make your own fins

> 10 years ago
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markh
markh
WA
20 posts
WA, 20 posts
15 Feb 2005 6:19pm
Hi all,

If you were interested in making your own fins (not just coz I'm a cheapskate, but ya gotta do something in the morning before the breeze comes in), does anyone know if you can get pieces of fibreglass in approximately the right thickness ready for cutting and sanding?

I'm located in Perth and I'm guessing that I am looking for a company that would have offcuts or something similar.




decrepit
decrepit
WA
12885 posts
WA, 12885 posts
15 Feb 2005 7:01pm
I make all my own, but I lay them up myself.
Doubt that any body would have already layed up offcuts suitable for fins.
You may be able to buy a sheet of epoxy/fiberglass that a lot of professional fins are made from, I think it's called s10. It's made under high pressure, giving excelent fibre to resin content. Not sure about suppliers, fiberglass & resin sales may be able to help, or you could try a google search.
Cheapest way is to lay up your own, you can pre cut the cloth so you don't have to so much sanding.

decrepit
ruffasguts
ruffasguts
WA
15 posts
WA, 15 posts
15 Feb 2005 9:35pm
Hi,
I am also interested in making my own fins.

decrepit, what is ment by "laying them up"

How easy would it be to shape a fin from a sheet of epoxy/fibreglass ?

elmo
elmo
WA
8895 posts
WA, 8895 posts
16 Feb 2005 6:15am
There was a mob in jandakot which sold fibreglass laminated sheet of various thickness's and grades for industrial and boating use.

Sorry can't remember the name of them but if you headed west of the freeway at armadale rd turned right at the lights at shopsjust past overpass. it was in the front row of factories in a light industrial area on your left.

Alby


Plan for tomorrow.
Live for today
markh
markh
WA
20 posts
WA, 20 posts
16 Feb 2005 6:32am
thanks for the advice guys, laying them up yourself is probably the way to go, just wanted to get straight into the sanding.

hoop
hoop
1979 posts
1979 posts
16 Feb 2005 8:03am
You can get G10 which I think is used for circuit boards.Once you have made a fin and find out it's a complete prick of a job, you probably wont mind paying a few bucks for a decent fin .

jim
markh
markh
WA
20 posts
WA, 20 posts
16 Feb 2005 8:06am
Your probably right hoop, but the fun is in the making

lauriew
lauriew
WA
53 posts
WA, 53 posts
16 Feb 2005 11:45am
G10 is likely available from electrical supply houses, we bought a panel about 10yrs ago and then had to glue it together cause it was too thin. The really great thing about g10 is the plies are so regularly spaced that you can use each ply as an indication of thickness for foiling. Just imagine that as you sand through each ply it looks like the ring of a tree. This means that it forms an appearance like contour lines on a map. Without this it can be a real bitch to get a good foil. Oh and don't forget that after managing to get a good foil you have to have a decent profile, good lateral twist and then good torsional twist too and then box em right so they don't stick out, don't fall into the box and don't allow water through. All in all I prefer to buy em but if you reckon its gonna be fun then youre a different man to me. 8" Disc sanders are likely the best tool and I recommedn buying some cheap ****ty fins second hand and refoiling them first to get your eye in. The layup if you wanna do that yourself is around 50-60 plies of 200gsm plain to get sufficient thickness, if you use polyester be wary of exotherming resin due to ply thickness.

Enjoy
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
16 Feb 2005 6:59pm
quote:
Originally posted by ruffasguts


decrepit, what is ment by "laying them up"
How easy would it be to shape a fin from a sheet of epoxy/fibreglass ?



Laying them up is the process of impregnating the cloth with resin.

Shaping depends on your skill with a grinder/sander. If you've never done it before, it's very easy to stuff the whole thing up. There's also the "eco" factor, grinding fibreglass or epoxy is a health hazard.

As laurlew says, having nice flat uniform layers is a great aid to shaping, but you do a lot of grinding!

decrepit
Greenroom
Greenroom
WA
7608 posts
WA, 7608 posts
16 Feb 2005 8:42pm
having second thoughts yet markh

GONE WITH THE WIND
markh
markh
WA
20 posts
WA, 20 posts
17 Feb 2005 8:32am
Not really Greenroom.

The idea is not to make a commercial success but to have a crack at something that is in the realms of possible success.

If you lay up a couple of fins, whether out of g10 or glass etc. and you stuff em up, what have you lost - some time and spare change. If the fins dont work you can just chuck em in the bin.

If the thought took you to try and make a whole board for instance, you could be spending hundreds and ending up with something that doesnt work and also needs a mini skip to dispose of.
choco
choco
SA
4186 posts
SA, 4186 posts
17 Feb 2005 4:20pm
it would be easier to get hold of a good quality fin and make a mold of it,then it's just a matter of laying up the cloth in the two halves and clamping together,this way you will know that your going to get a perfect foil and it allows you to play around with the fibres to get differences in twist etc.
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
17 Feb 2005 8:49pm
quote:
Originally posted by choco

[blue] make a mold of it,then it's just a matter of laying up the cloth in the two halves



Been meaning to try this for a while but haven't got round to it, my idea is to have about 2 layers of cloth on the outside, (to hold the fin together) but the inside just unwoven strands, (rovings) traveling along the fin.
A fin made entirely of woven cloth is wasting most of the fibres, and weave orientation can affect the ratio of flex to twist. Having most of the fibres aligned with fin profile should give more predictable results and be stronger.
Any thoughts anybody????

decrepit
hoop
hoop
1979 posts
1979 posts
18 Feb 2005 7:56am
I used to make fins for Multifin about 100 years ago. The moulded ones were done with unidirectional glass.This stuff was pretty heavy duty gear so you dont need to spend ages putting down heaps of layers. You can lay the fibres to what you think is going to work best for twist or stiffness(Whataever you want the fin to do)This might take a few goes to get it right.You can still put a few layers of light woven cloth in the mould to finish it off nicely.If you put extra layers on once the fin is out of the mould it will change the chord of the fin a fair bit.I still think making fins is a complete prick of a job,Moulded or handshaped.But good luck trying.Let us know how you go.

jim
Shane
Shane
WA
202 posts
WA, 202 posts
20 Feb 2005 9:29pm
I have a fin mould taken off a high aspect ratio slalom fin that I have used to make a number of quite successful fins. Anyone is welcome to use it if they like. It was fun and satisfying for a while but as your expectations for the a perfect product increase and you spend most of a week breathing fumes and itching with fibre, you tend to see bought fins as exceptionally reasonably priced. Anyway, this fin mould is accurate and will do fins up to about 44cm. I also have the back end of a broken board with a tuttle box which I have used to mould 'heads' onto the fins. Let me know if these are any use.

Shane
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