Balancing and sharpening help

[6sHyper]

Ok so i'd like to start sharpening my own props, so what kinda tools are you guys using and what things should i be buying, any good links or tips would be greatly appreciated as i have really not much knowledge on this, thanks.

[Brushless01]

Im using the Grim racer prop balancer, metal file, sand paper and then some polish.

[GP73]

Best guide:

http://www.offshoreelectrics.com/info-pages/sharpenandbalance.php

[egneg]

Any magnetic balancer, 220/400 grit wet/dry paper, 6 or 8 inch single cut file, a set of needle files, modeling clay. These are the necessary items then once you get going you may want some rifler files, cupping balls, and a 1" x 30" belt sander with 120 grit such as found at harbor freight. http://www.harborfreight.com/1-inch-x-30-inch-belt-sander-2485.html Never Dull and other polishing compounds are optional but aren't really needed.

[SweetAccord]

This is a awesome balancer: http://www.offshoreelectrics.com/proddetail.php?prod=ose-80310

If you make the prop shaft sharp (make the end point into a needle) and centered and balance it with no prop on it (I use drop of nail polish on end of shaft), and add a razor blade on the side where the shaft touches (less friction) you can get an extremely sensitive balancer and perfectly balance your props. You may also add a drop of light oil on the prop shaft to make it even more friction free to get the ultimate balance point. It's more work though but I'm accurate to the T.

The best polishing compound I find out there is Mimbro 6 Cleaning/Polishing. Will give you a mirror finish when you use it with a soft head dremel and it goes a long way. I polish stainless steel props with it and they always come out with a mirror finish! And I do mean mirror to where you can see yourself clearly. On beryllium props it's amazing.

[785boats]

There is a school of thought that highly polished surfaces on props has a tendency to vaporise the water across the blade, reducing efficiency. I always leave a satin finish on mine.
Anyone got proof either way?
Cheers.
Paul.

[siberianhusky]

A respirator with good dust filters! Most important thing if you're working on berrylium, serious health issues with the dust and it's cumulative, it never leaves you body once it's in there.
Paper masks don't cut it at all, use one and sand some drywall, see how much dust you blow out of your nose!
To be safe you should do all your prop work wet and never use any type of machine that can raise lots of fine dust.
It's not only your health but everyone and anything that lives in your house.
It might take a little longer by hand but the end results can be exactly the same. Probably better as you have more control and material comes off slower!

[PDR447]

yes beryllium is BAD. I'm sticking with prather stainless props personally. sure I may not have the BEST prop possible for my boat due to limiting my selection but for sport boating I'm fine with that. then I don't have to bother even handling beryllium.

[SweetAccord]

There is a school of thought that highly polished surfaces on props has a tendency to vaporise the water across the blade, reducing efficiency. I always leave a satin finish on mine.
Anyone got proof either way?
Cheers.
Paul.

Yes there is proof. There is a web page where they proved a prop (for all out speed) tha was polished on both side is faster. Quote "a slippery prop is a faster prop" as I recall. They did extensive testing and found +1 +3 MPH faster if I'm recalling correctly. It's not huge but every thing helps.

They also stated for hole shot and lower RPM like racing (turning) having a finish is better. So it depends when you break it down what you are doing with your boat that determines what you want to do with the prop.

[sailr]

I don't polish mine. Water "sticks" to a polished prop. If you leave it unpolished, it breaks the capillary action.

[SweetAccord]

Here is the quote from the page: it's not as much as I thought but it's still faster and I have found the same results:

"Generally speaking, props that are high polished on both the face & back, including the hub; will achieve the highest top speed. However there is some advantage to a rough or less smooth surface, on the (back) of the blade area. It gives more bite for short course acceleration, however can cause drag at higher speeds. There's little to no difference between a satin finish on the back of the blade vs.high polish on both sides, until (very high speeds) are reached. I've tested the above polished vs satin props on the same boat, back to back. Satin = 72mph and polished = 72.4mph. You can draw your own conclusions weather it's worth polishing your props, however I polish mine for max speed potential.

Should both anterior & posterior facing surfaces need polishing"? There are conflicting opinions RE: this subject. Some say / never polish the BACK of the blade; as this is the push area and should be left untouched. And somewhat ruff to allow for more bite, for the prop to dig-in with less slip. I agree with the above, only when operating at lower RPM!! With today's surface drive applications and high RPM; it is vital that both sides (Back & Face) of the prop blades, be polished! The entire surface of the prop should be as smooth as possible, to reduce drag and increase efficiency. Props that are thin and sharp, with (both sides of the blades polished); pierce, and flow thru the water with less resistance. A slippery prop is a fast prop........!!!! However when heat racing in a short oval course, there is some advantage in keeping the back side of the blade somewhat coarse. This allows quick acceleration, and helps pop the boat, while pulling out of the turns."

Paul Govostes

Source: http://www.rcprops.com/TechNotes/rcprop_tech_info.htm (http://www.rcprops.com/TechNotes/rcprop_tech_info.htm)

[785boats]

Well there Ya go.
Thanks for that Sweet. So a bit of a mixture. All good info.
Cheers.

[SweetAccord]

Well there Ya go.
Thanks for that Sweet. So a bit of a mixture. All good info.
Cheers.

:laugh:

[6sHyper]

Wow i never even noticed this topic got going, thanks for the info guys, i had already gone and bought a balancer, i ended up getting the aquacraft grimracer, is this a good one?

http://www.offshoreelectrics.com/proddetail.php?prod=dh-aqub9575

Also i keep wondering since i haven't recieved my balancer or my new props yet, whats the process of balancing a 3 blade? i would imagine it must be different than a 2 blade.

[NORMKRIS]

[QUOTE=6sHyper;297882] whats the process of balancing a 3 blade?

Lots of time and be very patient!:Praying:

[wiskers]

A respirator with good dust filters! Most important thing if you're working on berrylium, serious health issues with the dust and it's cumulative, it never leaves you body once it's in there.
Paper masks don't cut it at all, use one and sand some drywall, see how much dust you blow out of your nose!
To be safe you should do all your prop work wet and never use any type of machine that can raise lots of fine dust.
It's not only your health but everyone and anything that lives in your house.
It might take a little longer by hand but the end results can be exactly the same. Probably better as you have more control and material comes off slower!

If one were to use oil or water along with filing and sanding would you still contaminate the air in the house? Should one be doing this outside? I realy would like to try balancing and sharpening a prop or 2, but this berrylium info makes me nervous.

[6sHyper]

hey guys i just recieved my balancer and some new props from OSE, man Steve ships so fast every time!! the best service i've ever had to be honest.


anyways i'm really looking to sweeten up this x447/3 i have for my 33" DF mono, so if anyone has some good pointers for simple things i should do to this prop i would GREATLY appreciate the info, thanks.

[bbosncali]

Quick question just happen to notice that a 120 30in ch belt be used with a hobby bench sander I just happen to have one my question is how would you apply it? Is it to help sharpen cause that's the only way I see it working thanks

[egneg]

Quick question just happen to notice that a 120 30in ch belt be used with a hobby bench sander I just happen to have one my question is how would you apply it? Is it to help sharpen cause that's the only way I see it working thanks

I use it to not only to sharpen but to detongue, back cut, and thin/balance as well. When using the belt sander make sure you wear a mask and wipe the area down with a damp paper towel when done. It takes a bit of practice and I use the area above the back plate as it's more forgiving.

[bbosncali]

Ok I think I got it... thanks for the help...

[BHChieftain]

http://www.osha.gov/dts/hib/hib_data/hib19990902.html

[Steven Vaccaro]

I have seen a racer use one of these.
http://www.micromark.com/Variable-Speed-Mini-Belt-Sander,7757.html
Because of the size and portability, its very cool and on the wish list some day,

[D&D]

To add my comment as to wether a prop should be polished on both sides; look at any of the professional racing boats.......

[Steven Vaccaro]

To add my comment as to wether a prop should be polished on both sides; look at any of the professional racing boats.......

Its not a one to one comparison.