A Shipwright in Training

Since WB put a link to this little site on their home page, I feel it’s prudent to make one thing abundandtly clear: I’m a rank newbie.  Granted, I know my way around a woodshop and I have amassed a sizeable arsenal of tools over the years, and I generally know how to use them with a modicum of skill  BUT when it comes to building boats, I’m a newbie.  Therefore, from time to time, or maybe on a regular basis, I’ll state something here with great confidence that will be stunningly wrong.  Or only partially wrong.  Or only wrong in one instance but dead right in the tropics during an eclipse.

You get the picture. 

So, when that inevitable comment comes that reads something like this: “I’ve followed with interest your fascinating treatise on why water is not, in fact, wet. I feel compelled to tell you to never write another word for as long as you live, and to issue a formal apology to anyone who has ever been exposed to your thoughts.”  I would hope that said writer takes a deep breath, recalls when (s)he was a newbie, and respond accordingly.

And now, for today’s errata and subsequent correction.  I think I’ve said on more than one occasion that the good thing about cotton as caulking is that it swells up nicely and forms a gasket when wet.  Actually, when cotton gets wet, it becomes slippery and unmanagable, and we generally don’t like it.  Thus, if you have a leaky seam, you don’t see people shoving cotton into it to stop the leak.  You see people slathering tar or putting on a sticky patch from the outside.  One person wrote asking if we used a cotton / wool blend ever, because wool has nice waterproof qualities.  The answer to that was, “no” by the way.

So here’s the deal with cotton.  We don’t really want it to get wet.  What makes cotton good is that it acts as a gasket because it’s flexible and it conforms to the slight irregularities in the wood surface when the wood swells around it.  See, the wood swelling is the important thing, not the cotton.  You could just as easily use nylon string.  What matters is that it conforms fully to the wood surfaces in the joint as the wood swells.  When the wood swells, it pushes up tight against the cotton, and the cotton, for all intents and purposes, acts like a solid rubber gasket. 

So, there you go.  Fact of the day.  Try not to be too hard on people who confidently spout off about cotton swelling and filling gaps between planks.  They’re young, just like you once were.

This entry was posted on Wednesday, March 14th, 2007 at 9:01 pm and is filed under Classes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.