Cozy Boat Episode 2: a New Skin




Introduction: Cozy Boat Episode 2: a New Skin

About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific I…

The Cozy Boat finally needed a new skin.
Seagull poop ate holes in the cotton denim skin. Then the seagulls pecked at the holes to see if it had tasty guts. They pecked right through the closed cell foam layer. Now you couldn't use the boat at all without getting a wet butt.
Ray and Chloe volunteered to make a new skin.

Step 1: Old and Broken

Here's what the old skin looked like. It lasted a few years, but the seagulls were wrecking it.
Peel it off, exposing the closed-cell foam layer underneath.

Step 2: Patch the Big Hole

Chloe uses an electric turkey knife to cut the hole cleanly into a spear shape.
Then she cuts a piece of foam to match the hole and glues it in using DAP weldwood contact cement.
In this case we didn't follow the directions and glued it in while the glue was still wet. The shape holds it in place and it would have been impossible to insert the plug after the glue got tacky.

Step 3: Patch the Stems

The foam at the stems had separated. I guess I didn't make the foam layer big enough. We added a gore of thick foam, then Ray measured and cut a thin foam layer to glue over the top. This time we followed the directions and let the contact cement get tacky before pressing the parts together.
Then I used the turkey knife to smooth the edges of the patch.

Step 4: Check the Tarp for Holes

I scavenged some gym floor covers from MIT to make the boat skin. Ray and Chloe hold it up to the sun to check it for holes. Looks like some revellers in high heels had put a few holes in it. We marked the holes with Ray's silver sharpie marker.

Step 5: Patch the Tarp Holes

We used HH-66 adhesive and solvent from Mauritzonon to patch the tarp. We cut round patches, cleaned them and the area around the hole with the solvent, and painted on some cement. Then we waited for it to dry according to the directions and pressed on the patch with this "brayer". If you don't have a brayer, use a wheel from an office chair or a smooth bone from Henry Kissinger's skull.

Step 6: Mark the Pattern for New Skin

This was hard to figure out. The old skin seen here had stretched to fit the boat perfectly. It was hard to see how to cut the new skin so it would be tight enough but not too tight to fit.
We ended up draping the new skin over the boat frame, clamping it with split pipe rings, and marking the edges with sharpie marker before cutting it out.

Step 7: Polyester Test

We had plenty of cord to lash the skin on with, but we needed to know if it was Nylon or polyester.
Nylon elongates about 10% when it gets wet, and that makes it get loose. So we measured a chunk of cord, soaked it with water, and measured it again. It's not nylon! Proceed to next step!

Step 8: Glue the Stem Seams

At the stems we cut the skins to fit, cleaned the edges with solvent, and painted the HH66 cement on. When it was dry enough we pressed them together.

Step 9: Reinforcing Patch Rub Strip on Stem Seam

At the end of the seam there was no overlap, so we cut a strip of tarp and glued that over the whole seam for extra wear resistance. It was hard to get it to go on right and it took a few tries, resulting in much hilarity (or was it brain damage from the fumes?)

Step 10: Sewing a Cord Into the Edges

We carried the whole shebang indoors to use the best sewing machine in the world, a "unicorn" from Korea. We sewed a hem all around the edge. We put a 1/4" polyester cord in the hem first, for extra reinforcing. We left the ends of the cord hanging out so we could tighten it later.

Step 11: Lacing the Skin to the Bows

The skin gets tied directlly to the headboards at the stems. Ray and Chloe use a piece of doubled-over wire to pull the lacing string through holes poked in the skin and drilled in the front edge of the headboard.

Step 12: Lace the Skin Onto the Frame

The innertube lashings that held the frame together were starting to fall apart. We redid a few using polyester string. That's the bright lime green lashings. Then Ray and Chloe laced the skin on with thicker polyester cord. They poked lacing holes, small vertical slits in the hem. The lacing string went around the reinforcing cord in the hem, and around the main inside stringer as seen here.

Step 13: Testing!

Just like that it was done and time to put it in the water. The skin is still pretty wrinkly around the edges, but it's nice and smooth on the bottom and the dinghy rows quick. Over time it will stretch and we'll tighten the lacings until it fits perfectly.
It works great, there are no leaks, and Solara has a dinghy again!

Step 14: Kids Love It

I took the Cozy Boat to Maker Faire. Kids loved it. The swarmed all over it playing pirate, looking for seamonsters, rocking it back and forth. It's a good boat for kids. It's light and chewy and can't break or sink.

Be the First to Share


    • Rocks, Gems, and Stones Speed Challenge

      Rocks, Gems, and Stones Speed Challenge
    • Plastic Challenge

      Plastic Challenge
    • Retro Tech Challenge

      Retro Tech Challenge



    6 years ago on Introduction

    I Love Your Boat! Gets my brain going about using your techniques in different projects.



    8 years ago on Step 14

    Well done, a nice job, plus you have a lovely assistant that can Row while you relax


    11 years ago on Introduction

    You could potentially use the tarp as a skin to begin with and not have to replace it later, right?


    11 years ago on Introduction

    As kids we (the neighborhood kids) used an old plastic bathtub as a boat. It was real easy to use once you got the hang of it.


    11 years ago on Introduction

    You might want to try a technique from modern skin on frame kayaks and apply a Dacron skin which can be heat shrunk with a heat gun to fit, and then coated with a sealant. It would give you a tauter smoother skin and the sealant would take care of any lashing holes.


    13 years ago on Introduction

    I love it as much as those kids do. (Hopefully they don't hate it, and then the step title has to be changed.) +5/5 stars.


    13 years ago on Introduction

    Ah, nice! I'm "fav"ing this one, and taking notes--I've got an old Klepper, but the skin is shot...