Marine Electrician required

[WillD]

We have had some issues with our Hull rusting; we thought we had the problem fixed in October but the rust has returned! 

 

The issue has been caused by electrolysis but we don't know enough about electrics to go looking for the problem.

 

Does anyone know of anybody in the cambridgeshire/Bedfordshire area who can help?

[matty40s]

What was the fix done on the boat in October??

[Alan de Enfield]

17 minutes ago, WillD said:

The issue has been caused by electrolysis

 

I cannot help with a suggested electrician, but, what makes you think the problem is 'electroylsis' rather than any other forms of corrosion ?

 

What waters are you on ?

Are you plugged into a mains hook-up / landline ?

Edited March 2, 2021 by Alan de Enfield

[WillD]

32 minutes ago, matty40s said:

What was the fix done on the boat in October??

We had a galvanic isolator wired up the wrong way which would have exacerbated the problem and then we had the Hull sanded, welded and re-blacked. 

32 minutes ago, Alan de Enfield said:

 

I cannot help with a suggested electrician, but, what makes you think the problem is 'electroylsis' rather than any other forms of corrosion ?

 

What waters are you on ?

Are you plugged into a mains hook-up / landline ?

We had someone come to inspect it who said as much. We only noticed the problem after we had been out and about so it's on the 12v system. 

 

We're on the Great Ouse and we're plugged in with a galvanic isolator. 

[Alan de Enfield]

3 minutes ago, WillD said:

We had someone come to inspect it who said as much.

 

I very much doubt an 'electrician' would know very much about corrosion, I think your would need a qualified surveyor with relevant experience and knowledge - it could even be MIC which looks very similar - particularly if it has reappeared after having the work done to the Hull - MIC can live under the new blacking and then break out.

 

MIC is being more frequently found, particularly in Eastern rural areas with nitrogen based run-off from Agricultural land

 

What does the rust look like ? (Pictures ?)

 

 

Is it anything like this ?

 

 

 

[Tony Brooks]

I don't understand ho you can wire a galvanic isolator "the wrong way" I would expect it to work either way round, although any monitoring may not.

 

And what qualification/experience did this "someone" have. Would they have recognised microbial corrosion? That can leave bright pits much like galvanic corrosion and it needs far more hull prep to deal with it than a quick pressure wash off.

 

No to sure how a negative earth boat would suffer 12V corrosion unless a large, long term, 12V load was earthing through the hull.

 

Crossed with @Alan de Enfield

Edited March 2, 2021 by Tony Brooks

[GUMPY]

4 minutes ago, Tony Brooks said:

I don't understand ho you can wire a galvanic isolator "the wrong way" I would expect it to work either way round, although any monitoring may not.

There was a school of thought that says the GI should be between earth and the hull thus isolating the hull. They are wrong, it's all to easy to bridge the GI when used that way  with an aerial or similar

[WillD]

45 minutes ago, Alan de Enfield said:

 

I cannot help with a suggested electrician, but, what makes you think the problem is 'electroylsis' rather than any other forms of corrosion ?

 

What waters are you on ?

Are you plugged into a mains hook-up / landline ?

We had someone come to inspect it who said as much. We only noticed the problem after we had been out and about so it's on the 12v system. 

 

We're on the Great Ouse and we're plugged in with a galvanic isolator. 

1 minute ago, Alan de Enfield said:

 

I very much doubt an 'electrician' would know very much about corrosion, I think your would need a qualified surveyor with relevant experience and knowledge - it could even be MIC which looks very similar - particularly if it has reappeared after having the work done to the Hull - MIC can live under the new blacking and then break out.

 

MIC is being more frequently found, particularly in Eastern rural areas with nitrogen based run-off from Agricultural land

 

What does the rust look like ? (Pictures ?)

 

 

Is it anything like this ?

 

 

 

It's all over without the raised pitting. 

 

Since we've moved off the boat and stopped using electrics, it hasn't got any worse. 

 

Everyone we've gone to has said it's galvanic corrosion. The suspicion is that, as the fit out was done by a previous owner, it was potentially done wrong.

 

[Alan de Enfield]

2 minutes ago, WillD said:

We had someone come to inspect it who said as much. We only noticed the problem after we had been out and about so it's on the 12v system. 

 

We're on the Great Ouse and we're plugged in with a galvanic isolator. 

It's all over without the raised pitting. 

 

Since we've moved off the boat and stopped using electrics, it hasn't got any worse. 

 

Everyone we've gone to has said it's galvanic corrosion. The suspicion is that, as the fit out was done by a previous owner, it was potentially done wrong.

 

 

Maybe one of the 'everyone you've gone to' can advise how to overcome the issue.

The problem with 'a mate said' or 'a guy on the internet suggested ...' is that you have no idea of their skill set.

 

You are doing the correct thing by looking for a qualified person but I really don't think that an 'electrician' is what you need, 

 

Don't discredit MiC (you are in a prime area for it)

 

 

 

All the best, however you go about solving it.

MICROBIOLOGICAL-CORROSION.pdf

[Troyboy]

It might be worth contacting Mark Douglas Marine Ltd,  Mark  is a qualified Marine Surveyor and covers your area . His website is www.markdouglasmarine.co.uk  phone number 07596 454701.

[WillD]

5 hours ago, Troyboy said:

It might be worth contacting Mark Douglas Marine Ltd,  Mark  is a qualified Marine Surveyor and covers your area . His website is www.markdouglasmarine.co.uk  phone number 07596 454701.

Thanks very much