ALUMINUM prop......WOW!

[Ub Hauled]

yes they can, I have seen Berillium Copper props bend like they were paper, but they are more resilient then you'd think

[Shooter]

Sad day on the lake folks. She went into a spin and the hull detached from the deck. Never seen anything like this before without hitting anything. One of the sponsons smacked the lake sideways and it just tore the deck off. A little epoxy should do the trick, but this hull is Frrrrrragile!!!!

All back together. I took her back out and and then encountered another problem after about 2 minutes of running. Stopped dead in the water. Disconnected the batts, taped up again, and it went about 300ft and stopped. I repeated this several times before I ran out of tape!! I've narrowed it down to the SC. Judging from the info on the forum, it sounds like the cap. I ordered a few from Kintec this morning.

Geeeeezz...never had this much trouble with a boat before. I can't complain though because I've never had a boat out the box this FAST for the price! (I think my last FE after all said and done was around $600!)

Anyways, simply just trying to do a prop comparison. Still love the UL-1, but am quickly getting frustrated with the fragility.

[Shooter]

BTW - The Aluminum props only have 1/4 the mass of a Beryillium prop!! 2grams compared to 9grams!! These things are light....and as someone else mentioned suprisingly resiliant.

[Fluid]

The prop mass difference is completely insignificant compared to the rest of the rotating mass. It is such a small percentage of the total motor rotor and cable that there can be no noticeable difference in performance. But an aluminum prop has major disadvantages over a CuBe or SS prop - the most important being the inability to take a sharp edge. The aluminum alloy used in boat props is a coarse-grained metal that is too soft to take an edge. The result is a noticeable performance reduction compared to CuBe. Fool yourself if you want to, but the main advantage of an aluminum prop is the lack of the need to balance it.



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[Shooter]

Fluid - I agree completely with the inability of holding a sharp edge. This is no doubt a bummer. Would plastic props suffer this same predicament??

I question however the significance of the rotating mass. At the RPM's we are running, ANYTHING would seem to help. The prop hub mass doesn't have much of an effect since it is closest to the centerline, but the blades are THE farthest rotating mass from the centerline in the entire system. I think your comment "no need to balance" indirectly supported this.

Probably a moot point if we can't hold a sharp edge though....

[Fluid]

Question all you want, but the only thing that a reduced rotating mass does is reduce the time needed for acceleration. It would have no effect on top speeds. But that percentage of mass difference is so tiny - far less that one percent - that any difference would never be noticed in a boat. It would be covered up by the increase in cavitation - in fact acceleration of the boat could be even slower if the prop speed becomes too fast to 'hook up' quickly.



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[Eodman]

What kind speed do you lose with an aluminum prop? For fun running & ease of use I would think the aluminum one would be the way to go!

Are we talking 8 - 10 mph or just 2 or 3?

[6S HYDRO]

definitely not 8-10, and probably not 2-3.

[Jeff Wohlt]

I remember Chris Fine telling me about the benfits of Alum props...I could never agree on that one. Sounded like it was better.

I never saw any difference but I did remove a couple blades long ago when a Octura prop would have survived. With high rpms I have heard of people throwing blades of on alum props.

We all ran alum props on our bassboats years ago....we then went to SS.

When you are fishing a back end of a cove in 2 feet of water and don't trim your motor up and the alum blade hits the bottom you can bend a blade...then you run it and blow your lower unit seal out.....the SS it does not bother.

I see Alum as better than CF but not near as good as BU or SS.

[Shooter]

I haven't completed the testing yet, but so far I haven't measured any significant difference in top speed. Assuming a frictionless axis of rotation, there is no theoretical difference in max angular velocity between a lighter or heavier prop, so top speed should be the same. However, the prop theoretically will spin up to RPM faster (more angular acceleration!!) Perhaps too much acceleration as Fluid mentioned.

If you are looking at it just for convenience (no balancing, no cancer causing dust, etc....), I'd say Go For It!!