Knockin' the bottom out of it.....!

[zkimball]

I read a recent post in which Dhadley talked about the newer hubs failing to provide the same lower unit protection as the older rubber hubs. I've heard for years about the danger of tearing up the output shaft and gears when hitting something, but in thirty years of bottom knockin', I've never seen it. NOT ONCE! My father-n-law is an outboard mechanic and I've not seen this as a frequent problem.

Question.... Is it? I'll give you that, in Florida, we're usually hitting mud or sand, but is this a great problem elsewhere? Just wondering..... Z

 

[BAYLINER185]

Re: Knockin' the bottom out of it.....!

well, most of the lakes her ein AZ are rocky bottoms. Some have sand but most are river rocks and I have seen at my local prop shop 3 SS props that have LARGE "BITES" taken out of each blade. REALLY scarey looking, you can imagine what it would have sounded liek to bust up a prop like that and image what the output shaft or even the rest of the gears must look like in those outdrives.

Frankly I dont know how any one bottoms out thier prop, it means they are going into really shallow water. I can understand hidden underwater objects but in most cases our lakes are marked really good and you have to be crazy to navigate into areas that are unmarked and assume they are clear. If Im unsure of how deep an area is I simply wont enter it and stay clear of any area thats looks liek it could be either really shallow or littered with crap that will bust up my prop and the rest of my boat.

 

[ASCTLC]

Re: Knockin' the bottom out of it.....!

We fishermen go into shallow water quite often. That's what makes some of us so successful, especially well after dark. One would never learn a lake if they didn't go into such waters just because they're not marked.

Andy

 

[BAYLINER185]

Re: Knockin' the bottom out of it.....!

Yea I agree but as much as there are some really cool looking areas beyond the NO MARKERS UP STREAM markers in the lakes I go to my Stainless prop and outdrive and boat bottom are way more important to me then risking it all entering those areas.


A day of fishing and bringing nothing home, but a boat that can go back out then next day is still better then a day at work LOL

 

[zkimball]

Re: Knockin' the bottom out of it.....!

Here in Florida, we seldom see a "Do Not Proceed" sign unless there's a reef or a dedicated manatee fornication zone ahead.

Still, even with your rocks, does the boating community, at large, experience a significant amount of engine damage secondary to hitting bottom or obstruction? Should the type of hub be a consideration in my choice of props?

Thanks! Z

 

[jimmbo]

Re: Knockin' the bottom out of it.....!

Here in Aberta you 'might' see a sign stating " CAUTION, shallow areas in lake" but no reference as to where they are other than in the lake. 5 years ago I was running on my usual lake and went into an area where I hadn't been before. My chart of the lake said 12 ft of water, my depth gauge was reading pretty much the same. About a mile from the nearest shore, suddenly it changed to 4 ft, 3 ft, 2 ft, then bamn, bamn, bamn. I had been going about 21-22mph. The boat stopped. I used a paddle over the side and it was less than 2 ft. The boat was sitting on a pile of texas pea gravel(big rocks). all 3 of my SS props blades were bent and torn. Skeg was fine except a small twist. After getting the boat floating again I got it to plane but the vibrations were very noticible. It took me about an hour and a half to idle back to the launch. I replaced the prop, spun it and it visibly wabbled. 2 days, a new propshaft and I was back on the lake. Dealer cost on the VP SX propshaft was $580 canadian back in 2002. I keep the old one under my car seat.

Edit
prop was a Raker with rubber hub

 

[wca_tim]

Re: Knockin' the bottom out of it.....!

Less than two months ago I caught something with the prop in the water (going slow) took a chunk out of one blade on old style laser 11 (sold hub) and sheared the lower unit drive shaft right at the oil ring groove... Mercruiser alpha 1.... Cost me a new lover unit... I have one with a plastic hub now. Not sure if it would have saved me or not. But chances are it's a lot better than the solid one in that respect...

Food for thought...

 

[zkimball]

Re: Knockin' the bottom out of it.....!

Thanks a lot. I've always heard of it, just never seen it.

Now, has any one seen or experienced this with one of the newer hubs? I intend to buy a new Turbo Off Shore 1 and it requires one of the newer metal/plastic hubs. I've heard they don't provide the same protection. Is this something to worry about, or is this simply where we're going and I need to get used to it?

Again, thank you for taking a couple of minutes to respond. Z

 

[Tail_Gunner]

Re: Knockin' the bottom out of it.....!

I read a recent post in which Dhadley talked about the newer hubs failing to provide the same lower unit protection as the older rubber hubs. I've heard for years about the danger of tearing up the output shaft and gears when hitting something, but in thirty years of bottom knockin', I've never seen it. NOT ONCE! My father-n-law is an outboard mechanic and I've not seen this as a frequent problem.

Question.... Is it? I'll give you that, in Florida, we're usually hitting mud or sand, but is this a great problem elsewhere? Just wondering..... Z

Well if you can imagine a lake bed or sea floor being made of solid grantite and your stainless steel prop smacking it with no clearence, you decide, do you want a rubber hub that will shear and spin, or a composite sleeve fitted onto a metallic insert that will just deform down to the metal you decide .....

 

[wca_tim]

Re: Knockin' the bottom out of it.....!

In thinkin more about the plastic vs rubber ones... has anyone ever spun one of the new plastic ones?

Based on my experience, the material binding the ones with the rubber hubs should be overall as strong as the plastic ones, and probably will take just as much force to spin free as the newer plastic ones - especially since the plastic inserts aren't bonded / glues to the sleeve. The big differences would be that the rubber ones will lose more strength over time, can't be easily replaced by you and me and that the plastic ones once deformed even partially will not spring back on ther own the way the rubber ones will.

I haven't done side by side comparison of this in boat propellor hubs, but have a lot of backround and experience with the associated materials (rubber and plastic).