New Prop for Alberg 35

[Pendragon35]

Help! I have an Alberg 35 with a Yanmar 3gm30F engine and a three blade prop. Today a diver cleaned the hull and called to say one blade is missing! So I'm going to need a new prop. The propeller is in an aperture in the rudder. I have never bought a prop much less installed one. Any help/advice on where to start would be very much appreciated. The boat is located at Anchorage Marina, in Baltimore. What will I need to know to even look for a new prop? Thanks in advance for your help.

[Greatest Lakes]

Depends on if you want a fixed or feathering prop. Max prop and Ewol make good feathering props. If you are going to do fixed, there are tons around.

You will need to know shaft diameter, length of taper if any, engine horsepower, gear ratio of your transmission and the length of your waterline. But there should be a size and pitch on your old prop e.g. 18R10

You will not be able to use a folding prop due to clearance issues. Being an alberg 35, it's not exactly a speed demon, but you might still appreciate the .4kts you can get from not dragging a prop through the water. Oh, and you will likely want a 3 blade as a 2 blade can often get a weird vibration from the way the water flows around the keel.

[fstbttms]

Talk to a local prop repair facility. They will ask you questions about displacement, engine h.p., transmission gear ratio etc. Then they will recommend and source the correct prop. Your diver will be able to remove the old one and install the new one.

[Mickeyrouse]

Most propellor manufacturers have a website that will assist you in spec’ing a prop. Michigan wheel does it, Campbell also, and no doubt others. I used a Max Prop for about 20 years. Be forewarned that they require greasing at least annually. That was not possible for me. Excessive wear ensued, then excessive vibration. After the busted motor mounts I went to a Campbell fixed 3 blade.

[fstbttms]

Originally Posted by Mickeyrouse

Be forewarned that they require greasing at least annually.

The owner's manual for the Max Prop Classic (the model that you had) doesn't even recommend lubrication that often. Every two years at most and I've worked on many that were years past that with no issues.

BTW- Max Props (all models) can lubed underwater, so the claim that you were unable to properly maintain yours is specious.

[SailingHarmonie]

Originally Posted by Mickeyrouse

Most propellor manufacturers have a website that will assist you in spec’ing a prop. Michigan wheel does it, Campbell also, and no doubt others. I used a Max Prop for about 20 years. Be forewarned that they require greasing at least annually. That was not possible for me. Excessive wear ensued, then excessive vibration. After the busted motor mounts I went to a Campbell fixed 3 blade.

Maybe, just MAYBE the failing engine mounts were the cause of the vibration that you actually blamed on the prop.

The idea that the prop destroyed your engine mounts is quite far-fetched.

And for the OP: If you have not specified a prop before, and you are not the technically inclined sort to dive into the minutia of prop selection, PLEASE go to you local propeller specially shop and just do what they say.

And be sure that you maintain your zincs. It is POSSIBLE to break off (instead of bending) a bronze prop blade through an impact, but it is more likely that you have seriously degraded metal which then become much more brittle and likely to fracture instead of bending.

[Celestialsailor]

Originally Posted by Pendragon35

Help! I have an Alberg 35 with a Yanmar 3gm30F engine and a three blade prop. Today a diver cleaned the hull and called to say one blade is missing! So I'm going to need a new prop. The propeller is in an aperture in the rudder. I have never bought a prop much less installed one. Any help/advice on where to start would be very much appreciated. The boat is located at Anchorage Marina, in Baltimore. What will I need to know to even look for a new prop? Thanks in advance for your help.

I think I would try to find out why you lost a blade. There might be a problem you need to solve first.

[boatpoker]

lets see a few photos of the prop ... Stray current corrosion is a likely possibility.

Replacing the prop without determining the cause suggests you will be replacing it again.

PS. Take the old prop to a prop shop, they can match it.

[Mickeyrouse]

Originally Posted by fstbttms

The owner's manual for the Max Prop Classic (the model that you had) doesn't even recommend lubrication that often. Every two years at most and I've worked on many that were years past that with no issues.

BTW- Max Props (all models) can lubed underwater, so the claim that you were unable to properly maintain yours is specious.

Reardless what is or isn’t in the manual- which I still have- a representative of PSS told me “grease is your friend” encouraging frequent re-lubrication. The closest yard is two days away, not always available at that. Underwater work is not my forte, and scuba workers are not available for yacht work where we live. Commercial divers are, at commercial day rates. These guys are used to working in the offshore oil industry and don’t get their fins on for less than a $1000 per day. I checked.
We cruised several thousand miles over several years, and frankly I can’t say I ever discerned much speed advantage. Clearly I didn’t test in lab conditions- comparing before-and-after of fixed vs. feathering in identical wind, sea, sail, and loaded boat conditions. No doubt others have made rigorous tests of one versus the other, which would involve changing the props with its attendant haul-outs. I only speak from my experience. Likely different hulls have different results.
Unquestionably its efficiency in reverse is a god-send when the errant mudbank finds its way under your keel.
But “ specious” claims? I didn’t get the prop re-greased as much as it needed. Serious wear and attendant vibration ensued. Motor mounts (three, on two separate incidents) broke.
The Max Prop ( a second, un-worn replacement) has been on my garage floor for the past 6 years.

[Mickeyrouse]

Originally Posted by fstbttms

The owner's manual for the Max Prop Classic (the model that you had) doesn't even recommend lubrication that often. Every two years at most and I've worked on many that were years past that with no issues.

BTW- Max Props (all models) can lubed underwater, so the claim that you were unable to properly maintain yours is specious.

Reardless what is or isn’t in the manual- which I still have- a representative of PSS told me “grease is your friend” encouraging frequent re-lubrication. The closest yard is two days away, not always available at that. Underwater work is not my forte, and scuba workers are not available for yacht work where we live. Commercial divers are, at commercial day rates. These guys are used to working in the offshore oil industry and don’t get their fins on for less than a $1000 per day. I checked.
We cruised several thousand miles over several years, and frankly I can’t say I ever discerned much speed advantage. Clearly I didn’t test in lab conditions- comparing before-and-after of fixed vs. feathering in identical wind, sea, sail, and loaded boat conditions. No doubt others have made rigorous tests of one versus the other, which would involve changing the props with its attendant haul-outs. I only speak from my experience. Likely different hulls have different results.
Unquestionably its efficiency in reverse is a god-send when the errant mudbank finds its way under your keel.
But “ specious” claims? I didn’t get the prop re-greased as much as it needed. Serious wear and attendant vibration ensued. Motor mounts (three, on two separate incidents) broke.
The Max Prop ( a second, un-worn replacement) has been on my garage floor for the past 6 years.
Since then, no more busted mounts.

[Mickeyrouse]

Oh- one last thing. The hub for a Max Prop requires significantly more shaft length than a conventional fixed blade prop. Finned-keel boats will have no difficulty, but those with prop apertures in attached rudders may encounter a tight fit. I fitted an 18” two-blade on to a 1” shaft. I barely had room on the shaft and in the aperture.

[Pendragon35]

[QUOTE=If you have not specified a prop before, and you are not the technically inclined sort to dive into the minutia of prop selection, PLEASE go to you local propeller specially shop and just do what they say.

And be sure that you maintain your zincs. It is POSSIBLE to break off (instead of bending) a bronze prop blade through an impact, but it is more likely that you have seriously degraded metal which then become much more brittle and likely to fracture instead of bending.[/QUOTE]

This is precisely what I plan to do.

[JimsCAL]

I have a 16 inch 2-blade folding prop on my 3GM30F. A couple of thoughts and comments.

1. Check the transmission ratio as there were a couple of options. That will affect the prop pitch.
2. Diameter will be limited by your aperture size. You need a minimum clearance to avoid problems.
3. You might be able to use a feathering prop, but doubt a folder will work in an aperture like the A35 has. I would stick with a fixed prop.
4. Consider a 2 bladed fixed prop if one with sufficient diameter can be fitted. It can sit in the aperture vertically and greatly reduce drag when sailing.

[fstbttms]

Originally Posted by Mickeyrouse

But “ specious” claims?

Because I guarantee that wherever it is your boat lives in Texas, there are hull divers close by, capable of lubricating your Max Prop. But apparently you don't have your bottom cleaned either.

[gonesail]

the 3 blade campbell sailer prop is said to be a good solution for full keeled boats.