Building the Raptor

[cthippo]

I've been making noise about this project for a while now, so I figured it was time to formally start a project thread about it.

The genesis of this project was the annual WAKE demo day in May where I paddled a Sterling Grand Illusion. I've tried many different boats, but this was the first I liked almost as much as my 9.5' Emotion Edge. It was 17' long, but all the displacement is in the middle so it turns faster that your average long boat. At only 24" beam I found it uncomfortably tight for my 6' 1", 256 lb size extra-fat ass, and at $5000 it was way way outside what I could ever afford. But, if you can't afford it, build it!

The design I came up with is 5.3 meters long by .66 wide (about 17' 4" x 24") and is being built using the cedar strip method vice carbon fiber in the original. I also raised the cockpit coaming some to give me more room to move my feet inside the hull on long trips.

Once the design was drawn up in Freeship, I lofted the stations from the table of offsets and then the whole project went into storage for a while.

[cthippo]

Actual construction started by building the beams that are the base for the strongback. I laminated these up from 6' long lengths of fir flooring I got at the Re-Store. Unfortunately, I did a fairly crappy job on this and so they will probably get replaced with 16' 2x6s. Live and learn, right?

I also got various pieces of OSB and particleboard at the Re-Store and glued my lofted stations to them with 3M 77 spray glue. These were cut out on the bandsaw and mounted on short blocks of 2x4 and screwed into the rails of the strongback. I found the best way was to get them all in place and then go back and straighten them up once the strongback was a little more rigid. As I mentioned earlier, the existing strongback will probably get pulled apart and re-built, but this gives you a pretty good idea of how the completed article will look.

[cthippo]

Now comes the tedious part, making the strips. The finished strips need to be 18+ feet long and so cutting them from one piece of wood is not really an option. This first batch I made from whatever scrap wood I had laying around just to get the process figured out. The strips are 3/4" x 1/4" pieces scarfed together to length and will be beaded and coved to fit properly.Right now I'm using one foot long pieces of aluminum channel to hold the pieces in alignment while they dry. The two ends are glued, wrapped in plastic wrap, and placed in the channels. A 3/16" x 3/4" piece of aluminum bar is then placed over it and the whole thing gets clamped to dry. Or, at least that's how I've been doing it.

The problem I'm having is that the glue expands as it dries and so I sometimes end up breaking the scarfs trying to get them out of the clamps. Also, the glue doesn't seem to be setting up properly and so about half the joints end up having to be re-done. Still working on the process here.

The other big issue still to be solved is cutting the bead and cove on the strips. Most people use a standard router table and cut one side, switch bits, and cut the other side. I think it's important for the sake of consistency to cut both sides at once and so I'm building a machine to do so. I found the 1/4" bead and cove cutterheads online and now I'm hunting for motors to mount them on. The plan is to build a machine with two 3/4" HP motors driving two cutterheads which cut both the bead and cove in a single pass. I'm also hoping to build a power feeder.

[PAR]

You don't have to pre-assemble the strips, just butt them as you install them.

[cthippo]

Originally Posted by PAR

You don't have to pre-assemble the strips, just butt them as you install them.

How do you clamp them so they come out fair?

[PAR]

If a butt falls in a particularly curvacious area, then a temporary batten behind the strip is all that's necessary.

[cthippo]

OK, I'll give that a shot.

I have a fondness for curvaceous butts that strip

[PAR]

Are you trying to say you like to toss a good batten at a curvy butt?

Technically, I haven't asked so you don't have to tell.

[LP]

My head hurts. . . . . .

[cthippo]

I like big, healthy butts and I cannot lie. Prefer them coved rather than beaded though...

I found an ad on Craigslist about a big scrap lumber pile at a house being remodeled and managed to get enough lumber to (probably) complete the prototype. Basically, I pulled out everything I could find that was nominally 1" thick, which ended up encompassing a number of species. Once the nails were pulled out, I ripped them to 1/4" thick and then chopped out the knots and more obnoxious nail holes. The pieces were then scarfed and bundled up by appearance. Since I don't have all the parts for the bead and cove machine yet, I'm going to bevel the edges of the strips with a plane and fit them together. I got some 3/4" brads to stick them to the frames and then once the whole thing is glues up the brads will get pulled out. For the final boat I plan to use plastic brads which will be left in, but the brads and the gun that shoots them are budgeted for the end of next month.

Based on the numbers of usable finished strips I think the bottom of the hull will likely be mahogany with pine and fir around the waterline. The decks are going to be 3/16" plywood I salvaged from a shipping crate. This first prototype may well never be finished, but is useful for developing the process. once I have all the tools assembled and working together, I'll go ahead and get the cedar for the final boat. Either that, or the prototype will work out well and I will move on to a different design for the next one.

[cthippo]

Just a quick update with some pictures of the stripping process. It's going much faster than I thought it would!

I'll describe my process in a later post, but right now, back to work!

[LP]

Makin' progress, CT.

[cthippo]

More pictures of the stripping process.

I'm on lift 16 now and productivity is falling as the area being worked on shrinks. There is less I can do between periods of waiting for glue to dry. Oh well.

I've started pulling the brads on the lower lifts and planing the hull in preparation for sanding later.I'm looking forward to using plastic brads on the next boat and not having to pull all the damn things back out when it's done. It may mean I end up destroying the strongback to get it out, but then I may end up coming close trying to pull the metal ones out that got buried in the wood.

Once the stripping is finished I will plane and sand it smooth, and then put the outer layer of glass on in before it's removed from the strongback. Once it comes off I can clean up the inside and glass it. Rather than stripping the deck, I plan to use plywood over frames.

I'm loving this strip building technique and finding the work to be more fun that my SOF boat was to build.

[PAR]

Try shooting the metal brads through short lengths plastic banding straps, the type used when shipping large or stacked items on a pallet. This will prevent the brad from burying in the wood, goo doesn't stick to it and they can be used to help remove the brads when it's time to pull them out, just by pulling and wiggling the straps. Other materials can be used for this, including bits of plastic packaging tape covered plywood, sheet metal flashing, popsicle sticks, etc.

[cthippo]

I apologize for the lack of pictures, but progress is being made.

Last weekend I I went to Neah Bay with mom for a few days and while we had a great time, my dry bag wasn't as dry as I thought and my camera did not survive. I'll try to get some cell phone pics, but it's questionable how they will turn out.

On the plus side, I got the hull closed in yesterday. I went up from the gunwales to lift 16 as shown in the prior post, and then started at the centerline and moved outwards until the gaps disappeared. Since I started pulling brads and planing the hull as it was closed up, the bulk of the planing was finished and just some touchup remains. Next step is to sand the hull, shape the bow and stern, and then I'll be ready to glass the outside.

My buddy estimated that I will need about a gallon of resin to fill some gaps and then glass it inside and out. Does this sound about right to you guys? Anyone have a source for dynel tape to put along the keel? I've found it in 54" fabric, but not just tapes. Can someone point me to a thread on here with a primer on fiberglass?

I'm looking forward to getting it off the strongback, even if it means hours trying to get the inside of ther hull planed.