Sunday, March 30, 2008

Weekend progress and a visit to an F44SC project

Yesterday was a day for taping. The pictures are not much too look at, but I got a lot done: all interior taping along the hull seams is now done, including the bow compartment up to about 4" of the (as yet non-existent) bow bulkhead. Much of the taping was done using DBM1708 tape; this was my first experience with the stuff and I definitely appreciate its ease-of-use (especially back in the aft-cabin!) but have some reservations about how much resin it wants to swallow. Next up on the job list will be starting the daggerboard case taping, and closing in the bow.

For fun and a sense of progress, I also trimmed off the extra flash on the front of the aft-cabin:



I had posted a question about hull thickness for the front aft-cabin hatch on the F22 builder's forum, since the Lewmar hatches I was looking at (even their low-profile models) all specify 15mm minimum. I checked with Ian who said it's perfectly fine to add a ridge of foam around the perimeter of the hole to build up to that, so that's good.

For Sunday I had made arrangements with Allen (he's building F44SC #1, link somewhere on the right) to make a trip down to see his project. It is a not-so-secret plan of mine to build an F44SC someday and sail away, so this was an informative trip for me and and I also wanted my wife to see something in person to get a real idea of the size of this boat. The drive is about four hours long (ok, 3.5 if I'm flying low), so we left early and arrived around 10:30am. Then commenced a few fun hours of general and boat-related discussion, and a good look at Allen's hulls. Wow - having seen his lamination work up-close, I can definitely say he is doing a very, very nice job. Here's one of the pictures I took:

Thanks again Allen for letting me come by, much appreciated.

After getting home, I decided to do one more small job on the F22: making then glueing the cabin deck stringer into place:

It should be ready for final lamination tomorrow.

Friday, March 28, 2008

Cutting the daggerboard blank

Regrettably I was pretty sick this week (with strep throat - zowie, haven't had that since I was a little kid!) so nothing new on the hull join work. My neighbor however finished the 3D CAD file for the daggerboard, and machined it today out of a solid cedar blank that I made up last August. I had been saving those pictures but this is a good time to post them I guess.

When I made the blank I went to Martin's Lumber in Everett and bought several pieces of very nice, very clear, Western Red cedar, in 2"x8"x8' dimensions. This is an expensive way to do it - the wood was well over $200 as I recall. After cutting them to a better length, I ripped them into chunks a little over 2" thick and got ready to laminate them all together.

I was worried about the glue joints ending up too dry, so I coated each joining side with raw epoxy, then slathered on a layer of bog for good measure:

After all of the pieces were glued together, I then clamped it all up:

After the bog dried, I "post-cured" it in a black garbage bag in the sun, but otherwise the blank just sat because the 3D file wasn't ready yet (hasn't been a huge priority for either my neighbor or me, obviously :). This month things were finally ready; here's a picture of the 3D model:

My neighbor first did a test board in MDF (which I test-fit in my daggerboard case) and today he cut the real board out of the blank. Here is a picture of the CNC machine in the middle of a rough-cut phase on the first side:

Here's a short video of the CNC machine in operation:

video

The audio isn't much :) but I think it's pretty cool to see the machine in action.

Here's a picture of the "finished" product:

Frankly it looks really beautiful; it's a shame it will all be covered up in glass, fairing compound, primer, and paint (I'm thinking of painting it yellow, for capsize emergencies). Anyway, next steps will be coating it with a sealing coat of epoxy, then starting the glass and uni layers. (And yes, we made sure to under-size the board to account for the thickness of the glass layers).

Sunday, March 16, 2008

Hull joined

Sometime in the middle of the week, I went ahead and glued my daggerboard case into the lower (port) hull half (my daggerboard is not ready yet and I decided not to wait). Yesterday I joined the hull halves. Everything went about as planned, however I was unable to get the fwd deck sections to come much closer than about 1/4"; I used Menno's technique and also tied straps over the upper hull half in an attempt to draw it down some more. In the end, I just cut some thin foam strips and bogged them into the gap.

Pictures of the hull joining are not too impressive, since there's not much to see. Here's the daggerboard case, keel-side view:

Forcing bog into the gap between the deck sections:

Bow section tied down:

Deck section joint with daggerboard case bogged into place:

After letting the hull joins cure overnight, I got started this morning sanding down all of the joints and getting things ready for taping. I forgot to put masking tape on the little wood blocks you see in the picture above; some of them were fun to remove (ie, grip the block with long pliers and twist it off). I got most of the joints ready for taping (everything except the lower bow section). I taped the outer transom areas, the outer cockpit join, the inside deck seam, and the inside keel section right behind the daggerboard case. Here's a picture from near the end of the day:

Climbing underneath the daggerboard case to get to the bow is lots of fun; on the other hand, it does make a nice work table inside the boat.

Oh yes, almost forgot: Stu from Bellevue came up and paid me a visit this morning; he's considering building a boat and we had a good time chatting about stuff. Thanks for coming by, Stu!

I've also been researching hatch choices. Lewmar's Low Profile series seems like it would be a good fit for the foredeck hatch. Their instructions say that the hull/deck thickness should be at least 5/8" (15mm) thick, which means it's not very suitable for the aftcabin fwd hatch (which is about 20"x20", mounted on 3/8" core). If anyone has a suggestion for the aftcabin fwd hatch, please email me.

Regarding Frontrunner fabric: I didn't try any Corsair dealers like Ian suggested. Instead, I called Lockfast (US distributor for Frontrunner) direct; I was able to buy some fabric however their minimum order is six yards. I went ahead and got it, but I'm hoping that some other builders might want to take some off my hands, cheap! :-) Let me know if you're interested - the color is "Koala", basically a light grey.

I'm gone on a business trip this week so I won't be able to do any boat work for awhile. Which is too bad, since I'm feeling very excited about being at this stage of the project (but it'll all be there when I get back).

Sunday, March 9, 2008

Daggerboard case install prep and bow web installed

I'm slowly marching closer to getting my two hull halves joined. The two big jobs that are left are installing the daggerboard case, and installing the bow web. I did most of the case install prep work this weekend, but I don't want to install it permanently until after I've finished the daggerboard itself and verified that it will work. (With the hull on its side in the form frames I won't be able to insert the board into the installed case because the tent walls are too close.)

Getting ready to install the daggerboard case is not too hard so I won't spend too many pictures on it. Here's the initial cut-outs, viewed from the keel side:

Case fit was excellent; was just the right length. Here's the dry-fitted case from the keel:

And from the deck:

I also got the bow web installed this weekend. I had rough-trimmed the bow area before, but now I needed the final precise cut. Here I'm getting ready to mark the cut line using the bow template:

After trimming both halves:

(In case you're wondering about that gap you see between the two halves; it's unfortunate, but I think I had some settling of the pier blocks under my strong back on the my first hull half (the upper one in the picture above). The gap runs aft to between form frames three and four; fortunately, the critical points (beam bulkheads) appear to have been unaffected. I have no choice at this point but to fill it in when I join the hull halves, and pray that my boat doesn't sail with a permanent lopsided tilt.)

After trimming the bow area back I then spent a lot of time staring at the bow web, being somewhat nervous about this important part. Like Menno I used a strip of foam between the web and the side of the bow, to help shim it up to the centerline of the boat. My foam strip needed to be much thicker than Menno's though; don't ask me why.

Here's a view from above:

Side view:

I tried to make sure the 3/8" rod (through the top of the bow web) was level, but most of my effort was spent making sure that the rod through the bow pole pivot was vertical and plumb. If that angle is wrong, the bow pole may point off at a weird angle and look funny.

Here's one more picture from the bottom:

Finally, this picture from inside shows my strategy for keeping the bow web in the right location; the 3/8" steel rod is stuck into a hole on the board, which is screwed to the top of the frames:

Well, that's that. Let's hope that I've installed it correctly.

In local news, I was happy to see that Fiberglass Supply moved their location from down near the Oregon border, to only about an hours drive north of me. I drove up there Friday morning to pick up some epoxy and carbon fiber; they seemed like nice folks. They did not have carbon uni in suitable weights unfortunately; I ended up ordering some from Soller Composites. I also had an impossible time trying to source PETP bushings online; I didn't try calling Johnson Composites (as suggested by Grant) but it turns out that Ian is selling them, so I'll just order some from him. The other item I'm trying to find is some Frontrunner fabric for the rudder case sleeve. I have not yet found a online retail supplier for Frontrunner; I might try calling Lockfast tomorrow to see if they'll sell me a yard or two.

Anchor well done, rudder started

Here's the finished flange for the aft bunktop, that I did last week. Turned out pretty good, IMO:

I also finished up the anchor well blank. The outer laminate was easy to do. Right after I did the inner laminate, I used a simple jig to try to let it cure to the final dimensions as accurately as possible:

I'm taking a shot at constructing my rudder from foam. I vacuum bagged two 3/4" sheets together to make a blank; this picture shows the rudder blank with the rough outlines traced in, plus some HD blocks curing in front of it, and finally you can also see part of the trimmed-up anchor well off to the right:

Here's the HD inserts curing in the rudder blank:

I'm experimenting with polyurethane glue here for the first time. I can see it has some definite advantages, especially the foaming/space-filling ability.

Here's me wrapping the rudder insert with carbon fiber:

(Yeah, I grew a winter beard - it's a lot grayer than the last time I had one. My wife doesn't like it though; I may have to trade its removal for a new power tool or something. :))

All finished with the carbon wrap, but before peel ply:

I deviated slightly from the plans; my insert has two+ full wraps of carbon from top to bottom. This was mainly because I thought it would be easier this way than messing with separate pieces of carbon.

Wrapping the insert was easier than I expected. I coated the insert with bog before I started to wrap it, this seemed to help the carbon to "stick" to it. I also put two full turns of peel ply around it, followed by plastic, followed by duct tape in several places.

This morning after I unwrapped the insert (not much leverage for yanking on the peelply...had to use pliers to get a grip) I was very pleased with how the carbon stayed nice and tight around the insert. Here's the unwrapped insert sitting next to its home-to-be in the rudder blank:

Last, I used Grant's trick of using part of the scrap foam from the slot cutout as a spacer, to get the insert centered within the blank. I bogged the insert into place rather than use the poly glue:

Next steps on the rudder will be cutting out templates for the foil sections, then shaping.

Sunday, March 2, 2008

Aft bunktop flange and anchor well prep

Well, so much for "getting back to boat building", as I said oh-so-optimistically last month. Let me get the whining out of the way: 1) the weather stayed cold and I'm a big chicken; and 2) I've been putting in a lot of extra hours at work. Which sucks - but work is what pays the bills, both for food and epoxy. Have to keep that in mind.

I finally got back out to the tent and taped the underside of the aft-cabin front panel:

The next day I slid my upper hull half over to the side on 2x4's, so I could work on the aft cabin bunktop flange from the outside:

On my first hull half I didn't do all of the flanges that I should have, so I'm trying to do a better job now. I knew from taping the aft bunktop on the the first full half, that there's very little room to get in there. For the flange on this one, I decided to make a cut-down mold plate by tracing the real bulkhead:

In the picture above, I'm using my daggerboard-to-be as a work table.

After covering the mold plate with masking tape, I fitted it into place:

Then I mixed up a bunch of bog (you have to fill that crack up quite a bit, in order to have a reasonable curve to the glass) and taped against the mold:

(Sorry, you can't see much in that picture but it was the best of the bunch.)

When I got up this morning, the flange glass was still a bit tacky so I decided to let it sit another day. What I should have done was work on mounting my bow web in the hull, but because it was a bit chilly I decided to work on the anchor well for awhile instead. This turned out to be more work than I expected and I didn't get much else done today.

Here I was routing out the slots for the battens:

The plans say to make four mold patterns, but the back of the well is almost 4' wide; I guess you could get by with just four, but you'd have to leave the battens hanging out quite a ways unsupported. So I went back and made a fifth one. Here's the the basic mold all done:

After the mold was ready I planked it and then bogged between the planks and filled in all of the holes:

That's where I left things for today.