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View Full Version : Is it good a mirror like polish on a prop?



jkr
01-16-2012, 02:23 PM
Recently i polish a prop to a mirror like finish.
I love the sound that makes but is it good?

egneg
01-16-2012, 04:31 PM
Depends on who you talk to. If you like it that is all that matters.

LarrysDrifter
01-16-2012, 05:11 PM
A polished prop makes a different sound than a non polished prop?

jkr
01-16-2012, 05:54 PM
Listen.
http://www.youtube.com/watch?v=IX4NeBhdeuU&feature=player_embedded
at 0:05-0:08
I don't know much but after 3 years is the first metal prop with mirror like polish that sounds like outrunner.

pyroM!KE
01-17-2012, 12:21 AM
Listen.
http://www.youtube.com/watch?v=IX4NeBhdeuU&feature=player_embedded
at 0:05-0:08
I don't know much but after 3 years is the first metal prop with mirror like polish that sounds like outrunner.

Im not sure what sound your talking about..I get my props from dasboata .. He has been into racing FE baots for years and he does all my props..They all have a nice finish but there not polished..I think polishing is more of a bling factor..
Heres my boat running his prop.. http://www.youtube.com/watch?v=8c28E85OaFo

jkr
01-17-2012, 09:22 AM
6835168352
Is it good to have that finish or blurry?

camaroboy383
01-17-2012, 11:16 PM
no you dont want it polished like that in my opinion... its not making it faster..shiny like that kinda slides it into the bernouli principle..(kinda)...props should be roughened up with fine sand paper..run some 800 grit over that thing,, it will be faster,, and still look good...of course none of the above matters if its not sharpened,, i like my props sharp enough to cut paper,,sharper is good but cuttin paper is fine......

hope this helps,,Alden

jkr
01-18-2012, 05:00 AM
Yes this helps but 800 grit isn't bit thik?
Something like 1500 grit would be better don't you think?

egneg
01-18-2012, 08:15 AM
I stop at 400 grit.

camaroboy383
01-18-2012, 09:15 AM
800 is not too course..i find its plenty course for the job and still leaves the prop nice looking...doesnt matter what you use,,,the point is the prop will be faster if its not polished....some of the fastest props in the world are some of the most ugly ones you would ever see....leave the prop with a brushed finish and you will like it...

alden

jkr
01-18-2012, 10:42 AM
Going to try it this weekend

Jeff Wohlt
01-18-2012, 10:56 AM
If you ask Tom from Octura he will tell you leave a matte finish on them...water releases better from the prop. Does it matter that much...doubt it but do sand the ride planes on the hull which will do more.

Gimp
01-18-2012, 11:09 AM
sand the ride planes on the hull which will do more.

Scuffed ride pads will go faster than a nice polished paint? What grit do you suggest?

jkr
01-18-2012, 11:31 AM
What are the "ride planes"?

camaroboy383
01-18-2012, 02:10 PM
any ride surface,, 1200-1500 ive seen courser used...but this will for sure free up the hull...again,,,we are kinda entering the bernouli priciple.. run the water in your sink full bore,,,,take a spoon and lightly grip the handle with your thumb and pointer finger on the sides of the handle,,,,now slowly introduce the under side of the spoon to the water,,,notice how the spoon is pulled into the water stream....now run a flat piece of anything the same way and notice how it doesnt pull into the stream but repells from it..this exact reason is why the jae riggers work so well,,,very flat running surfaces..now sanding them frees them more..makes it like rolling on ball bearings..this applies in ride surfaces and props....the smoother it is the more it will stick in the water....

alden

Jeff Wohlt
01-18-2012, 02:14 PM
I think 600 is good. Scuffed but not leaving a rough surface.

LarrysDrifter
01-18-2012, 02:56 PM
Sand enough to take the shine away. You want a flat, dull surface. I sand to remove the orange peel that you eventually see after beginning to sand.

Gimp
01-18-2012, 03:06 PM
Thanks for the hull into, I always wet sand and polish after paint, so this will eliminate a step, at lease for the bottom lol.

When sanding the prop, does it make a difference which direction you sand in?

Boaterguy
01-18-2012, 03:44 PM
i would assume along the blades (tip to TE) would be better than across the flow of water.

Fluid
01-18-2012, 07:00 PM
Prop or hull finish has absolutely nothing to do with Bernouli! Surface finish effects the friction between the object and water - but wait, most of the front of the prop blade runs in air, not water. If you care about learning the fastest finish, by all means listen to the guys who never set a SAW record, they certainly know what's best. :doh:



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6BOOST
01-18-2012, 08:16 PM
Prop or hull finish has absolutely nothing to do with Bernouli! Surface finish effects the friction between the object and water - but wait, most of the front of the prop blade runs in air, not water. If you care about learning the fastest finish, by all means listen to the guys who never set a SAW record, they certainly know what's best. :doh:

.

Do you have anything helpful to add and give advise on or you just wanted to stop by and let everyone know that everyone who has posted has no idea (compared to you) Fluid?

6BOOST

Fluid
01-18-2012, 08:27 PM
This topic has been discussed many many times, and the OP could have used a search to find out - but he chose not to make the effort. Those here who really do have fast boats have posted their findings repeatedly but no longer do so because they are told they are wrong by the ill-informed...who then continue to spread bad info to new boaters. Frankly I got tired of all the BS posted about prop finish (Bernouli? Really?) hence my post. If you don't like it, then simply add me to your Ignore list instead of making yet one more post which adds absolutely nothing positive to anyone's understanding of the topic.



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Gimp
01-18-2012, 08:29 PM
Prop or hull finish has absolutely nothing to do with Bernouli! Surface finish effects the friction between the object and water - but wait, most of the front of the prop blade runs in air, not water. If you care about learning the fastest finish, by all means listen to the guys who never set a SAW record, they certainly know what's best. :doh:
.

Can you please elaborate Fluid? After taking a Fluid Dynamics class I have a lot of interest in the subject. My assumption was polishing gives higher speeds due to a lower Reynolds number (in piping at least, we didn't cover stuff like this in class). Resulting in smoother laminar flow. Looking at 1:1 props, most are polished (but that also helps with corrosion).

I was skeptical of the scuffing at first, hope you can enlighten me a little.

6BOOST
01-18-2012, 08:49 PM
BTW, your cred is....?.

If your sick of peoples stupid questions why waste your time trying to make everyone sound like an idiot if not to glorify your own knowledge? Seems to be a recurring theme on this forum, you enter, write some droll remark about how no one has any idea then exit without offering the correct information. Your talking about more useless posts not adding anything positive to the thread, yet your first post in it was exactly that, useless and belittling. Next time you don't feel like answering the same stupid questions Jay, how about rather than me add you to my ignore list, you just don't post unless its to help, or you tell the OP to use the search function rather than come across like an arrogant dick.

6BOOST

Edit: My cred is nill, hence the reason I didn't post a reply;)

Rumdog
01-18-2012, 08:50 PM
^^yup!^^

camaroboy383
01-18-2012, 10:42 PM
I did say (kinda) i did not say they were directly related... its an attract and repell thing wich they both have in common.... JKR asked a simple question and i gave an answer,,unlike you,, i know people that have plenty fast boats,,, guess what,, there prop isnt shiny....simple.....dont try to discredit me cause im new here... i know plenty... you do whatever you like to your prop JKR...just be sure its sharp... maybe fluid will tell you how he is the fastest in the nation.......... what do you think 6boost???? will fluid spill the greatest speed secret ever??????


Alden

6BOOST
01-18-2012, 11:02 PM
maybe fluid will tell you how he is the fastest in the nation.......... what do you think 6boost???? will fluid spill the greatest speed secret ever??????


Alden

Doubt it, but apparently the pro's have already shared the info somewhere, we just have to look for it lol. I have 3 of the same prop for my 3080 mono, if I get time I'll test polished vs matt vs shot peened finishes with proper saw timing equipment not just gps, won't be for a few months tho.

6BOOST

camaroboy383
01-18-2012, 11:06 PM
your in oz,,, you know tim duggan???bryan rutley?? greg moss?? aaron alberico??

Alden

camaroboy383
01-19-2012, 12:55 AM
jkr,, i watched your video above,, has your setup changed at all since then?? i noticed the hull starts to porpoise,,,your main goal should be to settle that boat down... beleive it or not.,,geez ill probably get shot for sayin this,,,but,,,if you have issues getting it to settle down try a 3 blade prop..it can help the porpoising on certain setups...many many very fine adjustments to the strut and rudder,,along with fins and tabs if you have them..explore the settings one piece at a time,,if you go changing everything at once you will risk never getting the proper setup...

jkr
01-19-2012, 09:33 AM
camaroboy383.
The porpoising efect made because i am trying to make selfrightning without flud chamber.
The steps of the hull doesn't help me with the cg.I had to pull my lipos a bit back.
The next step is to put 2s 2p (14,8v) to get as lower cg as i can.

sailr
01-19-2012, 10:03 AM
I do NOT polish my props! The theory is that the polished prop "sticks" to the water while an unpolished one tends to shed water. I file mine down and then sand with 280 grit and finally with 400 grit but I don't go crazy.

egneg
01-19-2012, 10:49 AM
Prop or hull finish has absolutely nothing to do with Bernouli! Surface finish effects the friction between the object and water - but wait, most of the front of the prop blade runs in air, not water. If you care about learning the fastest finish, by all means listen to the guys who never set a SAW record, they certainly know what's best. :doh:
.

Although I have not personally partaken in SAW events my props have and hold records in different parts of the world.

Doby
01-19-2012, 12:14 PM
Opinions differing from Jay's are not allowed.

camaroboy383
01-19-2012, 12:36 PM
which hurts the hobby more than promotes it.........