A ZIP-Builder's Diary (Cont'd)

by Dave Coleman, San Francisco Bay Area, California

Chines - 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 - 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.

Epoxy - I'm using TAP Plastics Marine epoxy for gluing (slow curing since it's been a little cool here and it's good down to 40° F). 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.

Side Planking - I'm using hydrotek 1/4 inch ply. 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.

Donor Boat - I watched on craigslist for a derelict runabout with trailer. The goal was to use the trailer, deck hardware, outboard controls, and even the windshield if I get lucky. I got a response from my boat-wanted ad and a guy in the sailboat salvage business delivered to me a 16 foot boat with trailer for not much money. I stripped the boat of usable parts, cut it up with the sawzall, and took it away in pieces. I stripped the trailer of old bunks, verified the wheel bearings were OK, adjusted the movable dimensions for my boat, and installed new bunks. In the end I couldn't use the steering box and cable, nor the outboard controls or windshield. But I did use the wiring harness, steering wheel, fuse panel, speedometer, and lots of deck hardware.

Glassing & Epoxying - I saw on the Boatbuilder 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 to be it was too good to be true. But to me it's 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 50°-ish 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.

Cutwater - 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 (much later), and so pulling on the bow eye won't pull on the cutwater. I sanded and polished it and the two stern pieces and got them chrome plated. They came out shiny and quite impressive.

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 this 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. I guess the moral of the story is to measure the motor yourself way in advance.

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 have 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.

Interior and Floor - I probably ruined 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.

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 items.

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. The overall approach is to cut slots in the 1/4 inch plywood to fill 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 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.

Outboard Motor - Other boats I've owned have been inboards so these delicate little outboard creatures are new to me. After mounting the new Honda 25 4-stroke on the boat, 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 just now (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 a lot - though not yet back to its original perfection. So, another lesson for this old boy.

Rub Rails - I bought 3/4 inch hollow stainless rails from West Marine and my approach is to rip some 3/8 by 1 1/2 mahogany strips and dado 3/4 slots to contain the stainless. The real Honduran Mahogany is a treat to work with, straight fine grains and not too hard to rip 1 1/2 in one bite on my portable table saw. But bending it was another matter. On one side I tried steaming, but either I didn't do it enough or what I was asking was impossible because I got lateral cracks in the center of the strip. The crack will be covered by stainless, so no worries there. For the other side I cut 4 to 5 inch lateral slits and the kerfs at the bottom to relieve the slits. It bent pretty readily, but got some flat spots that needed fairing. The wood is a lighter color that makes a nice contrast to the dark sides and deck "planks".

Decking Stripes - I filled the slits 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 kind of lumpy. After glassing and more epoxy, the lumps are pretty well disguised, but there is some color variation. In retrospect, I would mix the thickener in with a stick in a small tub, and then transfer to a bag.

Glassing the Deck - I bought 4 oz 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.

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

Windshield - I decided to make my own brackets. 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 only place I could find on the web.

Registration Numbers - I ordered vinyl numbers off the web and mounted them per the instructions. The numbers look fine, though if I were to do it again I'd try to get them curved downward at the ends, or cut them apart for mounting. As they are, straight decals mounted on a curved surface, they curve upward at the ends looking a little goofy. Another possible complaint is that gold letters with black outline don't show up with much contrast on a dark mahogany hull. I don't mind but some state bureaucrat might.

Outboard Motor - When I bought the motor, the shop asked me about the age of my gasoline. I wasn't sure but we started it anyway and it purred like a kitten, idling so smoothly you would hardly know it was running. So I took it home (on the uncompleted boat) and continued with my boatbuilding for several months. When it came time to try out the controls it would hardly run at all. I've tried several approaches to no avail. It still runs somewhat rough. It's my own damned fault for letting the initial rather aged gasoline evaporate in the carbs. So I may have to confess my stupidity and pay the shop to clean the jets.

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 (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.

When we got back we were able to roll it up (on the trailer of course) onto the deck where I built it at the side of the house so it's not taking up driveway space anymore.

So it's ready for Tahoe, though a bit late for this year.

The project was great fun and I'm quite proud of the results.

Complete Project Photos and Commentary