Ganymede Construction Notes

February 4, 2010

My eldest daughter, Kristen, asked me to build a kayak she could use. Kris is 42, fit and athletic, but tends to be easily distracted, so I want a boat that will perform well but be very stable. It also has to be a simple design that will be easy to build, because she wants to participate in its construction and lives 120 miles away.

Just as I was looking for a design that would fit these criteria, Nick Schade announced his Ganymede. This is a 13-foot boat, 24-inches wide, that can be stitched together in a few days from six pieces cut from three sheets of plywood. The design is about as simple and straightforward as it could possibly be, but still attractive and likely to paddle well. It has a flat bottom, so it should be very stable.

Kris allowed that, since I wouldn’t let her pay for materials, I could store the boat at my house on Cape Cod and use it as a guest boat, so I’ve decided not to build the Wood Duck hybrid. She will be visiting in a couple of weeks, so we plan to cut and prepare the plywood parts then. Next month, when my shop warms up, we’ll assemble the hull and deck.

I plan to modify the design somewhat by adding bulkheads and hatches, along with foot pegs and deck rigging. The deck will be varnished Sapele and the hull painted Okouome. I swiped this photo of Nick paddling his prototype from his website. This boat can be built in three deck heights; ours will be an inch lower than his.

February 12, 2010

I had to scrap my trusty old Chevy Tahoe. After fifteen years of hard use and more than a quarter of a million miles, it was still running like new, but the frame rusted through and there’s not enough steel left to repair it. A sad consequence of all those New England winters and years of sitting on the piers in Woods Hole.

I used this truck to haul plywood from Boulter’s in Somerville, a job too big for my GMC Envoy. So this time I ordered plywood from Chesapeake Light Craft. Their price is the same as Boulter’s and they will ship up to 16mm combined thickness anywhere in the continental U.S. for a flat rate of $99. Factoring out the Massachusetts sales tax and the cost of gas for the Somerville trip, that works out to only a $50 premium, and the carton will make a great floor mat for the shop to boot.

Unfortunately, CLC got hit with two big snowstorms in the past week, so they weren’t able to ship the plywood out until today. I’m hoping it arrives by next Friday, so my daughter and I can get cracking on her new boat.

February 21, 2010

The plywood arrived on Tuesday, well packed between two large sheets of corugated cardboard that wrapped around the ends. The sides were protected by eight foot long 1/2″ x 3/4″ mahoghany strips that are sure to find a use one day. The quality of the CLC plywood is considerably better than the stock I bought last year from Boulter. This time I didn’t have to work around any big imperfections.

Kristen drove down from New Hampshire this weekend and we laid out and cut the six major panels that will become the hull and deck. Kris wants to do as much as possible on this boat herself, so I just set things up and showed her how to do it. We traced the full sized patterns onto the plywood using artist’s transfer paper (a.k.a. carbon paper). On the Sapele, we darkened the lines with a fine point Sharpie.

The shipping crate protected the plywood from the concrete floor. We then set the plywood on sheets of 1″ styrofoam and Kris used my Porter-Cable trim saw to cut out the pieces. More detail on this technique can be found on my Merganser page.

We didn’t follow the suggested layout from the plans, but instead cut the deck pieces from the sheet of Sapele and the hull pieces from the two sheets of Okouome.

We also did not scarf the sheets together, as I prefer to use double-taped butt joints. The bottom joint will be behind the seat and the side joints will fall beside the seat. We stapled the sheets together to hold them in alignment while we traced the patterns. Kristen is an accomplished seamstress and noted that this was not unlike laying out a clothing pattern on cloth.

We cut the rear deck piece out of the center of the sheet, then taped the two remaining pieces together and cut both sides of the front deck at the same time. For the hull parts, we did the same thing. That assures that the side pieces will be identical and therefore symetrical. Here’s Kris holding the rear deck piece, which is going to be spectacular when varnished.

February 25, 2010

It’s still too cold in my basement/garage/shop to work epoxy, and I want to join the bottom and side panels to their full length before Kristen returns, so we can stitch the pieces together and glass the inside on her next visit.

I once built a sailboat on the deck of a rented condominium, so nobody in my family is surprised that I am now building a kayak in my kitchen. I had to move some things around, and be very careful not to spill any epoxy. 

When we laid out the pieces, I made short marks at the seams and at each end of a three-foot straightedge so I could check alignment of the panels. As it turned out, this was not necessary. The pieces aligned perfectly just by pressing them together. I then taped the seams with packaging tape to hold the pieces together temporarily. Putting a small dog ear on the tape makes it easier to remove. I then flipped the panels over and firmly taped the seams on the other (outer) sides. This will keep them aligned and minimize the amount of epoxy that spreads from the seams.

Then I removed the tape from the marked (inside) seams, slipped some 4-mil polyethelene under the seams to protect the floor, and mixed up a one-ounce batch of epoxy. Note that I had moved the resin, hardener, cloth and plywood pieces upstairs a few days ago to warm them up.

I poured a small amount of the epoxy into a separate cup and added some Cell-O-Fill to thicken it slightly. I poured the thickened resin on the seams, where it quickly filled in the spaces between the panels. Then I laid three-inch wide strips of bias-cut four-ounce fiberglass cloth on the seams, poured on the remaining unthickened epoxy, and worked it into the cloth with a disposable chip brush. The light cloth pretty much disappears and you don’t need a lot of epoxy on it because you will just have to sand it off later.

I laid another sheet of 4-mil poly over each seam, covered them with scraps of plywood, and weighted them down to hold everything in alignment. Today I did the bottom panel and one side. Tomorrow I will do the other (outer) side of the bottom panel and glue up the second side laid on top of the one I did today to assure that both sides are identical. On the third day I will tape the outside of both side panels.

The single layer of light cloth on each side doesn’t make strong joints, but is sufficient to hold while we stitch the panels together and apply six-ounce cloth both inside and out of the whole hull.

March 1, 2010

After the epoxy set up hard I moved the panels to the shop, where the 40 degree temps will slow the curing until I have time to sand the joints before the epoxy gets too hard. I did that today, then planed and sanded the side panels to the cut line. I’ll leave the bottom panel for Kristen to plane the next time she comes down, so she can experience this part of the process.

The butt joints are surprisingly strong and the cloth reinforcement is not discernable to touch. These joints are not as strong as puzzle joints, and weaker than scarfed joints, but still strong enough for our purposes.

March 5, 2010

This week I sanded the butt joints, planed the edges of the panels and cut out the cockpit opening and coaming pieces. Also cut the three hull assembly forms. Outside temps have been in the mid-30s all week, with constant snow and wind. My house sits on a hill with full exposure to the northeast, so the snow doesn’t fall so much as it blows by.

Temps in the shop, which is under the house but with a garage door on the west side, held steady around 40 degrees. I was able to bring this up to 50 with an electric heater. This is the absolute minimum temperature for working epoxy. March came in like a lion, so I’m hoping it will go out like a lamb and bring us higher temps when Kristen next visits on the 27th. I’d like to get the shop up to at least 60 when we assemble and glass the hull and deck. Once the epoxy sets up, we can leave it for a few weeks to fully cure.

March 25, 2010

Last weekend I drove up to Maine for the Maine Boatbuilders Show, where I spoke with both Nick and Eric Schade, as well as the rep for MAS Epoxies. The temperature in Portland was 70 degrees and throngs of joggers, walkers and cyclists were out in T-shirts and shorts. This weekend, however, doesn’t look as good. The forecast for this area is sun with temps in the 30s.

Kristen comes down tomorrow, though, and we will proceed with work on her Ganymede. I’ve been keeping the resin and hardener in the kitchen, and have an electric heater that will raise temps in the shop about ten degrees. Our plan is to stitch and spot glue the hull and deck pieces tomorrow, fillet and glass the interior of hull and deck on Saturday, and glass the exterior of the hull on Sunday. Worst case: we move the boat back into the kitchen!

March 27, 2010

The cold weather has been raising havoc with our plans. Temps have been in the low 30s outside and about 50 in the shop. Kris arrived late yesterday afternoon so I turned on the electric heater while we had dinner and got the shop up over 60 degrees. We stitched all the panels together and tack welded them with thickened epoxy, then shut off the heater for the night.

This morning the epoxy welds had set up but were still soft. By noon they seemed pretty hard so we started pulling stitches and the seam began to separate. We stitched it back together, set the deck on the hull, put the heater under the boat and covered it loosely with 4-mil polyethelene. It is now 70 degrees under the cover so it should be curing okay. Will try again tomorrow to pull the stitches, fillet the seams and sheath the inside. Here’s Kristen imagining she’s out on Back River.

March 28, 2010

We awoke today to a deep freeze with outside temps at 20 and the shop at 40, so won’t be doing any more on the boat. The forecast for next weekend is much better, so we’ll plan to resume work then. We ran into two minor glitches when we sewed the hull panels together that I didn’t mention earlier.

First, we apparently laid the bottom panel out backward, so the butt joint ended up in the forward area instead of behind the seat as planned. It won’t matter once the hull is sheathed and painted.

Second, the bottom panel came out about 1/2 inch too long when we stitched the sides on. This apparently the cumulative effect of it being about the width of a pencil line too wide. I dropped the last foot or so below the side panels and planed it to fit, which solved that problem. Kristen has made me swear that I will not proceed with work on this boat when she is not here, so I won’t be posting again until next weekend.

April 3, 2010

When you read how many hours it should take you to build a kayak, know that those figures don’t include time setting up and cleaning up your shop. Kristen’s on her way from New Hampshire, and hopes to fillet and sheath the inside of the hull and deck today, so I spent two hours this morning setting up the shop.

After sweeping the floor and covering it with cardboard and plywood to catch epoxy drips, I set up a work table on one side, moved the long table to the other side and covered both with 4-mil polyethelene. The long table is two factory-reject flush doors set on collapsible sawhorses.

I then set the hull back on its sawhorses and rewired it to the forms in a way that won’t interfere with the sheathing. The epoxy, cloth and additives, as well as the application tools, are upstairs getting warm. I’ve had the electric heater on all morning and the temperature in the shop is about 60. It’s actually about the same outside, so we’ll open the garage door when we start work.

Kristen got here about 2:00, and it’s a warm sunny day, so we opened the door and filleted and glassed the inside of both the deck and hull. Kris caught on very quickly and insisted on doing it all herself, so I was relegated to mixing epoxy. It took about two hours to do the work and it seems to be curing pretty well.

I’ll leave the electric heater on until we go to bed. If the epoxy hardens enough over night, we’ll turn the hull over and sheath the outside with 6-ounce cloth tomorrow. I noticed this morning that I had attached the rear part of the deck upside down, so the X marks where we drilled the wire holes show. Will try to sand them off before we sheath the top of the deck. My feminist elder daughter insists on calling the cockpit the V-pit!

April 4, 2010

The work we did yesterday cured pretty well, so this morning we trimmed the excess cloth, then turned the hull over, rounded all the edges with a plane and sanding block, then sheathed the outside of the hull with 6-ounce cloth. This is noticably heavier material than the 4-ounce cloth we put on the inside. It does not smooth out as easily and absorbs a lot more epoxy.

I neglected to bring the resin and hardener upstairs to keep it warm last night, so this morning I set both in a bucket of hot water while we had breakfast. What a difference it made! The warmth made the epoxy much thinner and so it soaked into the cloth more easily. I have Kristen’s permission to trim off the excess cloth and roll on a second coat of epoxy tomorrow, since that should be done before the base coat is fully cured and she had to head off to her mother’s family for Easter dinner. Here are some photos of this morning’s work.

Trimming off excess fiberglass cloth

Edges rounded off and sanded – ready for sheathing

Hull sheathed; floor epoxied!

April 5, 2010

When you don’t squeegee enough resin from the cloth, you get corrugations like this where the cloth floats up on the excess resin. We thought we had done it right, and the bottom looks good, but both sides have this. I suspect it has to do with my lack of experience with six-ounce cloth. Like anything with kayak building, this can be fixed, but will require more fill coats and more sanding.

Today I trimmed off the excess cloth and sanded the edges that wrapped around the ends of the boat. I also hand sanded the corrugations. Many builders wait for the epoxy to fully cure before sanding, but I find it easier to sand when it is still somewhat soft. I then added patches of six-ounce cloth at the ends where they are likely to get bruised. By cutting the cloth on the bias, 45 degrees off the direction of the fibers, I was able to mold the cloth around the compound curves and avoid fraying of the edges.

Temps outside hit 70 today, so I opened the garage door and recoated the outside of the hull with epoxy to fill the cloth weave. This can be done any time, but you get a better chemical bond if you do it within 24 hours of applying the underlying coat. Finally, I applied a 12-inch wide piece of six-ounce cloth to the underside of the deck, just aft of the cockpit opening, to stiffen this area where paddlers are likely to sit when entering or exiting the boat.

April 7, 2010

Air temperatures broke records across southern New England today: 90 in Boston; 92 in Providence and Hartford. A brisk on-shore breeze kept it to 76 on the Cape, though – perfect for epoxy work, so I opened the shop door and went to work correcting the corregation problem. First I lightly sanded the whole hull with 60-grit paper in my random orbit sander in order to show the high spots. Then I sanded off the drips and sags. Finally I attacked the corrugations.

The epoxy was pretty well cured, but still ate up a lot of sanding disks. I managed to eliminate about 90% of the ridges, sanding clean through the cloth on the worst ones; the remainder will disappear during the final finishing process. I said before that there were corrugations on both sides, but the side that Kristen did had only sags. All the corrugations were on the side I did! I then applied another thin coat of epoxy using a thin-nap roller and tipped out with a disposable foam brush.

The weather is supposed to cool off tonight, and I have other things to do, so I’ll put this project aside until next week. I ordered foot pegs and some other supplies from Newfound Woodworks and CLC on Monday. The Newfound order arrived yesterday; the CLC order was shipped today. So next week I’ll install the foot peg studs and build up the fillets in both ends of the boat before I attach the deck to the hull.

I’ll also cut and fit bulkheads but not install them. I decided to put in bulkheads but not hatches, so need to attach the deck before installing the bulkheads, which will have deck plates in them for access to the ends and be held in place with marine silicone caulk so they can be removed if needed for repairs to the hull or deck.

April 12, 2010

When we filleted the seams, we had trouble getting the dookyshmutz to stick in the ends because they are so steep.  So today I sanded the original fillet to get a good bond, propped the stern up on a six-foot stepladder, set the bow on the floor, and poured a stiff mix of thickened epoxy into the seam. The next time I have some unthickened epoxy mixed, I will lay a strip of 9-ounce fiberglass tape on the new fillet. Tomorrow I’ll do the same to the stern.

Here are before and after shots of the bow. Now that the sides are fully cured, the corrugations cannot be seen or felt. I had been planning to paint the hull, but it’s looking so good, we may varnish it. The butt joints between the plywood panels look a lot better than scarfed joints and are not as obvious as the puzzle joints found in kit boats.

April 13, 2010

Today I laid a similar fillet in the stern. Unlike the bow fillet, this one sagged toward the bottom, which is not a bad thing, as that is the area most likely to need the extra mass. One of the last steps in building this boat will be to add end pours, which will reinforce the hull to deck joints in the ends.

April 26, 2010

Kristen has been too busy with work and family obligations to work on the boat lately, so she said I could keep working on it so she can use it this summer.

Today I cut and fit – but did not install – the bulkheads. When the weather warms up a bit I’ll coat them with epoxy. I won’t install them, though, until after I attach the deck to the hull, so that I’ll be able to reach the entire interior seam when I fillet and tape it. I also marked the locations of the foot pegs, but ran out of time to glue them on.

April 30, 2010

We’ve had a week of cold, raw, wet weather, so I haven’t been doing much on the boat. I tacked the foot peg studs in place with five-minute epoxy that took a day to cure. Today, though, the sun returned to Cape Cod and temps hit 73, so I took care of the next steps. I bias-cut some three-inch squares of cloth, cut holes in the center, and used them to permanently attach the foot peg studs to the hull. Then I reinforced the bow and stern with an extra layer of six-ounce tape on the inside seam.

On this photo of the foot peg studs, you can see the neat butt joint of the bottom panels. The pen line on the right marks the location of the forward bulkhead. Left click on any of these photos to enlarge them.

With some epoxy left over, I coated the outside of the bulkheads, being sure to cover all the edges and fill the bolt holes. The next time I mix up a batch I’ll coat the other sides. I have some shrubs to plant tomorrow, but may start the job of attaching the deck to the hull.

May 2, 2010

By far the most onerous task when building a kayak is taping the inside seams when attaching the deck to the hull. It’s not especially difficult, but it is awkward, stressful and very, very messy. Today I bit the bullet and taped one side; I’ll do the other side tomorrow after this side sets up.

Typically, when assembling a stitch and glue boat, you carefully stitch the deck to the hull, tack-weld the two halves together, remove the stitches, fillet the seams, then tape them with two or three inch wide strips of fiberglass. The instructions for this boat are very different. In an effort to simplify the process, Nick lays out a less stressful way to do it. He says to tape the deck to the hull with strapping tape, tack-weld the seam with CA glue, seal the seam with masking tape on the outside, then tape the inside seam without filleting it.

I chose a middle ground. I used the strapping tape to align the deck to the hull, sealed the outside of the seam with packaging tape, skipped the tack-weld stage, but used a bunch of bar clamps and a couple of strap clamps to hold the two halves together. I then set the hull on edge so that the seam I want to tape forms a valley, and clamped it to a stepladder to hold it in place.

I had intended to fillet the entire seam, but didn’t make up enough shmutz, so only filleted the middle area between the bulkhead locations. I used the West System empty caulk tubes to spread the thickened shmutz, which works well – certainly much easier and cleaner than the freezer bag approach. I then saturated strips of nine-ounce fiberglass tape and applied them to the seam, using Nick’s nail on a stick approach to push the tape into the ends, and the brush on the other end of the stick to smooth them into the seam.

May 3, 2010

This morning I removed the clamps and the strapping and packing tape from the seam that I taped last night, and inspected the work. The result looks pretty good. There are some small bubbles in the seam where it is not filleted, but this boat will have sealed ends so I don’t expect any problems from water getting under the tape. Some epoxy seeped through the seam in a few places, but it was still soft enough that I could shave it off easily with a utility knife. This afternoon or evening, I’ll tape the other seam.

May 4, 2010

Too many chores and errands yesterday, and this part of the project is so unpleasant that any excuse to put it off will work. Conditions were ideal today, though, so I taped the other seam using the same techniques as before. When I used the caulking tube to fillet the seam on Sunday, I had problems with air bubbles coming out. With the tube only partially full, the plunger traps air with the schmutz. Today I drilled a 1/8″ hole in the plastic plunger to allow the air to escape and that worked very well. This is by far the best way to apply thickened epoxy schumtz to seams. West says the tubes can be reused, but I was not able to get the hardened mix out of the spout. They are cheap enough to be disposable anyway.

May 5, 2010

The second seam came out very well too. I’m surprised at how well the tape worked without a fillet, although there is no harm from having the fillet in the cockpit area. The nine-ounce tape holds a lot of resin which filled the seam and formed its own small fillet. The unthickened resin also ran down the seam to within an inch or so of the ends.

I was planning to pour thickened epoxy into the ends today, but it looks like that will be unnecessary. I would rather do the end pours after I have varnished the deck and installed the lift toggles, so that they encase the screws holding the fairleads that hold the toggles. Today is perfect weather for yard work, so I might set the boat work aside until the weekend.

May 8, 2010

Since my last post I took the boat outside and sanded the deck in preparation for sheathing. The deck fit the hull perfectly in the area of the cockpit and back to about a foot from the stern. You may recall that I had cut an inch or so off the bottom at the stern so that it would fit between the sides, and that left the deck a little big in this area.

At the other end, the deck overhung the hull up to 1/4 inch on each side between the cockpit and the bow. I quickly cut this down and feathered the edge of the hull sheathing along the sheer using my 45-year old Craftsman belt sander. As always, I need to state that a belt sander can do a lot of damage in the blink of an eye, and shouldn’t be used unless you have lots of experience with it.

After sanding the overhang, it became evident that the seam between the deck and hull about six inches back from the bow had not been sealed by the interior epoxy, so I clamped the deck down with strapping tape and wrapped the outside of the seam with clear packing tape. I then turned the hull over, set the bow on a piece of thick styrofoam and lifted the stern onto the top of a stepladder. You can see pictures of this technique on my Shearwater page.

I then mixed up three ounces of epoxy with enough wood flour to give it the consistency of mustard. Since this boat doesn’t have deck hatches it’s a long reach to the ends from the cockpit. To extend my reach I used a grabber that my mother had bought when she got too frail to reach the upper shelves in her kitchen. At this point things got really exciting.

As I started to tip the cup of thickened epoxy it slipped out of the grabber and quickly slid into the point of the bow, still holding most of the epoxy mix. Now, I suppose it wouldn’t do any harm to have a cup of thickened epoxy glued into the bow of the boat, but it also would not serve the purpose of sealing the seam and would block any other attempts at an effective bow pour. I then grabbed the stick with the nail on one end and the brush on the other that I used to spread the tape on the interior seams. I was able to catch the cup with the nail, tip it over to dump out the epoxy, and drag it back to within reach.

While I was dragging the cup back with the nail, however, the brush somehow broke off the other end and slid into the pool of epoxy in the bow. Once again, I could have just left it there, but at that point it became a challenge that I couldn’t resist. After a few tries, I was able to retrieve the errant brush with the nail on the stick, and then I used the stick itself to push the epoxy into the seam at the bow. This photo shows that the epoxy actually filled the seam and sealed the deck to the hull all the way to the tip of the bow.

This morning I turned the boat back upright, removed the packing tape and sanded off a small amount of epoxy that had seeped through onto the deck. It’s cool here today, though, and the epoxy is still soft, so I’ll leave the strapping tape on for another day or two before sheathing the deck.

As long as I’m not going to be sheathing the deck today, I decided to also seal the last inch or so of the seam at the stern. After taping the open seam with clear packing tape, I turned the boat over, set the stern on the floor and propped up the bow. I then mixed up a small batch of epoxy – 1-1/2 ounces – and thickened it with wood flour. This time, though, I attached the cup firmly to a stick with strapping tape so I wouldn’t lose it.

This worked well and this close-up shows that the seam filled very nicely.

May 11, 2010

We’re getting another week of cool weather and rain here on Cape Cod and this is not conducive to epoxy work. The boat is ready to have the deck sheathed, but that task will have to wait until temps return to 70 degrees or more. At this point the bare hull weighs in at 28 pounds. I expect the finished product to come in about 35 pounds. Hoping to finish in time to take it to Nick’s gathering in Groton on June 5th.

May 12, 2010

Today I added up the cost of materials for this boat and it came to about $980. That includes $55 for the plans and shipping costs of materials that I had delivered. The largest single item was the plywood at $291, followed by epoxy resin, hardener and fillers at $132 and fiberglass cloth and tape at $126. I bought all of these items on sale during the off-season.

The seat, backband, foot pegs, deck plates, knee pads, lifting toggles and miscellaneous hardware came to about $220. Sandpaper, gloves, brushes and rollers, copper wire, strapping and masking tapes, mixing cups and sticks ran about $120, and the varnish will add about $36 more. I haven’t kept track of the time involved because much of my time was spent helping Kristen. I think I could probably build one of these boats in about 50 or 60 hours, though.

May 16, 2010

Ideal weather has returned to Cape Cod and we’re back to dry 70 degree air so it’s time to finish up the epoxy work on this boat. Yesterday I sheathed the deck with four-ounce fiberglass cloth using a technique that is a lot easier than it sounds. This involves applying a strip of masking tape around the hull about 1-1/2 inches below the sheer, curling up the lower edge to catch any drips. You then cut the cloth so that it overlaps the tape and epoxy the cloth onto the deck and onto the tape.

Nick includes this in his instructions, but I first learned it from Valclav Stejskal of One Ocean Kayaks. I spread the resin on the deck with a thin foam roller, then used a chip brush to work it into the seams and along the sheer onto the hull.

I had planned to remove the tape and the excess cloth this morning, but found, when I returned home from a night on the town last evening (this is a very small town so it was early) that the epoxy was dry to the touch but still soft.

This is the perfect situation for the next step, so I stayed up a little later, scribed the cloth with a sharp knife just above the tape and then stripped the tape and excess cloth off. The result is a clean edge that is easy to feather off before applying the filler coat of resin. When I think back to the hours I spent sanding off the rough edges and stray strands of fiberglass from the sides of my Shearwater and Merganser, I am very glad to now know how well this technique works.

May 17, 2010

Today I finished cutting the cockpit coaming risers out of some scraps of 9mm Okuome that I had on hand. After carefully dry fitting all the pieces, trimming them to fit, and spreading a trash bag inside the cockpit to catch drips, I mixed up three ounces of epoxy, thickened it with wood flour and Cell-O-Fill to the consistency of ketchup (thicker than mustard, but no where near peanut butter) and glued the whole thing together. Note that when building a kayak one can never have too many of Home Depot’s 99 cent clamps.

May 18, 2010

I started to sand out and sheath the cockpit coaming today, but after cleaning up the inside edge with a Stanley Surfoam plane I realized there were some big holes that needed filling. So I mixed up about 3/4 ounce of epoxy and added enough wood flour to make a thick paste (way beyond peanut butter) to patch the voids.

Then, with lots of time on my hands, I cut two small pieces of 9mm Okoume that I will attach under the coaming to bolt the backband to. Then I made another front bulkhead because the first one proved to be about 3/8″ shy of the underside of the center of the deck. Finally, I coated the new parts with unthickened epoxy and added another coat to the deck to fill the weave of the cloth.

Kristen is coming down this weekend to renew my flower garden and introduce me to her new dog, Pepper, a two year old English Setter that she rescued from the pound. I expect to have the boat finished enough to take down to the pond for sea trials. It will still look pretty rough, and won’t have the watertight bulkheads installed, but Kris can get a feel for how it paddles and I can get some photos to post.

May 19, 2010

A cold wet rainy day and I have other things to do, so no work on the boat today. I did stop by our local hardware store for some foam rollers, though. This is a locally-owned “small-box” store that is not part of any chain. They sell three-inch disposable foam rollers for 69 cents that work as well for epoxy and varnish as the $4 rollers sold by the marine stores. On a whim I asked about buying a whole box and wound up with a box of 24 for $11.45 including tax.

May 20, 2010

The weather has cleared and the forecast is for a week of perfect kayak building weather. I want to have the boat ready for sea trials on Sunday and fully finished for Nick’s meet in Groton on June 5th.

Today I brought out the big guns – my old belt sander and the router – to finish the cockpit coaming. Then I masked the deck around the cockpit, put the trash bag back inside to catch any drips, and glassed the coaming.

Some builders skip this step, but I think it’s important for strength, especially since the top of the coaming is only 3mm thick. Note that it is neither necessary nor desirable to wrap the cloth around the outer edge of the coaming or under the deck.

May 21, 2010

After trimming off the excess cloth from the coaming, I took the boat outside and sanded out the hull. Then I took it back into the shop, turned it over, and laid a fillet of thickened epoxy under the coaming lip. This is a bit tricky because the boat is upside down, but not difficult, using a tongue depressor to form the fillet.

I made the mix pretty stiff, using one heaping scoop of wood flour for color and four heaping scoops of Cell-O-Fill for body, added to three ounces of epoxy. I use coffee measuring spoons for scoops. With the same mix I glued and filleted the backband tabs under the deck.

That didn’t take long, so I also rolled a finish coat of epoxy on the hull (but not the deck). Finally, I stripped the masking tape off the deck while the epoxy was still soft. The weather forecast is not great for this weekend, but I’ll temporarily install the seat, back band and foot pegs tomorrow in hopes that Kristen can try the boat out on Sunday.

May 22, 2010

While the epoxy is still relatively soft, I sanded the underdeck fillet and trimmed the drips from the deck that came from coating the hull.

Then I temporarily installed the seat, back band and foot pegs. The Newfound seat is relatively large, but looks lost in the spacious cockpit. The IR backband fits nicely, though.

Here is a closeup of the back band attachment tab glued in under the deck.

The boat still needs to be sanded out and varnished, but shows nice lines for such a simple design. Will try to get some photos of Kristen actually paddling it tomorrow.

May 23, 2010

Sea trials today!

One happy camper!

This boat is terrific – super stable, highly maneuverable and tracks surprisingly well for a flat bottom boat. Kristen was amazed at how easily it moved through the water. Before I could say “No – don’t do that!” Kris stood up in the cockpit as she got out of the boat in the water. Any other boat this narrow would have instantly flipped, but this one didn’t even wobble.

May 24, 2010

After Kristen left yesterday I removed the seat, backband and footpegs in preparation for finishing the boat. As I pulled off the foot pegs, though, one of the studs broke loose. Apparently the five-minute epoxy I used to attach it didn’t hold and it ripped out the patch of cloth holding it to the side. I also noticed some voids in the small fillet between the coaming and the deck. I mixed up a tiny batch of epoxy and thickened it to putty consistency, used it to glue the stud back on and then to patch the fillet, smoothing it out with a gloved finger.

Today I cut four more patches of six-ounce cloth and reinforced all four foot peg studs. Then I applied unthickened epoxy to the coaming and inside the cockpit to fill the cloth weave, and rolled on a final thin coat of epoxy on the deck and bulkheads. This should be the last of the epoxy work except for the end pours.

Acording to MAS it takes five days for their epoxy to fully cure, even in this warm weather, and I want it to be fully cured before I sand it out and varnish it. So I’m going to leave the boat work for a few days and catch up on some yard and house chores.

Next weekend I’ll sand out the hull and varnish it. Then next week I’ll do the same on the deck and cockpit. That will still give me a few days to attach the lifting toggles, do the end pours, install the bulkheads and reinstall the seat, backband and footpegs before heading off to Groton on the fifth.

May 30, 2010

Friday I started sanding out the hull and yesterday I finished sanding the hull and deck, as well as the inside of the cockpit, in preparation for varnishing. This is grueling work, done mostly with a random-orbit sander and 120 to 150 grit paper. This took about four hours and went through dozens of disks, as they fill quickly when sanding epoxy. The trick here is to get a perfectly smooth surface. It’s okay to see the cloth weave but not okay to cut into it.

Then yesterday afternoon I swept out the shop, put away the epoxy and most of the tools, and laid a paper drop cloth on the floor. Then I gave the hull an initial coat of Minwax Helmsman Marine Urethane. This stuff flows beautifully, dries quickly and forms a very hard surface. It also costs about half as much as marine varnish. The downside is that it doesn’t last as long. Since this is going to be a guest boat and has no hatches or deck rigging, putting on a fresh coat each year won’t be much of a chore.

Today I sanded out the hull with 220 grit paper in a vibrator sander – hand sanding all the edges – and recoated the hull with Minwax. I need to be very diligent with the work this week in order to have the boat ready to show in Groton on Saturday.

May 31, 2010

This morning I used a sharp wood chisel to clean off the drips on the deck from varnishing the hull, then cleaned the deck with Interlux 333 brushing liquid. When it had thoroughly dried I brought the boat back into the shop and varnished the cockpit, bulkheads and deck. While the deck dried quickly, the interior was still wet six hours later. Apparently there was not enough exposure to the air to dry it, so I took the boat back outside where it set up quickly.

Here is the rear deck, showing the spectacular grain of the Sapele.

And here is a very strange oddity: the two panels of the front deck appear to have been cut from a single piece of plywood, with the grain flowing cleanly between them. While both panels were cut from the same sheet, they were actually cut from opposite sides of that sheet.

June 5, 2010

Well, I’m bummed! I rushed the finish work and skipped installation of the lifting toggles and end pours, so the boat would be ready for Nick Schade’s Meet at the Beach in Groton today. Normally that would be a two-hour drive from my home on Cape Cod. After driving an hour through torrential rain, wind and lightning, though, I had made it only to New Bedford, which is about one-quarter of the way. By then, the roads were flooded, water was gushing out of catch basins and there was an inch of water in the boat. Since the forecast is for similar weather all weekend, I turned around and headed home.

If I had used a cockpit cover, I might have kept plowing ahead. I have two covers: one is too big for this boat and the other is too small. Fortunately, I had installed waterproof bulkheads, so the water didn’t slosh around too much, which would have been dangerous. The boat traveled well, however. Here is what it looked like before I left.

I haven’t found a commercial rack to fit this vehicle, so I use foam pads on the factory cross bars. I cut the angles off the foam pads  to fit the flat bottom, then lashed the boat to the cross bars in the usual manner. Since most car-topping mishaps involve the load pulling the rack off the vehicle, I added a third strap around the boat and through the back doors. This is the way I carry my kayaks locally.

I was going to be on the highway today, with forecasts of strong gusty winds, so I also added bow and stern straps. This boat does not have lift ropes added yet, so I had to be more creative. I wrapped a 20-foot strap around the cockpit coaming, crossed it over the foredeck, and hooked the strap to holes in the car’s frame with ratchet ropes. This worked so well under horrendous conditions, that I suspect it is stronger and more effective than the usual bow line setup. I also looped a strap around the after deck and trailer hitch, but took it off after a couple of miles because it looked like it was about to blow off.

June 7, 2010

In my rush to finish this boat last week I applied the last coat of varnish too thick and got a lot of runs and sags. So today I sanded it once again with 320-grit paper and laid on another coat – thin this time. This took less than an hour. Later this week I’ll attach the lifting toggles and do the end pours. Here is a photo of the front bulkhead, which is installed with clear marine silicone caulk.

June 13, 2010

This boat is now completed. Final weight came in at 37 pounds. This is two more than design weight, due most likely to my addition of watertight bulkheads and lifting toggles. The Sapele deck is well worth the extra cost and difficulty. It looks a lot darker than it appears in this photo. A boat made entirely of Sapele would be simply spectacular.

This past week I installed a bungie to hold the back band in place, and made the final end pours. Here is a shot of the rear bulkhead and backband bungie. I used a Dremel tool to drill the pilot holes for the screws, as there was not enough room between the underside of the deck and the bottom for a conventional drill.

I attached the lifting toggles to 1/2-inch fairleads that are screwed through the deck with 1-1/4-inch stainless steel screws. These screws extend about an inch into the hull. They are then encased with thickened epoxy by the end pours. These photos show the bow pour, with the boat upside down. Before the pour you can see the screws; after the pour, they are buried in the epoxy.

In my opinion conventional end pours only add weight where you least want it and tend to break loose if the ends of the boat suffer an impact. Instead, I elevate one end of the boat upside-down on a sawhorse and pour four ounces of slightly thickened epoxy into the other end that primarily reinforces the deck to hull seam. I used the same cup on a stick approach as shown earlier for the partial end pours.

I also use West G-Flex epoxy for end pours because it is designed to stick well to previously cured epoxy, remains more flexible indefinitely than other epoxies, is pre-thickened, and is available in an eight-ounce repair kit that is perfect for this purpose.

In summary, this was a great father/daughter project that produced a simple but beautiful and well-performing craft that could become a family heirloom. It could use another coat of varnish, but I’ll do that at the end of the season after it collects a few scratches.

9 Responses to “Ganymede Construction Notes”

  1. Kristen Says:

    I had no idea “plywood” could be so beautiful!

  2. Dee Says:

    Thank you for sharing. Kristen, that’s awesome…..and you are haveing so much fun!! I can’t wait to see it complete.

  3. Bill Kerr Says:

    Hi Wes

    Don’t know what I find more interesting on your site, Kayak construction or prototype RR information.

    Rgerads Bill

  4. Kristen Says:

    Thanks for doing the worst of it, I’ll return the favor in the garden, next visit 🙂 I can’t wait to try this boat in the water. So exciting… Kris

  5. Oakwood Says:

    Beautiful work. Both boat and blog. Congrats.
    Back on June 5th, I would have unloaded the yacht, and paddled along the roads! 🙂

  6. Chris Roberts Says:

    Well done looks great

  7. Fergal Says:

    Thanks for the build notes. I’m looking at doing this as a first project (no boat building and little carpentry experience), and this is very helpful. Cheers, and I hope your daughter is enjoying the finished product!

  8. Ron Says:

    This is exactly what I have been looking for! I want to build a relatively inexpensive kayak to see if this is a sport that I can really enjoy before I spend a ton of money on gear. My only concern in that I am a larger paddler, and I am not sure if it could handle my weight. Do you know the load capacity of this design?

    • twofootartist Says:

      This design can be built in three heights depending on person size. Ours is the middle size. The largest will handle a paddler up to 250 pounds. Even though this is a simple design, materials will run about $1000 plus a couple of hundred for paddle, pfd & gloves. Add to that about 50 hours of labor and you have a ton invested. I recommend renting a few different boats until you get a real feel for what suits you best before taking on any building project. You can find more information at If you consider a kit, you should budget another $200 for supplies that are not included in the kit.

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