How to build this fin:
I love classic D fins on my longboards. Couldn't find any from suppliers so I dug around and found a really cool post on Swaylocks by Austin Surfboards. So the techniques are not all mine but a combination of copycat stuff from Austin and trial and error on my part. Enjoy!
Monday, April 2, 2012
Outline cut out, those are not smudges they are dust particles on the lens of my camera.
Yes it's fat! Adjusting the thickness and the foil with planer.
Rails/Foil/Concave Nose pretty close to where I want them to be.
Sorry that I don't have a bunch of shaping photos but I'm a one man operation. I may use the GoPro camera for the next project. Gonna walk away for a day or two and then look at it again to decide if this is the final shape. Next Step is to seal the EPS with spackle before glassing. This is a step I normally would skip but this foam has very large beads and definitely needs it.
Started a new project yesterday. This board is for an inland surfer friend. WakeSurf to be exact!
So these first 2 photos just show the main ingredients; 1lb EPS blank halves and a luan stringer. For those of you are are unfamiliar EPS is Expanded Polystyrene (styrofoam) the 1 lb measurement is a way to explain the density of the material (it takes 1 lb of raw material; polystyrene pellets, to make one cubic foot of "expanded" material so 2 lb EPS would be more dense and would weigh more. This particular blank was obtained from Greenlight Surf Supply.
In this photo you can see the nose rocker a bit better. This blank is 6'2", I want my finished board to be 6' so why a 6'2" blank? Well I don't want all that standard nose rocker for this blank so I will pull my template toward the rear of the blank to reduce the nose rocker.
So as I was getting ready to glue this baby up I thought I would go ahead and decide on a template. This way I could work on the template while the blank glue was setting up.
So this is an existing spin template that I use to shape long boards up to 10' 2", I used some pinstripe tape so the outline would show up better in the photos. This looks good for the front of the board.
This is a pretty standard shortboard "Thruster" spin template. It picks up the back half of the board.
So this is the new spin template created to make this board I added some length to it so I can use it for future boards up to 6' 6"
Ok Now back to the blank:
Tape up the edges for the stringer, I'm using Gorilla Glue and it makes a mess. The tape will keep the glue from staining the white foam when it foams up. It will not just pull off, it will require that I grind off the hardened foam from the glue. The tape will give me a buffer or guide if you will. The second I see the tape start to deform I'll know to back off.
Spread on the glue with a 2" brush with the brstles cut down to 1 inch. Stack up the three elements as you go. I let it sit for a couple of minutes then layed it onto the table. Note the table has a sheet of wax paper running down the center of the table.
Clamp it up, I could have left it standing on it's side and weighted it down with bricks or something but then what would I do with all my clamps?
So after grinding off the hardened foam from the glue, removing the tape etc. You now see the blank on my shaping stands and the outline of the template for the shape being cut out. Let me explain what's going on here. I use a router with a very long straight cut bit to cut out the outline. The smooth part of the top 1/8" of the shaft rides along the template. I use a full size router with a variable speed control. I dial it way down to the lowest setting possible to where it just cuts the foam clean. THIS IS VERY IMPORTANT! Do not try this with a skinny little router bit or with high RPM! One little bump on the bit to knock it out of perfect balance at high speed will cause it to warp and break in a split second, thus becoming a bullet! If you are thinking about doing it this way I would recommend most people not try it. I have many years of experience with this tool from my wood working days. Plus using a handsaw is just as good and makes you more versatile. I still cut many shapes with a handsaw and the ends get cut off with a handsaw.
Wednesday, February 8, 2012
The Fin Outline shape is done. Still needs the leading and trailing edge to be foiled but it has been sanded smooth with 80 grit sandpaper and is ready to be laminated to the board (if I put it on the board) still haven't decided.
The next few pics are of the board after laminating with 4 oz cloth. Before I laminated I did a sealer coat with thinned out laminating resin. No Styrene just acetone to thin it out. Wanted to make sure I got good adhesion to the wood. The lam came out nice and tight. Hot coat next!