Blank Building Anyone?

Does anyone know about building blanks? What chemicals are used in their production and are they avail. through Fiberglass Supply or some other chemical co.? Just a crazy thought.Thanks,TS

Are you talking about urethane or polystyrene blanks?

Polyurethane, but whatever is easiest and most available really.Thanks,TS

blanks like what Clark make are highly toxic to produce. not worth burning your garage and house down. it’s easier just to get Clark. i think the person who starts producing mass amounts of polystyrene blanks will have the edge. i’d rather work with epoxy so that i may live a few years longer.

The making of urethane foam is very toxic, expensive and difficult to do. It takes a large capital outlay for molds, chemicals, safety gear, etc. Conversely it is quite easy to make a polystyrene blank. You can generally get blocks of foam locally from insulation foam suppliers. The rocker templates are made from 1/8 inch masonite. They are attached to the block with nails and you then slice the foam with a harp, strung with a piece of nicrome wire, that is powered by a variac. A variac is a voltage regulator. For the foam, look in the yellow pages under insulation and look for a supplier of foam. Almost every major city has at least one. For the variac, they are available from Wicks aircraft. They have a nice voltage regulator for hot wiring for about $100. I think they also have wire. They have an online catalogue at www.wicks.com. The harp is just a piece of plywood cut in a U with the wire strung across the open end. It has to be wide enough to fit across the foam your cutting and deep enough to cut the thickness of the blank. Give yourself lots of room on that one. You attach the voltage regulator to each side of your harp (we use alligator clips), turn the regulator up to about 25 volts and your ready to cut. Set the wire on the templates that are attached on either side of the foam block and push the wire slowly through the foam. When you finish the deck, hook the wire under the templates and pull it through the bottom. It helps to have a fan blowing down the block of foam to cool the exposed wire that’s outside the block otherwise that portion of wire super heats and you break a lot of wires. After you’ve cut your blank, set it on a shaping rack bottom up. Get a piece of hot wire long enough to reach the length of the blank and about 2 feet extra. Attach a piece of wood (these are handles) to each end of this wire. Now attach the voltage regulator to each end of the wire. Now you need to find the middle of the blank and mark it on each end. You need a friend to hold one end of the wire while you hold the other. Set the voltage at about 70. Stretch the wire from end to end on the marked center of the bottom of the blank and turn on the variac and slowly pull the wire from the bottom of the blank to the deck. You now have the blank cut for the stringer. You need five bar clamps to glue up with. For a stringer you can use 1/8 or 1/4 inch Luan plywood which is available at Home Depot. This stuff doesn’t shape great but its easy to find and works. You can also use 3 mil PVC which comes in 4x8 sheets and is available from sign supply companies. Comes in colors and looks great. For gluing Luan you can use good old Elmer’s glue. For PVC there is a glue called Roo Glue that works well. You can probably find that on the web. When you glue up, you wet both sides of the stringer and both sides of the blank line up the parts and then bar clamp it together. And that’s about it. Any questions?

Oh yea, after your done making your blank, call 321-223-5276 and order your epoxy and Additive F from Resin Research. You didn’t think you were going to get all this info without an ad, did ya!

Thanksalot Greg! I appreciate your taking the time to explain all that. Clyde Rogers of Edge Performance fins and Hamilton surfboards suggested you as the epoxy guru to get the goods from. What are yoyyr prices like? Are they about the same as system 3 sb112 or whatever that stuff is? Are balsa or basswoods for stringers usually obtained through local specialty wood stores?Thanks,TREV

Our prices are less that Systems 3. Our products for surf and sailboards are much broader and they don’t have Additive F. Additive F makes building surfboards with epoxy MUCH easier. I used to buy stringers through a specialty wood shop. I’d forgotten about that. They would just cut up a piece of 1x6 poplar of spruce.