I have 2 old preshaped surf blanks with a default at the end of the rail (see photo). It seems the machine did a weird thing. Anyways, I was thinking of increasing the diamond tail in order to remove this default. What do you think? Do you have any others advices?
You can always scarf on a piece to get the tail shape you wanted. Provided it is that critical to you. Run stringers up two to three times the length of add on and sandwich the center stringer. Good glue surface possibility there. Perhaps a trash can tail with multi fin availability.
I took out 2" of tail length to make up for a similar FU where I cut the tail too thin. I thought that a bit of lowered tail rocker and rocker low point moved backward wouldn’t make such a difference. The board ended up looking OK, paddling like a pig and being the slowest one I’ve ever built.
“It’s only ignorant not to ask”. Hello Mr Monk, a “trash can lid” tail is a long radius rounded tail used to some extent by Greg Liddle and other Hull makers. It adds a lot of surface area to the tail for picking up the wave early. As you probably surmise, it is hard to turn or pivot on. For middle of the board riders and using the rail to turn. Never amounted to much but it does have some fans.
Always funny with the quotes Huck. Onya. Classic stuff. Classic movie.
I took out 2" of tail length to make up for a similar FU where I cut the tail too thin. I thought that a bit of lowered tail rocker and rocker low point moved backward wouldn’t make such a difference. The board ended up looking OK, paddling like a pig and being the slowest one I’ve ever built.
I think the group would need to see your intended design and some better photographs of the pre-shapes before saying if the two can be sucessfully ‘married’ so to speak.
Your design: dimensions, plan and profile view, ideas for rails and bottom
Your pre-shapes: dimensions, top view, side view, angled view of bottom.
I’m guessing that the tail slice in the original design had some shoulder and that got propogated up to the next slice when cutting path was generated.
The operator just set the specs high at the tail for “miss stringer” or “do not cut end off stringer”. The cut looks otherwise faithful to the design.
Just cut off the extra stringer and foam and you should have what you wanted. You may need to fill the rails a bit.
Thanks for your advices. I was also thinking of filling a lil the rail with microfiber after sanding the foam. Increasing the diamond is not a good idea?
Uh… The rails and tail and nose, deck and botom were not finished with a CNC cut blank as your pics show. All the hard parts have been done by a machine and now you get to touch the board with abravsive material and sort things out. Kind of makes one appreciate from scratch hand shapers. less than 15 minute ready to glass finish. Are you actually stuck on 1.5"length difference??? Glass board then wood tail block and glass patch wood tail or hid the foam repair with fancy fiberglass if the 1.5" will make or break the CNC cut shape. Even a girl can do it.
I was thinking about this solution like on the link you forwarded me, finishing the end of the like some twin fin. Finally I decided to increase the diamond tail.