My Prop

jimbo36 · Post by **jimbo36** » Sat Mar 06, 2010 8:37 pm

O.K., I'll bite, nice prop.

Rodman · Post by **Rodman** » Sat Mar 06, 2010 8:44 pm

jimbo36 wrote:O.K., I'll bite, nice prop.

Paul was wondering about the clearance, I had because its a bigger prop then the boat came with.

9rock · Post by **9rock** » Sun Mar 07, 2010 1:57 am

Rodman wrote:
jimbo36 wrote:O.K., I'll bite, nice prop.
Paul was wondering about the clearance, I had because its a bigger prop then the boat came with.

That looks like a lot of prop for that boat , and the bottom looks pretty bad , what kinda speed you getting

9

MTP · Post by **MTP** » Sun Mar 07, 2010 6:21 am

9rock wrote:That looks like a lot of prop for that boat , and the bottom looks pretty bad , what kinda speed you getting

9

W/ 9 looks like a ton of drag down there

foofer b · Post by **foofer b** » Sun Mar 07, 2010 7:15 am

Rodman, I don't think you have enuff engine for that prop. I imagine that is why she was bogging down. Plus I was advised against anything less than the 1.5-2" of clearance I have between the prop and bottom. It looks as though you only have an inch or less. Lastly, are you sure the prop hub won't rub the strut?

foofer b · Post by **foofer b** » Sun Mar 07, 2010 7:31 am

Actually yours might be ok. It is only 1" in radius larger than mine.

RWS · Post by **RWS** » Sun Mar 07, 2010 7:34 am

When was the last time this boat saw the correct WOT?

Overpropping overloads the engine and can lead to catastrophic failure.

What is the spec for WOT and what is your actual?

RWS

jimbo36 · Post by **jimbo36** » Sun Mar 07, 2010 7:43 am

Rodman, Aside from the prop clearance, your bottom is as 9rock has mentioned, BAD. I have done several restorations and the only one I did with a bottom that looks like yours was a 1970 Chris Craft Commander. Looks a bit like the surface of the MOON. This has got to have an effect on your boat's performance. I had mine soda blasted (like sand blasting but more gentle on the gelcoat) to remove all the old antifoul build up. If you have any blisters (osmosis, I did) you will need to grind them out and fill/fair with epoxy. Followed by 2 coats of epoxy rolled over the entire bottom. I used MAS because it does not produce an amine blush in the curing process that needs to be removed otherwise. Followed by 3 coats of anti foul. First coat a differant color so that when the top 2 coats start showing through it's time for another coat. I have always used Interlux Fiberglass Bottomcoat, but I am in fresh water. Not a small job but you will appreciate your work,

even if you can't see it below the waterline.

mr elevman · Post by **mr elevman** » Sun Mar 07, 2010 8:53 am

i would agree with jimbo my bottom looked like yours and i had it soda blasted and i picked up 3 knots at 2500rpm and got on plain sooner i was told 1.5 inch clearence minn and hears the reasion why the cavatation that comes off the outter diamiter of the prop ( the little air bubbels) is now compressed by the hull and will cut in to the hull i have 14x11 twin 318 and 4000 rpm 32 knots two gps units

RWS · Post by **RWS** » Sun Mar 07, 2010 9:33 am

mr elevman wrote:i would agree with jimbo my bottom looked like yours and i had it soda blasted and i picked up 3 knots at 2500rpm and got on plain sooner i was told 1.5 inch clearence minn and hears the reasion why the cavatation that comes off the outter diamiter of the prop ( the little air bubbels) is now compressed by the hull and will cut in to the hull i have 14x11 twin 318 and 4000 rpm 32 knots two gps units

\\

Cavatation and some really bad hull vibration is possible when the prop tip to hull clearance is too tight.

It could be that he's fine and it's the camera angle.

RWS

Peter · Post by **Peter** » Sun Mar 07, 2010 9:44 am

soda blasting is fine, however if you have a significant
osmotic blistering problem I think sand is better.
[Done properly]. The nice thing about sand blasting
over soda is that it would tend to open more of the
blisters. If there is a whole boatload [

] of
blisters, you really want to open them all up, before
grinding. If you don't, they'll still be hiding... As far
as the issue of damage to gel coat, certainly after
grinding, filling, fairing, to do a proper bottom job,
you will need to apply several barrier coats. [This
will take care or " repair" whatever damage the
structurally useless and hidden gel coat sustains.]

prowlersfish · Post by **prowlersfish** » Sun Mar 07, 2010 11:09 am

Get a 14x10 on it ad see what happens . Bet you will be happy when you do

Rodman · Post by **Rodman** » Sun Mar 07, 2010 11:13 am

prowlersfish wrote:Get a 14x10 on it ad see what happens . Bet you will be happy when you do

The bottom I know is in need of work. I am not sure what to do with it , or just let someone else do it so I do not have to have the headache. Far as the prop, I am looking for a 14x10 used prop now.

prowlersfish · Post by **prowlersfish** » Sun Mar 07, 2010 11:45 am

A prop shop may trade you as the bigger prop is worth more to them ( unless its a odd size) the right shop may let you try diffrent sizes