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Slick Trick
By:Rob Macks
Date: 4/10/2001, 11:58 am
In Response To: Re: Bubbles under glass (Larry C.)

: Dale,
: I used a fillet of thickened epoxy to smooth the transition and used 4 oz
: strips of bias cut cloth instead of tape. I rarely use tape anymore. The
: bias cloth cut with a fabric cutter, makes it easier to follow the curves.

: Larry C.

I don't use Nick's cockpit coaming method, but I agree, the problem is that glass will not go round anything less than a 1/8" radius without lifting, no matter if it's convex or concave.

Epoxy has no tack strength, so the stiffness of the glass fibers are enough to lift off the epoxy coated surface leaving an air gap. You must either build a fillet to ease the sharpness of the angle or use some method to press the glass in place. On convex surfaces, plastic wrap can be used to press glass to conform to sharper angles. On concave surfaces it is more difficult to fashion hold down methods.

I agree with the suggestion to not use seam tape but bias cut cloth instead since bias cloth will conform to complex shape easily.

My coamings are made of hardwood and I don't cover them with fiberglass as I know it is problematic to cover a lot of curves and small surfaces with glass.

I do make a an under lip fillet which is simple to do and perfectly uniform. I make it with 3/4" OSD clear plastic tubing available at most hardware stores. Buy a long enough piece (about 3') to run on one side of your cockpit plus an extra 6" to rap around the ends. I make the fillet on one side of the cockpit at a time. Place your boat on it's side to make work easier and to work with gravity. Mask off the lip edge of the coaming and the point on the deck where the fillet will stop, roughly half of the 3/4" diameter.

Apply thickened epoxy into the lip space and press the tubing into it from the center side to the bow and stern ends. You want to run out of epoxy before you reach the ends of the tubing so the fillet will self feather. Use a plastic squeegee to remove all excess resin that my squeeze out on the tube sides.

Once the resin has set totally, pull out the plastic tube. You will have a perfect semi-circle fillet with a high gloss finish. If you have any voids dig them out, fill and press the tube back in place until set-up.

I use the plastic tube to measure and define the height of my cockpit lip during lip construction, so when I make this fillet the tube fits exactly.

All the best,

Rob Macks
Laughing Loon CC&K
www.LaughingLoon.com

Messages In This Thread

Bubbles under glass
Dale Jeffers -- 4/9/2001, 8:04 pm
Re: Bubbles under glass
Larry C. -- 4/9/2001, 9:48 pm
Re: Got no bias
Geo. Cushing -- 4/10/2001, 12:23 pm
Slick Trick
Rob Macks -- 4/10/2001, 11:58 am
Re: Slick Trick
mike allen ---> -- 4/10/2001, 3:17 pm
foam trick
Paul G. Jacobson -- 4/10/2001, 10:22 pm
Re: foam trick
John Monfoe -- 4/11/2001, 8:29 am
Re: Bubbles under glass
Arthur -- 4/9/2001, 8:18 pm
Re: Bubbles under glass
Nick Schade - Guillemot Kayaks -- 4/10/2001, 9:34 am
Re: Bubbles under glass
Roger Conrad -- 4/9/2001, 11:56 pm
Re: Bubbles under glass
daren neufeld -- 4/9/2001, 8:29 pm