Leading edge of Prop

LubeDude

Admiral
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Oct 8, 2003
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How sharp should the leading edge of the blades on a prop be, and what is gained or lost by sharpening them?
 

salty87

Commander
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Aug 12, 2003
Messages
2,327
Re: Leading edge of Prop

i know this one, if it ain't sharp enough for me to cut myself...i want my money back.<br /><br />mine (inboard) have always been really sharp when in good shape.<br /><br />i guess there's a point where the blade is so sharp that the metal gets weak and could flex. but, if they aren't sharp enough they will create turbulence and lose efficiency.
 

snapperbait

Vice Admiral
Joined
Aug 20, 2002
Messages
5,754
Re: Leading edge of Prop

I used to sharpen the blades on mine (skeeter f-80 w/70johnrude) to cut thru the summer hydrilla weed growth that would take over the lakes round here... I mean like a knife..<br /><br /> Never saw a performance loss or gain, other than not getting bogged down in the weeds... Green stuff in the rooster tail... :D
 

LubeDude

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Oct 8, 2003
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Re: Leading edge of Prop

Thanks, I forgot I posted this and just remembered, Seems to me that it would help performance some, Im going to sharpen my four blade and see if it makes any improvements, Its dull as a rock now, it wouldnt cut through hot butter.
 

Scaaty

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May 31, 2004
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5,180
Re: Leading edge of Prop

The sharper, the better....but lawnmower type sharp, not knife
 

walleyehed

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Jun 29, 2003
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6,767
Re: Leading edge of Prop

A sharp leading edge adds drag to the back side of the blade as well as the usual front side.<br />The blade will actually ventilate at a lower angle of attack if sharp vs. slightly rounded.<br />I ruined a 500.00 Raker doing this, and it was explained to me later (Repair shop) why this doesn't work in most cases.<br />EDIT: If ya ever get a chance, look at a Hydromotive TX-4, one of the fastest props available...no sharp edges, only a perfectly rounded contour the thickness of the blade.
 

vidar

Petty Officer 2nd Class
Joined
Jun 30, 2003
Messages
165
Re: Leading edge of Prop

this is true in sub surface props...on true surface props is sharpe on leading edge and sqare w sharp corners at trailing edge... but this propblades are entering and leaving water....
 

LubeDude

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Joined
Oct 8, 2003
Messages
6,945
Re: Leading edge of Prop

Ok, should I sharpen or not, the edges now on the turbo prop are rounded?? :confused: :confused:
 

walleyehed

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Jun 29, 2003
Messages
6,767
Re: Leading edge of Prop

I would say call the manufacturer on this one, LD. I think I know the answer, but I won't stake my Boat on it...... :cool:
 

Ralph 123

Captain
Joined
Jun 24, 2003
Messages
3,983
Re: Leading edge of Prop

If it ain't broke don't fix it. I wish I had a nickle for every post that goes like: "my boat was fine until I did xy & z - now it's broken... please help"
 

ThomWV

Senior Chief Petty Officer
Joined
Dec 19, 2003
Messages
701
Re: Leading edge of Prop

I have a hard time immagining walking out and taking a file or a grinder to one of my props. I've had them new and I've had them used, no matter what we're talking about two, three, maybe four hundred bucks here. This ain't like some $20 lawn mower blade we're talking about here. <br /><br />I've found a better way. I give my prop guy his hundred bucks and we start dialing my prop in. When I finally say its done it will either be because we have exhausted either my supply of money or his decades of hard earned knowledge about props. I don't tell him to sharpen blades or round off blades or bend some cup into or out of blades. I tell him where the boat is run, and when and how, and I tell him what its doing and what I want it to do. Sometimes he tells me my expectations are not achievable, sometimes he tells me they are and he can or can not do it. The guy never shoots me any blanks. You need to find one like him.<br /><br />Thom
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: Leading edge of Prop

I sharpened a prop once, Did not gain or lose anything, so I don't bother with it now.
 

walleyehed

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Joined
Jun 29, 2003
Messages
6,767
Re: Leading edge of Prop

I'll be talking with Larry at Turbo tomarrow...I will ask what they think and relay the message, unbiased, whether I'm right or wrong....<br />We know there are 2 types of props involved here, and I'll see what they recommend for surface and sub... ;)
 
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