A newby to swaylock. Lots of good info. Ive searched the archives and cant find what I am looking for. I was wanting to know if anybody has any tips for making sure your fin box is put in straight. I have been putting the fin in the box and eyeing it all the time and it always seems to look straight when installing, but when its finished, I sometimes see that its not. Is there any guides or templates that could be made that will do the job. Any info and pics would be great
You should insert a fin in the box, tape the space between fin and box so as not to have resin flow into the box, then hold the fin in the right position with tape fixed to the rails on one side and the tip of the fin on the other. Look from the nose towards the tail to check if it sounds OK. If the bottom of the board around the fin box is flat, you may use a square against the fin. Unfortunately, many boards have some sort of concave or V in that precise area, making the use of a square quite difficult. If it’s V, you may use what we call a “fausse équerre” (false square? Doc?) which is a square whose angle can be modified then tightened .
mds, Working on surfboards is a little like working on boats: you have to use your eye alot. Besides that, you can get a fin that you know sits straight in the box, and use it exclusively for setting fin boxes. Put the fin in the box and screw it down just like you would if you were going surfing. Set it in place with white colored resin (won’t show through on the deck). Then hold it in place with a long piece of tape: the tape should be about 18" long. Pinch the middle of the tape to the top of the fin, and attach the ends to the rails. Then get back to the nose of the board and eyeball it.
VERY IMPORTANT: Keep the background behind the board as simple as possible: like a blank wall. Slanted objects or lines can throw off your perspective and create optical illusions. Look carefully at the fin, making sure it is a 90 degrees to the bottom surface of the board. Or, if you have V in the tail, equal angles on each side. Then go back to the tail and sight the fin to be sure it is pointing directly at the nose. Adjust if necessary until it all looks right.
Also, if you wear certain types of glasses, like graduated lenses, (I do) they will distort what you are looking at. Take them off so you are seeing what’s really there. Doug
When you’ve got it in and taped upright, check it from both the back and the front about a dozen times, and adjust if necessary.
Then walk away and come back and check it again, all before it gells of course.
With all the bottom contours and shape, the continual visual check will let your eyes tell you it’s relatively straight from all angles.
A good clear background makes a lot of difference in helping you see to get it straight. Use a piece of cardboard with some solid crosshairs, horizontal bottom, vertical fin.
Howzit mds, The new Bahne fin boxes have a pointed tip at each end of the box which you can center on the stringer to make sure it’s centered. They also have a raised lip to keep any resin from getting in to the box when installing.Aloha,Kokua
I always use 2 pieces of wood cut to the width of the finbox. First, they’re flat on top, so they’re easier to tape than a fin. Second, they’re just wood, so if they get stuck in with resin, its easier to drill & chisel them out and I wouldn’t kill a fin in the process. And lastly, you can sight from one to the other & out to the front of the board so make sure everything’s straight. You can even see a twist in the box if your tape is too tight somewhere and fix it in time…
