"Pinning a prop", ever heard of this?

[Rowroy]

I was talking to the local marine parts guy and he mentioned that he no longer re-hubs props, but rather "pins" them. Apparently, what he does is drive several brass pins through the hub from the outer radius of the prop, thereby linking the prop, hub, and inner hub together.

He states that he can do this at a fraction of the price of a traditional re-hub job and it's much safer and will last longer. When I pressed him on maintaining alignment, he said that was a "non-issue" because the pins will hold everything in place.

This sounds like a BS fix to me, but I'm also a boating novice. Has anyone else heard of this? Am I crazy for thinking this is crazy?

 

[Silvertip]

Re: "Pinning a prop", ever heard of this?

Besides being a poor excuse for a repair, it eliminates the benefit of having a cushioned hub. The cushioned hub helps reduce lower unit damage from a prop strike with an underwater object. Note that I said reduces!!! Hit anything like a rock at full speed and the cushioned hub won't help much.

 

[tx1961whaler]

Re: "Pinning a prop", ever heard of this?

It's a BS fix. He's either too lazy, greedy or unskilled to do a proper repair. That said, I have pinned spare prop that I keep in the boat for emergencies. It is a spun prop that is dinged up pretty bad and is the wrong pitch. I have only used it once.

 

[Silvertip]

Re: "Pinning a prop", ever heard of this?

And chances are the next time that prop strikes anything it will be junk because cushion hub props are not designed for "shear pin style" operation. I suspect the hub would be destroyed.

 

[Silvertip]

Re: "Pinning a prop", ever heard of this?

And chances are the next time that prop strikes anything it will be junk because cushion hub props are not designed for "shear pin style" operation. I suspect the hub would be destroyed so now you need a new prop instead of just re-hubbing.

 

[Rowroy]

Re: "Pinning a prop", ever heard of this?

That's what I thought.

 

[sdsaw]

Re: "Pinning a prop", ever heard of this?

I had a SS Yamaha prop that needed rehubbing and took it to a highly recommended shop out this way and he warned me that he couldn't guarantee that it will hold/last.

He advised to drill and tap and install some SS screws to pin the hub to the prop if it didn't hold(didn't have to)

If you go this route(pin) I would tap the holes(10-32) so that they will be removable in the future.

Scott

 

[pvmtsux]

Re: "Pinning a prop", ever heard of this?

sounds shiesty

 

[Frank Acampora]

Re: "Pinning a prop", ever heard of this?

Non carborundum illegitemi. It's latin, look it up. Don't let the nay-sayers get to you. I pin props all the time.

As a repair, if done correctly, drilling radially in from the outside and driving in pins, it is legitimate and functional.

IF the pins are sized properly, they will shear at about the same amount of force it would take to spin a new hub. If you size the pins (usually 3 or 4) so that their TOTAL cross sectional area is equal to what a shear pin on an old fashioned prop of the same size would be, they will shear on impact. Thus hitting something is a non-issue. Alignment is also a non-issue--it is just as good as or better than the rubber hub. AND, The pins won't slip just from aging like a rubber hub would do. So, the repair is permanent for the life of the prop or until you customize it with rocks.

The only issue I have found is that the bronze hub is as difficult to drill as stainless and requires a high quality drill. Since most castings have some entrained abrasive particles, drill bit wear is also an issue--but drill bits can be re-sharpened.

So: ask your repairman if he sizes the pins for a safety factor--if he does not, then think twice about having it pinned. If he does, then don't worry.

 

[Dhadley]

Re: "Pinning a prop", ever heard of this?

I had a SS Yamaha prop that needed rehubbing and took it to a highly recommended shop out this way and he warned me that he couldn't guarantee that it will hold/last.

He advised to drill and tap and install some SS screws to pin the hub to the prop if it didn't hold(didn't have to)

If you go this route(pin) I would tap the holes(10-32) so that they will be removable in the future.

Scott

If he's having trouble with Yamaha hubs holding he may be using the cheaper version of the hub. If he will use the high-performance version they won't burn out as easy. Especially if it's on a higher hp Yamaha that has the exhaust temp issues.