I've decided the time has come to start to think about building my own fins.

Any hand shaping tricks and tips before i give it a go. probably going to need to buy a sander/polisher or could i get away with an orbital sander?

Sanding polisher with hard pad for shaping fins. You can use a router to start accurate reducing thikness. Drawing multiples guide lines is the key.
I build some daggerboard (simple straight lines) and foil mast, i shape them by half, so one flat side as r?f?rence, profile on other side.

I've always used right angle grinders. I have a vice set up to hold fins horizontally instead of vertice. Use sheets, with profiles of vary lengths and a profile gauge to check shape. The trick with a grinder is to use smooth continues sweeps along the contours, don't try going across. I then hand sand with 80 grit across the contours to get rid of any ridges.

I'm now using end grain palm for the interior it's very light and has great compression qualities. Then several layers of carbon over the top.

Fine paper with high speed way better than rough and going thru grades. I use 100 then 240 on the machine and it can be clear coated (spray) with almost no hand finish required
But wet sand 240 and 360 after machine to be safe.

Rubber pad about 10mm thick a bit more dense than a deck pad or yoga mat would be
Hard pad will gouge an edge too easily and give you half moons. Or flat the apex of draft too much.
Soft pad will catch the edge of the fin and throw it at you.
In the middle is nice and u will find it :)

Ozito variable speed sander polisher is top stuff as its cheap and runs well and truly fast enough but you will use it for boards too maybe

Section templates cut from card.
Or one of these threedesign.store/ make it long enough it can do your board blanks too.

I've always use a coarse steel file

Thanks for the tips,

might try all the methods. Looking at a sander polisher but have an angle grinder already and all the guys I know that have a lifetime of making fins use an angle grinder. How hard can it be prob need coveralls.

The coarse steel file I hadn't thought of. Seems like a very accurate way to go.
was going to cut section templates. I've modelled a couple of fins. Would be interested in a home cnc machine. Any suggestions for an a3 bed?

Look at the blue carve cnc

I have some experience with DIY CNC.
You will be disappointed with the flexy stuff like the blue carve or similar, unless you are only doing soft materials.
It makes much more sense to go for a minimum of the printNC rigidity. The printnc is good because the community will hold your hand through it. It is certainly not the ultimate, but it doesn't cost the earth and it is reasonably rigid for a first go at making a CNC.
It's not hard, anyone who can do an ok job of building a board will make a good job of it

Gestalt my experience is with aluminium, so this may not be applicable, but FWIW: On my finer grades I use air driven tools, predominately a flat pad random orbit and to a lessor extent, an air driven 'angle grinder'. If you have a decent compressor already, it's an option worth looking at as the tools are not expensive. The upside is you can do everything under the cover of water so no dust in the lungs, eyes or on the shed walls etc. and much better fine control as you can dial in the speed you want. Downside is realistically you have to work outside where the water has somewhere to drain. Your compressor can't be a pissweak Bunnings bit of kit unless you join a couple of them together and that's probably where the cost really lies. I do all my coarse grunt work on a kick arse 100mm wide linisher. Fab bit of kit, but scary powerful and will easily reduce ally or fingertips in a jiffy. For G10 and composites I would think a fine 'scotchbrite' belt might be as aggressive as you need to go and I am guessing for the casual fin maker it's probs overkill.

^^ That's a good point re the linisher - the cheapo vertical belt sander table at the big green shed would be a handy addition if making a few

I've often wondered if 3D printing can produce anything really strong. If so fins might be a suitable subject.

Wal, have a look at what Flex is doing. Think it's on the fangy fins thread.
But so far, he's only doing Fangy style low aspect fins. 3D printing works very well there, just a small amount of tip flex.
I'm very impressed with the wear properties, just as good as Fangy's aluminium ones in the ultimat wear test, Liptons very abrasive weed. That tears G10 apart, doesn't touch the printed ones.

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decrepit said..
Wal, have a look at what Flex is doing. Think it's on the fangy fins thread.
But so far, he's only doing Fangy style low aspect fins. 3D printing works very well there, just a small amount of tip flex.
I'm very impressed with the wear properties, just as good as Fangy's aluminium ones in the ultimat wear test, Liptons very abrasive weed. That tears G10 apart, doesn't touch the printed ones.

www.seabreeze.com.au/forums/Windsurfing/Gps/FangyFin-DIY-help--hints-and-show-us-ya-fin-page?page=23

The 3D stuff is pg 23 - but it's still relatively early days for Flex and me as to how much carbon we need/want. Upside - you can let your imagination run riot for not much $. Downside - tip wear is poor if you introduce it to Mother Earth. Also, reshaping is a little trickier than expected. I use a thin sealant epoxy layer over the 3Dprint. The print is soft in comparison to the epoxy, so when sanding you have to be super careful not to 'dig in' and divot the profile. As per Kato, the coarse steel file is good here too. (Apologies for the mini post hijack)

My tip, buy a good mask.

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fangman said..

www.seabreeze.com.au/forums/Windsurfing/Gps/FangyFin-DIY-help--hints-and-show-us-ya-fin-page?page=23

The 3D stuff is pg 23 -

Thanks for that link.
Great stuff.

I had to google what a linisher is. Now that's the tool I'm missing!! I've got some fins I need to tweak the bases on and am hoping to turn a us base fin into futures bases.

found this vid - ?si=6ektAGgCX08pzEYl

Cheers Martin,

great link fang man, those fins look like pieces of art.