prop orientation

[margitchris]

Is a prop's RH or LH orintation read from the stern? So a RH prop will turn clockwise to move the boat forward when viewed from the stern? I took my old prop to a shop and was told is was really a bit beyond reconditioning. In addition to being distorted in pitch it didn't "sing". ( The guy held the prop by a rope strung through the hub and banged the blades with a wrench. Instead of a bong he got a clank.) So, for a Yanmar 2gm I'm looking for a 13" diameter, 10" pitch, 1" shaft RH prop. Does that sound right?

[ILikeRust]

Why would it matter whether the propellor "sings" with a bong rather than a clank? It's not a church bell or symphony gong - it's a boat propellor.

I could see that a dull thud or clunk *might* *maybe* *could* indicate a crack somewhere in the propellor, but I do not think that just because a propellor doesn't ring like a bell automatically means it's no good.

[Rachel]

Is a prop's RH or LH orintation read from the stern? So a RH prop will turn clockwise to move the boat forward when viewed from the stern?

Yes, that is how the "handedness" works.

[Paulus]

An automotive shop talked me into replacing the ball joints on my SUV a while ago - he showed me how much wobble and clearance there was with the car on the lift... He convinced me and I let him do the $1,200 job. When done, however, I asked him if he would put the car back on the lift and hand me the crowbar he used to show me the "need" before - I duplicated what he did to show me and got the exact same result - wobble and clearance just as before.

All of a sudden this was somehow acceptable and my car was good for another 80,000 miles....

Make sure you "sound" your new prop before pulling out your wallet....

[mitiempo]

A solid prop should ring and one that has lost the zinc in the bronze due to electrolysis will have a dull thud or clank sound. Manganese bronze can contain up to 39% zinc and is commonly used for propellers.

[margitchris]

As he was preparing to sound the prop, he was commenting that they degrade from the inside out. He spent time with me and charged nothing. He didn't even try to sell me another prop; said to look on Ebay. He seemed pleased to talk to a sailor and told me several sailing stories.

[Rachel]

If it's a bronze propeller, then just out of curiosity, does the metal look pinkish at all (maybe only in places)?

[margitchris]

Thank you for the reminder, Rachel. In truth I had forgotten to look for the pinkish hue, but the prop was painted with various coats of anti-fouling paint anyway. I had definitely noticed the tell-tale hue in other bronze hardware I had removed from the boat.
I am
in shock with the price for new Yanmar motor mounts...
sore from contorting my nearly 60 year old body into rediculous spaces...
and once again apalled at the shoddy work of the person/persons who repowered the boat way back when. A particleboard panel was used to support the fuel tank...
glad to have removed the fuel tank because the rubber hose rudder tube, which is otherwise inaccessible, needs replacing.

[Rachel]

Particle board!? Ugh, I can see why you are now closely evaluating everything. I've seen various boats that were "Oh, it's been re-powered!" and then you look more closely and wish that instead they could just have left the old engine in place and handed you the new one in the factory crate because the installation was so bad. I haven't seen particle board yet though.

[mitiempo]

The anti fouling may have been the problem. A prop shouldn't be painted except with the specific coatings designed for propellers.

http://forums.sbo.sailboatowners.com/sh ... ing%20prop