Hi! Atus!

Hey Everyone! I Just got re-employed and been busy making that transition. The Summerbreeze "Princess" will resume building soon! Kevin

Build aDinghy: Part 15

While its helpful to have an array of tools, glues and equipment when building a boat, there's one piece of equipment that rarely gets mentioned in how-to articles: an eraser.

Here you can see how, after snapping a centerline, I laid the keel-shoe on for test fitting offset from center. Of course I didnt catch this until after I had traced its outline in deep, dark pencil lines. I need the outline to drill the pilot holes for the screws that hold the keel. These are driven from the inside so the pilot holes will guide me when I'm under the boat.The large childrens eraser shown is my constant companion. I've since re-measured and re-marked the lines.

Old Saying: Measure once, curse twice!

Build a Dinghy: Part 14

Last time, I detailed how the oversized bottom was dry fit and cut to size. Here, you see the results of all that planning, marking and measuring. After buttering the chine logs, the stem and the transom with straight epoxy adn letting it soak in for a few minutes, I next applied a thickened glue mixture containing colloidal silica and milled wood fibers. ( The silica spreads out smooth, a charachteristic I'll appreciate when tooling the squeeze out into beads, called filets ( fill-its) along the chine and bottom. The milled fibers offer greater adhesive strength. So I mixed the two to take advantage of the best properties of both.

After the glue was set, I used a putty knife ground to shape to make my filets and a another putty knife, this one filed knife-sharp, to scrape excess squeeze out. If you catch epoxy at just the right time, you can scrape it smooth. Its way easier than sanding. After the glue fully cured, I used a plane, and then sandpaper, to round the chine and transon/bottom joint so it will take fiberglass better. Glass cloth reinforcement doesnt like sharp corners. I'll be applying +/- 45 6-0z biaxial cloth. Since its not woven, the individual strands dont make all those in and out bends, which is weaker. Additionally, the +/- minus business means the fibers run at a 45-degree angle to one another, instead of at a right angle. When laid across the chine, all the fibers will contribute to strength. With woven cloth, only half the fibers are working, the other half are just along for the ride. Knitted fabric is great. I'll be using peel-ply to provide a smooth finish.

In these pics, you see the chine joint after glueing, scraping, planing and sanding. Looks great, right? Also shown are two views of the dry fit stem. this was machined from VG doug fir, 3/4" x 1." Its glued, and screwed onto the boat with 1-1/2" silicon bronze flathead, square-drive, wood screws. You can see the counterbores I made along its centerline pretty clearly.

The keel adn skeg are next, then the boat gets turned over to work on inwales, outwales, breasthook and quarter knees. Joinerwork--real fussy stuff. But very rewarding.

Build a Dinghy: Part 13

After installing the chines and sanding/planing them flat as detailed in last post, its time to dry fit the bottom. The bottom is built oversized. I had already marked centerlines on the bottom, as well as on the transom, the frame and the stem of the boat. So after laying the rough cut bottom atop the upside down boat, I crawled under and lined everything up. Then I came "topside," checked everything again, and tacked the boattom to the chines, transom, stem and center frame with brad nails.

Next, I traced around the bottom overhang. I sanded a pencil flat to make this line as close as possible. Then I removed the bottom and clamped it to a scrap sheet of plywood. I set my circular saw for a shallow and cut out the shape just outside my line. Then I placed it back on the boat, and used a plane and sandpaper to bring the bottom to its exact size, rounding it somwhat at the chine so it will take fiberglass cloth better.

Next, using a shop-built spacer gauge, I pre-drilled the holes in the bottom through which the 1/2" screws into the chine would go. This gauge was the designers suggestion and a good one. Another tip I got from a friend, was to "knock down" the little bumps left by the drill with sandpaper to ensure a flatter fit on the chine ( Thanks Bob!). Finally, I applied a straight coat of expoxy, followed by a thickened mixture and screwed the bottom on. Check back to see the results--I've got squeeze-out to manage!

Build a Dinghy:Part 12

Well, spring is here, and with it, yard work and two fishing boats to get into the water. Slowed my progress a bit for awhile. Got back to building and dry fit the chines.Had a problem in that I overcut the notch in the frame. You can see it in the photo. I made the depth OK, but was too wide. I used a short piece of chine as a marker to make the cut, but unfortunately, that little cut-off was thicker than teh rest of the chine. Sloppy dressing on my part. Oh, well. I'll fill it with thickened epoxy adn move on. You can also see here where the chines butt against the transom an stem. Those fits came out great. I used the technique of clamping the pieces in position and then running a saw through the joint several times to make a perfect fit. The idea comes from Greg Rossel's book, "Building Small Boats."

When I had the chines clamped in position, I drilled and countersunk for the 1/2" silicon bronze screws. The chines are glued with epoxy and screwed. (The designer calls for nails, but I chose screws for the additional control in such long skinny pieces. I countersunk them just a hair, as the plywood is only 6MM, or 1/4". Though I have drills and power drivers, I drove the screws with a manual screwdriver, loaded with the appropriate size squre drive tip--better control. Also, note how I taped the handle so as not to befoul it with epoxy.

After screwing and gluing, I cut the excess chine nearly flush to the sides with a pull saw, then a cheese grater( surform tool). Final dressing to flat was done with a low angle block plane, using a level to make sure I was flat to provide maximum gluing surface for the bottom, which goes on next.

Build a Dinghy:part 11

Business travel, spring yard chores, building docks and getting my big boat ready have taken most of my spare time. Today, I dry fit and glued the major parts together, converting a pile of wood into a boatlike object.

I used plywood pads and machine screws to assmble and test fit. The pads prevent the head of the screw from creating a bigger hole to fill later. I attached the stem at the bow, using a length of cord wrapped around the planks to bring them together. I then attached the frame. Moving aft, I used more cord to pul the planks against the transom sides. Doing so revealed that I needed to bevel the sides and bottom of the transom some more. So I dissassembled adm reassembled 2 more times, shaving the bevel with a fine set plane til I had good mating surfaces. Epoxy is great and fills gaps, but good wood to wood fits are hard to beat.

Once the fit was right , I drilled pilot holes for my permanent fasteners. I dissassembled everything again and coated the surfaces to be joined with epoxy. This soaks in to the wood, so that my subsequnet thickened mixture doesnt soak in and starve the joint. I let that gel, then I applied the thickened mixture and re-assembled everything, this time with silicon bronze ring nails (transom and frame) and silicon bronze wood screws (stem.)

It was 50-degrees F tonight. Using the fast hardener gave me about an hour to do all the gluing, reassembly and clean up of drips, spatters and squeeze out. I masked the permimeters of the joints with packing tape (epoxy doesnt stick to it) which made cleaning easier.

Build a Dinghy: Part 10

This picture shows the scarf joint after sanding it out. I used a Fein Multimaster http://www.feinus.com/ to bring the glue line close to flat. Since cured epoxy is very hard, and I wanted to get the glue line flat without sanding through the plywood veneers, I used the Multimaster to sand just the glue-line. This tool has a variety of attachments perfect for finish work in tough situations, and where precision is required. I highly reccomend this tool for boatbuilders.

Once the glue line was nearly flat, I finished sanding the old fashioned way: with sanding block and long board.

No that I've pre-fabricated all the major parts, the next post will show initial assembly. She's gonna look like a boat soon!