December 18, 2009
November 24, 2009
As described in Part 21, these quarter knees were cut carved and shaped from a glue-up of 1" x 4" pine . That way I didnt end up with "short grain" along one of the "arms" ( You always want wood grain to follow the load paths.) Shaping was done with a low angle block plane, a spokeshave and a rasp. The rough shape was cut with a jigsaw. These will be installed 1/8" high of the sides and transom, then planed flush for a mating fit.
November 23, 2009
I made my quarter knees--the corner braces at the transom-from a glue-up of 1-by pine.I lapped the corners and and sed four boards for each "blank." I the cut the actual knees to shape, beveling their sides to fit the flare of the boat sides and the rake of the transom. Gluing up this way allowed me to orient the grain in the direction of the stresses. It is stronger than a solid piece of wood and easier than laminating curved pieces or steam bending. Here's a pic of the blanks in which you can see how I arranged the overlapping glue-up. I will post a picture of the final shaped knees later. Here, I have beveled the arms that rest along the transom, using a block plane. More shaping and beveling to come.
November 1, 2009
First coat of paint went on and I'm happy with the job I did sanding and fairing. Cant see the 'glass om the chines. Ok, I can, up close, but it came out really good. If you are sharp-eyed, you'll notice I have'nt yet painted the port side of the boat--thats the side on the right in the photo. There, you can see the biaxial glass cloth. I'm treating this first coat as a prime coat anyhow: it showed the high spots and other minor imperfections that where hard to see on the unpainted wood. Most of this coat will get sanded off, then I'll aplly the "real" first coat--and then one more!. That messy rubrail low in the picture? Thats masking tape. Those rails are going to be finished natural.
October 12, 2009
After installing the rails and breasthook, I flipped the boat over and glassed the chines. I used 6-inch wide biaxial tape, which is lower profile than woven cloth.( Its knitted, so doesnt have the ins and outs of a weave). It also doesnt have a hard selvage edge to have to sand and fair in smoothly. Its also stronger.
First I dry fit a cut piece of biax. Then I applied epoxy resin to the chines. Then I smoothed the fabric in with a plastic spreader. then I used a spreader and brush to apply more resin atop the fabric, wetting it out.
After that cured for 24 hours, I applied another coat of resin to fill the weave, "painting" it wide of the fabric edge to help fair it in. After that cured, I mixed Microlight fairing filler with resin and "bogged" the chines, making a real smooth transistion from glass to wood, as you can see.
I then coated the entire hull in epoxy. I wasnt planning in this--its optional really, adding weight and expense--but I had som many drips that I brushed out from apllying the 'glass to the chines, that the boat was half-coated already. So I just rolled on another coat,tipping-off with a foam brush to remove the stipple.
Finally, you see the glass-like surface and the new "owner" in the shop for a progress check (my daughter Keira)
To put the guardrails--rubrails, guards, pick your term--I had to soak them in water for a few days. I used a piece of gutter to do this, blocking the ends and filling with water. Then I weighted the wood to keep it submerged.
When I tried dry fitting them, they crackled alot at the transom, where in addition to a good bend, the rails also have to twist to follow the sheerline. Soaking them made them pliable. I then clamped them in place, then let them dry for three days, removed them, applied glue and put them back. This is every boat builders favorite shot: every clamp in the house (almost--49 clamps; I own 58!).
Youc can see in the top pic how the rails over hang the transom. After teh glue dried, I cut them flush using my Japanese flush cut saw. Using the boat to make cuts that way ensures a perfect fit every time.
September 21, 2009
August 23, 2009
When the spiders have laid eggs in and around your project, you know you've let it sit too long. Well, I'm back a'building! Glued and nailed the keelson to my Summerbreeze. The designer calls for placing the boat on the floor, getting in and using your weight to keep the keel tight to the hull bottom while nailing. When I tried that, I was able to get the keelson on center at the transom and stem, but it "wandered" amidship (delflected to the side). Here's how I did it intstead.
1. Marked centerline on boat bottom.
2. Placed center of keelson on the C/L, clamped it down, traced it.
3. Removed the keelson and drilled pilot holes within the tracing from outside. (hull bottom)
4. Buttered hull and keelson with epoxy, nailed it down into the transom, applied a clamp bar, and nailed into the center frame as well.
5. Climbed under boat and nailed through pilot holes into keelson, stopping at the center frame.
6. Moved the clamp forward of the center frame, --half way to the stem--and applied a second clamp to the keelson at the stem
7. Climbed under again and finished nailing through the pre-drilled holes.
Here are pictures of my clamp, the resulting glue line, and the aft end of the keelson, nothced to accept the skeg ( I have to make the skeg next). Wouldnt want to put the keelson on without cutting that notch--would be difficult to cut it after its glued in place! The tan strips either side of the keelson are plastic strapping tape, used to keep squeeze out from making a mess.
July 8, 2009
June 9, 2009
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!
June 1, 2009
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.
May 28, 2009
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!
May 20, 2009
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.
May 5, 2009
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.
April 21, 2009
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!
April 15, 2009
The changing economic scene may drastically alter the way we buy new boats in the future. Many senior executives at boat manufactures I've spoken with recently have hinted that the days of dealers having boats in stock ready for delivery, may be coming to an end. Instead, we'll go to a boat show, see a model, and then place an order. If you want a 23 and all they have built is a 25, then you'll be told " its the same as the 25 except a little smaller." Waiting 2-3 months for a boat will become the norm. Its not just that consumers arent spending, but commercial banks are changing the way they loan money to boat dealers ( and RV, lawn equipment, piano, and other high end products). In the past, a dealer would get financing from a company likey GE Capital http://gecommercialfinance.gecapsol.com/cms/servlet/cmsview/ComFin_Corp/prod/en/main/index.htmlthat would allow them to purchase boats interest free for about 6 months. After that, they would have to start paying nominal interest, say 1-percent a month. After a year, the boat would have to be paid off in full. This worked for dealers because it enabled them to stock boats with little cash outlay. Once they sold a boat, they would pay it off. Remember that it can take 4 months or longer to sell a boat. So with the free interest, the dealers ability to discount the boat to the consumer looking to haggle was possible. But now, the floor planning banks require 5-percent of the loan after 6-months, followed by another 2 percent every month til the end of the term. At todays boat prices, a 20-footer costs $30K, its not hard for even a small dealer with light inventory to still have millions of dollars in inventory . With just a mil in inventory, a small amount, that guy has to come up with $50, ooo after 6-months and $20K every month following. Its crushing, it takes the ability to discount the boat away as profit is eaten by interest. So what are dealers doing? They arent ordering boats from the factories for stock. Now the model of ordering a boat and waiting months for it is already established, in the high end boats and in larger boats targeted at wealthier customers. Knowing they have a sale, an ordered boat can be discounted somewhat and the dealer is happy to make and service the sale becuase he's making profit. But for "Joe Sixpack" this means buying something sight-unseen, and probably at a higher cost, because the boat will no longer be produced in high volume. For the dealers who service and sell smaller boats, the diminished profit potential, and the loss of "impulse" sales, means its not worth being in business--they will do something else ( I would). Many who choose to stay may die trying. The landscape is going to change dramatically.
April 14, 2009
OK, I told you all about the sweet piece of VG fir I got to machine into various structural members for the Summerbreeze I'm currently building. Here's how I got out the rub rails from that board. The plans call for a 1/2" to 5/8" thick by 1.5" wide strip to be utilized for the gunwale, or rubrail, or guard,if you prefer. This is the batten that's installed on the outside of the planking at the sheer. I was fine with that, but concerned about the exposed end grain at the top of the plank. I could just install this rail, then install a similiar rail inside as an inwale and then cap the top with a covering board. BUT....I want open gunwales, with spacers, both for the aesthetics, and for the functionality of being able to turn the boat over after a sail and having all the water run out. So here's what I came up with.
I measured and marked the width of both rubrails on the edge of my board, adding, and marking for, 3/8" wide rabbet( short L-shape) to be cut out. When installed, the rabbet will cover the exposed grain of the ply at the top of the sheer. I tacked my trusty aluminum channel as a fence, set my saws depth of cut to 6mm (1/4"), the planking thickness. I then made two very accuarate cuts with the aluminum guide, each side of my marked width. I then used the saw free-hand to make about 20-kerfs(cuts) between the accurate cuts. I then chiseled out the waste. Voila! Rabbbeted rubrails! All I have to do now is remove the rest of the waste, then mark an cut down the center and I'll have two rails with protective sheer rabbets. ( Hey, did I just invent a new term?)
This technique is very easy when you're chisleling across the grain. Here, I had to do it along the grain, which is very splintery work. You go easy, pushing the chisel slow and steady. I also wore leather gloves which saved my from getting porcupined about a hundred times.
April 13, 2009
Whether its a go-fast, a sportfisherman or a little plywood boat like this Summerbreeze I'm building, when you build light, you have to build stiff. Stiffness is what maintains the hull's shape. Here, stiffness is acheived largely by the use of rails cut from dimensional lumber. I'll need to cut Gunwales, inwales, a keel ( shoe) and chine stringers.
I selected a 1" x 12" x 12-foot long piece of vertical grain Doug Fir for these parts. Douglas fir is strong for its weight and glues better than oak. The vertical grain insures better bendability and increased reliability. It has less chance of cracking or splitting in service because with such straight grain I can cut it so that the load paths all run along the grain. If the grain were wavy, the forces exerted on the parts in service would find a "way out" following the grain to the edge of the board and cracking it. Hey, buying a board like this is no guarantee, it just ups the odds. Nor is it cheap. I paid 60 bucks for it.
Of course I'll get my two chines, two rubrails, and my keel shoe from this one board. I'm going to use pine for the inwales, as I have a nice length of it. Plus, the contrast with the fir, which is a tad darker than pine, will look good when all is varnished.
Notice how I'm using one piece of plywood set up on horses as the bench for this boat. In the background is my bottom, glued up and waiting to be trimmed to shape. In the foreground is the board I'm cutting my rails from. I use a circular saw set to the design bevels and run it along a piece of aluminum channel as a fence to keep me cutting straight. The board is clamped, the channel is tacked to the work station and my cutting lines are heavily marked.
The Summerbreeze design has a number of goals. Its to be a lightweight boat, under 70-lbs or so. It's a rowboat that can sail reasonably well. Its interior is kept wide open for sprawling space by using a leeboard instead of a centerboard or daggerboard to get upwind.
Its also designed to be easy and inexpensive to build. One way of keeping costs down is to use materials to the fullest, and designer David Beede accomplished that goal with Summerbreeze: it requires just two sheets of plywood.
How we made the 11'6" hull sides (planks) out of two 8-foot sheets--by using the scarf joint-- was detailed in the last post.Here we use the other common method of lengthening sheets of plywood in small boat construction: the butt block.
To make the bow of this boat, I cut two 32" long trinagles off the corners of a sheet of ply. These are flipped and attached to the front of edge of the sheet using butt blocks. The blocks are 3-inch wide strips of 1/4" (6MM) ply. Thats a 12:1 width to thickness ratio, the same as the scarf bevels, interestingly.
After cutting the triangles, I do a dry fit, and mark everything : centerlines, outlines, etc as shown in the photo. Next, I wet out the joints with straight epoxy and let it soak into the veneer for about ten minutes. This prevents the dry wood from sucking all the glue out of the joint. After the wet out has soaked in, I apply another coat of epoxy, this time with a thickening agent, to all the mating surfaces. This coat is the thickness of stiff batter. Then all the parts are laid in place and pressed in gently.
I used paint cans for clamping weights, using packing tape or other plastic on their bottoms to prevent them from sticking to the glue. Also note how I used the squeeze-out to form a filet (bead) along the butt blocks. Filets make the joint even stronger. You want squeeze-out becuae it shows you that you have complete glue coverage. But cleaning up the hardened epoxy is tough....
April 7, 2009
Here's the results of the scarf joints detailed in Part 5: 11'5" planks from 8-foot plywood. Once bent around the frame, flare and curves will be induced, transforming these straight cuts into sweet lines. ( I will probably have to round the angle aft, where the stern rocker forms, just a little more.)
The other photo shows a closeup of the joint itself. You can see I'm about 1/64 high on one side, a result of my temporary table ( 3/8 plywood) deflecting under clamp pressure. No biggie, just means a little more sanding and filling than anticipated.
April 3, 2009
Last time, we saw how mating bevels were cut prepatory to joining two pieces of plywood to achieve a length longer than the standard 8-feet. Here we see the glue-up. I use epoxy, as it is tough and strong. Others have had success with weldwood, resorcinol, and even contruction adhesive out of a tube. I'm comfortable with epoxy, having used it for decades. Comfortability with an adhesive's properties and working times is almost as important as what glue to use, as you can "blow" a glue up if the unexpected happens--like the glue setting up before you've aligned your pieces.
Here we see the mating bevels first slathered with straight epoxy, which is allowed to soak into the grain. This prevents a "glue-starved" joint. After a few minutes, I apply a thickened mixture, adding colloidal silica to the glue mix, and paint that on. The planks are flipped, the bevels mated and all is clamped, weighted and screwed to the work table. I applied lights for heat, to help the cure. Note that the clamping bar (the shelving) and the work table are covered with polyethylene film to prevent sticking to the work.
I'll leave this clamped up for at least a day, then stow the planks in a safe place while I glue up the bottom. This design uses a cool technique for getting an 11-foot boat bottom out of a single 8' sheet of ply.....
This boat, a Summerbreeze, designed by David Beede (http://www.simplicityboats.com/) uses plywood, 11'6" long for the sides. To get the length, I used a scarf joint and glued two sheets of ply together. This involves cutting mating bevels on the pieces to be joined. Here we see the begginning of the bevels; and then the nearly complete bevel. I did the cutting with a low-angle block plane and then finished with a sanding block. You could also use a power plane, a belt sander or a grinder. I like the zen aspect of hand-planing: here I put on some Pink Floyd, a pot of coffee, and just zoned-out for an hour.
A scarf joint is as strong as the original plywood and, when bent, wont show a hard spot like a butt block does. In Part 5, I'll detail the glue-up.