Prop sharpening & other tips for new boaters
#1
Thread Starter
My Feedback: (12)
Join Date: Jun 2004
Location: Columbia,
SC
Posts: 8,044
Likes: 0
Received 0 Likes
on
0 Posts
Prop sharpening & other tips for new boaters
Do I need to sharpen and balance my new prop?
The question of whether props need to be sharpened and balanced, and how it should be done comes up often. The answer to the first question, should they be balanced, is absolutely yes! Prop manufacturers sell unbalanced, dull props. In theory, they could balance and sharpen them before they sell them, but since boaters tend to "personalize" their props it's probably best that the manufacturers sell raw props. Shipping them raw also makes them less succeptable to damage during shipping and handling in stores.
So, what does a new person do with this raw prop? Well, there are several choices. The first is learn to sharpen and balance props. I provided links below to help those who might want to do this. Another option is perhaps you have someone local who can sharpen it for you. And the final option is many of the racing oriented online vendors offer a sharpening service. For a small fee, they will take that raw prop you order from them and send it to you sharpened, balanced, and polished and ready to put on your speedy new boat. If you're not excited about spending a couple hours with the prop, a few files, an assortment of really fine sandpaper, and a prop balancer, I heartily recommend letting someone else do it for you. If you're too proud to do this, consider the fact that many racers also use this kind of service.
I was going to extract information from a bunch of places and perhaps write an article on sharpening and balancing props. But if someone else has already done this, and better than I would have done, I'm just going to link to their information.
How do I sharpen and balance my new prop?
Here are some articles that describe prop sharpening, balancing, and modifications:
http://www.offshoreelectrics.com/prop_balance.htm
http://www.rcprops.com/TechNotes/rcprop_tech_info.htm
http://www.geocities.com/jwohlt5362/Propguide1.html
http://rcboat.com/prop.htm
Note, many props are made of an alloy containing beryllium. Dust containing beryllium is hazardous. Here is a link to a fact sheet: http://www.state.nj.us/health/eoh/rtkweb/0222.pdf When working with this material, it's important to wear a dust mask, and take steps to control the dust. I prefer hand tools, rather than a dremel, because it reduces the amount of dust generated, and the distance it spreads.
What about after run oil?
Working on this section. Until it's done, here's some links to get more information:
http://rcboat.com/after.htm
How can I find other boaters in my area?
As I was writing a reply about an upcoming race I realized many people reading this thread may be interested in finding other people to run boats with, and perhaps race. Here's links to 2 North American based boating organizations:
North American Model Boating Association (NAMBA) http://www.namba.com
International Model Power Boat Association (IMPBA) http://www.impba.net
How do you choose which one to join? Go to the web sites, find your district and look for the nearest club. Each of the organizations has strong and weak areas, pick the one that works for the place you live.
How do I choose the right size prop for my boat?
Here are some charts showing ranges for common boat sizes:
http://www.funrcboats.com/prop_chart1.htm
Octura prop chart that Ron posted:
http://www.pirespreto.com/octura_catalog3.htm
How much oil should I add to bring my fuel up to nn%?
To determine the quantity, do the following math...
Ounces of fuel times desired percentage = desired ounces of oil
Ounces of fuel times actual percentage = actual ounces of oil
Desired ounces of oil minus actual ounces of oil = needed ounces of oil .
Note that this will be a bit off because you have to pour off a bit of fuel to make room for the oil you add. This means you'll end up starting out with a lower amount of oil and fuel, throwing the calculation off a bit. However, rather than worrying about it, the above will give you a slightly higher than the desired oil percentage , which certainly won't hurt the engine...
Here's an example:
128 ounces times 18% = 23.04 desired ounces of oil
128 ounces times 12% = 15.36 actual ounces of oil
23.04 - 15.36 = 7.68 needed ounces of oil .
The question of whether props need to be sharpened and balanced, and how it should be done comes up often. The answer to the first question, should they be balanced, is absolutely yes! Prop manufacturers sell unbalanced, dull props. In theory, they could balance and sharpen them before they sell them, but since boaters tend to "personalize" their props it's probably best that the manufacturers sell raw props. Shipping them raw also makes them less succeptable to damage during shipping and handling in stores.
So, what does a new person do with this raw prop? Well, there are several choices. The first is learn to sharpen and balance props. I provided links below to help those who might want to do this. Another option is perhaps you have someone local who can sharpen it for you. And the final option is many of the racing oriented online vendors offer a sharpening service. For a small fee, they will take that raw prop you order from them and send it to you sharpened, balanced, and polished and ready to put on your speedy new boat. If you're not excited about spending a couple hours with the prop, a few files, an assortment of really fine sandpaper, and a prop balancer, I heartily recommend letting someone else do it for you. If you're too proud to do this, consider the fact that many racers also use this kind of service.
I was going to extract information from a bunch of places and perhaps write an article on sharpening and balancing props. But if someone else has already done this, and better than I would have done, I'm just going to link to their information.
How do I sharpen and balance my new prop?
Here are some articles that describe prop sharpening, balancing, and modifications:
http://www.offshoreelectrics.com/prop_balance.htm
http://www.rcprops.com/TechNotes/rcprop_tech_info.htm
http://www.geocities.com/jwohlt5362/Propguide1.html
http://rcboat.com/prop.htm
Note, many props are made of an alloy containing beryllium. Dust containing beryllium is hazardous. Here is a link to a fact sheet: http://www.state.nj.us/health/eoh/rtkweb/0222.pdf When working with this material, it's important to wear a dust mask, and take steps to control the dust. I prefer hand tools, rather than a dremel, because it reduces the amount of dust generated, and the distance it spreads.
What about after run oil?
Working on this section. Until it's done, here's some links to get more information:
http://rcboat.com/after.htm
How can I find other boaters in my area?
As I was writing a reply about an upcoming race I realized many people reading this thread may be interested in finding other people to run boats with, and perhaps race. Here's links to 2 North American based boating organizations:
North American Model Boating Association (NAMBA) http://www.namba.com
International Model Power Boat Association (IMPBA) http://www.impba.net
How do you choose which one to join? Go to the web sites, find your district and look for the nearest club. Each of the organizations has strong and weak areas, pick the one that works for the place you live.
How do I choose the right size prop for my boat?
Here are some charts showing ranges for common boat sizes:
http://www.funrcboats.com/prop_chart1.htm
Octura prop chart that Ron posted:
http://www.pirespreto.com/octura_catalog3.htm
How much oil should I add to bring my fuel up to nn%?
To determine the quantity, do the following math...
Ounces of fuel times desired percentage = desired ounces of oil
Ounces of fuel times actual percentage = actual ounces of oil
Desired ounces of oil minus actual ounces of oil = needed ounces of oil .
Note that this will be a bit off because you have to pour off a bit of fuel to make room for the oil you add. This means you'll end up starting out with a lower amount of oil and fuel, throwing the calculation off a bit. However, rather than worrying about it, the above will give you a slightly higher than the desired oil percentage , which certainly won't hurt the engine...
Here's an example:
128 ounces times 18% = 23.04 desired ounces of oil
128 ounces times 12% = 15.36 actual ounces of oil
23.04 - 15.36 = 7.68 needed ounces of oil .
#2
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
Those are excellent articles Chuck. I had those saved until my 'puter crashed about a month ago.
Another good article: http://rcboat.com/prop.htm
Another good article: http://rcboat.com/prop.htm
#3
Thread Starter
My Feedback: (12)
Join Date: Jun 2004
Location: Columbia,
SC
Posts: 8,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
No problem Ron, just trying to share information. I added your link to the list so everything is in one place. I also finished the opening paragraph, which had just ended in mid-sentence.
#6
Senior Member
My Feedback: (1)
Join Date: Jun 2005
Location: Quinton,
VA
Posts: 728
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
Chuck, I found it very helpful. I was a COMPLETE NEWB to boats 3 months ago and with the help of this forum I think I have been recategorized as just a NEWB.
#7
Thread Starter
My Feedback: (12)
Join Date: Jun 2004
Location: Columbia,
SC
Posts: 8,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
Thanks for the feedback. If you think of things that would be useful to add to this thread, let me or Ron know. Have you hooked up with any clubs? The Old Dominion club in Chesapeake is having a race late August. If you've never seen one it's worth the trip, even if you're not ready to race yet.
#8
Senior Member
Join Date: Aug 2005
Location: Chesapeake,
VA
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
Hey, I have a Octura X432, and I have a devil of a time getting up on plane. Would back cutting help fix this?
#11
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
Here is an Octura prop chart to help you figure out what prop that you need with the pitch and diameter in both SAE and metric measurements:
http://www.pirespreto.com/octura_catalog3.htm
http://www.pirespreto.com/octura_catalog3.htm
#12
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
I have some prop charts that I finally found that I will send to some people at no cost, just PM or e-mail me your address. It's an older one so most of the newer props aren't on them. It does cover Octura, Prather and ABC props in all sizes. It shows the prop diameter and pitch in both SAE and metric numbers and expected speeds at several RPM ranges figuring in a 15% slippage factor. Copies are limited.
#13
Junior Member
My Feedback: (2)
Join Date: May 2005
Location: COLUMBUS,
GA
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
looking for a place near georgia that i can send my props to get sharpen and balanced please let me know if you guys know of any thanx
jorge
jorge
#14
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
I don't know of any place near you to send them to but www.cmdracing.com sells them sharpened and balanced in Florida. Go into the Dockside and on the left is the Prop Wall. It's a .pdf that is updated daily in case you don't see what you need. You can request props also. I got 4 of them last winter, the service is great. If you look at the pix of the month, some of the ladies in there are Andy's employees!
As an addition to my posting above, I can not fax or e-mail the prop charts. Your name and address will be completely confidential.
As an addition to my posting above, I can not fax or e-mail the prop charts. Your name and address will be completely confidential.
#15
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
I balance and sharpen my own props. I use a Magnetic Balancer for checking my progress, and use Bear Abrasive polishing sticks. These are six inch long pencil sized hard polishing sticks used to polish out mold cavities mainly in plastic injection mold shops. They come in all grit sizes, flat or round and can be shaped on a small grinder to help get the ends started for polishing whatever contour. After I have all of the surfaces rubbed down with these I will switch to wet/dry sandpaper and then compounds to lightly buff and polish.
Using the stones give you much more control on keeping the shape of the prop, and progress down past the sandcast or sandblasted finish faster than just sandpaper. Especially in the "kick-out" lip or "cup" area of the blades, where all the control is needed to help hold a good back edge.
These products can be found in such large machine tooling catalogs such as MSC in the abrasives sections.
Using the stones give you much more control on keeping the shape of the prop, and progress down past the sandcast or sandblasted finish faster than just sandpaper. Especially in the "kick-out" lip or "cup" area of the blades, where all the control is needed to help hold a good back edge.
These products can be found in such large machine tooling catalogs such as MSC in the abrasives sections.
#17
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
The two primary prop suppliers are Prather and Octura. Others maybe APC or Dumas. Each one of these companies only supply you with a raw casting. The balancing part is left up to the buyer, and it must be performed before the prop is used - this can be done with a file, and a balancer. It is your choice to further it by sharpening/polishing for better performance.
There are companies that sharpen for you for a fee. Ive noticed prices, and there is usually another 1/2 to 2/3 total tacked onto the price of just what the prop would cost.
Expect to not be so good at the polishing or the sharpening deal on your first prop. Those stones I've mentioned for polishing are worth hunting out if you plan on taking up prop work. Otherwise, just a small fine tooth file will do the job of getting it balanced and ready to go.
The company that sells the boat should have already balanced the prop for you if it comes ready to run. Electrics that are commonly sold have plastic props, until you step into the competition type. Most nitro boats use metal props.
There are companies that sharpen for you for a fee. Ive noticed prices, and there is usually another 1/2 to 2/3 total tacked onto the price of just what the prop would cost.
Expect to not be so good at the polishing or the sharpening deal on your first prop. Those stones I've mentioned for polishing are worth hunting out if you plan on taking up prop work. Otherwise, just a small fine tooth file will do the job of getting it balanced and ready to go.
The company that sells the boat should have already balanced the prop for you if it comes ready to run. Electrics that are commonly sold have plastic props, until you step into the competition type. Most nitro boats use metal props.
#22
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
Use a prop balancer. The one that Top Flite has for just under $20.00 works great, almost too well for a first-timer, it's really sensitive. We use the same one that they do for plane props. Even the R/C car guys are using them to balance tires.
#23
Thread Starter
My Feedback: (12)
Join Date: Jun 2004
Location: Columbia,
SC
Posts: 8,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
Some of the links in the original post don't work any more, but it looks like there's a time limit on how long a post can be edited. So, here's an updated list.
Note, many props are made of an alloy containing beryllium. Dust containing beryllium is hazardous. Here is a link to a fact sheet:[link=http://beryllium fact sheet]http://www.state.nj.us/health/eoh/rtkweb/0222.pdf[/link] When working with this material, it's important to wear a dust mask, and take steps to control the dust. I prefer hand tools, rather than a dremel, because it reduces the amount of dust generated, and the distance it spreads.
ORIGINAL: piper_chuck
How do I sharpen and balance my new prop?
Here are some articles that describe prop sharpening, balancing, and modifications:
http://www.offshoreelectrics.com/prop_balance.htm
http://www.rcprops.com/TechNotes/rcprop_tech_info.htm
http://www.geocities.com/jwohlt5362/Propguide1.html
http://rcboat.com/prop.htm
How do I sharpen and balance my new prop?
Here are some articles that describe prop sharpening, balancing, and modifications:
http://www.offshoreelectrics.com/prop_balance.htm
http://www.rcprops.com/TechNotes/rcprop_tech_info.htm
http://www.geocities.com/jwohlt5362/Propguide1.html
http://rcboat.com/prop.htm
#24
My Feedback: (1)
RE: Prop sharpening & other tips for new boaters
Previous thread:
I included snapshots of the stones I use on my props for shaping and polishing. They seem a little forein to use at first, but once you work with them a little bit, its as easy as using a crayon. I consider it the only way to properly hold a contour when rubbing down a cupped surface. Sandpaper slaps around too much, and can wipe out any edges without realizing it until after it happens, plus these hold their "edge" a lot longer. In fact if properly lubricated while polishing with light oil or mineral spirits, indefinetly as you go. If you restrain the area that your polishing like near hub details, it is soft enough to form itself to the radius as it does its polishing.
Give them a try if your not using them already, you wont go back to sandpapers.
Bear Abrasive polishing sticks. These are six inch long pencil sized hard polishing sticks used to polish out mold cavities mainly in plastic injection mold shops. They come in all grit sizes, flat or round and can be shaped on a small grinder to help get the ends started for polishing whatever contour.
Give them a try if your not using them already, you wont go back to sandpapers.
#25
Junior Member
Join Date: Sep 2005
Location: Cincinnati,
OH
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
RE: Prop sharpening & other tips for new boaters
Hey Ron what does it mean when it says cupped? Is this better, just a preference thing or is there a special application for this? Also, What does cut imply? What's cut?