- Jan 15, 2011
- Reaction score
There’s a ton of theories on that, and I’ve actually been involved with a pretty broad spectrum of them. None of them have stood out as superior, and without really hard data taken same day, boat, weight, driver, conditions and course, I think it’s extremely hard to argue.
The general average I’ve seen is 400-1000 grit. I know that some guys swear by speedcoat, and others that have run it say it’s a waste of money.
Even your “raw casting” gearcases aren’t raw, they’re generally DA’d with 400. Some guys like the random marks from the DA, some like sanding directionally with water flow, and others like to polish.
I can tell you that the wet sand water runs off faster after I’ve sanded than before I’ve sanded.
I think there’s a balance somewhere in that window I described above.
I think being straight and not having big bumps or pockets will gain you less friction than the minimal differences in surface finish. Especially considering how little of the boat is in the water at speed.
There’s also a reason bottom paint slows a boat down considerably. Like, multiple MPH.
I have also heard it explained like this, take 2 sections of glass and add a little water between them now try and pull them apart...not so easy. Now add a little imperfections such as a few grains of sand for example and the glass comes right apart. Heard everything from dimpling the bottom of the hull to a high polish, there is speed coat on certain areas of my stealth whether or not it helps it I’m not really sure I suppose a test would have to be done before and after to confirm any real change.
Your boats looking great keep it up!