Contact   Imprint   Advertising   Guidelines

Making a homemade foil reinforcement plate for shinnster

Forum for hydrofoil builders.


Bletti
Frequent Poster
Posts: 318
Joined: Thu Feb 26, 2015 9:13 am
Kiting since: 2000
Gear: Slingshot Rally 10m
Brand Affiliation: None

Making a homemade foil reinforcement plate for shinnster

Postby Bletti » Sat Dec 17, 2016 12:26 am

Hello,

I'm buying a zeeko spitfire and want to mount it on my old shinnster. The shinnster has a fair bit of flex and I'd like to stiffen it up with a removable plate, similar to the new shinnster plate (110cmx20cmx1cm). However, I'm unsure on which material i should use for the core of the reinforcement to give the best compromise in stiffness per dollar and kg. Originally it was suggested to me to use g10 wrapped in carbon and vacuum bagged, but I'm wondering whether I can get away with cedar or another type of wood or something else to use wrapped in carbon. I don't mind if I need to make the reinforcement plate a little thicker if I use wood instead of g10. What materials would you guys use and how thick would you build it? Thanks

Image

BWD
Very Frequent Poster
Posts: 3140
Joined: Thu Jun 05, 2003 3:37 am

Re: Making a homemade foil reinforcement plate for shinnster

Postby BWD » Sat Dec 17, 2016 2:28 am

9mm baltic or russian birch plywood has similar strength properties to g10 and costs very little in comparison, comes in 5'x5' sheets for maybe $20 or so.
Coat it with epoxy and try it, if not stiff enough, apply a couple of 2" carbon uni tapes both sides.
or just lam the whole thing in 5-6 oz carbon cloth if you want to be cool looking...

tmcfarla
Frequent Poster
Posts: 242
Joined: Sun Apr 16, 2006 6:35 am

Re: Making a homemade foil reinforcement plate for shinnster

Postby tmcfarla » Sat Dec 17, 2016 4:23 am

I did this for my Shinnster. I used 6 layers of carbon fiber with 3mm plywood in the middle. If I were doing it again, I'd skip the plywood and use just the carbon fiber.

I laid everything up on the board(covered in wax paper), weighted it down and let it dry. Once done, I drilled 4 holes for the foil, through carbon plate and board, then two holes at the very front of the carbon plate and one more in the middle (7 holes total). I added threaded inserts to board, but bolt-through would work fine to. When you are drilling the holes, put a bolt through after each hole, or the holes in the board and plate won't be perfectly aligned.

All in all, mine works well. It is plenty stiff and there is enough floatation that the contraption won't sink. I used cheap plywood and it is beginning to rot through, but it still rides well.

i wanted to keep the curvature of the board, otherwise the other suggestion of thick plywood would probably be fine too.

Bletti
Frequent Poster
Posts: 318
Joined: Thu Feb 26, 2015 9:13 am
Kiting since: 2000
Gear: Slingshot Rally 10m
Brand Affiliation: None

Re: Making a homemade foil reinforcement plate for shinnster

Postby Bletti » Fri Dec 23, 2016 1:58 am

Thanks for the advice! I was thinking of using 6mm marine plywood with t nut inserts in the plate for front straps and around the plate edges. I wonder if I should go for a thinner plywood to get a better rocker match? Also what foil do you use on your shinnster Tmcfaria? How far from the tail did you mount it?

BWD
Very Frequent Poster
Posts: 3140
Joined: Thu Jun 05, 2003 3:37 am

Re: Making a homemade foil reinforcement plate for shinnster

Postby BWD » Fri Dec 23, 2016 6:40 pm

Forgot to mention earlier to match rocker, you can use 3 layers of 3mm birch ply, glued together with epoxy. Also if using wood, over drill size of insert or bolt holes and pot in with epoxy...

User avatar
Bille
Very Frequent Poster
Posts: 3139
Joined: Sun Sep 04, 2011 5:37 pm
Kiting since: 2003
Local Beach: Lake Mohave
Gear: Ozone Edge
Brand Affiliation: Barz Optics
Jaybar Dynabar V7

Re: Making a homemade foil reinforcement plate for shinnster

Postby Bille » Sat Dec 24, 2016 3:23 pm

*
Last edited by Bille on Sun Dec 25, 2016 6:28 am, edited 1 time in total.

tmcfarla
Frequent Poster
Posts: 242
Joined: Sun Apr 16, 2006 6:35 am

Re: Making a homemade foil reinforcement plate for shinnster

Postby tmcfarla » Sat Dec 24, 2016 9:38 pm

Bletti wrote:Thanks for the advice! I was thinking of using 6mm marine plywood with t nut inserts in the plate for front straps and around the plate edges. I wonder if I should go for a thinner plywood to get a better rocker match? Also what foil do you use on your shinnster Tmcfaria? How far from the tail did you mount it?
I have a zeeko black and white, should be about the same weight as spitfire. My plate lines up with about the fins. I'm on vacation now, but can send a picture in a couple weeks. Carbon was really easy to do, and it keeps the curvature of the board, which I like. The general idea I used was that plate should overlap front and back feet, 4 bolts where foil goes, and a couple extra bolts for the rest of the plate.

On zeeko b/w, my back foot is over mast attachment, this may not be true with spitfire, so you may need to do something like two bolts in front, 4 for plate, and 2 at back of plate. Where the foil mounts (relative to back of the board) is far more critical than where the front and back of the plate is.

Bletti
Frequent Poster
Posts: 318
Joined: Thu Feb 26, 2015 9:13 am
Kiting since: 2000
Gear: Slingshot Rally 10m
Brand Affiliation: None

Re: Making a homemade foil reinforcement plate for shinnster

Postby Bletti » Wed Dec 28, 2016 3:49 pm

Thanks for the advice everyone! Just waiting for the carbon to dry :D

I'll post more details later.
Attachments
20161228_130240.jpg


Return to “Hydrofoil Builders”

Who is online

Users browsing this forum: No registered users and 2 guests

cron