: Slowly but surely I’ve been making lots of progress on my first
: Petrel. What an absolutely awesome design! I even had a chance
: to do some inlay work around the cockpit coaming.

: After glassing the top I separated the deck from the forms some 2+
: months ago. I quickly glassed the inside of the deck as the hull
: sat nicely off to the side with the strongback and forms intact.

: Two weeks ago I removed the strongback and forms and glassed the
: inside of the hull with a nifty orange and black carbon Kevlar
: fiber cloth (ebay id 120708217998). The Kevlar stiffened and
: strengthened that hull like a rock! Though I had to ask myself,
: did it look narrower, or was that a trick of the eye?

: Well, 3-days ago I laid the deck on top of the hull for the first
: time and found … the deck was significantly wider than the
: hull – by as much as 1.3” at the cockpit! Welcome to my
: nightmare!

: My first guess was that the deck slowly splayed while out of the
: forms for those 2-months. So in a panic I quickly cranked clamps
: to the deck looking to correct the difference from the hull. And
: ending up cracking the deck in 3-places!

: Only then did I pull out a tape measure and found what I didn’t
: expect. The deck matched nearly exactly the forms from whence it
: came. It was the recently glassed hull that was way, way out of
: whack.

: So here’s question #1 – has anyone else whose used Kevlar
: experienced this “shrinking” behavior? And question #2, what
: to do next? My guess with some advice from a wise friend is to
: sand off a good portion of the Kevlar particularly around the
: chines, reglass but this time with spacers holding the hull beam
: to spec as the hull cures.

I'm not sure that the Kevlar/Carbon will make much of a difference inside the boat, but regardless neither of these materials shrink, they are pretty much completely non stretchable nor shrinkable in a laminate, glass too. The resin though does indeed shrink as it cures, that's why spreader sticks are suggested.

Now a cure, it will help a heck of alot to have help for this, doing it alone will be at best seriously tricky. First I'd take the hull outside and let it sit for several hours in the direct sun, a warm day will help, it might soften the resin enough (with the black carbon) to soften the resin enough to allow the hull to be spread a bit. Having pre-cut spreader sticks will help (width from the plans) to hold that shape once it's spread, easier to pull from each side at the same time and in the middle first, then work to the ends. If this doesn't work, a black poly tarp draped over the hull will increase the temps considerably. Epoxy is a thermoset plastic, softens with heat also goes back to full strength when cooled. Generally most resins you'll come into contact with start to soften at around 150 degrees, wear gloves and don't be in a hurry :)

Bill H.