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Hairline crack in hub

Posted: Wed Dec 06, 2017 12:17 pm
by Capt steve
Hi guys. Capt steve here with another question. I hope I don’t get jumped on again but here goes :)

Inspecting one of our boats this morning and found a hairline crack in the hub. The boat is turning a three blade sensinech prop. I’m sure it’s not good even though it just looks like a small stress crack. Gonna pull another boat out til I know how bad it is.

Thanks for opinions

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 2:53 pm
by Scarecrow
I don't think I would run it, especially with it being a tour boat.

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 6:14 pm
by Scarecrow
I was just being nice. LOL

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 6:36 pm
by skinnypockets
Capt steve, Good to see you're on top of your pre-flight inspections. I would be comfortable riding with you anytime! :thumbleft:

:rebel: :florida: :old_glory:

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 6:57 pm
by SWAMPHUNTER45
Send it back to Sensenich for them to inspect

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 6:59 pm
by Capt steve
Thanks skinny!!!! I took the boat offline this AM. Any idea what causes this? I assume the hub is milled from a solid piece of aluminum. Is the issue that a big chunck of aluminum can fly off and free the blade? That sounds very ugly. Thanks for helping!

I always err on the side off caution when it comes to safety. I had a bad feeling this wasn’t good. Is this a common failure?

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 7:21 pm
by Capt steve
SWAMPHUNTER45 wrote:Send it back to Sensenich for them to inspect

Thanks. Was planning on reaching out to them first thing in the AM. Silly question but doess sensenich manufacture the hub as well as the blades?

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 8:15 pm
by SWAMPHUNTER45
They do, it should be branded, but I am not sure if it is outsourced or CNC in house.
All the hubs I have gotten from them had the name embossed on outer clam shell.

Either way it is their product and quality control is very important to them.

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 8:45 pm
by Capt steve
I can’t thank all of you guys enough. I’m kinda thrown into this situation and am educating myself as fast as I can. This board is a big help as far as learning. Please don’t misunderstand and I’m not comparing myself to you guys that have been doin this a long time, but I can drive these boats. I run a very set coarse and don’t stunt around doing 180’s. I don’t need to do that to satisfy my costumers. They mainly wanna see wildlife and I just need to tingle there toes with a nice turn now and then. I get a little better everyday. I also don’t drive small boats, which from what I’ve learned swamp much easier then the ones I’m driving. Rest assured my passengers safety is always my number one concern!

Re: Hairline crack in hub

Posted: Wed Dec 06, 2017 11:18 pm
by Capt steve
ladyblackwater wrote:Capt Steve you are doing everything right. If all Capt.'s were like you there would be a lot less mishaps on the water. My question for you, is this prop on the same boat you had a belt box problem with?


As a matter of fact yes. Do you think that the slight wobble due to the bearings could have caused a stress crack? Or am I reaching?

And thanks for your encouraging words!

Re: Hairline crack in hub

Posted: Thu Dec 07, 2017 7:40 am
by SWAMPHUNTER45
BOOM there you go!

Had a buddy wipe a BBC (mains) out a few months back and bad bearings in a belt drive were the leading suspected cause.
Gonna call him this morning and tell him to go over the hub and blade yoke with a magnifier looking for hairline defects.

You have to learn your drive lines feel and when you pick up anything unusual start looking for the reason. We won't always find the root cause but being attentive is the best prevention.

Re: Hairline crack in hub

Posted: Thu Dec 07, 2017 8:42 am
by Capt steve
SWAMPHUNTER45 wrote:BOOM there you go!

Had a buddy wipe a BBC (mains) out a few months back and bad bearings in a belt drive were the leading suspected cause.
Gonna call him this morning and tell him to go over the hub and blade yoke with a magnifier looking for hairline defects.

You have to learn your drive lines feel and when you pick up anything unusual start looking for the reason. We won't always find the root cause but being attentive is the best prevention.


Great discussion. With all the help I’ve received from you guys I hope that this helps someone else as well.

Re: Hairline crack in hub

Posted: Tue Dec 12, 2017 9:34 pm
by Capt steve
Replaced the hub/yoke. Boat back online. Thanks for everyone’s help!

Re: Hairline crack in hub

Posted: Wed Dec 13, 2017 7:14 am
by SWAMPHUNTER45
That's was the best way to proceed.

Re: Hairline crack in hub

Posted: Wed Dec 13, 2017 7:28 am
by Capt steve
Thanks again guys!

Re: Hairline crack in hub

Posted: Wed Jul 11, 2018 3:33 am
by sanshandaobojue
Capt steve wrote:Thanks again guys!

So you get hub replaced, and the manufacture sensenich confirmed that was a crack? That's serious if you were not found.
From picture is not very clear, usally the crack is due to the material defects and vibartion will lead to faticue crack after a period of running, and can be test by PT(penetration testing) better than visual inspection.
Hopelly to get some more continues information to avoid.