Ray
Well-known member
Being raised in the era of through hub exhaust motors with out shear pins I was caught off guard this last week when a little twig popped the prop on my 60 year old 3hp Seahorse angle foot motor. No tools in the mini boat, and no spare materials to make a pin out of. To say my proverbial pants were around my ankles is an understatement. I did discover that the mini boat does not paddle nearly as well as the BB3, which is three times its size.
After getting back home I took the prop apart and noted that the shear pin was a piece of 1/8 inch brass rod. Easy enough to find and make a handful of pins to keep in a tool box.
However, I went searching for additional info and noted on iBoats forums that brass rod is the recommended DIY method, but that the factory pins are not brass. A parts site does not state what they are made out of. Some posts claim a weak stainless steel or cast iron is used for old Johnny Rude shear pins. One poster prefers aluminium nails cut down to fit since brass rod is too brittle and prone to snapping at the slightist offense. Lots of posts about using common nails which are way too hard and could result in the prop being stuck on the shaft with a partially sheared pin.
I can order some factory pins, but with shipping the cost is about 500% over the price of brass rod from Ace Hardware. And the brass rod makes about 36 pins rather than just one from the parts dealer.
As of yet I have not been able to find 1/8 inch aluminium rod, but I think a local welding supply shop might have that kind of material.
So, what have users of antique outboards used for shear pins when a factory replacement is not an easy option?
After getting back home I took the prop apart and noted that the shear pin was a piece of 1/8 inch brass rod. Easy enough to find and make a handful of pins to keep in a tool box.
However, I went searching for additional info and noted on iBoats forums that brass rod is the recommended DIY method, but that the factory pins are not brass. A parts site does not state what they are made out of. Some posts claim a weak stainless steel or cast iron is used for old Johnny Rude shear pins. One poster prefers aluminium nails cut down to fit since brass rod is too brittle and prone to snapping at the slightist offense. Lots of posts about using common nails which are way too hard and could result in the prop being stuck on the shaft with a partially sheared pin.
I can order some factory pins, but with shipping the cost is about 500% over the price of brass rod from Ace Hardware. And the brass rod makes about 36 pins rather than just one from the parts dealer.
As of yet I have not been able to find 1/8 inch aluminium rod, but I think a local welding supply shop might have that kind of material.
So, what have users of antique outboards used for shear pins when a factory replacement is not an easy option?
