View Single Post
Old 28th June 2007, 07:07 PM   #2
Ian Fox
STARBOARD
 
Join Date: Aug 2006
Posts: 532
Default RE: tuning by sandpaper

Hi Valentine,

It is a debateable point, with many issues and variables.

In most cases, you will compromise the original finish and graphics on the board (fin)
and - unless at the very highest levels - any speed difference will be minimal.

If you're not sure of what you are doing, the best advice is probably don't do it.
Or at least not without some direct further instruction or on hand guidance specifically from someone with proven experience and skill with this. In all cases, if the process went wrong, it could reduce performance, destroy the product and cancel any warranty on the product. Please be aware of that.


For boards: (most typically, performance boards like Race/Slalom/Speed)

Use quality wet and dry sandpapers only (3M is a good brand)
Use something around 400 Grit.
Use it only wet and in good (clean) condition.
Use a very straight and even sanding stick or block for boards.
Use only VERY light sanding pressure.
Use a very very even sanding motion - along the water flow line.
Do not allow the paper to clog up, or dig in the edge while sanding.
Concentrate your efforts on the back half of the board, where most of the hi speed planing occurs.
(what you are looking to do is make a perfect flow line, and leaving a fine, regular pattern of small scratches running perfectly in line with water flow along the bottom of the board.)
You will find that some class rules for racing ban the "excessive" re-finishing of production boards from manufacturer's finish.

For fins; (most typically, performance fins like Race/Slalom/Speed)

You can use a finer grid like 800 or 1000 as the flow is different.
You have to be really careful, as the foil shape is much more 3 dimensional - and over a much shorter dimension - than the (relatively flat) underside of a board. The leading edge area is the most critical on the fin, but it's also the most easily disturbed or damaged by unskilled or over ambitious sanding.
Here it is really easy to sand a flat (where there was once a subtle foil) or minutely change the profile (radius) of the leading edge - and in doing that, turn a good fin into a dog.
Or the even less likely situation of turning a bad one into a great one.
Sanding the trailing edge to a razor sharp finish has small performance potential, but a much bigger potential to cut your foot, hand etc...Ask someone who knows..
You will find most guys wisely take good care (on and off the water) of the original finsih of hi performance fins, avoiding the need to sand them, rather than risk damage by trying to refinish them.
(of course, if the fin needs refinish, it will be better to have it done correctly than not, and if the operator REALLY knows what to do, it's not so risky).

And so just to be sure that everyone understands that we are giving information
but NOT recommending this technique, let's repeat the original warning again :

If you're not sure of what you are doing, the best advice is probably don't do it.
Or at least not without some direct further instruction or on hand guidance specifically from someone with proven experience and skill with this. In all cases, if the process went wrong, it could reduce performance, destroy the product and cancel any warranty on the product. Please be aware of that.


Cheers ~ Ian
Ian Fox is offline   Reply With Quote