hi swaylockers.
i post this photo of fcs foam core ,to discuss the way of how the make it .
i cut a new fin to see ,how they put the fiberglass ,and what kind of mould they use ,to produce them.
from the picture can see ,thre is no foiling ,so should be mold ,but the fiber are continous only from on side ,
i think is not rtm ,probably in autoclave ,this discussion is for who make fins by own.
aloha
pat
[img_assist|nid=1051478|title=fin|desc=|link=none|align=left|width=100|height=75]
Hi patricksurf,
I think the fin is made by rtm using heavy metal molds for mass production. The honeycomb pattern is from the core mat being used.
http://www.youtube.com/watch?v=1u-2GvhghQA
Mike
Vacuum assisted rtm could be used also but the resin in both methods has to be set to kick when the mold is full.
hi
wave slider
if you see the photo of the tab ,fcs attach
are full fiberglass and cut in a second time ,so the mold is bigger in that area ,and after the cut ,by hand or cnc .but if the make with rtm ,why dont make all the shape complete finish .
is a mold because the are no finish foiling on the side fin.but
i dont understand how they can fill the normal 4 oz fiberglass with rtm .
any idea ?
patricksurf,
the core material takes the place of the fiberglass layers which makes it possible to make the fins light and strong by using less fiberglass. I took a light rtm course at Cerritos College about two years ago so I can’t really remember a whole lot. Trimming is still required on the finished part after it comes out of the mold. I picked up a set of Aercore fins for Probox fin boxes the bases had to be cut and slotted for the fin boxes. It might be cheaper for fcs to mold the fins with a wide base and cut the tabs into the fin base.
Mike
thanks! really useful pics
i know that is not easy brake a 90$ fin
If I was to build those, I think I would laminate each side of the fin individually without the core, once gelled I would grind the laminate flush with the mold, and then sandwich them together using a piece of coremat to fill the space and lots of extra resin for squeeze out…
other possibiliy could be make a mold with 2sides and compress the sandwichbetween both sides. its close to rtm light
Indeed thanks for the pics!
I would build them like wooddave describes.
