: if you carved a kayak out of one piece of wood how would you know if it
: wouldn't sink.

Well, first you would see if the log floated.

Then you would remove some wood so it was lighter.

When you were finished you would try to float it again.

If you are seriously considering carving a log into a boat e-mail me and as soon as I get my home computer back online I'll send you a scan of an 1890's article on building dugout canoes. It is from Daniel Beard's "An American Boy's Handy Book". A facsimile copy of that title was published about a decade ago, and there may still be copies of that edition available. Try amazon.com

The finished boat is considerably wider than the log it was cut from. The article explains the entire process, but basically, you fill the hollowed log with boiling water and steam the thing to soften the wood, then you force it wider by inserting thwarts and wedges. When it cools, the thwarts are in there solidly, and the width is whatever you want.

If you don't flare the log, then the stability is lousy, and the opening is too small for you to sit in comfortably.

Personally, I'd update this technique and use a hydraulic bottle jack, or maybe a screw-type automotive (tire changing) jack. Such tools are far more common these days than they were a century ago.

For a deck you would probably need two logs, or perhaps you would be able to slice the log in half lengthwise and hollow out each section before steaming or boiling and bending them to shape.

The old method used small fires to remove the wood in the interior of the log. The charcoal and ash were regularly scraped out over the week or so it took to burn the thing down to size. With a chainsaw and bit of luck you could remove a good deal of the center of the log in a few minutes, but the method of doing this is rather dangerous, as you are working with the tip of the chainsaw, and a lot of the chain is exposed. I mention it, but I don't recommend it. A lumber making rig might be adjusted to only cut part way into the log and remove a wedge of heartwood to speed the process.

Any cracks that may form as the log dries (if you keep it in the water and wet the log won't dry), or other leaks, are chinked with thickend pitch and maybe some sawdust.

Hope this helps.

PGJ

Oh, and I'm not going to waste my time trying to carve ironwood, either.

hope this helps

PGJ