Wet Sanding or Dry Sanding

L

laser170654

New Member
I was wondering which way to is better to sand
the foils, WET or DRY? What are the benefits of each?
As well, what should be done to some small dings in the
bottom of laser? Gelcoat doesn't work because the dings aren't
deep enough! Any help would be great!
Thanks
:confused: :confused: :confused:
 
In the summer i sailed an opti which is a bit different, but same idea. I use 1200 grit and wet sanded, it worked well. All the other people at the regatta (Opti North Americans) did same thing. Using a higher number of grit can never hurt, but u might want to try a part of boat with the grit u prefer. If i leaves lines in gelcoat go to higher number of grit or else you will remove gelcoat too fast.
 
Wet sanding allows you to use a higher/finer grit like 400, 600, or 1200. I've seen a bell curve indicating the advantages of using higher grits for smother surface. Basically the higher the grit the higher the hull speed of the boat needs to be. For the Laser you should not go over 600 grit on the blades or hull. 1200 is just wasted effort. I use 400 cause its faster to get the dings out. For the small nicks and dings on the hull I use gelcoat. Actually its a resin based touch up kit I got from west marine. Its a resin paste, hardner and different color additives for the color you want.
 
There is an excellent article on gouvernail's website:
http://schrothfiberglass.com/LaserMaint.htm
Scroll down to "How to make your bottom pretty"
The article is for the hull, but the same method can be applied to the blades.
I do not think that 1200 is "wasted effort" as has been suggested. One can of course always wonder about the effects of sanding. A couple of scratches are not that bad. Spending an hour with some Teflon polisher already does a lot of good. However when it comes to the blades: those should be perfect. ANY scratch, ding or other imperfection will count many times since the blades take so much more pressure of the water.

Finally, you can dry sand. It is faster, but very dusty and not good for your health.

Good luck

GWF
 
wet sanding is quicker and easier,the wateracts as a lubricant and coolant for the sandpaper ,it also clears away the dust which would cog the sandpaper.There are finer grades of sandpaper available to use dry,but most applications for these are for automotive refinishing where the main requirement is to produce a key on a sound surface to allow the paint to stick.wet sanding will produce no dust important as breathing in dust is bad for your health.
 
As well as 1200 grit being overkill I also do not believe in polishing the hull. It's my opinion that a fair and clean hull is faster than a fair, clean, polished hull. To me water that beads is "flow resistant" compared to water that will flow clean across the hull.

GWF thinks otherwise. Which is cool, we all have our ideas that we prefer. Mine are just faster, (sorry George couldn't resist!).

I do believe that perfect blades are crucial.
 
GWF and Rob B are both correct.

Bethwaite wrote some stuff in a book about Laser rudders, how shiny they were made, and stalling.

Beading water is probably bad. Waxing may be bad because it can make water bead.

But...I believe the considerations have to include looking for answers to the question, "How will the boat perform after it has been soaking in the water for a while?"

A well designed coat of polish may become "soaked" with water and also discourage dirt from bonding.
Also, remember, it is your boat and its foils which are moving. The object is to move a little water as short a distance as possible.

The characteristics of flowing air and water are of interest to the sailor but it is even more important to understand that the water is not flowing but being displaced.

Now my brain hurts.
 
[FONT=&quot]I also believe that wet sanding is the way to go. On the issue of beading water I too have read the articles that say that this is slower than a 600 to 1200 grit wet sanded finish. I also believe that it has more to do with "if I feel that the boat is fast, then the boat is fast" psychology has more to do with it that foil finish. Probably because you can just forget about the foils and the finish and get your head outside the boat. Besides time spent sailing is more fun than time spent wet sanding.

Having said that these wetsanding projects can be good to do in the winter or days with no wind but don't miss sailing inorder to wet sand.
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