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Unregistered
26th August 2007, 11:21 AM
Was very happy to receive my iSonic 76 yesterday, but none of my fins would fit including drake fins from previous years (the drake fin provided with the board did however). I've spent the last two hours attempting to carefully sand the fin box (at least I've got little fingers to fit in the box), as if i sanded my fins further they would be too loose in my other boards.

I know there will always be manufacturing tolerances, but why is the accompanying fin also smaller. Are you using different molds this year... they seem to be shrinking each year. Just a little frustrating and fiddly... especially if I'll have to do this with all new boards.

Well, hopefully the board sails like a smaller version of the 87 and it will all be worthwhile.

steveC
26th August 2007, 12:28 PM
Your post has brought up a concern that I think is rather important, at least from my perspective. When you think about all the tolerances between different boards and fins, it can be too challenging, particularly if also working the special screws needed between US and metric sized fins.

The last thing a customer wants are tolerance differences in the board's integral fin boxes. I can say with my boards that there has been great synergy over more than 15 years. Quite frankly, the Water Rat Tuttle boxes are incredibly consistent, and that has made quite a difference integrating different fins and brands over the years. No one wants to start having to change things that you know are right from the past. If one has a cache of fins over time, especially ones that have worked in so many boards, you certainly don't want to start hacking things with abandon.

martwald
27th August 2007, 07:21 PM
This is an issue that really bugs me.

Recently I ordered a few Techtonic fins and they all required serious sanding to fit into my F2 Missile XS, SX M & iSonic 87. Fortuneately the fins boxes seem the same throughout as all fins fit the same in the various boards.

In addition to this, the fin supplied with my F2 Missile XS required extensive sanding to fit the board it was supplied with!

Now I have to admit that the stock fin provided with the iSonic fitted perfectly and so this thread is aimed at F2 and Techtonics so really shouldn't be here but perhaps some users of this forum would comment if they have had the exact same problems.

Surely it can't be that hard for all fin and board manufacturers to tighten up in this area.

steveC
28th August 2007, 12:29 AM
Hi Martwald,

Regarding Tectonics fins, I've got six of them with Tuttle bases and I've never had to sand a single one. They have always worked perfectly with no modifications needed. I also find True Ames fins to be right on with the tolerances of their fins. In addition, I have a number of Lessacher fins too, and they all work well, except one is a bit on the tight side, but it still fits.

So all and all, my experiences support a position that fin manufacturers are doing a great job with their tolerancing. So, I must consider your findings to be very unusual, at least with Tectonics fins. I could be mistaken, but isn't the F2 brand using Powerbox in their small and medium boards with cavity type boxes?

Unregistered
28th August 2007, 05:38 AM
If the tolerances on the fin boxes are so sloppy, what about the shapes of the boards?? I wonder how consistent the rocker lines are...
My Mike Labs and Tectonics fins fit like swiss watch parts. Would you tolerate a car tire that doesn't fit the rim?

martwald
28th August 2007, 06:56 PM
No the F2 smaller range use tuttle boxes.

As I said the sanded fins now fit the F2 and SB boxes perfectly.

It wasn't just a little bit of sanding either. I had to buy an electric sander and I was at the fin for about a half an hour, being very careful not to take off too much from one side or the like.

The other point was that the fin provided with the Missile XS required significant sanding to get it into the box.

The problem is with the fin heads not the boxes, as all boxes are the same.

Surely someone else has had this problem???

Phill104
28th August 2007, 07:57 PM
I maybe wrong but I believe SB tightened up on finbox tolerences a couple of years back bringing the boxes closer to spec. If they were too wide before then some sanding may be required to fit newer boards.

Looking at the hire/demo kit at brog reveals that all the SB fins seem to fit all the boards so tolerences must be quite good.

Whenever I buy select fins they do require quite a bit of fitting but I would rather they be too tight than too loose.
All fins require some fitting, some more than others.

I would be miffed if I bought a board and the stock fin needed fitting though.

Unregistered
29th August 2007, 10:52 AM
I have had the same problem with Tectonic fins as well as Vector fins,all needed sanding to fit into my boards.The same goes for friends who have purchased these fins.

martwald
29th August 2007, 07:09 PM
With an electric sander the process doesn't take too long so I'm not overly bothered the time, suffice to say I've another Falcon in the post to me.

My concern however is that you could sand too much off one side or do it at an angle resulting in a fin which is very precise in its design not having the expected laminar flow over it, although I doubt this would have any noticeable effect.

I'm off to gps-speedsurfing to ask the same question.

WSguy
29th August 2007, 07:26 PM
I have had the same problem with Tectonic fins as well as Vector fins,all needed sanding to fit into my boards.The same goes for friends who have purchased these fins. Recently I had to sand down a Tectonic fin to fit a Naish board. It's no big deal, though. I was a bit frightened that I took too much off with the disk sander on the electric drill, but it fits quite well in the box now. I can't see why you guys find this important.

martwald
29th August 2007, 07:55 PM
Well I guess the fact that a pair of select fins I purchased before going to Weymouth last year were so far off that after a hour of sanding I still couldn't use them (I only noticed the poor fit at the event) and so I stuck with the stock fins.

The simple fact is that they should fit and you shouldn't have to sand a whole lot. I understand that a little bit of sanding being required isn't a bad thing, ensures a perfect fit, but the requirement of an electric sander and lots of time seems excessive???

Erik Loots
29th August 2007, 08:03 PM
Sanding your finhead... there was an intresting story in the dutch surfmagazine about that (written by some very fast guys)

It was about this (till it fits) :

1) start with the width of your finhead
2) make the top of your finhead bit round (like tectonics)
3) (if is still doesnt fit) sand the backside of your finhead till it fits properly.

I have seen people go very fast with a fin that wasnt very tight in the finbox...
I have seen people go very fast with a fin to deep in the finbox...
I have seen people with fins that where so tight in the box that the hard foam around the box damaged
I have seen people that need about 20 min for fitting fin properly (every time)

There is some middle in sanding where the fin will fit most boards (99%). THat is for me:

bit tight in my Carbon Art boards. (I once forgot the screws and did 65kmh/36kn and fin was still in finbox)
bit less tight in my Starboard Isonic 2006

Unregistered
29th August 2007, 10:24 PM
l build boards for a living and give the fin a whack with a rubber mallet.All fin brands have fitted so far in chinook boxes.

martwald
29th August 2007, 10:48 PM
Are you sure you don't just use yer head

Unregistered
30th August 2007, 12:15 AM
No, the mullet gets in the way

Unregistered
30th August 2007, 08:14 AM
The Rubber mallet has worked for me . Some of my customers have thought they needed to sand the fins l supplied because they were so tight. l am saying that chinook boxes are a good standard size, and other brand boxes may varie. Maybe l haven't come across a brand of fin that is way out, even select fins fit. Just try a gentle tap and see if things give. These are wave boards though.
You will learn more from questions than insults.

Unregistered
19th September 2007, 04:21 PM
With an electric sander the process doesn't take too long so I'm not overly bothered the time, suffice to say I've another Falcon in the post to me.

My concern however is that you could sand too much off one side or do it at an angle resulting in a fin which is very precise in its design not having the expected laminar flow over it, although I doubt this would have any noticeable effect.

I'm off to gps-speedsurfing to ask the same question.

hahahahahaha- like anyone would notice!

cj0ne2
19th September 2007, 05:56 PM
....never bought a Select fin that fitted first time!
I have always had to sand them down quite a lot.

Unregistered
20th September 2007, 01:37 AM
I have, fitted better than the 2 drake fins supplied with the iS133, no sanding whatsoever