Aluminum props from China/Japan for Gas and Nitro boats ?

[James E Beasley]

I see a ton of these on eBay now. I was always told that aluminum props were dangerous and would throw blades at our rpms. Anyone using / tried these yet? Are they using better alloys that make them strong and safe? An aluminum prop weighs less than a brass prop so this would also affect rpm, torque, etc I would think? Would appreciate your thoughts and observations. James

 

[Glenn Gates]

James, Since the Alum. would have a lower tensile and sheer strength Than BeCu or S/S The blades would depart sooner. BUY AMERICAN!!!!!!!!

 

[moparbarn]

same as full scale high performance boats, james. seen any hot rod ob's or ib's sporting aluminum? nope, all polished stainless, for a reason B) . it's not entirely uncommon for an ob, running a stainless surfacing prop to sling a blade, i've done it on a couple bass boats. bet foley has too........alumnium would be like russian roulette, with a hachet . plus, we're turning WAAAY more rpm's than the full scale boats.

 

[shoboat]

James,

I received your order the other day, Thank You!

I would not risk the safety factor on our boats with an aluminum propeller.

Some customers sling stainless steel blades off now with the power we are making these days.

From a liability standpoint I want nothing to do with them.

Enjoy Testing,

Mark Sholund

 

[anthony_marquart]

I tried one of the aluminum CNC blades from Zipp,.. It seemed ok,.. but my other props worked better so it never got much use..

 

[RaceMechaniX]

I can't say specifically to some of the foreign props, but the 7075 props Andy was producing were pretty stout. I have beaten on a 6720/3 he made with a CMB35RS with no problems. A helpful tip if you do use one is to sand down the milled finish like you would finish a normal prop. Pay particular attention near the hub where cracks are likely to start. The counter rotating sets of aluminum props from Fightercat Racing have been popular with the electric cat guys. I have seen several SAW runs with high power systems and the props survive including the frequent flip and tail blow-out. These are also 7075.

 

[Joe Petro]

We tested some 7075 CNC aluminum props for the gas boats and did not have good luck.

All threw blades. We will not sell them.

Up to 50mm they have been great. No problems at all, even on the 20 boats.

The diameter and mass of the larger props make then unsafe.

We do sell some 70 and 78mm cast aluminum props that have been excellent. I even race my Easy Vee with one and have never had an issue.

The CNC props are very nice, but for any size over about 50mm, I would use them as display props only.

Don't even ask me how the carbon fiber gas props worked..................

Joe

 

[anthony_marquart]

Joe has a cool job!!!

 

[James E Beasley]

Thanks guys for the great feedback. Confirmed what I already thought was reality. James