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[AlanP]

Ian, thought you where on holiday, holiday cant be that good checking the forum. (project X coming along nicely)
Alan

[craig dickson]

Just a quickie, does it make any difference polishing the bottom of the hull on a fast electric boat?
 
Alan

I have been watching these threads with interest. We are in the land of fluid dynamics and that gets potentially very complicated. Personally I prefer the highly polished option with the application of a wax finish even though I hear the views on the alternative matt type finishes with various grades of wet sanding etc.
A concern I have with matt type finishes on model boat hulls is; What happens when you get a bit of grease or muck(from your hands) on the hull? With a matt finish it tends to get ingrained and stuck on the surface. With a highly polished surface I would suggest that such a surface remains relatively unaffected (the crap does not stick to it) and even if some does it is certainly easier to clean quickly in race conditions.
Consider a model sized hull and a finger print of muck on it compared with a full sized hull. The impact of that (on a small model boat) will in relative terms be massive in respect of any frictional turbulence created compared with a full sized power boat.
I would sooner have a hull surface that is easy to keep consistent in respect of its finish. And for me the ultra wax polished surface delivers in that respect. And as has been mentioned this has the benefit of the looking good factor which I think is an extra benefit.
Interesting topic.
Cheers
Craig

[martno1fan]

Craig wet sanding with 600 paper isn't going to cause too much of a problem it only needs to be enough to create a dull finish nothing more,in any case for fun running I wouldn't advise doing it id leave alone but for someone racing it is most definitely the way to go,even if it gains you 1 mph .Like I said though there are paints and coating available that create the same effect,Teflon been one which as you know is non stick  .
Wax is a big no no as it sticks to the water,as for it looking good no one sees the bottom unless your boat spends its time bottom side up  .
People have been wet  sanding there hulls for years especially the SAW guys over in the states.
Mart

[black magic racing]

the gains you are going to see you will NOT  see  if you start to wet sand your boat you will have to keep wet sanding it and that will slowly eat away the gel coat,there are many does and dont for this,but really for what you are doing and the fact that we dont race on millponds but in rough water it really is not going to make any difference

[martno1fan]

the gains you are going to see you will NOT  see  if you start to wet sand your boat you will have to keep wet sanding it and that will slowly eat away the gel coat,there are many does and dont for this,but really for what you are doing and the fact that we dont race on millponds but in rough water it really is not going to make any difference

Well Mercury and other companys must be wrong  .As for wet sanding with 600 grit paper eating away at gelcoat all I can say is your gelcoat must be very thin,no way will it eat away at gelcoat by giving it a light rub down,No dif to a painter dulling the paint ready for the next coat,takes 5 mins to do.
Heres me thinking racers would want that little edge over the competition, weve allready heard Jans findings when compairing his wet sanded hull versus waxed .

to quote Jan
 
Racing around a 30 x 30 x 30 m course with just two boats, the difference was sufficient to lose a place every ten laps or so.
Given the fact that we ran about 30+ laps in the 7 minute heat, this was enough to drop significantly in the overall results, specially as there were more than 2 boats at the start (usually 4-6 boats).

Regards, Jan.
 
seems it made quite a difference  .
Mart

[black magic racing]

we are talking about TOY boats here,maybe if we had 3000 bhp engines maybe wet sanding would be the way to go,but we have other things to consider,we dont race flat out for 20 minutes,we have dead boats,rescue and other things to think about,the gains of maybe 1 mph you would not see,as for having the edge its called mr dremal and works well indeed
my rigger is wet sanded due to the fact at speed it sits on top of the water and the least contact i can make is always good,but racing a deep v where the boat is in the water,pushing it self through the water i dont think you will notice the gains,
each to there own,at the end of the day if what ever you are doing works for you then stick to it