galvanic isolator

[bizzard]

Having said that.Wooden boat owners happily sailing about in the belief that their boats can't be zapped by this invisible phenomenon suddenly opens up like a Tulip as all its metal fixings,nails,roves and screws ect have been zapped and all suddenly let go at the same moment and everyone falls through the bottom.

[sebrof]

Wow, I am confused now...!!

 

It seems that if you spend most of your time in a marina, connected to a shoreline 240V feed, then effectively you are dissolving your hull at a rapid rate, even with a Galvanic Isolator...??

 

Even if you only connect for one day a week, then inevitably your boat will corrode before your eyes....!!

 

I don't hold much hope for my prospective boat as I can only cruise at weekends due to work committments, and in December I work 7 days a week, so even that is compromised.....

 

Seriously...what can you possibly do to evade this corrosion? I thought regular blacking, anodes and a GI would do the job....

 

Paint it properly. God knows why narrow-boaters just cover their boats in tar.

[cereal tiller]

Having said that.Wooden boat owners happily sailing about in the belief that their boats can't be zapped by this invisible phenomenon suddenly opens up like a Tulip as all its metal fixings,nails,roves and screws ect have been zapped and all suddenly let go at the same moment and everyone falls through the bottom.

a friend of mine bought a lovely 30 foot bates starcraft and replaced ALL the brass screws in the hull,hundreds of them!

the boat had been used mainly in salt water.

[bizzard]

a friend of mine bought a lovely 30 foot bates starcraft and replaced ALL the brass screws in the hull,hundreds of them!

the boat had been used mainly in salt water.

Salt sea water is much kinder to wooden boats than freshwater,the salt has a slight preserving effect.

[theguitardoctor]

Paint it properly. God knows why narrow-boaters just cover their boats in tar.

 

Recommended procedure would be....??

 

I'd love to know the correct way, as it seems to be just black it every 2-3 years and it's protected...

 

Off course they work!!!!

 

Simple test that was done on our boat and neighbours boats

 

Here we are plugged in 24/7

 

I had a new A new wide beam never been in the water, launched 2009, didn't go anywhere really, but a year and a half later it was taken out for survey as I had sold it.

 

The amount of pitting in just a year shocked me and my neighbours, at the same time we were talking to a surveyer and a qualified electrician, who carried out a simple test, as one of our neighbours boats produced a lot of air type bubbles a bit like a aspirin in a glass.

 

I'm not a electrician, but he Put a

1) meter one end to the shell and one to the mooring ring with the boat connected to the mains and it reg 6.1 stray volts

2) done the same test, but disconnected the shore line and hardly nothing!

 

The test surprised us all and went down the line of boats carrying out the same tests and different degrees of results but all showed stray current

 

My neighbour that day got hold of a Gavonic isolated and had it fitted ,

 

Carried out same test

 

With or without shoreline connected. Measured hardly anything! And no fizzing bubbles

 

Over the next week a total of 4 of us had GIs fitted

 

Of course if your moored next to someone that's plugged in and with no GI I imagine your boat is still going to attract stray current from him.

 

It be interesting if somone here on the forum done the same simple test, and confirm his results. Please as it's a simple 5 minute test but with sup rising results

 

There are more expensive galvanic transformers which you can buy from £400 but a Gavonic isolator you can buy for around £75

 

They work Gavonic isolators stop stray current which helps you stop electrolisis, stray current, and damage to your hull through pitting

 

Big ships use a transformer system but in a grander scale

 

I'd sooner pay £400 now for it to be properly protected than £000,s later due to the need for overplating..!! If indeed a Galvanic Transformer protects it fully regardless of other neighbouring boats stay current...

[sebrof]

Recommended procedure would be....??

 

I'd love to know the correct way, as it seems to be just black it every 2-3 years and it's protected...

 

2 Pack epoxy. And take it out annually to repair any abrasion damage. Should last almost forever if looked after.

 

I'd sooner pay £400 now for it to be properly protected than £000,s later due to the need for overplating..!! If indeed a Galvanic Transformer protects it fully regardless of other neighbouring boats stay current...

 

You can have either a galvanic isolator, or an isolation transformer. See the SG page for why the latter is better.

 

SG

[theguitardoctor]

2 Pack epoxy. And take it out annually to repair any abrasion damage. Should last almost forever if looked after.

 

 

 

You can have either a galvanic isolator, or an isolation transformer. See the SG page for why the latter is better.

 

SG

 

Well I'm not going to get into the whole 2 pack epoxy vs bitumen based as that seems to bring up arguments both for and against as it is. I've seen as many people knock the virtues of Comastic as I have Intertuf bitumen for example....but I do agree with the science of the Galvanic transformer over the isolator....it's finding one that's suitable.

[bigcol]

For the money, the Gavonic isolators do work,and very well

 

It be great if somone from the forum does the simple test, and to see the results.

 

Proof is in the pudding!

 

Col

[theguitardoctor]

For the money, the Gavonic isolators do work,and very well

 

It be great if somone from the forum does the simple test, and to see the results.

 

Proof is in the pudding!

 

Col

 

The downfall seems to be that if you have one, it helps, but really your neighbour needs one also or it's only a matter of time before the corrosion takes hold...

[bizzard]

Its probably best to keep out of the electrically charged Tizer fizzy waters of marinas.

 

I wonder if electric eels have galvanic isolators and or anodes?.If not they maybe they'r culprits,especially at the seaside.

[theguitardoctor]

Its probably best to keep out of the electrically charged Tizer fizzy waters of marinas.

 

I wonder if electric eels have galvanic isolators and or anodes?.If not they maybe they'r culprits,especially at the seaside.

 

 

Eels... Genius....

 

If I could stay out of the marina, I would, but with working 6 days a week, it's not so easy...hence the need for a solution before the problem starts..!

[sebrof]

Well I'm not going to get into the whole 2 pack epoxy vs bitumen based as that seems to bring up arguments both for and against as it is. I've seen as many people knock the virtues of Comastic as I have Intertuf bitumen for example....but I do agree with the science of the Galvanic transformer over the isolator....it's finding one that's suitable.

 

One gives you a superbly strong, hard-wearing, impermeable layer, and the other starts dropping off as soon as you leave the marina.

 

Is the entire world shipping industry wrong? Because that is what you are suggesting.

[theguitardoctor]

One gives you a superbly strong, hard-wearing, impermeable layer, and the other starts dropping off as soon as you leave the marina.

 

Is the entire world shipping industry wrong? Because that is what you are suggesting.

 

 

I'm not saying anyone is wrong, but I can find as many boat owners that say the same thing about epoxy in that it falls off in sheets as water gets behind it in which case it needs stripping, whereas it's possible to patch in or touch up more common blacking finishes.

 

Who's right, who's wrong...? The person who has found what works for them. If you ask me, its all about the preparation...both finishes are probably fine if applied correctly at the correct intervals.....

 

The question is...does epoxy protect you from galvanic corrosion then...??

[sebrof]

I'm not saying anyone is wrong, but I can find as many boat owners that say the same thing about epoxy in that it falls off in sheets as water gets behind it in which case it needs stripping, whereas it's possible to patch in or touch up more common blacking finishes.

 

Who's right, who's wrong...? The person who has found what works for them. If you ask me, its all about the preparation...both finishes are probably fine if applied correctly at the correct intervals.....

 

The question is...does epoxy protect you from galvanic corrosion then...??

 

Yes.

 

If water can't get at the hull, there can be no galvanic corrosion. Or rust. 2-pack epoxy will protect the hull much better than ordinary blacking - provided, as you say, that it is applied properly onto dry, bare, metal.

[theguitardoctor]

Yes.

 

If water can't get at the hull, there can be no galvanic corrosion. Or rust. 2-pack epoxy will protect the hull much better than ordinary blacking - provided, as you say, that it is applied properly onto dry, bare, metal.

 

With the same preparation then surely even normal blacking would stop galvanic corrosion if it properly sealed and formed a barrier to the water....?

 

With that in mind, I have seen several boat owners paint their hulls with red oxide primer, or similar, and black over this...good or bad idea..?

[mike e]

With the same preparation then surely even normal blacking would stop galvanic corrosion if it properly sealed and formed a barrier to the water....?

 

With that in mind, I have seen several boat owners paint their hulls with red oxide primer, or similar, and black over this...good or bad idea..?

 

I think its time to fit a G I

[bizzard]

Am working on an old 1980's Alvechurch boat in dry dock at the mo.Hull in very good nick for its age,simple electrics.No galvanic isolator.

Minimal slight outbreaks of Electrolosys present and again i've noticed these little outbreaks are close on where internal electrical,appliances are ( Shower pump ,water pump,a couple of mains sockets ect). Boat last docked about 6 years ago. 4 anodes at the extreme ends and will go again,Not a live aboard.

Must press on,frost is going. Bizzard.

[Phil Ambrose]

If you unplug your car battery charger but leave it connected to a battery the charger will still be drawing power from the battery (albeit at a very low level).My understanding is that the expensive chargers must include transformer coils to isolate the battery from the charger and prevent it being backfed allowing it to be hardwired permanently to the bank.If you find a reliable 30A charger that can be permanently connected let me know.

 

Numax 30amp, fit and forget.

 

 

Phil