It'll Float

The bottom plywood has been trimmed, planed, filed and sanded. So the planking is now completed. Screw holes have been filled, sanded, filled, sanded, filled...you get the idea. A coat of clear epoxy has been applied to seal the plywood and get ready for fiberglassing the hull. One of the sheets of plywood used for most of the bottom is significantly lighter in color than the others, but since the bottom will get painted, it will not matter.

Now the beauty of the Okoume wood is evident and it looks like a boat! (capsized). I suppose it would float if pressed into service now, but there is a lot more work to do before I can play.

Some Tips and Things Leaned along the way

Raising the bar: So far I've been happy that I raised the form that the boat frames mount to. The plan says 24" off the floor, but I raised it to 32". With this small boat, I have not found it to be too high. The working level for the sides was good as I could sit on a stool for much of the work and it kept me off my knees. It is easy to get underneath the boat for various checks and bottom installation.

Recycled Ping-Pong Table: This has been a could base for mounting the forms while covering the carpet. Surrounded by 1/4" plywood, it does not move around and is a stable platform. If I had it to do over, I would add a 2x4 reinforcement from side to side directly underneath the form feet. It rocks slightly when pushed from the side as I only have a 2x4 reinforcement down the middle of the tables underneath where the 2x6 mounts down the middle. With the carpet and padding underneath the protective plywood, it flexes a bit underneath my feet and is very comfortable to stand on, unlike cement floors.

Gum Containers: I looked at an empty Eclipse gum container and being a pack rat it looked too good to throw out. So I asked myself, "Self, What could you use this for?" And the self answered, "Screws". They are terrific. The top unscrews for loading, the clear top allows seeing what's inside, it opens as a shaker spout for or the clear top pops open. Way cool. I'm chewing alot of gum now trying to get enough containers for all the different screw sizes. Maybe they should advertise that!

Screw Lube: Sometimes screwing goes better with a little lube...get your mind back on track, we're talking boats here. After breaking a couple of the silicon-brass screws, I started putting a small amount of "Screw-lube" on the tip and the problem went away.

Dry Wall Screws: I used these screws for the temporary screw blocks and while they may be cheap and drive home easily, but they also sometimes break when removed. I didn't learn my lesson and kept using them, and had another three break off when removing the screw blocks on the second front bottom piece.

Broken Screw Removal: When the cheap drywall screws are broken off at the surface with nothing to put a vice grip on, what do you do? They have to come out or they would rust later. After digging through my shop, I found a roll pin with an I.D. about the screw shaft diameter. I filed a short spiral so it would cut the wood around the screw shaft when rotated counter-clockwise. I chucked it up and started pushing and boring around the screw shaft. It would smoke and act like it wasn't going to work until with a bit more brute force it would grab the screw and out it would come. Drilling clockwise into scrap wood would remove the screw shaft so I could reuse it. I used it more than I would have liked.

Beginning at the Bottom

The first step was bending the forward end of the long battens into position by sawing a horizontal kerf back almost to the frame and then installing screw eyes and turnbuckles to pull them down into position. The kerf was sawn on the table saw before they were epoxied in place.

The fitting of the first bottom piece involved making some measurements to determine if I could start with a half sheet of plywood. The answer was "Yes, but not a perfect rectangle". I needed about 24 1/2" from center line of the keel to the widest part of the side. So I split the 4'x8' sheet with a slight angular cut, 25" wide on one end and 23" on the other using my circular saw and 8' guide board. I positioned the sheet onto the bottom using the factory 90 degree corner straight edge along the centerline of the keel with enough length forward to make it to the tip of the stem. Three positioning screws were put in along the straight portion of the keel. Then screw blocks were started about midway down the side and put in every 3" to pull the bottom down into place. After several blocks were installed, a line could be traced underneath by bumping the panel down into position and marking the underneath side, however the most forward part could only be guessed at because the panel was too stiff to bend into position. Then it was removed, rough cut to shape, and reinstalled.

Then the forward part where it needed to be fit perfectly into a butt joint was marked for another rough cut. The marking was done by putting a heavy coat of purple crayola along the previously fit side edge and then bumping the bottom piece down into the crayola to leave a line marked on the underneath side of the bottom. The panel was removed again and trimmed with the circular saw to within about 1/16" of the crayola line. Back on the boat and the slow process of fitting the forward butt joint was done - inch by inch. My 1" rabbet plane was great for getting the fit pretty close. Files and a paint scraper were also used. As a part of the joint was fit (sitting on the panel would push it into place), another screw block was put in place to bring it home. As the fit progressed, screw blocks were also placed along the stem to bring this side of the panel along. The panel began to overlap the stem as it twisted into position and excess material was cut alway with a handsaw. Every bit of extra panel removed made the bending easier. After about 4 hours of trimming, sitting and fitting, it was in place.

Then all remaining screw hole placements were marked along the chine and keel, the panel removed and screw holes placements were marked for the battens. Countersunk screw holes were then drilled for the remaining chine and keel holes that would not be using screw blocks. Straight holes were drilled for the battens as machine screws would be used for these during glue up. This panel was then temporarily clamped in place upside down on the other side of the boat to make sure it would be a good starting point for the other side. It was. It was traced onto the other half of the plywood.

A coat of epoxy was spread on the underneath side of the panel and all mating surfaces on the framework were coated with epoxy. Then a batch of thickened epoxy was spread on the framework. The forward part of the long batten was un-turnbuckled, the kerf coated with thickened epoxy and then re-turnbuckled into submission. The panel was then placed on the boat, the locating screws put in place and all screw blocks reinstalled. After putting in a couple along the chine in the middle of the boat, I moved forward to the transition joint and ensured that it was all coming togther in the same location, secured a screw block and then filled in the rest moving forward towards the bow. Then remaining holes got silicon-brass screws along the keel and chine. Machine screws #6, 3/4" long were used to secure the battens. A 24" reversible squeeze clamp was converted to a pusher and used from underneath to push the battens up tight to the bottom prior to screwing.

The next day, screw blocks were removed, countersunk holes drilled and 7/8" silicon-brass screws installed. The butt joint looked good with the largest gap being about 1/32". Excess epoxy was cleaned up and the forward part of the panel trimmed along the keel back to centerline or in the most forward part, cut and filed flush with the stem.

Back to the other panel with the traced line from the first panel. A bevel was hand planed on the panel edge where it would butt along the certerline of the keel to the previously installed panel. The bevel would provide a tight fit. Then it was rough cut, put on the boat and the whole fitting process began again. I thought it would be faster, but the keel centerline where the stem begins to curve also had to be precisely fit, and I think I was getting tired. It took forever, just like the first one. No clamps could be used on this one, so I had to make a few more screw blocks. It all came together nicely...epoxing in place would be another day.

The next evening, my friend Rick was recruited again and he dismantled the second bottom piece from the boat while I cleaned off my working table so we could put in screw holes and epoxy away. Rick is now a fully trained professional grade epoxy applicator guy so I've got him ready for helping with fiberglassing the hull. This second bottom piece went in place nicely and a couple of beers were consumed in celebration.

The next part was the last two pieces to finish the bottom. The first step was to make the reinforcing butt pieces for the joint. Pieces of 1/4" plywood were ripped the approximate width to fit between the battens. Each piece is about 9" long. They were then fit, epoxied, clamped and screwed with about 4 each of #8 3/4" screws. Then the bottom piece was cut, fit, epoxied, screwed and clamped. Pretty simple compared to the rest of the bottom and side pieces.

Second Verse same as the First

When I got ready for putting on the second side, I enlisted some help. With the first side, after juggling the long panel and then clamping, drilling, screwing, kneeling down, standing up, unclamping, reclamping, etc. about 100 times, I figured I needed to share the fun with someone else who has an interest in boat building. I called my friend Rick Meese and he eagerly volunteered to help. It definately went a lot smoother with two sets of hands. After mixing and applying the wet out coat of epoxy and then a thickened coat to the frames, Rick held the end of the panel while I put in the alignment screws and made sure the bow end of the panel mated up to the stem at the right spot. I put on enough clamps so the panel was self supporting and then Rick drilled a set of three holes while I sunk the screws in place. Then I would move clamps and we would do another group of three screws. At the front and the back with the severe wrap areas, Rick judged epoxy squeeze out while I clamped, belt clamped and brought out the arsenal of clamping power until the side was where it needed to be. This side went much faster with less sweat than the first. Thanks Rick!

The last photo shows both sides trimmed and faired along the upper side member (chine) and the battens in place being faired for fitting of the bottom plywood.

Outboard Motor purchased

Since the boat I'm building has a retro look, I wanted to get a classic outboard for it. After doing a lot of research on older outboard motors and joining the national Antique Outboard Motor Club (AOMCI), I attended a swap meet of our local Great Lakes Chapter of the AOMCI. I was focused on mid-fifties Mercurys and Johnsons in the 15-20 hp range and my preference was for a Mercury Mark 25 (18-20 hp depending on year). I had previously looked at a 1954 Mark 20, but the owner had a different idea about its worth than I did so I walked away on that one. I had another lead on a 1956 Mark 25 that was for sale by the brother of the guy that fixed our computer. He had a picture of the motor sent to my Blackberry and it appeared to be what I had in mind. At the swap meet, I did not find anyone selling a Mark 25, but did learn they were generally good motors and the 1956 Mark 25 had several improvements over the earlier Mark 20 and Mark 25 models. I was also advised to find a motor that already had the set-up for remote steering, shift and throttle control as these items would be hard to find separately. Having gained some good advice and a good contact for working out any issues I might have once I found something to work on, I pressed on.


The next day, my wife and I went and looked at the Mark 25. It had the remote control set-up, but needed a bit of TLC. Unfortunately his father was supposed to meet us there with the fuel tank for it but he could not find it and may have been lost in a recent move. I was told this motor had a new waterpump put on it two years ago and had been running fairly recently. The compression seemed good by pulling the starter rope. The motor colors are Sarasota Blue/Sand Tan. My wife thought the color combo was retro and would look cool. So knowing an old motor is a bit of a gamble, we reached an agreement on price, loaded it up and took it home.


It seems to me at this time that Sarasota Blue/Sand/Tan may be a relatively rare color combination. I've seen pictures of Mercury Green/Sand Tan, Sunset Orange/Sand Tan and Marlin Blue/Gulf Blue on other Mark 25's in pictures on the web of various antique motor club meets or in the Antique Outboarder magazine. I haven't seen this color combo yet. It reminds me of a 1956 two tone Chevy Belaire. Guess I'll find out as I learn more. I ordered and
received a service manual and fuel connector from East Coast Marine and hope to purchase a fuel tank, hose etc. soon and get this baby in a garbage can full of water and see if it fires up. Here's hoping I have an outboard and not just a pretty boat anchor.

March 6, 2010 Update:
I put together a 3 gallon plastic fuel tank with quick disconnect to tank fittings, hose, primer bulb and the connector to the motor. I did a 50:1 ratio mix by putting 2 1/2 oz. of two cycle oil and a gallon of gasoline in the tank....shaken, not stirred. Since it was a 50 degree sunny day, this was my chance to see if it would start. Using the bottom from a defunct shop vac, I put it under the outboard and filled it with water which was about 3-4" over the top of the cavitation plate. I hooked up the fuel line, opened the tank vent, squeezed the primer bulb about 10 times until fuel could be felt in the bulb and I could smell it. Then I set the choke and gave the starter rope a pull...nothing except water sloshing all over. I enlisted my daughter to hold the back of the motor to stabilize it while I gave another pull...nothing. Another pull...nothing. Took off the choke, squeezed the primer bulb again and gave another pull and hot damn...it started running! (Big smile on face). I saw a stream of water coming out the hole at the top of the lower unit indicating the water pump was doing what it should, and then I slowed the motor down to shift speed and shifted into forward. Water started leaving the barrel as the prop churned it up. Tried reverse and saw that it worked and then back to neutral. I revved it up a bit, then slowed it down and ran it for a while so some pictures could be taken. I disconnected the fuel line and it ran for a couple of minutes until the fuel in the carb ran out. Hurray....it all works!

Side Plywood Installation

Prefitting the side involved getting a 8' x 18" piece of plywood in place from the front of the boat back to where it ended just forward of the middle frame. Once it was bent in place and rough fit, a countersunk screw hole was put midway along the chine and one midway along the shear. These screws provided a repeatable location so the panel could be removed for trimming and re-fit in the same location. Once this piece was fit, then it was removed and put on the other side to determine if the fit was close enough to use as a template. The picture is of this trial fit on the other side of the boat. It was a decent fit, so it was traced onto another piece of plywood and cut.

Going back to the first side, towards the rear of the boat, 4' x 18" piece was fit and aligned to match up to the 8' long piece. An angular cut was made to establish a butt joint between the two pieces of plywood. Lines were traced onto the back side to show it locations along the chines, shears, transom and stem. Then the pieces were removed and laid out on a long make-shift table. Screw hole locations were determined for placing screws every 3" along the chine and shear. Location holes were drilled from the backside (which had the traced lines) every 18" or so. Then the pieces were flipped over and the final holes were marked on the face side and all holes drilled with a countersinking bit.

Butt joint bonding: A piece of plastic was put on the table and then a piece of painters tape adhered along the underneath side of the joint to prevent epoxy from flowing everywhere. One side of the board was screwed to the table using the predrilled holes, the second piece was butted tight and also screwed in place. A liberal application of clear epoxy was applied and a 4" wide strip of fiberglass tape was laid into the joint. After sqeegeeing the epoxy, a piece of plastic sheet was laid over the whole mess, a plywood piece of wood laid on top and clamped down.

The next day, after removing the clamps, the area over the fiberglass tape was fairly smooth but other areas had too much epoxy needing sanding. The second picture is my second panel for the other side of the boat and it did not come out as nice as my first one. It took quite alot of hand sanding to get this one smoothed down, but eventually it started to look better. Then I flipped it over and applied epoxy and fiberglass tape, but kept the tape shorter so it would not interfere with the fit to the chines and shear. A little more squeegee action and tighter clamping helped smooth it out. The whole surface of the plywood was epoxied as it will be on the inside of the boat and this is the easiest way to get it coated. This inside surface is the one shown in the prior picture showing the butt-joint clamping.

Securing to the boat: It was a marathon session gluing and screwing the plywood to the side of the boat. After mixing up a batch of epoxy, the frame surfaces and bonding area on the plywood was rolled and brushed with epoxy. Then a colloidal silica filler was added to the epoxy and this thickened goo was brushed onto frame members back to the middle frame. The panel was located to the frames with the previously mentioned locator screws. I rigged up a chain from the ceiling to support the rear of the long panel while I began clamping and screwing the front portion.

After clamping forward to the stem to ensure proper location, then clamps were placed adjacent to each screw hole and redrilled to put a pilot hole into the frame member and a #8 7/8" long silicon bronze screw was screwed into the hole. Progress was from the front of the boat rearward, removing clamps from previously screwed areas and re-clamping and drilling and securing three screws at a time. When I got to the middle of the boat, another batch of thickened epoxy was made and applied to the frames from that area rearward. In the forward and rear portions of the boat where the wrap is severe and a screw head may have pulled through, small blocks of wood were used with 1 5/8" drywall screws to secure the plywood in place until the epoxy cured. After 100 screws and almost two hours of non-stop action it was done. I worked up a good sweat and needed a beer.

The next day, the screw blocks were removed and replaced with a silicon bronze screw one at a time. Everything held in place. The overhanging plywood was trimmed off with a hand saw and planed and filed smooth with the chine, stem and transom. The portion along the bottom of the pictures will not get trimmed until the boat is flipped over. The last picture is at the transom after trimming off the excess side panel and sanding smooth with the surface of the transom. The way the side of this boat twists and rolls into the transom ("tumblehome" as its known in the auto and boat design community) is really cool. Since the boat is upside down, this roll is towards the bottom of the picture.