: So about that Adobe kayak…

They have been made from concrete, so why not from adobe? You would need to make a boat that had a displacement that would be somewhat greater than for a wood boat, but that is not too difficult. An 18 foot long and 24 inch wide kayak should have a maximum displacement around 600 to 650 pounds. Depending on hull cross section and sidewall height this might even be greater. If the boat weighs about 300 to 350 pounds then it could still carry a 200 pound paddler and have some freeboard.

The major problem with adobe as opposed to concrete is that adobe can be softened by constant exposure to water. You would need to solve this by coating the adobe boat with a suitable waterproof coating. A few layers of epoxy resin might do, or you might look at using some of the waterborne urethanes. You want the adobe to be very dry before you coat it, and it will probably soak up a lot of coating. For economy, you might try polyester resin.

Consider making many bulkheads and sealed, watertight, compartments in the interior. The added materials will certainly add weight to the boat, and reduce the interior storage space, but you'll probably need the cross bracing this type of construction supplies as adobe is not real strong. Any additional reinforcement that could be embedded in the adobe would help with the strength: wood lath, rebar, chicken wire, etc. Even straw would be a useful reinforcement.

Best of luck, and be sure to bring along enough PFDs on or first launch -- just in case the boat dissolves and leaves you without the option of a second launch.

Did Santa by any chance leave a bottle of something in your xmas stocking? Just wondering where you got the idea for such a boat.

PGJ