Where'd everybody go??

The other i550 builder's blogs have been awfully quite lately. I know that Kevin in Chicago has been hampered by the cold in his garage, but that hasn't kept him from making great strides in identifying a carbon fiber rig for these boats. Sounds like a great solution. He has posted a great deal of information on the rig solution in the i550.org forum.

At the "Dalsin Boatworks" facility progress has resumed after a blissful holiday vacation. Work continues on the (expletive deleted) keel. Sorry, I grew up in Chicago---must be a little Blago coming through. Anyway, after a couple of iterations of filling and fairing over the carbon fiber reinforcement, two layers of glass were laminated to the keel. I tried the suggestion of wetting out the glass on a mylar film and then carefully slapping the whole assembly onto the keel in hopes of getting a nice smooth surface. It turns out that this is not as simple as one might hope. I found that the mylar film created a barrier which made it tremendously difficult to remove any bubbles under the film (of which there were many!). After substantial spitting and swearing, I carefully peeled off the mylar film and smoothed out the bubbles by hand. After it cured the results were not too bad. There will be more filling and fairing, of course, but the results should be nice. I imagine that I will end up rolling a coat or two of epoxy over the final faired foil.

Stay tuned...

Happy New Year!

Hey gang! Hope everyone had a great holiday season!

It was super busy around here getting ready for the holidays and trying to get a bit of work done on the boat. Before Traci and I left for vacation, I got the aft two compartments cleaned out and coated with two coats of epoxy. Looks pretty nice...



With spending a week in the Florida Keys over Christmas, I didn't manage to get much done on the boat, but I did manage to get engaged!



We are planning a September wedding and a May boat launch. Obviously there is a lot to do!!!

After returning from vacation I got back to work on the keel (and guest lists!). I had a decent foil shape in the laminated cedar and needed to reinforce it with carbon. I had ordered 3" carbon unidirectional cloth from Sollar Composites, which worked great. I first cut a ~3/16" x 3 1/4" trough in each side of the foil centered at 30% aft from the leading edge and laminated in a single layer of 6 oz. glass cloth as a tie layer.




While the glass layer was still wet, 4 layers of carbon uni got laminated in and covered with saran wrap. So far it looks really good; after the carbon cured I set the keel between two milk crates and stood on it and it only deflected 1/8". I imagine I can get rid of that little bit of that flex with the two layers of glass cloth I'll add next. The resulting glass/carbon laminate was a little "low" in the trough which allowed me to fill with epoxy and West Systems Microlight #410 so that I don't sand through the carbon during fairing. The filler is curing now, so stay tuned!

The Big Picture

I guess I've been posting a lot of detail photos lately. Here's what the whole deal looks like so far:


Not a lot of grand changes lately. Just lots of dinking around with details. That's the keel sticking out from the starboard side (not in final position!). I've been working diligiently on fairing it out and it is hanging there with a bit filler on it.

Here is a picture of my modified longboard. This was a $2 alternative to buying a second $50 longboard. Not bad, I think.



A little more fairing on the keel and I will be ready to rout the channel for the carbon fiber reinforcement and do the lay-up.

Stay tuned!

Bit and pieces

Lately time to work on the boat has been scarce with the holidays upon us and other commitments. Nevertheless a little progress has been made, lately. In an effort to stiffen up the largely flat sections in the aft two compartments, I glassed in some structural members half way between the chine and the rail. Between f124 and f169.5 I tried encasing half of a piece of foam pipe insulation in two layers of biaxial. It ended up looking good, but only stiffened the panel a little bit. Not enough surface perpendicular to the hull panel, I think. Based on that result I glassed in a ~2" wide strip of plywood into the aft-most section---rock solid. I may go back and grind out the foam half-round, but there is a lot more to do in the short term. We'll see...

I also glassed in a sort of sheer clamp along the transom. The 3/4"x3/4" poplar ripped in the diagonal will provide a little more than an inch of surface to glue the deck down which will be good since I won't be able to tape back there.

My main focus is working on the keel. The handheld electric planner I bought has worked a treat thus far. I just requires the patience to only take off a little at a time. Get too aggressive and you will have many evening alternating between filling and fairing! I also got a 30" longboard that has been great to fine tune the shape. I bought a flexible longboard which will come in handy for fairing the hull, but modified to to make it rigid for fairing the keel. At $50 ea. for the rigid and flexible longboards, the modification was a good solution. I will post a pic when I can.

The Keel Deal

Over the last few days Traci and I got all of the bunk supports filleted and taped.

The supports are now ready for the bunks...except for one minor detail: The keelbox. And since the keel is not done yet, neither is the keelbox. So I finally bit the bullet and started working on the keel...so that I can create the keel sleeve...so I can build the keel box...so I can install the aforementioned bunks. Seriously, if you builders are waiting on something like kit delivery, get started on the keel!

I used the Gougeon Bros. white paper on foil construction as a guide to fabricating the foils, with a few minor deviations.

Using the table saw I ripped lengths of cedar 2x10 to the desired thickness of the foil (~1.62" for a NACA0012 foil mius the thickness of a couple of layer of glass). After rotating them 90 degrees to get the grain running perpendicular to the foil chord and flipping every other one end-for-end, I laminated them together with thickened epoxy. Using a handheld electric plane I got the rough shape of the keel.

A few more passes with the plane evened out the "steps" shown above and the foil was really starting to take shape.

I've got a longboard on order, so I should be able to get the final shape faired and ready for carbon fiber reinforcement and glass sheathing later this week. Then more fairing to the get the final shape.

All in all, everything is coming along quite well.

Under Pressure

As I mentioned in my previous post, I discovered that if the hull sides are stitched in tight to several of the frames the result will be a hollow around each frame. The hollow will ultimately require substantial fairing once the hull is flipped. More importantly, however, is that it takes a tremendous amount of force to pull the hull in tight to these frames. To me, it seems that pre-stressing the hull in this manner is not a good idea. I, for one, do not want my hull to contain substantial potential energy while it sits idle. After all, potential energy is what give bombs their power, right? I would worry that a minor collision in the area of a pre-stressed area could result in a substantial repair.

As an alternative I left the hull relaxed at these frames (all but 18 and 169.5). See pics below. I stitched the chine side and the rail side in tight and then transferred the curve of the hull section to a 2" wide piece of plywood. The 2" piece of plywood was sistered to the forward side of each frame with silica-thickened epoxy.



The "gap" on the aft side of the frame was filled with silica thickened epoxy and filetted as normal. One trick: the inboard side of the of the sister piece was beveled at 45 degrees to allow the glass tape to conform.

Every little bit helps

This weekend I got the centerline seam filletted and taped. I also stitched in a few more frames, and now the only frame missing is f110. I may wait to get that stitched in until I have the keel fabricated so that I can be certain that the frame is in the correct position. Or I may not...

I also fab'ed up an I-beam for between the transom and frame 169.5, ala what Kevin did on pipeDream.

One issue I have encountered is that with the zip ties drawn tight on frame 53.5 a "hollow" is created in the hull side panel. Doesn't seem right. I will have to ping the other builders to see if they have encounted this and what they did about it. I suppose I could leave the frame a little "loose" (i.e., have the frame away from the hull panel a bit midway up the hull). After all, the thickened epoxy will fill any space between the frame and support any compressive loads.

Lickety Split

The second batch of biaxial tape and filler I ordered on Sunday evening from JMSOnline.net arrived this morning via UPS Ground. Not bad at all. Great prices and quick shipping. Definitely a good source for builders in the Upper Midwest.

At long last...

...I got my biaxial tape. I ended up ordering 40yds (4" wide) from JMSOnline.net. Price was great (~20% less than West Marine), and shipped quickly. For builders in the upper Midwest this seems like a good vendor (located in White Bear Lake, MN) if you need items quickly---items shipped ground to Madison arrived in a day or two. I just order more tape and colloidal silica tonight, so I will let you know how the shipping routine goes this time around.

As we finally got the tape earlier this week, Traci and I made some great progress this weekend. We started by filleting and taping the chines. We departed from the "game plan" a little by stitching in frames 018 and 053.5 before we started taping. I found that with the stresses and sharp angles near the bow, it was difficult to keep the edges of the side and bottom hull panels meeting at the corners. By stitching in frames 018 and 053.5, we ensured that the bottom and side panels met ideally on their edges. This approach seems to have worked well---the frames line up well with the chines and the sheer. No real extra trimming necessary.

Next up: while we wait for more colloidal silica for filleting, I will try to stitch the remaining frames. Frame 089 still has me scratching my head as to what the best solution is to keep the frame from contorting until the cabintop in stitched in. I will figure some way to prop open the hull in that area until the cabin goes on.

Nice Arse...

Still waiting on biaxial tape from West... But I happened to buy 10ft of unidirectional tape at West last week, so I figured I would practice my filleting and taping technique on the transom where the ability of biaxial tape to conform to complex curves is not as critical.

In short, I think it turned out pretty well. Decide for yourself...

I mixed epoxy with colloidal silica to the consistency of thin peanut butter and made the fillet. I also wet out a ~2" margin on either side of the fillet with unthickened epoxy. Then, while the fillet was still wet, I wet-out a strip of glass tape and layed it over the top of the fillet gently working the tape into contact from the center outward. This technique seemed to work well and no bubbles were observed under the tape. Should be solid.