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Monday, February 25, 2008

Forward Bulkhead Glass-In

Surprise! Laminating Weekend! Despite what the weatherman was predicting, this last weekend was a clear, dry, rather balmy weekend for the northwest (in the 50s). So, I made a last minute decision on Friday to glass in the forward bulkheads. These were tabbed in using three layers of three, five and seven inch wide tabs. Both sides of the bulkheads were tabbed. All of our remaining bulk fiberglass has now been used. Need to order more.

The pictures below show before and after. Including the clean laminating table before, and the messy carnage afterward. Preparation! Of course, the trick to any job working with resin is getting everything prepped before catalyzing. All glass cut, tools cleaned and ready, extra buckets, stir sticks, everything within an arms reach when you need it. Some of the more important points I have discovered for laminating... Sequence the glass. That is, when you cut it, stack it in the order that it will be applied. With the first piece on the top, second piece under the first, etc. This helps reduce chances of mistakes. With knitted bi axial/csm glass, always keep the bi axial side up. This reduces the chances of snagging a fiber with your roller. Resist the urge to roll out bubbles between each layer application. This simply wastes time. Wait till the third layer (or last, whichever comes first) before attacking the bubbles. I have discovered one can lay up to three layers before it becomes difficult to roll out bubbles out of all three layers. When laying up each layer, squeegee out as many bubbles as you can with your fingers (wearing gloves of course). Its fast and you can get most of the big ones out. Leave the little ones for the rollers. When wetting out glass, pour resin over the top and use a big yellow resin spreader to distribute it evenly. If you have something you can "multitask" while the glass is "soaking" (like brush resin on the dry surfaces, get the fillet wet and positioned, etc), go ahead and do it. Sometimes (depending on the type of resin and ambient temperature) letting the glass "soak" in the resin can be just as fast as wetting it out with a roller. Be sure to squeegee off the excess. Don't "overwork" the glass with the rollers. As the resin starts to become "sticky" during the cure process, the rollers can snag a fiber and "pull it through" (like a hem unravelling on your shirt). This wraps around your roller. The more fibers you get wrapped on the roller, the greater the chance you will snag another one. If you wrap a fiber on the roller. Stop and clean it out (quickly of course). Don't sweat the teeny-tiny bubbles. Its the big ones you want to get out. Removing the small bubbles can be difficult, especially against the hull where the surface may be uneven for the roller. While you obsess about those tiny bubbles, back on the table, your resin is beginning to gel in the pot. I have found the bristle "bubble buster" rollers work great for getting the small bubbles out on uneven surfaces. Have a box of gloves ready to change out. Even the tough nitrile gloves will get holes and/or tear. And, as the resin on your gloves becomes sticky, it makes handling things difficult. Dont heasitate to change gloves often.

When laminating strips of glass, dont cut the strips too long. Once they are wetted out, they can stretch and enlongate simply when you carry it from the table to the target area. No you cant "squish" it back to its proper length. Example, for a 3 inch wide strip, a 30 inch length is about the max. If you have a second set of hands helping, you could go longer. I keep a pair of crusty scissors handy to cut away any excess of wetted glass should this happen. These tips come from experience of just one person doing the laminating. If you have two people, things can be much easier of course.

3/1/2008 Addendum:

When tabbing/laminating pourous surfaces like foam or Coosa, be sure to coat it generously with resin first before layering the glass. If you dont, the resin from the wetted glass will seep into the pours and starve the glass of resin AFTER you are done rolling. This will produce air bubbles that were not present/obvious during the rollup. You only notice it AFTER the resin as set. For the last bulkhead I did on that weekend, I did not coat the surfaces enough and there a number of bubbles "appeared" after rollup. Its not a big deal, and not worth grinding out and re-doing. Chalk it up to experience for the next time.

Building A Westsail 42: Forward Bulkhead Glass-In
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