What's the best finish on a prop?????

[Albert Araujo]

I am sure this question has come up before but what is the best finish to put on a prop in order to get the best performance? 1) Polish 2) Sanding disk swirls 3) Light bead or grit blast

 

[dwilfong]

I bet if you take 3 props all the same and give it different finishes It won't make any difference.

David

 

[Albert Araujo]

I asked the question because someone told me that Andy Brown mentioned to him that polishing a prop kills performance.

 

[dwilfong]

Albert I will put it to the test and see. I my self would like to know the answer.

David

 

[Tim leyde]

I asked the question because someone told me that Andy Brown mentioned to him that polishing a prop kills performance.

I agree.

TL

 

[shoboat]

Albert,

We have done quite a bit of research on this topic

and it seems most agree that a rougher surface is better.

I use a cretex wheel between 24 and 60 grit on mine.

I think on our set ups you will find that pitch,cup,and

diameter have a lot more to do with the performance of

our propellers. I can tell you there is no perfect finish on

our propellers that we have ran across yet. I can tell you that

we are looking at several finishes like the big propeller guys use.

Mercury Racing CNC finish, Hering Propellers, Lab finishes are

a challenge because our blades are a little smaller. Once you rough

up the face of the propeller surface with a cretex wheel or abrasive disc

you will not see much difference on the speed of the boat. The cavitation

with a smooth finish will be more pronounced with a polished face that is for sure.

We have tested many different finishes with my Stalker Pro and have found no

speed changes with identical propellers. I would encourage others to go to the

pond and test your best finishes and let us know what you found? FYI, You are going

to need a Stalker or better to see a little change in different surface preparations.

Have Fun Testing And Racing Fellas,

Mark Sholund

231.590.3023

 

[Albert Araujo]

Mark,

Thanks for the info. Just trying to pay attention to the small details that can give us free speed with little effort.

Thanks again,

Albert

 

[anthony_marquart]

I don't think there is any "free speed with little effort"!

Well,.. except for setup. getting the pipe length and prop matched up seems to be where 90% of my progress comes from.

Seems to me that after you get a good combo there,.. the additional speed starts to cost $$$,..

 

[Marty Davis]

I bet if you take 3 props all the same and give it different finishes It won't make any difference.

David

David:

I bet it will make a difference. We did this test, and I agree with Andy, the prop that is highly polished does not work nearly as well as the satin finish prop. MUCH more slippage.

 

[shoboat]

Guys,

The real problem with the polishing is that it ruins

the trailing edge sharpness. This rolled edge really

hurts the performance of the water exiting the face of

the propeller. You can polish the back of the blade if

you have time to waste. This did nothing for the propeller

accept looking nicer on the stand.

Have Fun,

Mark Sholund

 

[Norm Doerr]

Guys,

The real problem with the polishing is that it ruins

the trailing edge sharpness. This rolled edge really

hurts the performance of the water exiting the face of

the propeller. You can polish the back of the blade if

you have time to waste. This did nothing for the propeller

accept looking nicer on the stand.

Have Fun,

Mark Sholund

Heat treat before polish :0 I don't bother with polishing so no issues here. BUT for those that like thier props to look pretty.....

 

[John Knight]

I bet if you take 3 props all the same and give it different finishes It won't make any difference.

David

David:

I bet it will make a difference. We did this test, and I agree with Andy, the prop that is highly polished does not work nearly as well as the satin finish prop. MUCH more slippage.

I have done some personal testing in the past and the highly polished ones cavitate more and have more slippage. Andy is dead right - satin is the way to go. A medium grit sanding sponge puts a good satin final finishon the prop. Quick, easy and cheap.

 

[gil sonsino]

For years I spent lot of time polishing my props looking jewerely.After have received an Andy prop no more shiny wheels.

Gill

 

[hugh hargett]

Gil my boating buddies in OK have used a glass beads on the face of his prop for years. Its really old knowledge, but Andy is right.

 

[hugh hargett]

Guys,

The real problem with the polishing is that it ruins

the trailing edge sharpness. This rolled edge really

hurts the performance of the water exiting the face of

the propeller. You can polish the back of the blade if

you have time to waste. This did nothing for the propeller

accept looking nicer on the stand.

Have Fun,

Mark Sholund

Heat treat before polish :0 I don't bother with polishing so no issues here. BUT for those that like thier props to look pretty.....

Norm wat you method of heat treating?

 

[Norm Doerr]

Guys,

The real problem with the polishing is that it ruins

the trailing edge sharpness. This rolled edge really

hurts the performance of the water exiting the face of

the propeller. You can polish the back of the blade if

you have time to waste. This did nothing for the propeller

accept looking nicer on the stand.

Have Fun,

Mark Sholund

Heat treat before polish :0 I don't bother with polishing so no issues here. BUT for those that like thier props to look pretty.....

Norm wat you method of heat treating?

We have a heat treat furnace with digital controller and years of experience and research on what not to do.

www.hobbyheattreating.com

 

[dwilfong]

Guys,

The real problem with the polishing is that it ruins

the trailing edge sharpness. This rolled edge really

hurts the performance of the water exiting the face of

the propeller. You can polish the back of the blade if

you have time to waste. This did nothing for the propeller

accept looking nicer on the stand.

Have Fun,

Mark Sholund

Heat treat before polish :0 I don't bother with polishing so no issues here. BUT for those that like thier props to look pretty.....

Norm wat you method of heat treating?

We have a heat treat furnace with digital controller and years of experience and research on what not to do.

www.hobbyheattreating.com

Dang I thought he would trip you up and you would spill the beans.

David

 

[Marty Davis]

For years I spent lot of time polishing my props looking jewerely.After have received an Andy prop no more shiny wheels.

Gill

Gil:

The best product that I have found to finish the prop is Scotchbrite that you use on a bench grinder. You can get the disks in a lot of different grits, but the roughest grit is the one that we use (I think the White ones). Makes a great finish and is very easy to use. You also have to buy a tapered adapter to put the disks on the grinder.

 

[Bill Gibson]

but they look so PURTY when they're polished! :lol: couldnt help it........!

 

[shoboat]

Marty and Others,

3M or Dremel makes these small radial bristle discs that work Great.

I use them on my Foredom flex shaft with a variable speed pedal. When

you do over 1000+ propellers annually you tend to find a better way to do things.

Thanks For Reading,

Mark Sholund

231.590.3023