I have corrosion on my toe rails of the 35.5. I have noticed that other hunters with these toe rails are also showing signs of this corrosion. The corrosion is on the top side where it meets the fiberglass, not near any stainless bolts or stantions. This is a anodized aluminum toe rail. My question is has anyone stopped this corrosion with some paint or other product?? Looking for answers before corrosion eats away the rail. Help Please.. Regards Mike.
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aluminum corrosion?
Mike Can you describe what you mean by "corrosion"? or attach a picture? Aluminum oxidizes but never heard it described as corrosion. I guess it's possible for it to be eaten away cathodically if you have anything electrical or ground connections attached?? Don
Mike Can you describe what you mean by "corrosion"? or attach a picture? Aluminum oxidizes but never heard it described as corrosion. I guess it's possible for it to be eaten away cathodically if you have anything electrical or ground connections attached?? Don
Yep, they corrode. Ours has.
The prevention is a fresh water rinse. Always rinse your boat of salt before putting it away. It's kinda like a 'wet horse'. Well, bad analogy, 'wet horse' is a myth.
Anyway, back to the rail corrosion. Pitting is evident where aluminum is in proximity of stainless steel. That was caused by too long of an interval between washing after being drenched with saltwater in the early years of our boat and the subsequent cruise. The fix is in place. The boat is rinsed when brought into her slip. If anchored, (we always anchor while cruising) the boat is washed with our new deck-wash. It's sold by Newfoundmetals.com. Of course, it looks weird to see a boats' crew using freshwater to wash her down in an anchorage. We've noticed several people taking a picture. Two have even come over and asked about it. Our watermaker makes sixty gallons an hour of fresh water. That works out to about the flow rate of our deck-wash needs. We never have to stop washing until be run out of fuel. Fun. Too bad we didn't notice the corrosion beginning sooner. Once it started, washing was mandatory. Of course, all other topside components benefit from rinsing, from the mast on down. 'Rinsing' is THE maintenance instruction from Harken.
The prevention is a fresh water rinse. Always rinse your boat of salt before putting it away. It's kinda like a 'wet horse'. Well, bad analogy, 'wet horse' is a myth.
Anyway, back to the rail corrosion. Pitting is evident where aluminum is in proximity of stainless steel. That was caused by too long of an interval between washing after being drenched with saltwater in the early years of our boat and the subsequent cruise. The fix is in place. The boat is rinsed when brought into her slip. If anchored, (we always anchor while cruising) the boat is washed with our new deck-wash. It's sold by Newfoundmetals.com. Of course, it looks weird to see a boats' crew using freshwater to wash her down in an anchorage. We've noticed several people taking a picture. Two have even come over and asked about it. Our watermaker makes sixty gallons an hour of fresh water. That works out to about the flow rate of our deck-wash needs. We never have to stop washing until be run out of fuel. Fun. Too bad we didn't notice the corrosion beginning sooner. Once it started, washing was mandatory. Of course, all other topside components benefit from rinsing, from the mast on down. 'Rinsing' is THE maintenance instruction from Harken.salt water boat
Yes it is in salt water. The other post said that it may just need more rinsing with fresh water. Could be.
Yes it is in salt water. The other post said that it may just need more rinsing with fresh water. Could be.
My 35.5 ...
...is a '93. It is never on a dock. It basically lives on its mooring when we're not on board. Whatever fresh water rinsing it gets comes from rain. I have seen no signs of any sort of corrosion or pitting. Obviously if this is happening to your boat you need to find the source and stop it. I would start with a galvanic test between the salt water and the toe rails. There should be no electrical connection.
...is a '93. It is never on a dock. It basically lives on its mooring when we're not on board. Whatever fresh water rinsing it gets comes from rain. I have seen no signs of any sort of corrosion or pitting. Obviously if this is happening to your boat you need to find the source and stop it. I would start with a galvanic test between the salt water and the toe rails. There should be no electrical connection.
corrosion on toe rail
I do not have a picture but I will try to get one. I was at the boat today and tested the rails to see if there is any continuity between water and any other boat parts and the rails are isolated. It looks like rust on ferous metal, sort of pitted and eaten away.
I do not have a picture but I will try to get one. I was at the boat today and tested the rails to see if there is any continuity between water and any other boat parts and the rails are isolated. It looks like rust on ferous metal, sort of pitted and eaten away.
galvanic test
I tested the boat today and there is no conductivity between sea water and toe rail or any other part of the boat. That was my first concern.
I tested the boat today and there is no conductivity between sea water and toe rail or any other part of the boat. That was my first concern.
test method?
Mike I think you might be on the right track but using a digital voltmeter, if that's presumably what you did, won't reliably determine if there is any galvanic potential - there is no reference sensitive enough to rely on it. I still say it isn't corrosion in the true sense of the term but semantics is irrelevent since you care much more about how to fix it, regardless of what it's called. My guess is that there is some stray current too weak for the multimeter which is pretty useless in this case except for finding continuity. As you didn't find any, I'd bet your problem will be solved by connecting the toe rail to the nearby metals, incl any close proximity stainless which may be counter-intuitive but it will work. good luck Don
Mike I think you might be on the right track but using a digital voltmeter, if that's presumably what you did, won't reliably determine if there is any galvanic potential - there is no reference sensitive enough to rely on it. I still say it isn't corrosion in the true sense of the term but semantics is irrelevent since you care much more about how to fix it, regardless of what it's called. My guess is that there is some stray current too weak for the multimeter which is pretty useless in this case except for finding continuity. As you didn't find any, I'd bet your problem will be solved by connecting the toe rail to the nearby metals, incl any close proximity stainless which may be counter-intuitive but it will work. good luck Don
Mike
First, a good multimeter can test for continuity and low voltage too and yes, you do have a tad bit of continuity to the water because fiberglass does carry a current...it just has a lot of resistance. What is causing your corrosion is that you are getting a current into your toe rail via the fiberglass and it is reacting to the little specs of saltwater you still have after a sail if you don't rinse it off. Why would your fiberglass be carring a current? You could have a short someplace in your wiring (no wires are suppose to come in contact with the glass, not even the grounds). You could also be docking in water that has a strong current in it and this is my bet because of the other boats having the same problem. What can you do? Rinsing right after you dock will definately help. Finding a new place to dock might be considered. I don't think grounding your toe rails to other metals will stop it and it may actually make it worse (these other metals may have a better connection to the water via a grounding system).
First, a good multimeter can test for continuity and low voltage too and yes, you do have a tad bit of continuity to the water because fiberglass does carry a current...it just has a lot of resistance. What is causing your corrosion is that you are getting a current into your toe rail via the fiberglass and it is reacting to the little specs of saltwater you still have after a sail if you don't rinse it off. Why would your fiberglass be carring a current? You could have a short someplace in your wiring (no wires are suppose to come in contact with the glass, not even the grounds). You could also be docking in water that has a strong current in it and this is my bet because of the other boats having the same problem. What can you do? Rinsing right after you dock will definately help. Finding a new place to dock might be considered. I don't think grounding your toe rails to other metals will stop it and it may actually make it worse (these other metals may have a better connection to the water via a grounding system).
Well, that should clear up everything
It's hard to know what to do/who to believe when you get such contradictory responses. Don
It's hard to know what to do/who to believe when you get such contradictory responses. Don
testing rail
I used a meter supplied to me by a marine electrician for testing zincs required for galvanic corrosion. This meter tests for stray current to determine the amount of zinc required for thru hauls, keel bolt, etc.. So when we measured the current from the toe rail to the salt water there is no current flow registering on the meter and no connection to other bonded items. Fiber glass conducting electricity??? Fiber glass is used as a insulator material in High voltage situations 27,000 volts and higher and does not conduct electricity. If you are getting a reading it is probably because of the salt water on the fiberglass. The meter which we used I believe is a good way to test for conductivity. The only other meter which I can think of to try would be a megger meter which induces a high voltage and then measures if there is a flow. I have not yet done this test. I believe this is probably just corrosion as these test did not indicate a current flow. Yes, I do believe there is current flow in the waters where we are. Point Roberts Marina. I have installed a galvanic Isolator in line with the ground from the AC power supply. Have also checked for cables in the water, bilge. There is a coal port nearby and we get a lot of coal dust settling on the boats. This may be a factor??
I used a meter supplied to me by a marine electrician for testing zincs required for galvanic corrosion. This meter tests for stray current to determine the amount of zinc required for thru hauls, keel bolt, etc.. So when we measured the current from the toe rail to the salt water there is no current flow registering on the meter and no connection to other bonded items. Fiber glass conducting electricity??? Fiber glass is used as a insulator material in High voltage situations 27,000 volts and higher and does not conduct electricity. If you are getting a reading it is probably because of the salt water on the fiberglass. The meter which we used I believe is a good way to test for conductivity. The only other meter which I can think of to try would be a megger meter which induces a high voltage and then measures if there is a flow. I have not yet done this test. I believe this is probably just corrosion as these test did not indicate a current flow. Yes, I do believe there is current flow in the waters where we are. Point Roberts Marina. I have installed a galvanic Isolator in line with the ground from the AC power supply. Have also checked for cables in the water, bilge. There is a coal port nearby and we get a lot of coal dust settling on the boats. This may be a factor??
lyle
Hi Lyle, I have my boat moored in Point Roberts. This is in salt water probably the reason for the corrosion. Being in the river you must have a long trip out to go sailing? How long does it take for you to get out??
Hi Lyle, I have my boat moored in Point Roberts. This is in salt water probably the reason for the corrosion. Being in the river you must have a long trip out to go sailing? How long does it take for you to get out??
Mike
You test for continuity by measuring the oms. It is impossible that you don't have any oms from your toe rail and the water...but I guess you and your "electrician" know more then me...just like the "electrician" who re-wired my refrig knew more then me and I had to undo his crap. I guess all the boats in your marina who also have this problem have a problem with their boats too huh? Oh...that's what it is...it must be a Hunter issue. Please! Oh well....it's your boat. Poor boat...I feel sorry for it. BTW..if you don't think fiberglass carries a current, take the negative wire of your multimeter and put it on the negative of your battery bank and put the positive of the multimeter on your hull. Then take a wire from the positive terminal of the battery bank and press it against the hull. You will get a reading. How much of a reading depends on the size of the wire you use and how good of a connection you have to the fiberglass and the distance between the two. I just did it with a small wire and got 1.17 volts traveling 2' in glass with a mild connection. When I was troubleshooting an electrical short on my boat I once saw 9 volts in the glass near the windlass and the farther away I got from the windlass the weaker it got (fixed that of course). Most things do carry a current, just not much. Fiberglass is a much much much more resistance then metal but it DOES carry a current. It doesn't take much current to eat away at metal given enough time and saltwater. Note: this also explans why boats in your marina have a problem but the exact same model in many other locations does not.
You test for continuity by measuring the oms. It is impossible that you don't have any oms from your toe rail and the water...but I guess you and your "electrician" know more then me...just like the "electrician" who re-wired my refrig knew more then me and I had to undo his crap. I guess all the boats in your marina who also have this problem have a problem with their boats too huh? Oh...that's what it is...it must be a Hunter issue. Please! Oh well....it's your boat. Poor boat...I feel sorry for it. BTW..if you don't think fiberglass carries a current, take the negative wire of your multimeter and put it on the negative of your battery bank and put the positive of the multimeter on your hull. Then take a wire from the positive terminal of the battery bank and press it against the hull. You will get a reading. How much of a reading depends on the size of the wire you use and how good of a connection you have to the fiberglass and the distance between the two. I just did it with a small wire and got 1.17 volts traveling 2' in glass with a mild connection. When I was troubleshooting an electrical short on my boat I once saw 9 volts in the glass near the windlass and the farther away I got from the windlass the weaker it got (fixed that of course). Most things do carry a current, just not much. Fiberglass is a much much much more resistance then metal but it DOES carry a current. It doesn't take much current to eat away at metal given enough time and saltwater. Note: this also explans why boats in your marina have a problem but the exact same model in many other locations does not.
Stainless to Aluminum ?
Hey Mike, Would your meter indicate anything if one side was connected to a typical stainless steel bolt on the toe rail and the other were connected to the aluminum or is that galvanic differential too negligible to show up? I have a twenty year old 28.5 kept in brackish waters of the Chesapeake bay and have the 'corrosion' you speak of on the inside of the toe rail. Any salt water on deck flows down to the toe rail and off at the stern. I just figure the annodized aluminum surface coating won't hold up forever in a saltwater / brackish water enfironment. However, the staunchions and their bolts are S.S.and don't seem to have galvanic corrosion at the aluminum toe rail at those points. The annodized aluminum Genoa tracks are fastened with S.S. bolts and show no 'corrosion' and my much newer annodized aluminum deck hatches show no corrosion either. I'd conclude it's the posability of salt water laying against the annodized aluminum toe rail.
Hey Mike, Would your meter indicate anything if one side was connected to a typical stainless steel bolt on the toe rail and the other were connected to the aluminum or is that galvanic differential too negligible to show up? I have a twenty year old 28.5 kept in brackish waters of the Chesapeake bay and have the 'corrosion' you speak of on the inside of the toe rail. Any salt water on deck flows down to the toe rail and off at the stern. I just figure the annodized aluminum surface coating won't hold up forever in a saltwater / brackish water enfironment. However, the staunchions and their bolts are S.S.and don't seem to have galvanic corrosion at the aluminum toe rail at those points. The annodized aluminum Genoa tracks are fastened with S.S. bolts and show no 'corrosion' and my much newer annodized aluminum deck hatches show no corrosion either. I'd conclude it's the posability of salt water laying against the annodized aluminum toe rail.
stainless to alum
Yes I have to agree, there is no other corrosion at the point of disimalar metals, eg. alum/stainless. I believe this is because of the plastic bushings placed between them. I am starting to believe this is only corrosion due to the anodization wearing off. Just want to know if anyone knows what to coat it with or paint it with to stop this from getting worse.
Yes I have to agree, there is no other corrosion at the point of disimalar metals, eg. alum/stainless. I believe this is because of the plastic bushings placed between them. I am starting to believe this is only corrosion due to the anodization wearing off. Just want to know if anyone knows what to coat it with or paint it with to stop this from getting worse.
Franklin
Ouch!!! Did someone pee in your cornflakes this morning. Hope your having a better day! Mike
Ouch!!! Did someone pee in your cornflakes this morning. Hope your having a better day! Mike
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