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Put even more effort into your sanding . . .
By:Paul G. Jacobson
Date: 1/15/2001, 4:51 pm
In Response To: how much drag before/after sanding? (daniel)

: I recently built a Tern and a Coho - both had many drips down the sheer from
: when I glassed the deck. I have been sanding the Tern in preparation for
: varnishing... the hull is half done.

: My wife usually paddles the Coho, but the other day we had the boats out at a
: lakeside park with some friends, and my wife went out in the Tern.

: She said it felt faster, quote, "substantially faster", than the
: Coho.

: Do you knowledgeable types think this is possible? That there could be so
: much drag from all those imperfections and drips that sanding half the
: hull can produce a perceptible difference in speed?

: btw, lesson to first-time builders: SCRAPE OFF THOSE DRIPS WHILE THEY'RE
: PLIABLE! otherwise you'll be sanding for hours on end later on.

It seems to me that you have discovered a new force in nature -- something akin to gravity, magnetism and electricity: The positive power of sanding. I'm certain (well, almost certain) that the effort you invested in sanding was stored in the epoxy, much like a battery can store electricity, and that it helped propel your boat, providing your wilfe with an exceptionally smooth and rapid ride.

Unfortunately, I am sure YOU will not be able to feel this energy flow as by now the force is certainly expended. Your only hope is to "recharge" this boat, or another one, by spending a few more hours in sanding. It seems like you only have the Tern to work on now, so devote your efforts there. pay attention to the direction you sand, as I am sure that this is important. Sanding in the opposite direction could probably slow the boat down.

Since all this sanding will let you add energy to your boat, I'm sure you by now feel that all those drips are certainly a hidden blessing.

If you have gotten this far without giggling, then I'm sorry. Actually the preceeding is in jest. Sorry, I couldn't resist.

Sanding all the imperfections off of the hull might be great for a fractional amount of improved efficiency, but unless you are racing, or moving the boat at close to the theoretical maximum hull speed, then dings, blips, dripped varnish, etc. are just not going to be noticed by an average paddler -- and they will be trivial to a more experiwnced paddler.

Big question here: did you clock the boat and check the actual speed, or is this just an impression? Personally, I suspect the latter.

I can give a couple of "reasons" (actually they are guesses) as to why your wife thought the smaller boat went faster. The first thought is that this boat just fit her better. Perhaps she sat lower in the water, or had a narrower beam to deal with, and could dig in more with her paddle.

Perhaps she is too light for the larger boat and wind and wave move it more than she can, so the smaller boat is more controlable. On the water, with nothing as a nearby visual reference, it is difficult to judge distance, and even more difficult to judge speed.

If your only reference is the boat you are in, a shorter boat might seem to be moving faster than a longer one. If both boats are actually traveling at the same speed, the shorter boat travels its own length (a shorter distance) in a shorter period of time.

Her height above the water might even influence her view of the surroundings, and her impression of speed, so it could be the seat height, or the displacement of the boat which matter.

The point is, without an actual measurement this is of course a very subjective measurement.

The other point is that your wife obviously likes this boat, so now it is hers. Should you ever borrow it, remark on its great speed. At every opportunity be certain to remind her that she got the best of the two boats that you built -- and that you planned it that way. By all means finish the thing by Valentines Day and put a big ribbon on it.

Hope this helps

Paul G. Jacobson

Messages In This Thread

how much drag before/after sanding?
daniel -- 1/15/2001, 12:54 pm
Re: how much drag before/after sanding?
Tapio Manner -- 1/16/2001, 2:31 pm
Re: How hard do you want to work?
George Cushing -- 1/15/2001, 6:51 pm
Re: how much drag before/after sanding?
John Michne -- 1/15/2001, 6:46 pm
Put even more effort into your sanding . . .
Paul G. Jacobson -- 1/15/2001, 4:51 pm
I can see it now...
daniel -- 1/16/2001, 2:50 pm
Re: Power of Positive Sanding
Lee -- 1/15/2001, 7:01 pm
Re: Put even more effort into your sanding . . .
daniel -- 1/15/2001, 6:33 pm
Re: how much drag before/after sanding?
Nick Schade - Guillemot Kayaks -- 1/15/2001, 4:18 pm