Saturday, December 11, 2010

December 10 2010

Today we continued replacing frames on the port side of the boat from the tank room to the lazarette.   13 will be replaced, we are alternating every other frame so that Noel doesn't loose her shape.  We are using 3 1/4 inch wide x 3/8s inch thick kiln dried pine strips and epoxy, slid up under the shear clamp and notched into her sawn knees at the bottom end.

Since it hit a high of 55 degrees, we fiberglassed the rear deck.  We laid two strips 4 feet by 20 down the middle before calling it started getting cold.  It is a slow process to work with glass in the winter outdoors.  The resin flows like honey, and takes its time wetting out the cloth.  You have to heat up the resin and hardener to make them viscous enough to mix, as even sitting in the sun all day 5 gallons of resin doesn't flow very well after a 30 degree night.  The deck being 55 degrees, means it turns the resin back into honey.  That means it puddles under the glass when you wet the plywood on deck requiring you to squeedgee the excess from under the cloth, as it is now to thick to wet through the cloth.  If you leave the puddles, when you come back to fair the surface all the fiberglass gets sanded off, as the puddles are high spots.

Since we had a high of only 55, we were using fast hardener.  Things get interesting doing large surfaces with fast hardener.  We mixed 3 liter batches, only because my latest batch of mixing buckets liters is easier to see.  Grin.  West Systems epoxy works with 5 parts resin, 1 part hardener.

Once heated up the resin and hardener are mixed, after which you have a limited time window to spread out the resin on the cloth, before it cools back off and gels... or if you leave it in the mixing pot, the fast hardener has a pot life at 72 degrees of only 9-12 minutes.

With two people it isn't that bad, but both have to be in constant motion of rolling on the epoxy on the deck, the underside of the cloth.  Then the cloth is laid down, the top layer of cloth is then rolled with epoxy.  The cloth is then unrolled moving forward, while one goes back to squeedgee the excess out from under and off the top of the cloth, followed by air rolling with a ribbed roller...  Sometime between these acts, more epoxy is mixed and the process is restarted as it takes 2-3 minutes to mix a pot of resin of this size thoroughly enough that there are no spots that never harden.

It can be frustrating, wasteful, and risky doing glass work in winter... the show must go on.


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