How to make Wooden Fins
Hey guys ...ive noticed both here and at surfer mag ,crew are always asking about how to make wooden fins,,,so now i got my digi camera im posting the full wooden fin production start to finish.....
there is 30 photos in the series so if you could wait till the whole series of posts is up before replying...much appreciated....
also at the end of it ,,,if anyone has any ideas that may improve the system im always open to suggestions, but so far after building thousands of sets of wooden fins this is the simplest way ive found yet......
im also happy to answer any specific questions on details that may not seem apparent in this series.....
i can always post more pics in the future that highlight a particular stage in the construction....
ill always come back and check this thread for any queries......
ok description time......
1; mark fins on 9mm exterior ply and cutout with jigsaw...
2; clamp fins and clean up outline first, with sander....
3; foil fin using a medium soft pad , that way it comes out smoothe and blended avoiding the need for hand sanding...
4; one side fin done,straight off the machine...
5; using a mould release agent , apply to a piece of lamiex /formica or something hard and shiny....
6; lay out your centre fins in a row , keeping them close enough for the glass to bridge ,but far enough away so you can cut them out later...
putting resin in the fabric for the centre fins....
7;pull up the 2 layers of 6oz combined with surfboard lam resin....
8; carefully lay the glass over the centre fins , making sure you dont let the glass touch the table , keeping the glass just above the centre on the leading edge (allowing for roving reinforcement later)..
9; using the rest of the resin in your tub ,spread a thin layer of res over the table and place all your side fins flat side down in pairs, keeping a comfortable distance between them at the base so you can run you saw through later.....
10; view of glass on centre fins and side fins stuck to table....
11; cut your self the required length of rovings for the leading edges of the side fins (ten strands each) plus your glass for laying over....
12; dip your entire length of rovings into a tub of general purpose polyester resin(its thinner ,soaks up better and has way longer working time)....
13;cut wet rovings to length and place against leading edge of side fins(fins dont move coz there stuck to the table)...
14; lay your 2 layers of 6oz loosely over the top....
15; using your brush , press the the glass against the table between the fins (make sure you start in the middle of your row)coz the resin you used to stick your side fins down is tacky the glass will stick and you can get a tight stretched glass job over your fins, each time you press the glass between the fins it slides across the top of the fins you havent done yet(so make sure you cut your glass a little longer....
16;work out the bubbles with your finger and brush and smoothe glass till your satisfied...
17; hotcoat and go to lunch...
18; a few hours later peel everything off the table....
19;clamp the sheet of fins to a work bench and sand the flat side , also taking the opportunity to make any needed adjustments to the foil or the shape on the flat side....
20; your centre fins can be turned over , lay rovings in the leading edge (7 strands) in the same manner as the side fins, glass and work out bubbles....
21; lay 2 layers of 6oz down and laminate with standard surfboard resin ,glassing the flat side is fast and easy (no need for longer pot life resin) also you can get away with doing the centre fins with standard lam as well (coz its quicker ,and not as contoured , quicker and easier to work out bubbles.....
22; hot coat and go for a surf, when you get back you can pick up your sheet of fins and take a picture of them....
23; clamp your finished sheet back to your work bench, you need to sand your fins in odd spots later on anyway , so rather than sand each fin by itself sand each fin while its still in sheet form (makes it way easier to handle and is heaps faster)....
24; clean up all the bases of your centre fins and sand flats while still in sheet form....
25; using a glass cutting blade in your jigsaw, cut your fins out of your sheet(make sure you leave enough excess so you get a nice shape....
26; carefully pair your side fins, clamp and refoil(they stick together well coz youve already sanded them,if you dont sand the flat side they slide around on each other and its hard to get both fins even)....
27; board , with fins ready for glassing on....
28; finished glass ons in a 7 year old trade in (couldnt be bothered fishing a new board out the shop)....
29; some finished box fins(some things remain a secret)....
30; go test your fins and see if you can improve on them ,find out how areodynamically tuned that are...(woops hydrodynamically i mean).....
ok crew , hope you enjoy.....
regards
BERT