BOAT PROP: repair or replace?

This is a 14.75" diameter, 17" pitch aluminum prop from my boat. Did some damage to it last year and am using a Piranha propeller (spit).
Here's my aluminum prop:
http://igor.chudov.com/projects/Boat-Prop/
I want to go back to metal props ASAP. I wonder what do you think about the condition of my current propeller.
Should I attempt to grind it a little bit? It does not make sense to pay for refurbishing it, with all the hassle etc, it is easier to buy a new one for $99 at boat-props.com.
Is it really worthwhile to look for stainless props? I do not care much about "top speed", my boat is mostly used for "ski tubing" and such at below top speed. We do not water ski due to lack of skills and desire.
thanks
i
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Don't try and repair yourself. The prop will be out of balance and will tear up the outdrive. It is repairable by a local prop shop but as you say, for $100 you can buy a new one and repair of this one will be $60 to $80 depending on who does the work. SS will improve overall performance (not just top end) but at a lot more dollars.
Bottom line - buy the new prop and be done w/ it. Check ebay first just in case there is something there cheaper.
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thanks. I have not found anything on ebay that would be markedly better than a new $99 aluminum prop at boat-props.com.
I will also do a slight home repair of my old prop to use for emergency situation (for getting to the dock relatively slowly).
Most important: PEOPLE, DO NOT BUY PIRANHA PROPS!!!
i

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What problems did you have with the Pirhana prop?
Ignoramus26555 wrote:

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wrote:

I had blades fall off, in deep water. Happened more than once. Once they fell off when I tried to accelerate boat from zero starting speed. All blades fell off at once. It was in the middle of a clean lake.
i

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Home repair of propellers is not an option in my mind. I do not believe you will be able to "true" the blades of the prop. I question if it is worth paying to get them rebuilt either. I had one rebuilt a couple of years ago, then discovered the hub was slipping too. Figured I had sunk the money in the rebuild so I may as well have the hub replaced too. That prop never did run well. I finally ran it through a gravel bed and wrecked it. I bought a new OEM prop and it worked so much better. I never will rebuild a prop again. Greg
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It's not something you can repair yourself. I've had my propellers repaired for $35-$55. If you plan on dinging it again, stick with aluminum: your propeller will take a beating, but while it's absorbing the impact, less impact is being passed through to the drive shaft.

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I don't see enough damage there to cause much if any concern at all....
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On Thu, 23 Jun 2005 03:24:54 GMT, Ignoramus13822

That is very minor damage. If the boat runs OK, don't worry about it.
You need pitch blocks to repair a prop. You can't do it right freehand, nor can anyone else. Repairing that prop around here (MN) would cost you somewhere between $25 and $40, and it would run as good as a new wheel. If Mark in Forest Lake did it, it'd probably run better than a new wheel.
Stainless vs aluminum depends on motor, desired performance, and environment. I never run stainless props on northern glacial shield lakes (read rockpiles) because I'd much rather destroy a prop than wreck a lower unit or driveshaft. I've destroyed a few aluminum props, never damaged a motor. "Destroy" means tear whole blades off, not minor nicks as you show.
Stainless props are 4X the cost to buy and 4X the cost to repair. On my little green boat with a 115, a stainless prop adds about 5 mph to top end. I run stainless on lakes I know, aluminum otherwise.
On anything 75 HP or below, I doubt if you'd see any difference between aluminum and stainless performance.
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On Thu, 23 Jun 2005 02:11:48 -0500, Don Foreman

On the Texas coast, the bays are generally shallow and full of sand bars and oyster reefs. Most folks run stainless because ss props hold up much better in that environment.
The worst offenders are some of the tunnel drive boats. These typically use 4 bladed ss props and an electrohydraulic actuated jack plate. They will run onto a flat, shut down and wade or drift fish, then blast back onto plane with a big plume of sand, mud, and oyster shell. Personally, I don't like doing that to my boat, motor, prop, or bay bottom. Tunnel drives are also noisy and inefficient, but you can run at top speed in about 1' of water or less.
Pete Keillor
Pete Keillor
Pete Keillor
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I had been in the prop repair business with my dad up until a few years back, and if done properly they willl work as good as a new prop or better. It is not something that can be done without the proper pitch blocks. Other than flat filing any raised burrs off do not grind or file on the outer edges of the blade or attempt to thin an edge out. Its just as important to have equal surface area on each blade as it is to have them all the same pitch. You grind off the edge to remove nicks you'll only have to pay to have it built back up again if yu go the repair route.
NIcks etc on the leading edges of the prop will cause or induce cavitation, which may or may not affect performance but over time it will cause erosion of the blades at the root/hub section.
Rebuild should run between $25-50 bucks depending on type prop and amount of damage........hubs generally run $20 to 60 depending on the prop.....if your payaing more than that your getting shafted.....
A lot of repair stations use the zinc filler rod and the O/A to fill in nicks and missing pieces........This may last for some time but you will find it is very prone to breaking out, and a shop that TIG welds it up is the best route and it does not cost anymore overall.......
While shops maya play the balance deal on props it is highly unlikely that any shops balance most props other than the solid bore props and even then its unlikely...............Foks assume its out of balance due to vibrations but its usually always because it has one or more blades out of pitch that causes the vibrations. You can take a new wheel and check it for balance, and you would be surprised just how far out they are. Even in prop repair school, taught by Merc and back them OMC and Rundquist Prop Tools, they told us straight up, don;t waste time balancing these props......A prop run in water is different than a prop run in air, and variation in weight and balance will not have any effect on it, however its a marketing source for an extra buck for doing nothing to earn it. Only props I ever balanced were the typical bronzes found on ski natiques etc, again a non hubbed, ridgid bore prop.......never a rubber hubbed prop.
If blade shapes, surface area and pitch are the same and if its ground to carry the overall blade thickness on the repair to follow what ws original, it will be fine.
A prop actually only uses the outer 10% of its blade to do the work......the inner portion of the blade is needed to hold on the outer portion and does come into play at low or intermediate speeds, but most work is done by the outer 10% of the blade itself. This is why nicks and dings on the blades tips are important to have repaired. Your one blade tip looks pretty chewed up to me and I would be surprised if that blade itself was not also bent out of original pitch shape......so it really needs to be put on a pitch block and checked, repaired, and not merely file off the nicks etc......
On Thu, 23 Jun 2005 03:24:54 GMT, Ignoramus13822

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Thanks, Roy and others. I received many intelligent replies. I think that what I will do is buy a new prop, and I will grind down the old one a tiny bit to tidy it up slightly, to be used as a spare prop in case of emergencies.
i

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On Thu, 23 Jun 2005 11:51:28 GMT, Ignoramus26555

If you're gonna grind the prop to clean it up a bit the other un-damaged blade(s) should be modified the same way so all are identical. I had noticed vibration on a 7.5 hp motor that I did my own prop repair work on. It was because the two blades were not the same when I was done "repairing" it. Grinding on the larger blade until it matched the other one fixed the vibration. ERS

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If I was going to replace my prop with a new one, I would go with a Michigan Wheel brand or a Propco brand over OEM brands. Michigan wheel and Propco use a slightly different alloy which is more suitable to be able to be straightened and they are usually cheaper and are just as fine as OEM which usually cost more to buy.
Some of the hardest props to repair were the ones made by OMC/Johnson /Evinrude.........Merc, Mariner, yamaha and Volvo among the easiest........but propco and Michigan wheel a piece of cake and much more substantial and cheaper.
Unless you have a performance type boat, I would not use a SS wheel on. Folks think the SS wheels are able to do wonders, but in most cases they can not. On top of that if you hit something hard enough to really tear up a SS wheel you also have more risk in tearing up something else in the lower unit.....I would run aluminum, and use the extra money I saved and buy a spare composite or aluminum prop..........plus you pay more to repair stainless when its damaged, by almost 50% over aluminum repairs, and stainless does get tore up its not destruction proof like some will lead you to believe.
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I have had great luck and many repairs done by this guy he is great. IMHO. I have even bought new from him.
http://www.midwestpropeller.com
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Thanks to all. I just bought a $99.99 aluminum prop, plus $6.50 or so shipping. Made by Michigan wheel.
i
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Do it once and do it right. Put a new SS on there. Those are worth fixing if dinged. Props need to be balanced, and repairs and balancing will cost as much as new.
Steve
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