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11-10-2016, 11:08 AM
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#1
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Guru
City: Under a boat, in a marina in the San Francisco Bay
Join Date: Mar 2012
Posts: 615
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Underwater Shaft Anode Replacement Video
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Clean bottoms are FastBottoms!
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11-10-2016, 12:44 PM
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#2
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Guru
City: st pete
Vessel Model: 430 Mainship
Join Date: Sep 2016
Posts: 3,483
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Interesting.
I've been under boats a number of times for repairs, etc. It's a bit more challenging to do it without a tank......
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Seevee
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11-10-2016, 01:05 PM
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#3
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Guru
City: Under a boat, in a marina in the San Francisco Bay
Join Date: Mar 2012
Posts: 615
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Quote:
Originally Posted by Seevee
Interesting.
I've been under boats a number of times for repairs, etc. It's a bit more challenging to do it without a tank......
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I'm using a hookah in the video. I would consider it unprofessional to do this work without surface supplied air. Or to do it while wearing a tank.
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11-10-2016, 02:48 PM
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#4
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by fstbttms
I'm using a hookah in the video. I would consider it unprofessional to do this work without surface supplied air. Or to do it while wearing a tank.
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Unprofessional to use a tank?
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11-10-2016, 02:57 PM
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#5
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Guru
City: Under a boat, in a marina in the San Francisco Bay
Join Date: Mar 2012
Posts: 615
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Yes. I consider it unprofessional to wear a tank under a boat. Too much potential for damage to occur. Tanks should be left topside and used with a long hose, IMHO. This is known as a "SNUBA" rig.
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Clean bottoms are FastBottoms!
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11-10-2016, 03:37 PM
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#6
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Guru
City: Cary, NC
Vessel Name: Skinny Dippin'
Vessel Model: Navigator 4200 Classic
Join Date: Jul 2009
Posts: 5,841
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Quote:
Originally Posted by fstbttms
Yes. I consider it unprofessional to wear a tank under a boat. Too much potential for damage to occur. Tanks should be left topside and used with a long hose, IMHO. This is known as a "SNUBA" rig.
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Wow, now THAT is an angle I have never thought of when it comes to diving. hmmm
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2000 Navigator 4200 Classic
(NOT a trawler)
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11-11-2016, 10:25 PM
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#7
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Guru
City: Ashland, MA
Vessel Model: 1990 Silverton 40 aftcabin
Join Date: Jul 2016
Posts: 1,208
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If you bond your shafts using shaft brushes, shaft anodes can be eliminated. I made my own shaft brushes which work well. I verify my single (stern mounted aluminum diver's plate) anode's performance using my silver-silver chloride half cell.
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11-12-2016, 04:24 AM
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#8
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by foggysail
If you bond your shafts using shaft brushes, shaft anodes can be eliminated. I made my own shaft brushes which work well. I verify my single (stern mounted aluminum diver's plate) anode's performance using my silver-silver chloride half cell.
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Most shafts are bonded with or without brushes.
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11-12-2016, 04:27 AM
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#9
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by Tom.B
Wow, now THAT is an angle I have never thought of when it comes to diving. hmmm
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Neither apparently have all the bottom cleaners/prop changers that use tanks.
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11-12-2016, 04:37 AM
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#10
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,076
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Quote:
Originally Posted by fstbttms
Yes. I consider it unprofessional to wear a tank under a boat. Too much potential for damage to occur. Tanks should be left topside and used with a long hose, IMHO. This is known as a "SNUBA" rig.
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What sort of damage? Other than convenience, I wouldn't have thought the two approaches to be any different.
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MVTanglewood.com
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11-12-2016, 05:17 AM
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#11
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Guru
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,818
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While I use a hookah rig for the convenience of getting in and out of the water (no tank to take off), it also insures that I won't accidentally bang the tank against any part of my boat (including the prop) or my neighbors boat.
Ted
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Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
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11-12-2016, 07:30 AM
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#12
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Guru
City: Ashland, MA
Vessel Model: 1990 Silverton 40 aftcabin
Join Date: Jul 2016
Posts: 1,208
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Quote:
Originally Posted by Capt.Bill11
Most shafts are bonded with or without brushes.
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I disagree. Shafts are coupled to transmission gears embedded in oil. There is no reliable bonding bonding there. It does not require many ohms to prevent electron flow when the galvanic voltage differences between metals is only millivolts.
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11-12-2016, 07:37 AM
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#13
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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Some suggest jumpers over both sides of the shaft coupling to ensure no or less resistance there too.
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11-12-2016, 07:40 AM
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#14
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Guru
City: Ashland, MA
Vessel Model: 1990 Silverton 40 aftcabin
Join Date: Jul 2016
Posts: 1,208
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How do you place jumpers onto a rotating shaft? I can think of only one exception and that requires a thrust bearing.
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11-12-2016, 08:03 AM
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#15
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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Just copper straps from one side to the other.
I will try and find picture....
I also use a shaft brush and my transom zincs waste pretty well..but my shaft zinc looks new every year.
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11-12-2016, 08:10 AM
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#16
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TF Site Team
City: Jacksonville
Join Date: Nov 2008
Posts: 11,671
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Quote:
Originally Posted by foggysail
How do you place jumpers onto a rotating shaft? I can think of only one exception and that requires a thrust bearing.
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We added a jumper on ours. Using 2 ring lugs that fit the coupler bolts and ~3" of #10 wire. We jumper across the coupler on the same bolt. Our shaft is 2" diameter that spins at ~800-900 rpms. The shaft runs true and the alignment is good.
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11-12-2016, 08:18 AM
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#17
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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Yep...couple ways to do it...on high speed shafts that brushes may be an issue, the copper straps can be measures and weighed to help balance more accuratelt...but probably overkill.
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11-12-2016, 08:26 AM
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#18
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Guru
City: Under a boat, in a marina in the San Francisco Bay
Join Date: Mar 2012
Posts: 615
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Quote:
Originally Posted by twistedtree
What sort of damage? Other than convenience, I wouldn't have thought the two approaches to be any different.
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As OC mentioned, it is very easy to imagine a diver with a bulky tank on his back banging up a boat's anti fouling paint or even gouging the gel coat.
From a personal standpoint, when I see a hull cleaner in the water or on the dock with a tank on his back (which is not often), I assume he doesn't know what he's doing. In any event, I do not allow my divers to operate that way.
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Clean bottoms are FastBottoms!
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11-12-2016, 08:46 AM
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#19
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Guru
City: Ashland, MA
Vessel Model: 1990 Silverton 40 aftcabin
Join Date: Jul 2016
Posts: 1,208
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Quote:
Originally Posted by Larry M
We added a jumper on ours. Using 2 ring lugs that fit the coupler bolts and ~3" of #10 wire. We jumper across the coupler on the same bolt. Our shaft is 2" diameter that spins at ~800-900 rpms. The shaft runs true and the alignment is good.
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A picture might help. I cannot vision a jumper of any material connected to a rotating shaft. Of course, something could "rest" on top of such a shaft similar to what I call a shaft brush. My stuffing box is bonded but that doesn't by itself make an electrical contact to the shaft.
My first attempt to bond my rotating shafts used a bronze bar that rested on the shaft. It failed due to rapid wear. Today I use sintered oil impregnated bronze to make the shaft contact.
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11-12-2016, 09:37 AM
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#20
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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Like this........ from Nigel Calder's book.....
For my brush, I use a discarded out drive zinc...already has a bolt for the bonding wire and arm attached. Got 3 seasons from the last and free from the marina pile is hard to beat.
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