I have this real sick, old Zodiac twin fin that I would like to replicate as close as possible. I’m wondering how can I get the rocker from it and shape in into a blank? This is my first board BTW but I’m perfectly willing to take as much time as needed.
Make a rocker template from a long piece of cardboard.
It’s tough to describe the procedure in easy terms, so bear with me. First, hold the cardboard edge-on against and along the stringer like a long keel. Lay a pencil flat on the board, perpedicular to the stringer, and drag the pencil down the length of the board scribing a line on the cardboard. The area between the pencil line and the edge of the cardboard that was against the board, you cut off. Do this several times and it will come right down to a rocker template that will fit snug against the bottom of the board you’re templating.
As a step to make this a little faster, on the first pass put the pencil on a block of some sort, so it’s about an inch off the board surface.
This should give the process… now if you want a more durable template, use a more durable material or double the cardboard and glue it together; if you have packing box plywood (1/8 inch thick) it will make a very useful template once you’ve sanded the edge smooth.
Oh damn. Thanks that helps alot hah, that’s simple, I was fearing it would be super complicated. So I guess you just take a little off of the blank at a time till it fits the form of the template? Also I’ve been reading about bending the blank or something so you wouldn’t have to carve away as much? It’s a real thick board so it doesn’t matter much, but just for future reference.
The bendning rocker talk is refering to making your own blanks from EPS
(exspaded polystyrene) which can be bought from Lowes/HomeDepot.
Or you can Hot Wire the rocker in from a larger block.
If you are going witht he more traditional way, Clark or Walked blank, then
check the blank catalog to find a blank that is close to the right rocker you
are after. If using the Clark blank you want to minimize how much foam
you remove from the deck/top as the higher density foam is near the surface
and as you dig in the foam gets softer. So in short remove your material
from the bottom with standard Clark style blank.
If you glue in your rocker you can use you current board to form the rocker
of the EPS while gluing it up.
good luck
What is it to “hot wire” rocker? and what do you mean by glueing in the rocker? How could i use the board to do that?
hot wire: image starting with a large block of foam in stead of a foam blank that looks like a surfboard already (which is what you
have if you use a Clark style blank). No imagine heating a wire up by running current through it and putting a load (resistance) on
on the circuit so that wire heats up and becomes a “hot wire”. No with this hot wire you can cut the top and bottom side view profile
out of the block (like a hot knife through butter). This leaves you with a rocker curvered rectangular cube of foam which you can now
template and foil into a shaped blank.
glue up: now image thinner sheets of foam. glue them together while being held in the curve of your desired rocker and you have
something very similar to the result of hot wire cutting your blank.
search on “EPS” and “hot wire” and you’ll find some pictures of both approaches. recently headhigh and others have pictures of
glueing in the rocker. There are several pictures of different hot wire setups in the archives.
easiest is to start with clark blank that is already the rough size and shape/style that you are after (fun,fish,short board,long board).