Prop Polishing...

[andy21]

Hello Everyone...

Have got my R21 out of the water for a bit of a clean up ready to go back in for the weekend...

Have taken the prop off and just started to give it a polish as i'd heard it makes quite a difference... Does it?!? It had certainly lost its mirror finish and feels pretty rough...

Does anyone have any tips on doing this or a good product to use? I'm using Autosol and kitchen roll at the mo, has taken me ages to do half of one side of one blade!

Any info is good info! (kind of...)

Cheers in advance,

Andy

[Andy B]

Originally Posted by andy21

Hello Everyone...

Have taken the prop off and just started to give it a polish as i'd heard it makes quite a difference... Does it?!?
Andy

grip or slip?
now you've opened a can of worms!!!!

[andy21]

oh god!

Well i'm half way now... some shiny some rough... I guess that will give the best of both

What difference does it make then? Is slip a bad thing?

I figured a polished prop would slice through the water better :-S

Would be interested to read about this can of worms

Andy

[SCOTT671]

the last inch concave side rough
convex as a mirror hope this helps

[Hydrostream]

Originally Posted by andy21

Is slip a bad thing?

Without slip there would be no thrust

0 slip is 100% efficiency

A rough prop creates resistance

A polished prop creates drag

Just a few things to think about........

Ever wonder why a ships prop is finished with rough swirl effect?

Do a search on boundary layer separation

To be honest, I don't think it will make any difference you will notice in the seat of your pants.

Polished props look sexy though!

[larby]

I rekon cleaning Davy Jone's forest off your leg & gearbox would help more!!

[Andy B]

Originally Posted by Hydrostream

Polished props look sexy though!

lets face it, thats the real reason for polishing your prop

[andy21]

Originally Posted by Hydrostream

A rough prop creates resistance

A polished prop creates drag

Now i'm definately confundled!

It is starting to look sexy! Although my hands are now anything but... what with slipping on the blades :-(

Davy Jones has been treated to the full force of my pressure washer! :-D
Unfortunately so has my antifoul... got a bit carried away!

Andy

[Ace]

i can assure you if you go and feel that rough looking ships propeller it will be perfectly smooth, and that polish would have cost about £20K

a polished prop is best.

[Captain Chaos]

1st post in 5 years eh, ya nob

[Ace]

Originally Posted by Captain Chaos

1st post in 5 years eh, ya nob

i havn't had 7039 useful comments like you!

[Andy B]

Originally Posted by andy21

Does anyone have any tips on doing this or a good product to use?

Andy do yourself a favour and add this to your shopping list



http://cgi.ebay.co.uk/New-6-Bench-Gr...3A1%7C294%3A50

[Techteam]

IMHO polished is not best, It's just done to look good for your average boater and offer the best corrosion protection. Looking in the various prop boxes we use most have a fine lab finish, looks like satin, but the quickest props are very very thin then heat treated and just left.

[larby]

I'd imagine with the boat being kept in the water over here, keeping it clean is the main challenge! For that reason alone, I'd suggest you polish it. Less surface area for stuff to grip to.

James

[Techteam]

IMHO polished is not best, It's just done to look good for your average boater and offer the best corrosion protection. Looking in the various prop boxes we use most have a fine lab finish, looks like satin, but the quickest props are very very thin then heat treated and just left.

[Andy B]

It’s like wheel spinning your car,
Too much slip and you'll just sit there in a cloud of rubber,
Too much grip and you will stall or struggle to rev.
The prop needs too have enough slip to let it rev but also enough grip too transfer the thrust to the water!
Just about everyone has their own opinion on this but unless you at the top end of the performance curve it's not really going to make much difference to you.
so for this reason go bling!
Ever wondered what tho’s holes in the hub of your prop were for?
They are there to let some of the exhaust gases lubricate the blades.

[Andy B]

i should point out that that last post was for andy21 and that i am in no way try'n to give egg sucking lessons

[BluFin]

Originally Posted by Andy B

Ever wondered what tho’s holes in the hub of your prop were for?
They are there to let some of the exhaust gases lubricate the blades.

to put it another way
Ventilates when pulling away to allow prop to spin (cavatate) to let RPM build as speed increases the water pressure rises thereby closing over the holes ( - improves holeshot) so once up and running at a decent speed they are ineffective

[dowdy]

Try identical props,one satin finish,one polished,between two known marks acouple of times,with a mate timing you,you will soon find out if one is better than other,presume its speed you are after,personally i dont polish mine,the two cleavers i run look the biz without the shine

[Andy B]

Originally Posted by BluFin

to put it another way
Ventilates when pulling away to allow prop to spin (cavatate) to let RPM build as speed increases the water pressure rises thereby closing over the holes ( - improves holeshot) so once up and running at a decent speed they are ineffective

Yah! like the man said.....