Hello!
I have ordered a few surfboards that I have shaped my self through programs. A factory produces the boards that perform great.
However the fin boxes keep cracking. The box it self is not cracked but the glass on top!
Does anyone know why this keeps happening?
I have other boards professionally made that I can’t tell the difference. This one isn’t placed more shallow and it still cracks?
Greatful for any tips! Best regards!
Too much resin and not enough cloth around the box would be my guess.
Looks like a crack in the flange to me.
Is there a finpatch? One reputable fin maker told me that the reason for most fin system failures is due to the surrounding foam not providing enough support to prevent the box from flexing or rotating under torque loads.
Step away from the computer.
do all the work with your own hands. and then you will know…
Ray, thats Gold advice.
Maybe you shouldn’t run into rocks?.. Or better yet, tell the sander to take it easy on sanding the boxes down. Heat expands the plastic and makes them crack…but if you made the board start to finish, you’d know that…oh snap!!!
There are stress risers at the point of any change in elastic modulus. So, at the end of a plastic fin box, at each corner, there is one. As mentioned above, the only thing needed is probably more glass to stiffen the area and decrease the acute change in modulus.
