens are back in place, so I'm declaring success for tonight.

The screw guns got quite the workout this evening. I have two Dewalt guns, an old one and a new one. The old one died on me tonight (no kidding - wasn't a dead battery, as far as I can tell) while I was drilling new holes to screw the form frames to the strongback cross pieces. That slowed things down, having to switch screw bits for drill bits, etc, etc. I will be getting a new gun this week - life's too short to live with only one.

Sunday, March 11, 2007

Boat will be slightly heavier than expected

While working on the second float half, I noticed some lettering on the edge of my corecell foam that said "A550". This surprised me since I thought I had ordered and gotten A500 from Noahs, but upon checking the rest of my foam (way to go Jay - check the order six weeks after receipt) it turns out that it is all A550.

This discovery prompted me to go crunch some numbers. Using Ian's figure of 950 sq ft of foam to build the entire boat, I came up with the following total weights for different foams:

Pure A400 boat: 119 lbs
Pure A500 boat: 140 lbs
Pure A550 boat: 181 lbs

(these figures disregard the extra weight of HD inserts)

(Note, this is using the best-case (lowest) listed density for each Corecell variant, since Corecell actually specifies an allowable density range for each foam type: A400 density=4.0-4.6 lb/ft^3, A500 density=4.7-5.4 lb/ft^3m, and A550 density=6.1-6.7 lb/ft^3)

I can't draw an exact comparison since my boat will be a Frankenfoam boat (I have mixed foam densities) but still....60 extra pounds for using A550. I wonder what the expected load capacity of an F22 will be? The main F22 page on Ian's web site does not say (see specs at bottom of that page), and I don't know enough engineering to be able to infer or compute it. However, it's something I need to keep in mind: everytime you make a mistake (e.g., heavier foam, too much putty, tapes too wide, etc, etc) you're whittling down that load capacity number which will leave less room for beer, humans, food, and beer. :)

Second float half laminated and bulkheads mounted

I've been making steady progress on the second float half. I puttied between the planks and filled holes on Friday night, then laminated the inner skin on Saturday, and today I mounted the bulkheads and laminated the chainplate pad. Doesn't sound like much when I say it like that, but the time sure seemed to fly by. I considered trying to unmold the float half late tonight (Sunday night), but considering the cool temperatures and rainy weather, I'm going to play it safe and let it cure overnight. This is good progress though, and I'm looking forward to joining my first float half.

One big improvement I saw with this float half over the first one, is that all of the bulkheads fit with near-millimetric precision. I am 100% convinced that this is due to the improved plank-to-keel foam fitting. It was very cool seeing these parts fit so well. Only wish I could have done so well on the first float half.

I also made myself a cheap little fillet tool out of a small piece of plastic. At first I was going to make a handle for it, then said hell with it, it's going to get all gunked up anyway. Amazing what a few square inches of plastic can do; the resulting fillets were great: smoother and sized more consistent than the ones I did by hand before. One weirdness that happened while doing the fillets, is that some of the fillets turned yellow on me (obviously due to heat generated during curing, although I didn't think the putty was that close to 'kicking'). The fillets that experienced this did not appear to malform (no catastrophic meltdowns), but it certainly looks a bit odd. I'm hoping that this is not a fatal condition, but I sent a question to S3's support line about it just in case.

By the way, did I mention how awesome Thalco rubber squeegees are for laminating? I used one for the first time on this float half. A bit expensive, but you can easily drag them around the cloth and get the excess resin out.

Another pic of tape cutting central:

Here is a pic of the bulkheads all taped in:

(You can see the rain dripping from the door of my tent. I was dodging raindrops every time I carried a wetted-out tape from the garage. Temperatures got up to over 60 deg F though so I'm not complaining about a little rain with it.)

And here is the chainplate pad laminated to the hull side:

I tried to be extra careful with the chainplate pad...I'd hate to be sailing along some day and see that chainplate come ripping out of the float deck. (Do other builders have daytime nightmares like this?) Also, careful readers will note that since the chainplate pad went into this float half, that means this is going to be the starboard inner half. I know I said my first half was going to be the starboard inner, but changed my mind earlier this week when I couldn't wait to unmold the first float half.

[Edit: System Three responded to my query already (on a weekend, no less!) with the following response:

Hot epoxy will turn yellowish in color. So long as it is not brown you are fine.

Phew, good thing -- I'd hate to have all that work wasted.]

Thursday, March 8, 2007

Second float half planked

I finished planking the second float half tonight. This was my chance to try out some of the tips other builders have given me, so I was pretty motivated to move through the work.

There were three things I changed while doing this float half:

  • I had previously figured out that one big reason I was having trouble with the first float half was that I was using 1" panhead screws (panhead so they don't sink into the batten) but this was giving marginal results since I was only getting (roughly) about 1/8" penetration into the foam. That meant excessive thermoforming was needed to ensure the foam didn't pull away from the screw (if you go look at pictures of my first float half, you can see lots and lots of scorch marks - sometimes made myself sick with the smell of toasted corecell.) To fix this I changed over to 1 1/4" panhead screws, with a couple of washers underneath the head. Penetration is much better, you can sometimes see the pointy end of the screw through the foam. I didn't replace every single screw in the battens though, just on the three-four battens nearest the keel foam where the hull curve is greatest. This helped so much that I was only thermo-forming about a minute or so per plank, on the curved parts. However it is time-consuming to mess around with two washers for every screw, and I may look for a different solution when I get to the main hull. In retrospect, I really, really, should have experimented a bit more with different screws before getting started on my first float half (but Home Depot was cheap and local, and I was eager to get started).
  • Planked without the keel foam in place, then did a scribe cut to get the right miter angle on the vertical planks. This change was a total success, and I'm grateful to those who suggested it (and feeling stupid because I didn't think of it myself). Without having to worry about an exact keel foam fit on each plank, you can really move quickly. When done, I was able to slide the keel foam into place pretty easily -- the plank-to-keel meeting line looks nicely uniform the entire length of the float (unlike on my first float half ).
  • Planked without the deck flange mold plate in place. It definitely aided progress to not have to worry about the overall length of each plank. When I got around to trimming the excess foam at the deck join line, I made a mistake and trimmed it flush against the last batten. Unfortunately I did not realize that the last batten was not screwed in flush against the deck mold plate - so now I have a gap between the deck mold plate and the edge of the planks. The gap varies between 1/8" to 1/4" - not good, I'll have to fill it with putty which will make the boat slightly heavier (but I don't feel bad enough about it to make me want to unplank the entire float half). This was my fault -- I should have used the deck mold plate, or a piece of plywood the same thickness, to draw a line and cut against that. Despite its advantages though, I am having second thoughts about this change -- with my first float half, I was able to completely cover the plank-to-deck-flange angle with masking tape so there was no sticky issues there during unmolding. It's hard or impossible to do that here, when you slide the deck flange mold into place after the foam is planked. Guess we'll see when it comes time to remove it from the mold.

I hope my notes above help other F22 builders to not make the same mistakes I did.

Still though, I have to say that planking this float half was a success -- in about 8 hours I planked the entire float half from start to finish, completely by myself, and I feel confident that the planks are set nice and fair against the battens. Also note that this was all done with 8" wide planks (less than that in a couple spots), mainly so that I could re-use all of the same batten screw holes -- the process might go faster had I tried to use wider planks where possible.

This is the rough-fit of the foam against the keel batten (no keel foam in place):

(Notice there are very few scorch marks this time. The float half is completely planked except for the last foot or so down by the transom).

At first I used a piece of foam for my keel miter cutting guide, but it kept getting cut up by the jigsaw blade. I switched over to a piece of plywood, not perfect but good enough to finish the job. Here's a shot of how I did that:

(this was a self-posed shot -- so no, I don't actually make cuts with the jigsaw coming toward me :) )

Here's the view of the final cut:

This cutting of the keel plank angle actually worked so well, that in some places it left the fit a bit too tight to get the keel foam back into place. Had to go back and loosen those up a bit. I now have the keel foam back in place but I am now wondering if it will be difficult getting putty in between the planks and the keel foam. Guess I can always use a putty knife to open up a tiny gap temporarily, or even loosen the screws on the batten closest to the keel.

Finally, here is my planked float half with deck flange mold back in place:

Weather forecast calls for chilly weather and a zillion days of consecutive rain, but hopefully I can make more progress on the float half this weekend.

Tuesday, March 6, 2007

First float half out of the mold

I spent a few hours this afternoon loosening all of the screws and freeing up the float half from the mold. Here it is right after being popped out:

Freeing it from the mold was a bit painstaking (you tug here or there, it still doesn't move, then you go hunting for that tiny bit of putty that's still holding it down), but patience won out in the end. The float half looks good, in my inexperienced opinion, although there are one or two planks in the middle where I can tell they weren't quite flush to the the keel. A little putty will fix that right up later.

The exterior of the float half looked really good too:

I wish I had a better place to store it, but for now the ground floor of my tent will have to do - it's now waiting patiently beneath the hanging float decks. I blocked it up so there shouldn't be too much stress on it. When I get to the main hull, I will have to store the first hull half outside on sawhorses, covered with a tarp, but I didn't want to have to do that for the floats.

I noticed that the keel foam looks bowed (between bulkheads) after pulling it out of the mold. However I've heard other builders report that this is normal and that it will simply be forced back into shape when joining the float halves.

After popping the float half out, I spent some time cleaning up the tent and preparing the mold for the second float half. I got the keel foam glued into place and pulled some foam sheets off the pile to get ready for planking tomorrow. I'm going to plank this float half with the deck flange mold plate off the mold, like other builders have done. Hopefully that will help things go faster.

Monday, March 5, 2007

System Three on Epoxy and propane

I had an informative exchange with System Three's support folks today, which might be useful to others as well.

I submitted the following question:

What is the official S3 opinion on the use of propane heaters around fiberglass and epoxy work? The epoxy book does not seem to address this. I have read definitive opinions to the effect that kerosene and fuel-oil heaters are definitely bad. Opinions on propane seem to be divided, based on my casual internet surfing. But I have read that propane is a clean burning fuel, so what's the official scoop?


Twenty-five minutes later (wow! talk about customer service) I got the following reply:

On Mon, Mar 05, 2007 at 2:25pm Technical Support wrote:
Heating with LPG or kerosene:
The combustion by-products of LP gas are carbon dioxide and water. These combine to form carbonic acid, which will react with the amines present inthe epoxy hardener. The net result is that more blush will form. Blush, in and of itself is not usually harmful. Direct kerosene heat is different in that unburnt hydrocarbons are also present. These made combine with the curing epoxy to form a surface that is difficult to recoat or bond to unless vigorously sanded. We never recommend the use of kerosene as a direct-fired heat source. Indirect fired heaters (using a heat exchanger) are acceptable with either fuel. If your only heat source is propane then we recommend that the area be heated well in advance of any epoxy coating or fiberglassing, the room be quickly ventilated prior to using the epoxy for this application and the heat be turned off when the epoxy coating or fiberglassing cures. It may be turned back on when the epoxy is non-tacky to a medium touch. The above does not apply to bonding as very little epoxy would be exposed to the air in the room.

I had one other question for them:

One followup question: do the precautions you outline below also apply when working with a "no-blush" system, ie, your Silver Tip Resin?

To which they laconically replied:


(Direct-fired propane can cause blush? That's it?? What the heck was I worried about? :))

On Sunday when I laminated the float half, I followed their suggested procedure almost to the letter. Mainly because if I had had the burner on while I was laminating, the fumes would have just about killed me (something stinks while that thing is running - maybe it's the excess carbon dioxide). I did turn the burner on a bit too early according to S3, but I checked the laminate for blush before doing the bulkheads tonight and it felt fine. It's something I'll be careful about in future.

First float half bulkheads mounted

Today was another incredibly balmy day for the Pacific NW for this time of the year. When I left work it was 62 deg F. So when I got home I thought I would get started on mounting the bulkheads, but wasn't sure how far I would get. By the way, I've decided that this float half is going to be the inner starboard float half.

I had not yet made up the chainplate mounting pads, an oversight I was now kicking myself for. That was the first task of the afternoon, gluing up some foam for those parts. Then I moved onto the bulkheads.

I want to thank Ed for posting pictures of the bulkhead mounting jigs he used. That saved me time not having to think much about how to do it. So it was pretty quick to get to this point:

I'm probably making too big a deal of this, but yet, it was pretty exciting to see this thing start to take shape. Which is probably the reason I kept going when I should have stopped there for the night.

All of the bulkheads fitted nearly perfectly., something which seems amazing (but really shouldn't). Some small trimming was needed down by the keel edge, but I'm pretty sure this was due to my aforementioned rough job in that area. The transom was a bit tricky -- at first it seemed too long to fit into the specified place. Then I realized that the top and bottom edges needed to be mitered where it meets the keel and the deck flange, and that helped to make it right. The plans say the bow bulkhead is to line up with the aft edge of Form Frame #1 -- but this means it is not flush with the front of the bow planks which just looks, well, weird. I honored the plans and didn't bother Ian about it (worst comes to worst, the cavity can be filled in with putty :). This slightly rearward placement of the bow bulkhead also means that the bow stringer will likely be in the way, unless you accounted for this when you placed the stringer. I had seen Ed run into this in his pictures, but forgot all about it until tonight, so I ended up having to cut a small recess for the stringer as well.

I have formed epoxy fillets on previous projects, but unfortunately it is a skill for which mastery still escapes me. I did my best to make everything look clean and professional, but only succeeded partially (good thing these aren't visible). I also think my fillets were a bit larger than required; I jumped into the job without having made a specific filleting radius tool, so I had to eyeball it. You be the judge:

I will work on having a decent fillet tool ready before the next such job comes along.

After the fillets were all done, I then did the taping. Here is my vacuum bag board, converted over to tape cutting duty:

(Side note: I recently bought an EC Cutter from Jamestown Distributors . I didn't really need one, but it looked like a cool toy to try, albeit a bit expensive. My first impression is that as long as the battery is charged, it definitely does the job -- fast, easy cutting, with little or no damage or runs to the cloth. However the battery seems a bit on the small side although you can use the tool while plugged into the wall.)

Getting all of the bulkheads taped took me longer than expected. First you have to measure and pre-cut all of the tapes. Then, one by one I wet out each individual tape in the garage and carried them out to the tent and placed them. I worked through dinner because I was afraid of being out there all night. All this after a full day of day-job work too; I'll sleep good tonight. :)

Here is one final close-up picture of a completed tape job:

Although the chainplate pads were probably cured enough by this point to form and mount them, it was getting late. So I cleaned up my messes and called it a night. At the moment though the heat lamps are still on. I'll turn them off before I head off to bed but hopefully things will get at least to a semi-cure before that.

Sunday, March 4, 2007

First float half laminated

I certainly wasn't expecting to be able to post this today.

After breakfast, I went out to the boat tent to check the putty work from the previous day. It didn't get cure much more in the overnight chill, but everything had stayed in place (no major putty "runs"). The propane bottle had gone empty on me, so I took it to get refilled. After getting back I hooked it up and lit it off. Wow -- it sure doesn't take that burner long to heat up that tent. Well, with that in mind, plus the decent performance from the heat lamps the night before, I decided to go ahead and laminate my first float half.

First I sanded down the float half (the putty was just cured enough to be sandable), then vacuumed and cleaned it all off. My wife and son helped me to roll out the initial layer of glass, and then I trimmed off the excess:

So far so good. Then I got to work on the laminating part:

It's tough to take many pictures when you're laminating by yourself. I tried to grab the camera whenever it was time for a glove change, but sometimes forgot. The whole process went pretty well IMO. My putty job from the night before left some bumpy spots down by the keel join - I did sand these down, but not quite enough in some spots. Those bumps turned out to be problematic for the glass -- something to keep in mind for future. I think my rough-n-ready job of joining the float half pieces to the keel foam also contributed to unnecessary work in this area.

After wetting out the initial layer, I then did the extra flange reinforcement. Scrap glass worked great for this. I am becoming a huge fan of wetting out glass on a piece of plastic on a smooth flat surface -- it is soooooooo much easier: it wets-out super easy and you can easily force out any excess resin. Then you just carry it out (roll it up if it's a long piece) to whereever it needs to go and lay it in place. I tried to leave the flange laminate a little on the long side and will trim it later after the floats are joined.

Next was the extra bulkhead reinforcements; here is a picture of the aft bulkhead one ready to be laminated.

And last but not least, the bow stringer. I already had all four bow stringers ready -- it was nice to be able to just pick one off the pile. This is the stringer bedded down in putty, but before the extra reinforcements were added:

I was on the home-stretch now, all that was left was wetting out the uni and BD reinforcements for the stringer and laying them in place:

(In the above picture you can tell that I did not use a continuous piece of BD glass for the stringer reinforcement. My use of glass has been somewhat excessive to date, and so I've been trying to economize where possible. So the stringer has two 50" pieces cut off the end of the roll, and a small joining piece in the middle.)

That finished it for the laminate work. I then trimmed off the excess glass at the keel join, turned on the propane burner to help jump start the cure, and walked around the float half checking it over for excess resin, bubbles in the cloth, etc. The cloth bends around the stringer were again troublesome and needed special attention. Between the heat lamps and the propane burner going full blast, the laminate was curing quite fast - the areas with a single layer of glass were already almost dry by 5pm.

I had been really frustrated not being able to make significant progress on the floats, so today's progress helped my morale a lot. Mother Nature was quite helpful (got up to 60deg F) but I am also glad that my $200 or so investment in the heat lamp fixture seems to be paying off. My neighbor's propane burner works awesome too.