Question about a trolling motor prop

Hello. I have an older Minn Kota 65 trolling motor. When I got the motor it didn't have a prop. I took it to our local marine dealer and he searched all over for the replacement for it. He fianlly told me that this particular prop wasn't made anymore. He then told me he had a newer prop that he could drill for the shear pin and probably make it work. Long story short he drilled it out the prop fit nicely and it worked just fine. My son and I used last summer with no problems at all. A few days ago my son and my nephew took the motor on a giging trip they went on. They were pushing up river ( they were in about 5 ft of water so we know they didn't bottom it) in very cold water and all of a sudden they lost propulsion. They hauled the motor shaft up and there was no prop. The pin was still in the shaft so I have to think the prop cracked and split along where the holes were drilled (prob due to the extreme cold temp) . My question is this: is there anyway to treat the plastic in todays trolling props to avoid this same problem again? I have thought about about heating the prop before drilling it but I'm afraid I might warp it or get the pitch messed up or something. Does anyone think heating it would help? I know these props are relatively in expensive but at 15.00 - 20.00 a pop I would like to buy as few as possible. Thanks for any feed back you may have. Dave

Re: Question about a trolling motor prop

Hi Dave,...

1st off,... Plastic, when it gets Cold, is Brittle,... No way around it...
I suspect that's the root cause of the failure...
I'd also suspect it was cracked, Long before it broke...

While I really doubt that plastics can be "Heat Treated", to toughen it,....
I've heated the blades of the prop on my unit,+ bent a steeper pitch into it...
It's still workin' just fine, now many years later...

Re: Question about a trolling motor prop

Thanks Bondo. I appreciate your time buddy.