i have finally made the descision to make my own wooden fins i just thought i would rais the question would MDF be a good choice of wood as it would be pretty stiff. if you think this is a good or bad idea could you pleaes leave a coment

Ply wood works best, it’s cheap, the right thickness, easily availible (erina bunnings) and easy to use.


Besides, MDF is very water sensitive: it will fill with water with the first ding. It’s also quite heavy. Plywood is also easier to foil , following plys.

I’ve used MDF in 2 boards because it is super easy to foil This wood is ideal for templates, and you can use it in your boards but with a ding at the stringer you’re f*cked!

Plywood is what we call triplex. MDF is much easier to foil, plywood splinters of!!! But plywood is not water sensitive and much stronger.

MDF is Ideal to use as guides for wirecutting (if you use PS) and as outline template But as stringer you better use plywood.

*edit: Ow I haven’t read it good. You don’t wanne make a stringer, you wanne make a fin :). Take plywood, it’s like silly says, with plywood you can see the profile much better!

Why would you want to use MDF? It has no grain or character, as the others suggest go with ply or better still several different types of real wood.

Jase MMM

Hey, plywood IS REAL WOOD. MDF is wood powder mixed with some resin.

mate you can use basically anything for a fin core

how about bake a bread one

no seriously

plywood is great because it has layers

so you can clearly see the contours of your foil

the more layers the better the contours

the better your foil

dont think how easy it is to shape the materials

but how easy it to see the contours and create and accurate foil.

i use 8 ply thats 6mm …its top qaulity for airplane modellors

i double up to 12mm with some carbon fibre uni in the middle

so i can do a full foil that has a thin tip and is still stiff at the tips

this makes for a lightweight incredibly stiff fin

that looks sexy cuz of the contours

also if you chip it or ding it you dont have to worry about it sucking water

“MDF” stands for “multiple density fiberboard”. As the other posters wrote, it is a wood composite material that is heavy, relatively weak, and very sensitive to water, which will cause the embedded wood pieces to expand and rupture the glue joints. Think particleboard. Are you sure you weren’t thinking of “MDO”, which is “medium density overlay”, a special plywood with a smooth paper or plastic overlay used primarily for outdoor signs? While MDO is nice stuff (glue roughly equivalent to marine plywood), you pay extra for the overlay process, and that would be the first layer to go when foiling a fin.


Hey Balsa, howsit?

No disrespect meant, some of my best friends are ply-wood.

Jase MMM

I didn’t feel offended in any way, my friend. Just wanted to point out that plywood actually is sheets of REAL wood glued together whereas MDF is a by-product made from saw-dust.

MDF… I thought it meant “Medium density Fiber…Board” as oppposed to low density and High density… Never seen HDF nor LDF only heard that they might exsit. MDF however is the allpurpose common board in the wood/furniture (ikea etc) industry. The more common variety is the medium brown colour (oddly enough the same colour as the normal cardboard box… what a coincidence …or is it?) I’ve seen red, blue, green and Blck MDF boards as well…

The process as I understand it, is use up the by products of wood (saw dust) add some form of glue and press it in a mold. and bingo one has MDF…

as mentioned MDF is is easy to machine, route, foil what not as its homogenous in its structure ie… no grains to look out for. WE use it to make the normal el cheapo furniture that looks like the real thing but has only a thin layer of some veneer on surface. BUT also we commonly use MDF for templates and tool making (jigs and such) great for that stuff… and pretty easy to machine… BUT its not real wood (well …in a way it still is- But I says it aint! so there.) and It is very “allergic to moisture” ie. it gets some moisture it swell and is kakapoopoo in general. Also the strength of MDF is not nearly as strong as say similar thickness plywood (I’m going out on a limb here I have no de facto scientific proof other than what I’ve tried out… ). So imho… I’d say per pound (or kilogram) Plywood has a better weight/strength ratio and can be soaked everyso often.

oh well thats it for now… I’m out.

Jouhou, I agree with you: I always heard that MDF meant “Medium Density Fiber board”. And also agree it makes good templates. But that’s about all.

You are absolutely correct. My fingers got ahead of my brain. That’s really sad, because I am such a slow typist ;-> Medium Density Fiberboard it is. And while I have never run across LDF (although I’d take slim odds that it is what is actually sold as particleboard), I have seen HDF, which seems to be a specialty product.



i have finally made the descision to make my own wooden fins i just thought i would rais the question would MDF be a good choice of wood as it would be pretty stiff. if you think this is a good or bad idea could you pleaes leave a coment

MDF… good for templates

MDF… bad with water

Go with ply - you’ll get a much nicer effect. Apart from the issues you’ll face if it gets into any contact with water, the MDF I’ve seen around here is very dull and boring.

yeah dude my friend and I spent like a week resurfacing his half pipe, coutersinking screws and everything…

day after we finish it rains and ruins it, we didn’t have the cover over it because it hadn’t rained in like three months and wasn’t supposed to for a while.

but it’s very dihydrogen monoxideaphobic

Now if only we could get rexy to let us in the woodwork rooms at lunch…

yeah but i dont that is goin to happen mate i think we might just have to do it at my place