Dan's Alu fin 2015. Fin base material is HPR5 resin. Great stuff, rubber toughened, never cracks, no fabric reinforcement necessary. About the consistency of honey so it has to be heated to mix and pour which creates its only problem, lots of shrinkage.
In 61 was I soldier and I learned to play guitar. What shall we do with the drunken sailor i a moll. In 68 I heard the first time something
over WINDSURFING in Düsseldorf. And that was and that is my life. Wolfgang
Is there anyone out there who has a pinch of Cad skills? I have my fangyfin saved as a .stl file. I have found a company that is interested in casting in pure SiC or titanium. However they want 2D drawings of the fin with the dimensions. The fin was created in Onshape by a third party ( who is away on hols for a while) but I haven't figured out how to produce some scale 2d drawings with dimensions and export them as a pdf. If anyone can give me a hint or help, I would really appreciate it 
( you can pm me if you prefer)
You could try bugs, he's getting good with his sail making cad now, but whether he can convert to a PDF is another matter.
Can't wait to see how the casting works out whichever material it's done in, (maybe both so you can compare them)
A quick update on progress. To get the MkII cast in titanium $2400 and that's in China! To cast it in SiC was much cheaper, but minimum radius was 3mm which makes for a chunky trailing edge. To hard chrome the Aluminium - possible but no one wants to do as it contaminates the baths. I am still looking at some aluminium matrix composite alloys, but it is likely the cost is going to be too much. So , Aus808 had the best solution so far, aging and alloy grade ( possibly with anodizing as well - thanks Elmo) Regardless, the MkII will be cast next week as per the Mk I, and I am getting a couple made so one can be re boxed as a Tuttle for everyone to have a test crash with.
Select to expand quotemr love said..
CNC in Alum stupidly expensive??
Locally, unfortunately, yes. Not so much the CNC, but the set up costs were into the thousands. If you were mass producing you could amortise the set up costs and more likely you would go to China to do that anyway. 
Select to expand quotesailquik said..
I will be over there to do my best crash test dummy imitation in November!
excellent news Daffy! Are you planning on going for a sail too?
Select to expand quotepepe47 said..
What size did the fin end up Fangy?
The Mk1 is 21 and a bit wobbly given my expertise with metalwork and polishing. The MkII is 24cm and approx the same surface area.
Select to expand quotesailquik said...
I will be over there to do my best crash test dummy imitation in November!
Should I pack a few extra cameras
Select to expand quotekato said..
sailquik said...
I will be over there to do my best crash test dummy imitation in November!
Should I pack a few extra cameras
I set a high bar when it comes to stupidity, you may want to just pack your crochet needles and just watch:
Now I see why you wanted one out of Silicon Carbide, I'm not sure ali is going to cope with that sort of treatment.
been exchanging a few emails with Te Hau and convinced glazing is the go, after molding the fin he has two steel plates clamped onto the mold and into a hot box and baked until its as hard as a coffee mug, the advantage is if you wear the leading edge down you build it back up with a toughened resin and stick it back in the mold and bake it 
Select to expand quotekeef said..
been exchanging a few emails with Te Hau and convinced glazing is the go, after molding the fin he has two steel plates clamped onto the mold and into a hot box and baked until its as hard as a coffee mug, the advantage is if you wear the leading edge down you build it back up with a toughened resin and stick it back in the mold and bake it
shame about the Bunnings barrel nuts 
Select to expand quotekeef said..
been exchanging a few emails with Te Hau and convinced glazing is the go, after molding the fin he has two steel plates clamped onto the mold and into a hot box and baked until its as hard as a coffee mug, the advantage is if you wear the leading edge down you build it back up with a toughened resin and stick it back in the mold and bake it
nice keef! I am interested by the glaze idea - what is it made of and how well does it stick? I am thinking along the lines of a vitreous enamel coating applied to the aluminium might be comparable. Being made of glass frit it will be fine for hardness, so as long as the fin is not flexing and cracking the 'glass' it could have potential.
Select to expand quotefangman said..keef said..
been exchanging a few emails with Te Hau and convinced glazing is the go, after molding the fin he has two steel plates clamped onto the mold and into a hot box and baked until its as hard as a coffee mug, the advantage is if you wear the leading edge down you build it back up with a toughened resin and stick it back in the mold and bake it
nice keef! I am interested by the glaze idea - what is it made of and how well does it stick? I am thinking along the lines of a vitreous enamel coating applied to the aluminium might be comparable. Being made of glass frit it will be fine for hardness, so as long as the fin is not flexing and cracking the 'glass' it could have potential.
fangy send Te Hau a message he is very obliging and on the money with this stuff, he uses a nuplex epoxy 404 resin and it has a consistency of margarine(similar to araldite ) but will thin out with heat' the down fall is it's very toxic and when heated and very fumy' as for me I cant use it as I'm getting sensitized to the fumes of most of the fgi products , but if you heat the fin and put the resin on with a spatula it will thin and you can use a disposable brush
after its cured you can stick the fin in an oven at around 70deg
I used some exposed basalt fiber on the leading edge of the mxr copy (just to see how the basalt would sand ) and the glazing on the rest of the fin, after baking at 70deg the leading edge was easy to sand but the glazing was hard to sand with anything over 400 wet and dry
the 404 is an epoxy so it has flex and probably have a better chip resistance than g10 even before it has been baked
daffy Bunnings barrel nuts are about $1 each , I wouldn't trust them unless you used some sort of nylon washer underneath , standard brass nuts are $6 each so maybe one of each would be a good combo
I use to cook off my fins in the oven. Just normal resin/carbon etc . Then on one job I left it too long and too hot. Man what a bitch to sand, almost impossible. The surface seemed like glass. So maybe it is just the temperature that does it.
This made interesting reading
www.masterbond.com/q-and-a/how-properly-cure-epoxy-aerospace-industry
Especially the bit about some companies claiming that their epoxy cure fully at room temperature ( e.g. West Systems).
Gavins just presented me with this.
He's machined the rebate and bent a piece of Basils 20mm X 10mm bar, ready for me to shape the leading edge and fit to an endgrain palm blank, for a 21cm 50deg weedy.
This is a far superior job than I can do with a right angle grinder!!!!
Select to expand quotedecrepit said..
Gavins just presented me with this.
He's machined the rebate and bent a piece of Basils 20mm X 10mm bar, ready for me to shape the leading edge and fit to an endgrain palm blank, for a 21cm 50deg weedy.
This is a far superior job than I can do with a right angle grinder!!!!
any chance of some pics on the build mike ,
Select to expand quotekeef said..
>>>
any chance of some pics on the build mike ,
No worries mate, but it won't be straight away, Basil has got to slice up some more palm, and my shoulder probably needs to heal a tad more.
Select to expand quoteLessacher said..
A speedfin is not fast when she is worked in front over the box. Wolfgang
Because of the steep rake the centre of effort of the fin is a long way back, so if we move the fin back over the box, wont that have a deleterious effect on handling?
is Wolfgang talking about speed fins 
the forward boxed 50deg fins the tip of the fin is in the center of effort
