Experiments with Corebond?
Got a five gallon bucket of Corebond this weekend. This is a special two part adhesive with a putty consistency. It is specially formulated for use with foam. For the Westsail project, it's primary use will be bonding/bedding foam to the hull. Once the adhesive is smoothed and cured, you can glass right over it.
Of course one uses foam to save weight (lighter than wood and easier to cut). In that spirit, corebond is light as well. A piece of cured corebond will float in water.
Monday, August 28, 2006
Modern Art? or...
Experiments with Corebond?
Got a five gallon bucket of Corebond this weekend. This is a special two part adhesive with a putty consistency. It is specially formulated for use with foam. For the Westsail project, it's primary use will be bonding/bedding foam to the hull. Once the adhesive is smoothed and cured, you can glass right over it.
Of course one uses foam to save weight (lighter than wood and easier to cut). In that spirit, corebond is light as well. A piece of cured corebond will float in water.
Sunday, August 27, 2006
Cockpit Drain Replacement
Well, the existing (temporary?) cockpit drains that were installed by the Westsail's previous owners were replaced this weekend. Besides being the wrong type of fittings (plastic mushroom thru-hulls), they were bedded with silicone. I suspect they were temporary, but given what else we found in this boat one can't be sure.
Anyway, they were leaking, so I decided to replace them before the rainy season hits. And, following the rule "do it right, or don't do it at all", I installed permanent drains. The old drains came out quite easily.
Choice of Drain Size
The rule of thumb is to make the cockpit drains as large as possible. If you take a wave and fill the cockpit with water, you want it to drain as fast as possible. With a "center cockpit" we have less of a chance of filling up than with an "aft cockpit". Still, we want to maximize drainage.
Two inch diameter hose for drains would be ideal, but all two inch drains/scuppers I could find were too big for the "wells" molded into the cockpit floor. The largest I could find that would fit were one and a half inch diameter hose size.
Choice of Material
Traditional materials are bronze and stainless steel. Newer modern materials are nylon and marelon. Nylon is pretty much discouraged these days as UV will attack it, turn it brittle and crack over the years. Marelon is a "UV stabilized glass reinforced resin" material. Very light, very strong. It will bond with adhesives better than metals. Marelon can also be used for underwater fittings, though I personally am not comfortable with that (yet, I may be convinced later, bronze vs marelon seems to be a big debate in the boatbuilding community). Above the waterline they are perfectly suitable.
Forespar Marelon Cockpit Drains
We went with Forespar's flush mounted marelon cockpit drains at less than $20 each. The holes were routed with a 45 degree bevel and the drains were bedded with 3M 4200 adhesive/sealant with a backing plate made of Coosa board. The cockpit has three wells on the floor "molded" from the factory, plus there was a "pad", with no hole, in the portside aft corner that looks like it was intended to have a drain. So four drains total were installed. For now, as with the old drains, they all join together and drain through a garden hose out the stern tube. Installing and connecting them to thru-hulls comes later.
Saturday, August 26, 2006
Holey Moses!
Got a shipment of hole saws this week. I found few outlets that sold carbide tipped hole saws. We need carbide to cut the coosa board and glass. Cutting glass will dull a bi-metal saw almost instantly. Anyway, where I could find them, they were 20-30 dollars a piece. Then I found a place that sold 13 piece carbide holesaw kits up to 2 3/4 inches in diameter. They had a "toothed" and "grit" version. We bought one of each. With the Westail being framed with Coosa Board, these carbide hole saws will get plenty of use. We also got a bi-metal hole-saw kit, up to 4 inches in diameter, for wood applications.
All hole-saws, blades, router bits and drill bits that are (to be) used on glass get a mark with a yellow paint marker. This, to keep them separate from those that are used on wood. The wife gets upset when she has to use a "glass" blade on wood.
Tuesday, August 22, 2006
20 Pounds of Fasteners...
20 Pounds of Fasteners...
Originally uploaded by blobbus. Sunday, August 20, 2006
Floor Pads
Floor Pads
Originally uploaded by blobbus. Sunday, August 13, 2006
Got Glass?
Got Glass?
Originally uploaded by blobbus. Friday, August 11, 2006
Shiny New Miter Saw
Shiny New Miter Saw
Originally uploaded by blobbus. Oodles of Foam
Oodles of Foam
Originally uploaded by blobbus.
So we got the special order of Airex foam from Baltek yesterday. Man is this a lot of foam. This is probably all the foam we could ever use for this boat. But, it was the minimum order. So, except for the cost, I wont feel so bad for making mistakes. This is the C70.75 Airex ("the green stuff"), which is high density and will take screws with no problem (though I would not screw any major structural into it). This stuff will be used as a core material, of course. It can be cut and shaped very easily. And resin adheres to it very well. The most likely applications for the Westsail will be: * floor supports, near the side of the hull. Foam will be shaped and glassed over. * Shaping bases for head fixtures. * Engine supports (though I will probably laminate layers of Coosa for that). * Anywhere where we need to smooth out angles for glass (fillets), though I am still waiting on a box of fillet strips from Baltek for the bulkheads.