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how much drag before/after sanding?
By:daniel
Date: 1/15/2001, 12:54 pm

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?

I've read somewhere that in order for humans to perceive a change in just about anything, it has to change by at least 10%.

A further contributing factor might be that the Tern is lighter by probably five or seven pounds... A, it's shorter, and B, I built it second :) .

However, a... a... (what's the opposite of "contribute"?) counter-factor is that the Coho is supposedly three or four percent faster due to less wetted surface area.

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.

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