Piranha vs Aluminum

[geoffr]

Hi,

We need a new prop for our outdrive on our sailing cat. Wondering if anyone has used the Piranha props and has an option on them vs an aluminum prop.

How to Select a Piranha Hydrobite Boat Propeller

[senormechanico]

I thought I was going to see a picture of something aluminum bitten by a Piranha.

[44'cruisingcat]

Me too!


Only thing I'd be cautious about is if the drive isn't designed for SS props, the extra inertia of it might cause some damage to the gearbox when engaging gears.

[geoffr]

44'cruisingcat - Are you thinking that the composite props are as stiff as a SS prop, hence the comment about the inertia?

senormechanico - sorry about the unintended click bait

[a64pilot]

Originally Posted by 44'cruisingcat

Me too!


Only thing I'd be cautious about is if the drive isn't designed for SS props, the extra inertia of it might cause some damage to the gearbox when engaging gears.

Way back when SS outboard props first came into being, a bunch of us noticed something, used to be with an aluminum prop if you hit a rock , you bought another prop, now with SS if you hit a rock, you bought a lower gear case (foot).

I believe these composite props main purpose is to be sacrificial, that is they bust before anything gets hurt, and if you bust a blade, just pop in another one?

[goat]

Originally Posted by geoffr

44'cruisingcat - Are you thinking that the composite props are as stiff as a SS prop, hence the comment about the inertia?

senormechanico - sorry about the unintended click bait

You're welcome.

goat

[four winds]

Did a summer job renting pontoon and small CC Cape Horn boats. All were equipped with Piranha props and it worked out well for us. Some renters wouldn't even realise they were aground and would grind them down to the hub. Never had any other damage.

Prior years with standard props were much more costly with prop and foot repairs. Not to mention lost rentals do to those repairs.

The blades could be swapped out during turnaround and never lost a rental as a result.

At full power or heavy load there was some flex that effectively reduces power but only those that drove the boats before the conversion could detect it.

If you think there is a reasonable chance of grounding some day these props could be a smart decision.

[44'cruisingcat]

Originally Posted by geoffr

44'cruisingcat - Are you thinking that the composite props are as stiff as a SS prop, hence the comment about the inertia?

senormechanico - sorry about the unintended click bait

Well, that was weird. When I first clicked on the link in the OP, I was led to a page with stainless steel props. That's where the comment on inertia came from.

This time the link led to (presumably) the right place - composite props.
In which case my previous concern would be unfounded.