Corrosion iin cabin

[Kerry13709]

I seem to have a lot of corrosion on metal part in the cabin of my boat. It is a 1992 oceanis 405. I have had it for a little over a year, so wrote off the corrision to age and the BWI location of the boat before I purchased it. I put a pair of older but in good condition sunglasses I had kept in my car for several year, in the boat last year. I guess I had not put these on until this week. The metal frames had a lot of green corrosion on them leading me to think that I might have problem and that the corroded hinges and other metal parts might not just be corroded from age. I have Nigel Calder's Book on maintenance and he has information on something called galvanic corrosion.Is this possibly what is going on in my cabin? If so, how do I fix the problem?

 

[Ross]

You probably have a salt problem

When salt water bubbles burst some of the water becomes airborne and evaporates before it settles back into the sea. The salt that was desolved in that water remains airborne and driffs like dust. The answer to the problem is simply through house cleaning. ALL of the movable furnishings have to be removed from the boat and cleaned with fresh water, the interior of the boat must be washed with fresh water. A simple test for the presence of salt is to wet a piece of paper( towel,coffee filter toilet paper) with just a little water and wipe a couple of square feet of little used hard surface. Let the paper then come in contact with a gas flame in the flame turns sodium orange( think of those orange street lights) you have salt present.

 

[Bill]

dehumidifier

Hi Kerry,Galvanic corrosion is caused by stray electricity in the water. It will effect things like how long your zincs last and corrosion of metal parts in the water. It sounds to me like what you have going on in the cabin is just too much humidity in the cabin. I would bet it has some musty boat smells too? A dehumidifier will help a lot of that. Also make sure you have good venting like solar vents to help circulate the air. Generally people put the dehumidifer on the counter in the galley so it can drain in the sink. If your boat has a dehumidify setting on the air conditioner, that would do it as well.I'm sure lots of other posts here will help define galvanic corrosion more thoroughly and will have other ideas.Best,B

 

[robert taylor]

happened on my boat

i used to keep a little clorox in the shower sump in the head of my 36' catalina. i began to notice the tie rods and other metal parts in the head were corroding. i assumed it was a moisture problem. a friend of mine pointed out that clorox and water combine to make a dilute form of hydro chloric acid gas. (duh) i quit using clorox and the problem solved itself. i don't know if you use any clorox in the bilge, but if you do, that may be the problem.

 

[Ross]

When salt (NaCl) goes into solution

it devides into sodium ions and chlorine ions and that is where the cause of the corrosion lays. Yes, any source of chlorine will serve. One of the high school chemistry experiments involved making a sodium hydroxide solution and a dilute HCL solution and combining them to a Ph neutral solution. The result was salt water.