miscellaneous surface rusting on s/s and chrome

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captks

Member
Joined
May 13, 2020
Messages
19
Location
US
Vessel Name
Stout
Noticing small surface rusting on s/s in my engine room (shaft, stainless fuel lines from dual racor). It is also on the shaft (non-magnetic). When I go in the engine room I believe I can feel something in eyes/mouth when down there. It is not CO or exhaust as it started happening well before running engine (in winter visits to the boat).

Only thing I can think off is battery off gas but the lifelines I have in for house and crank are maint free and there is no bulgling / leaking.

thanks in advance

Captks
 
Do you keep ANY acidic cleaners aboard. If so get them off the boat. The containers likely are not leaking fluid but the corrosive gas can still make its way out of the container. That corrosive gas will destroy the surfaces of most metals and degrade other items.

At one place I worked we unknowingly ruined thousands of dollars worth of machine parts and supplies. The cleaners were stored in heavy plastic bottles and then in plastic pails. Didn't matter. It may have slowed the damage but did not stop it.

It all got booted out to an outside storage shed , just not untill we damaged a lot of stuff.

Do not ignore a battery. If the battery is overcharged it can off gas.
In this case the charger could be overcharging which will drive water and acid fumes off. It may be only one cell.
 
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Noticing small surface rusting on s/s in my engine room (shaft, stainless fuel lines from dual racor). It is also on the shaft (non-magnetic). When I go in the engine room I believe I can feel something in eyes/mouth when down there. It is not CO or exhaust as it started happening well before running engine (in winter visits to the boat).

Only thing I can think off is battery off gas but the lifelines I have in for house and crank are maint free and there is no bulgling / leaking.

thanks in advance

Captks

I would still take a close look at your batteries. AGMs can and do vent. And it does not have to be bulged to have issues. You might disconnect them all and let them sit for a bit. Then check voltages and see if one is down. If you cant disconnect them all at once you can pull one at a time (or 2 at a time if 6 volt) and test them individually. Typically though once disconnected you can usually just read voltage to see the bad one. Lifelines are awesome batteries. But once in a while they can go bad.

If not batteries, various cleaners or combination of cleaners can really get nasty. Any chlorine type of cleaner also. Hope you find it. Let us know if and when you do.
 
Thanks. I will take a harder look at the batteries. I have single start battery for the engine which starts my engine in about 2 seconds. Dont think its that one. Either my house bank or gen batt. (the bow thruster is not in the engine compartment).

I do not keep any cleaners down there. The only chlorine based cleaners are in the kitchen and in dockbox on flybridge.

I will advise what I find. Thanks for the input.

I will turn off inverters and battery swiches then start removing paralleling wires on bank 1 so that I can test each battery individually. Hopefully I find something.

Thanks again
 
Thanks. I will take a harder look at the batteries. I have single start battery for the engine which starts my engine in about 2 seconds. Dont think its that one. Either my house bank or gen batt. (the bow thruster is not in the engine compartment).

I do not keep any cleaners down there. The only chlorine based cleaners are in the kitchen and in dockbox on flybridge.

I will advise what I find. Thanks for the input.

I will turn off inverters and battery swiches then start removing paralleling wires on bank 1 so that I can test each battery individually. Hopefully I find something.

Thanks again

Even if it ends up not being a battery...we so rarely check our batteries that going through those steps is certainly not a waste of time. One other telltale sign is that while charging a failed battery may have a higher temperature. I was recently able to determine a bad AGM simply by touching it. The other three where ambient temp...the bad one was probably 120 degrees. A non contact laser thermometer may be helpful.
 
Even if it ends up not being a battery...we so rarely check our batteries that going through those steps is certainly not a waste of time. One other telltale sign is that while charging a failed battery may have a higher temperature. I was recently able to determine a bad AGM simply by touching it. The other three where ambient temp...the bad one was probably 120 degrees. A non contact laser thermometer may be helpful.

I shut off my inverters and removed wires to isolate each battery. I have Lifeline GPL-4CT 6v batteries wired in series to 12v and parallel. Each battery bank has 6 batteries. 660ah at 12v.

See pics for tested voltage. I ordered a battery tester so I can test capacity of each but wont get that until friday.

The engine cranking batt was 13.17v and the gen cranking batt was at 12.69

No sign of anything with the house batteries. Only area was 1st negative terminal on thruster batteries.

Thoughts?
 
I shut off my inverters and removed wires to isolate each battery. I have Lifeline GPL-4CT 6v batteries wired in series to 12v and parallel. Each battery bank has 6 batteries. 660ah at 12v.

See pics for tested voltage. I ordered a battery tester so I can test capacity of each but wont get that until friday.

The engine cranking batt was 13.17v and the gen cranking batt was at 12.69

No sign of anything with the house batteries. Only area was 1st negative terminal on thruster batteries.

Thoughts?

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While you are at it clean all the battery cable connectors and battery posts. Then put something like Boeshield on them to help prevent corrosion. I have a small, almost tooth brush like, stainless steel brush that I use for cleaning them.
 
captks...The only thing that looks funny is the gen battery is slightly low. But even that depends on last time it was on a charge cycle.

Your plan to load test them is good and I would follow through with it. But if you had a battery that was gassing bad enough you could smell it and it was causing corrosion I would expect it to be obvious.

Is your bilge a dry bilge? Or is there always water in it?
 
captks...The only thing that looks funny is the gen battery is slightly low. But even that depends on last time it was on a charge cycle.

Your plan to load test them is good and I would follow through with it. But if you had a battery that was gassing bad enough you could smell it and it was causing corrosion I would expect it to be obvious.

Is your bilge a dry bilge? Or is there always water in it?


Always a little water down deep in the bilge. Thisvis due to some water weeping through the dripless while underway.
 
If you determine that the batteries are not off gassing and the charger is not overcharging then load testing would be a good way to go. If one cell in one battery has a problem often a load test will show it.

I have I.D.d some problem batteries simply by recharging them, then disconnecting the " - " side of each battery and then letting the batts. sit for 5 or 10 minutes and then measure the voltage of each.

This will only work if each battery is isolated from the bank and then allowed to sit. It showed one battery that dropped almost 1.5V in that time with no loads, and no connection to the system. Even a 0.5V drop would show a problem.

THe other two batteries showed the same voltage as each other.
Meant at least one cell in that one battery was bad.

Your mention of a dripless shaft seal that is not dripless brings up a bug a bear to me.

THe shaft seal, dripless or not, is not completely water spray free. Part of my job, when still working, was to rebuild water pumps.
Many used exactly the same type of seal, just bigger. THey do NOT totally and completely block water escape as you are finding.

I found that there was a very fine spray , not much but definitely present, that was thrown and could travel. It is fine enough that you can't see it with a good seal but it was present and could be detected by holding a paper towel close to it for a minute or thereabouts. It would dampen the towel.
THat very fine spray can travel and starting steel parts nearby rusting.

Cover the dripless seal with an old fender cut to suit or some other block with a narrow slit on the bottom so the water spray is stopped and then drops into the bilge. Simple, not pretty maybe, but effective.

THis may be the cause of the rusting you are seeing. The cover will prevent the very fine spray from travelling, slowing any rusting and also dampness in the E.R..
 
If you determine that the batteries are not off gassing and the charger is not overcharging then load testing would be a good way to go. If one cell in one battery has a problem often a load test will show it.

I have I.D.d some problem batteries simply by recharging them, then disconnecting the " - " side of each battery and then letting the batts. sit for 5 or 10 minutes and then measure the voltage of each.

This will only work if each battery is isolated from the bank and then allowed to sit. It showed one battery that dropped almost 1.5V in that time with no loads, and no connection to the system. Even a 0.5V drop would show a problem.

THe other two batteries showed the same voltage as each other.
Meant at least one cell in that one battery was bad.

Your mention of a dripless shaft seal that is not dripless brings up a bug a bear to me.

THe shaft seal, dripless or not, is not completely water spray free. Part of my job, when still working, was to rebuild water pumps.
Many used exactly the same type of seal, just bigger. THey do NOT totally and completely block water escape as you are finding.

I found that there was a very fine spray , not much but definitely present, that was thrown and could travel. It is fine enough that you can't see it with a good seal but it was present and could be detected by holding a paper towel close to it for a minute or thereabouts. It would dampen the towel.
THat very fine spray can travel and starting steel parts nearby rusting.

Cover the dripless seal with an old fender cut to suit or some other block with a narrow slit on the bottom so the water spray is stopped and then drops into the bilge. Simple, not pretty maybe, but effective.

THis may be the cause of the rusting you are seeing. The cover will prevent the very fine spray from travelling, slowing any rusting and also dampness in the E.R..

I disconnected all the batteries and tested their voltage and it all looked ok. The battery tester gets here tonight so tomorrow I will do some capacity testing to see if I got a bad one.

Regarding the spray from the dripless, I do not think that is doing it. There really isnt a spray just a weeping of water coming out. Also there is no liquid on any surface just marks on my stainless or chrome items in the engine room. The dual racor has stainless steel tubing on the select valve that shows this rust is on the opposite end of the engine and below the engine. I cant see any spray getting there. I will put something over the open area and see if it gets wet.
 

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It is not at rest I am talking about. That weeping at rest will turn into a spray when you are running. That spray will travel. It is not at rest there is a problem with spray.
 
It is not at rest I am talking about. That weeping at rest will turn into a spray when you are running. That spray will travel. It is not at rest there is a problem with spray.

alright. Will cover that area and see. I truly do not think this is happening as there is no water on anything else even flat surfaces like the battery boxes. The only thing it is affecting is chrome and stainless as far as I can tell. My shaft is non-magnetic.
 
I’m with C lectric on this. I’ve seen it from other sources as well. ER intake blowers, leaking seals on raw water pumps, pinhole corrosion on raw water pumps, hp leaks in RO systems all put seawater into the air as well as on the deck.

Find a good surface you can do a tastes test on. Atomized seawater in a hot engine room is quite corrosive. If you determine it is indeed salt, then you’ll need to inspect the er underway with the lights off. Use a small flashlight with a tight beam pattern or a laser device if you have one.
 
I’m with C lectric on this. I’ve seen it from other sources as well. ER intake blowers, leaking seals on raw water pumps, pinhole corrosion on raw water pumps, hp leaks in RO systems all put seawater into the air as well as on the deck.

Find a good surface you can do a tastes test on. Atomized seawater in a hot engine room is quite corrosive. If you determine it is indeed salt, then you’ll need to inspect the er underway with the lights off. Use a small flashlight with a tight beam pattern or a laser device if you have one.

Ok guys. Will look underway. I noticed the start of this during a cold stretch here in florida. The boat had not moved and I saw the spotting on the shaft. I wiped it down and it came off easily. It was reddish brown and thought it was from the transmission (but wasnt). I returned and boat still hadnt moved and it was back. I just recently found spots in other areas in ER. Pulled the generator battery today as it failed the capacity test. Dont know if it was venting in the ER. Will go back on Saturday so there will be 48hrs without the battery on board and the boat not moving. We shall see.
 
Where is the generator battery. If it was bad it could have been off gassing more than normal which is a common result as batts. age. It only takes one cell to trigger the charger to not back off resulting in boiling of the electrolyte.

I think you are still of the opinion that YOU will see a spray. I doubt that. You might but that has not been my experience unless the spray is VERY bad. Cover it so the spray will accumulate on the cover, use a paper towel to accumulate the spray.

Cafesport's suggestions are good ones also.
 
Where is the generator battery. If it was bad it could have been off gassing more than normal which is a common result as batts. age. It only takes one cell to trigger the charger to not back off resulting in boiling of the electrolyte.

I think you are still of the opinion that YOU will see a spray. I doubt that. You might but that has not been my experience unless the spray is VERY bad. Cover it so the spray will accumulate on the cover, use a paper towel to accumulate the spray.

Cafesport's suggestions are good ones also.

Battery was aft of the exposed shaft against the gen (see crude pic below)

I understand what you are both saying, and will investigate on Sunday after ive had the 48hrs without the gen battery in the er. my issue with the water is that I have never seen any water on any surface. Just the signs of rust on items that should not rust. see pics below of chrome valve cover, racor s/s tubing and shaft (non-magnetic, so alloy)
 

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UPDATE.

Replaced the gen battery 5 days ago. Have not moved the boat since then. I cleaned the shaft when I replaced the battery. After 5 days I returned to find the same condition on the shaft. I put a piece of wood over the stringers to stop any spray at rest and it was dry with no spotting underneath.

Boat will be pulled next friday. Changing the dripless and doing some other maintenance. BTW, there are no caustic chemicals in the engine room.
 

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UPDATE.

Replaced the gen battery 5 days ago. Have not moved the boat since then. I cleaned the shaft when I replaced the battery. After 5 days I returned to find the same condition on the shaft. I put a piece of wood over the stringers to stop any spray at rest and it was dry with no spotting underneath.

Boat will be pulled next friday. Changing the dripless and doing some other maintenance. BTW, there are no caustic chemicals in the engine room.

that's concerning for sure. any other areas in the bilge or possible the laz showing similar signs of corrosion?
i keep thinking back to your original post of thinking you feel something in the air (in your nose/throat). do you still get that sensation?
it seems like you've looked hard at the batteries, but is it possible one has leaked some of it's electrolyte into the bilge? it might be a thought to put some kind of neutralizing solution in there and flush with large amounts of fresh water.
the only time i've seen corrosion form like that has been due to some kind of chemical leak. usually some kind of acid.
any chance of a holding tank chemical getting spilled? like muriatic acid?
 
that's concerning for sure. any other areas in the bilge or possible the laz showing similar signs of corrosion?
i keep thinking back to your original post of thinking you feel something in the air (in your nose/throat). do you still get that sensation?
it seems like you've looked hard at the batteries, but is it possible one has leaked some of it's electrolyte into the bilge? it might be a thought to put some kind of neutralizing solution in there and flush with large amounts of fresh water.
the only time i've seen corrosion form like that has been due to some kind of chemical leak. usually some kind of acid.
any chance of a holding tank chemical getting spilled? like muriatic acid?

Thanks for the info. The remainder of my batteries are in fiberglass battery boxes (6 - lifeline 4CT's each box). There is no liquid in the batt boxes. There is definitely areas in the ER showing this issue on stainless and chrome. I can definitely throw something in bottom of bilge and then flush. If this is acid Im assuming baking powder or something like that.
I've been keeping the ER hatch open as well as ports in kitchen and elsewhere opened in the hope that this would ventilate things. Alas, the problem persists. I am not getting the sensation like I originally did in eyes. Sometimes I think i feel it but dont know if Im just convincing myself of that. I did take some big whiffs near batteries (dont know how smart that is) to see if I smell or feel in eyes but nothing.
 
Thanks for the info. The remainder of my batteries are in fiberglass battery boxes (6 - lifeline 4CT's each box). There is no liquid in the batt boxes. There is definitely areas in the ER showing this issue on stainless and chrome. I can definitely throw something in bottom of bilge and then flush. If this is acid Im assuming baking powder or something like that.
I've been keeping the ER hatch open as well as ports in kitchen and elsewhere opened in the hope that this would ventilate things. Alas, the problem persists. I am not getting the sensation like I originally did in eyes. Sometimes I think i feel it but dont know if Im just convincing myself of that. I did take some big whiffs near batteries (dont know how smart that is) to see if I smell or feel in eyes but nothing.

i would try the baking soda solution in the bilge and see if there's any reaction.
this is a very strange problem, but one that needs to be solved.
 
maybe a litmus paper test of the bilge water. Or, even an open bowl with pure water in it, then test a few days later for absorption.

Fine copper bare wire is sensitive to Sulphur fumes. Turning black quickly. Pool water test kit. Another easy test to set up.

Get a young person's nose in there too for a smell check! Rotten eggs smell, chlorine, etc..
 
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i would try the baking soda solution in the bilge and see if there's any reaction.
this is a very strange problem, but one that needs to be solved.

I wrote back earlier, but I do not see it in the thread so here goes again.

I put the baking soda in the lower bilge and it did bubble. I brought the hose in the ER and ran about 20 gal of water into the bilge and had it pumped out by the bilge pump. I repeated this 3 times. I also took baking soda on a rag and rubbed it on all stainless / chrome / shaft that showed marks. The marks were removed. I then used water soaked rag to wipe it down then dry rag to dry it up. I ran water from the forward part of the engine bilge area until it drained in the low bilge I already flushed.

I think it did the trick. Im assuming the battery was the culprit and then my bilge doesnt go dry due to the long lift to the thru hull above the water line. Basically everything in that line drains back to the bilge once the pump turns off.

I will be checking again on Sunday and again on Tuesday. Thanks for the help all.
 
I've seen stale bilge water grow stuff that gave off corrosive gases. I've only ever seen it leave corrosion on copper, bronze, etc. however, not stainless.
 
ok then, hopefully that was it. flushing huge amounts of water should have diluted it enough and the pump took it out. i'd think about another flush in a week or so for good measure, but it may not be needed. fingers crossed.
 
ok then, hopefully that was it. flushing huge amounts of water should have diluted it enough and the pump took it out. i'd think about another flush in a week or so for good measure, but it may not be needed. fingers crossed.

I hear you! Weirdest thing that ever occurred to me in all my boating years. Thanks for all the help. Will advise if it comes back, but with the removal of battery which I think was problem, I think this took care of it. We shall see.
 
Battery was aft of the exposed shaft against the gen (see crude pic below)

I understand what you are both saying, and will investigate on Sunday after ive had the 48hrs without the gen battery in the er. my issue with the water is that I have never seen any water on any surface. Just the signs of rust on items that should not rust. see pics below of chrome valve cover, racor s/s tubing and shaft (non-magnetic, so alloy)



I am trying to get across you WILL NOT SEE WATER from the spray while running. There is not enough of it to accumulate but it will travel and cause rusting. It will be so fine, and unless really bad, it is virtually invisible.
Further, after running, E.R. heat will evaporate quickly it so no puddles or accumulation. That is what fools people. Maybe you are right but it sounds like you expect to see it. Not likely without the cover and then you can see it since it will collect on the inside of the fender, or whatever you use.

If the stuffing box is dripping while not running then those drips will be turned into that mist.

I will leave this alone now.
 
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