Wooden Two-Cockpit Runabout

I had always admired the beautifully restored wooden Chris Crafts and other vintage power boats. I specially admired the two cockpit runabouts. I built a model of a two cockpit Chris Craft. But why not build a real one. My online searches came up with a plan from Glen-L I thought would be suitable. It was to be small enough for my limited work space, and also have the classic cool factor. This is what I found this online Link to ZIP plans, and I bought the plans.

This Instructable is fairly complex, detailing the many steps involved. Maybe others can get guidance or inspiration from this. You may note that much of this Instructable is written in the present tense, like a diary. I think it's still readable.

I bought all the wood from MacBeath hardwood in Berkeley. Epoxy and fiberglass I got from TAP Plastic in San Leandro. Many parts plus the trailer came from a "donor boat" I found on Craigslist.

My garage is way too small even for a 14 foot ZIP, so I built a small 8x15 deck on the side of the house. I built the deck frame to last, but I knew the top would be thrashed by my boat building efforts so I put down cheap 3/4 flooring ply and painted it. My plan was to pull it up later after it rots (I give it about a year) and put down better decking. It was raining here in N Calif when I started building the boat so I'd work when it was dry then cover the boat with a tarp.

Per plan instructions, I built a temporary frame around which the boat would be built.

Frames

Frames are pieces that run the width of the boat and to which longitudinal pieces are attached. For the frames I used Sipo, real nice hard wood, not quite as expensive as Honduran mahogany, but looking about the same.

Per instructions, I had ordered bronze screws. For screwing into the hard wood I had to predrill giant holes and wax the screws. I struggled for a while with the Fearson screw heads, trying to use Phillips drivers. I finally saw the light and got a Fearson (Reed Prince) screwdriver and ordered the Fearson bits from Glen-L. The slightly different shape makes all the difference.

Chines

Chines are the lines that divide the "sides" of the boat from the "bottom". There are designated pieces of wood that serve this purpose.

The port chine didn't land on the stem with the right twist so I had to add a little beveled shim to make a flat landing place. Not sure if they land at the right place on the stem but the notches in the plans seem to encourage the wood to land where it lands.

Sheers

Sheer is usually defined as the curvature of the deck front to back. Sheers, in these plans, are the longitudinal pieces that form the upper edge of the hull.

Had a bit of struggle with cracking. I'm using Yellow Alaskan Cedar for the longitudinals. The towels and boiling water technique seemed to work, relaxing the wood and allowing both laminations to bend at the stem. But I think after I got the first lamination in place I let too much time go by and the second one dried too straight. It cracked when I re-bent it. My fix for the first crack was to epoxy and screw the crack together and move the cracked place to the stern where it would be straight. I had some other smaller cracking later which I epoxied in place. It looks shabby but when it's all put together I think it will be fine. If I were to do it over, I'd make 3 or more laminations.

Screws and Fasteners

I bought the fastener kit from Glen-L but in retrospect I think it was not a good plan. The bronze nails are hard to use, don't countersink, and can't be removed, so I've used precious few of them. The 3/4 inch screws they supplied are pretty short and don't give much bite into the sheers and chines. One inchers would have been much better. I've also got quite fond of the square drive heads that McFeelys sells. I've never had one strip out. Where bolts are required, I've used galvanized.

Side Planking -

For all planking I used Hydrotek 1/4 inch ply. This stuff looks like mahogany, has many plies, and is waterproof.

I butt-joined the 8' lengths in advance of putting it on the boat. Seemed to work OK without screws. I found that bending the plywood at the transom is much easier with a minimum of excess ply projecting back. I was struggling with the bend before it dawned on me to whack it off. For bending the second side at the stem I had to screw down some blocks for something the clamps could pull on. I remembered most of the time to erase (sand away) pencil marks on the plywood before epoxy could drip on it and enshrine the marks forever.

I've countersunk the screw holes joining to the sheer pretty deep with the idea of plugging. We'll see how that works out. If it's a bust (or too much work) I can paint a nice stripe at the gunwale as someone else has done and still have a lot of nice mahogany showing.... Well the plugs I used on the port side were too light colored. I gave up on the idea of staining them. Too much work and too messy, plus I may end up painting a stripe or having a large enough rub rail to cover them. I used Sipo plugs on the starboard and they looked much better.

Bottom Planking

I butt joined after the forward bottom pieces were in place. The forward bottom pieces took a bit of fussy fitting because they have to butt to each other and to the sides. The famous transition between lap and butt went fine. It's all going to be filled and painted anyway. The aft bottoms were pretty flat and easy. Before I put the bottom plywood on, I did manage to remember to unscrew where the building frame is attached to my plywood floor with vertically oriented screws. I figure I'll be able to reach the horizontal ones when the boat is covered.

Epoxy
I'm using TAP Plastics Marine epoxy (slow curing since it's been a little cool here and it's good down to 40F). I mix small batches in Zip-Loc bags, snip off a tiny corner, and squeeze it out. It seems to be working OK but I still end up with epoxy on my hands. Yeah, I know, use latex gloves. That's OK too but it still gets all over the tools.

In this step the plywood planking and transom are covered with fiberglass and epoxy. This involves painting the plywood with a sealing coat of epoxy, then draping with fiberglass cloth, and applying more epoxy to get the fiberglass to stick. Then more epoxy as needed to completely fill the fiberglass to make a flat covering. Oh yes - lots of nasty sanding to make everything smooth.

I saw on the Glen-L forum a reference to the fiberglassing technique where the fill coat is covered with a polyester (mylar) film. When the epoxy is cured the film is peeled off to reveal a perfectly smooth finish with no cloth poking through or need for sanding. The forum chat seemed too good to be true. But to me its also too good to ignore. I tried it on some scrap and it worked wonderfully. I was told by the old guy at TAP Plastics that I have to remove the film before 24 hours or it might not come off. My test showed it didn't come off after 6 hours (apparently not cured enough in my 50ish garage), but it did come off well after 9 hours, again at 18 hours, and again at 28 hours. So I think I have a good range of time. I'll try the transom first.

My neighbor and I did the transom this morning and I peeled off the film just now. It's quite shiny, flat, and wonderful. It took 4 hands to do it. I squeezed the epoxy out of a Zip lock bag and applied it with a squeegee. My neighbor followed about a foot behind with the roll of mylar and squeegeed out the bubbles. Used the same technique with the first bottom half, but we got bad ripples under the film that will need to be sanded down, then have a finish coat applied. Our conclusion was that there was more resin as compared to the transom. We'll try it with less resin on the other bottom half. ... No luck with that half either. My conclusion is that the film only works on small, very flat areas. And after lightly sanding the "wonderful" transom, glass and voids started to appear. All in all, it took more work and I would not recommend the approach. I used the textbook approach with the sides. They took some sanding, but not a huge amount, and they look great after varnishing.

I painted the bottom with brown "bottom paint".

The cutwater is the metal piece at the front of the boat that "cuts through the water". These add a lot to the looks of a wooden boat but have challenging curves. There are also two metal pieces at the stern that do not require fancy curves.

I would have preferred stainless, but my resource for doing it economically pooped out so I decided to do it myself with copper. The copper I was able to get was only 24 gauge (roofing flashing stuff), so my neighbor and I came up with a method of sandwiching two layers. The bottom layer had interlocking tabs which made a solid structure and held the shape it was given, and the outer layer was the smooth one.

I did cut out a hole for the bow eye, so the cutwater can be installed later, and so pulling on the bow eye won't pull on the cutwater. (much later) I sanded and polished it and the two stern pieces and got them chrome plated. They came out shiny and quite impressive.

Donor Boat and Trailer

At one point in this process I purchased a "donor boat" with its trailer. This sat in the driveway taking up space, but in addition to the trailer, I was able to salvage a variety of small parts for the new boat. I disposed of the donor boat and adjusted the trailer to fit the new boat. At this point the hull is done and the boat gets turned over and placed on the trailer. This took many hands. Thanks neighbors.

Interior and Floor -

Now the boat is right side up, sitting on its trailer and ready for work on the interior. I probably weakened the boat, but to make the small boat as comfortable as possible for people with legs, I cut back the frame gussets so they wouldn't be sticking out over the floor. The floor is 3/8 inch plywood and now covers the bilge nicely except forward of the front frame and aft of the back seat. I've tried to make it removable with screws accessible and pull-up handles so I won't need to pry it out.

For cockpit sides I used 1/4 ply except for one with 3/8 (plus 3/8 backing) for mounting the controls. Each panel has a big cutout for storage, access, and control cables. I made seat boxes to give a little height and used 3/8 ply for the removable seat and back pieces. These get upholstered later.

Motorwell

The specs called for a rather large well and since I am expecting to deck most of it over I extended the depth to end at the rear seat support. I think the was an OK approach since I still have just enough room under the well for the battery. It turned out I needed the full 33 inches of width for the steering arm, but I will be able deck over about half of the depth.

Transom cutout - Mine measured 15 inches exactly, and I bought a short shaft motor where the specs said it took a 15 inch transom height. Then to my surprise, the motor measured 17 inches. So I added 2 inches of height with some sandwiched plywood and a backer piece of 3/4 inside the motorwell.

Dashboard and Steering - The new steering box has a 90 degree mount so I angled the dashboard about 20 degrees to give it desired tilt. The steering box takes up quite a bit of room so I had to do some fussy fitting to get it to the right height, etc. I figured I would be having to remove the dashboard later to fiddle with gauges etc. so I cut it into two pieces so I never have to mess with the steering again. Things are pretty tight behind the dashboard, but I managed to get the salvaged speedometer and a new tachometer installed, together with a switch for nav. light, a switch to force the bilge pump, and a 12 volt outlet. It looks pretty good to me.

Decking

This is the exciting part. For each side I cut out a foredeck piece, a center deck piece, and a stern piece. It took three sheets of plywood since the foredeck pieces are so big.

Decking Stripes

I wanted to simulate the separate teak or mahogany pieces used on decks of the classic runabouts.The overall approach is to cut slots in the 1/4 inch plywood and fill the slots with pigmented epoxy paste to get the desired white stripes. I routed the slots with the plywood off the boat (laying flat). The #8 screw heads are pretty wide and I wanted to fasten through the slots as much as possible and I wanted narrow slots. So... I probably violated all boatbuilding rules - I fastened the deck to the deck frames using galvanized staples, as well as epoxy for glue. It sure was easy and fast to shoot the staples to fasten to the longitudinals versus putting screws in to fasten at the sheer.

I filled the slots with epoxy colored off white. This required masking all adjacent surfaces, which was very tedious but necessary. I mixed thickener with the pigment into the epoxy and squeezed in on from zip-lock bags. The difficulty was getting the thickener mixed in well enough and several places came out kinda lumpy. After glassing and more epoxy, the lumps are pretty well disguised, but there is some color variation. In retrospect, I would mix in the thickener with a stick in a small tub, then transfer to a bag.

Glassing the Deck

I bought 4oz cloth in 50" width and covered 1/2 of the entire deck at a time with the join at the center. It went on well, and the glass seemed to mask well the lumpy surface of the stripes. The stripes have yellowed a lot since they were put in, probably due to UV exposure. They look good though and I'm happy with the color. I put on a total of 4 coats of epoxy, sanding it down to (fairly) flat after the last coat. The neighbors would see the epoxy go on and be excited by the shiny dark appearance. Then I'd rough it up again with the sander. Now finally I've put on the varnish and to me it looks great.

Upholstery

I looked into having a professional do the upholstery. The chap we talked with said the first step was for me to buy and fit the foam cushions, then he would do the sewing and fitting to the wood seat bottoms and backs. He showed how he would do the tuck and roll. I decided to try it all myself using my brother's heavy duty sewing machine. For the backs I used a 1 inch layer of soft foam for the tuck & roll and a 1 inch layer of medium foam to be in back of that. For the seats I used 2 inch firm foam. It came out pretty well I think.

Deck Hardware - This is a fun part, adding the "bling". I through-bolted the fore and aft cleats but the other stuff is just screwed on.

Windshield -

Took one look at the prices for windshield brackets and decided to make my own. I used a piece of Ipe (Brazilian Iron-wood) that I had left from a decking project. It's very hard and heavy and it seems quite strong. I made two brackets for the center rather than having to route two deep grooves in the same piece. I attached pieces of rub strake stainless to the fronts of the brackets and they look pretty good. When I had the 1/4 inch laminated glass pieces cut, the glass guy warned that any pull on the glass or even wind from fast travel could flex the glass and break it. He recommended a solid (wooden) trough to support the bottom. I spent some time ripping and routing and found that there was no way the wood would bend to accommodate the edge curve of the glass and the curve of the deck. So I've ordered some specialized flexible gasket material from the web.

Electrical

I was able to use the battery switch, a fuse panel, and a long piece of wiring harness from the donor boat. I've got most of the wiring done now except for the deck-mounted and dashboard items.

Outboard Motor
Other boats I've owned have been inboards, so these delicate little outboard creatures are new to me. I hauled the boat to the dealer using the trailer for the first time. After mounting the new Honda 25 4 stroke on the boat and testing it, the dealer warned me about using new fresh gasoline and running the motor dry before storing it. I took the boat home and got back to work on the wood, ignoring the motor until about 6 weeks later when I tried to get it going again. It started but ran very rough and died frequently. So I changed the gas, put in some Sta-Bil and some cleaner, and ran it a lot today and it improved some - though not yet back to it's original perfection. So, another lesson for this old boy. A mechanic friend looked at the motor. He also thought it looked like a lot of work to remove the carbs to clean them but would help me do it if necessary. He suggested first that I run a strong solution of cleaner in the gas for a while, then let it sit with the cleaner in the bowls for a couple of days. He also increased the idle speed. I ran it as suggested, and though still not perfect it was good enough to try in the water. When I called the motor shop they suggested that I take it out and run it hard for a while in hopes it would straighten out.

Launching -

The neighbor who's helped me with the boat, a son-in-law, and I took it to a local lake, put it in the water, and gave it a good try. It was quite successful by all accounts. The motor seemed to straighten out and run OK. It got up to about 25 MPH at 5600 RPM. We ran it for just over an hour at various speeds. It sits in the water a bit down at the stern, and about the same with three men on board. When the throttle is applied the stern goes down a bit more but not alarmingly, then at just under 20 mph it levels out nicely on a plane. Revving it up to 5600 takes it up to about 25 MPH. More revs don't add much. Turning hard at speed induces cavitation at the prop (ventilation - whatever) and the boat slows down.

I adjusted the motor tilt to full down (nose down). That seemed to help the cavitation but reduced the top speed. Next time I'll try it tilted up two notches and maybe get more speed, though one notch seems OK and I figure I can just turn a little more gently. With my 2 inch skeg there is no side slip in the turns. The boat is pretty dry. The stern passenger doesn't get sprayed at all. A dribble of water came out of the bilge drain after we pulled it out, but the bilge pump never had enough to pump.

Storage

When we got back we were able to roll it up onto the deck where I built the boat on the side of the house. So it's not taking up driveway space anymore. It's ready for Tahoe, though a bit late for this year. In anticipation of the 6200 foot elevation at Tahoe I bought a 10" pitch prop to get the revs up better than the 12" prop that came with the motor. For storing the boat outside I bought a generic boat cover and carved it up a bit to fit tighter in the bow and looser over the windshield. I also made a cockpit cover out of sunbrella waterproof fabric. I'll use this to cover it when it's on the buoy at Tahoe. Both covers are on now and seem to hold out the rain well. I bought a cheap solar panel and rigged it to plug into the anchor light hole and keep the battery up.