No Anodes?

[Alan de Enfield]

28 minutes ago, Murflynn said:

Should I fit a cratch cover or a composting loo?

It wouldn't then be a realistic model.

It is thought they would drop their kegs, reverse out between two shileds, hang onto the shields whilst straining, then pull themselves back inboard.

 

On some archeology programme I was watching they had found 'staining' on the side of the viking boat and analysed it and found it was 'poop'.

 

Maybe to be fully authentic you could paint similar onto your model ?

[Jen-in-Wellies]

1 hour ago, Murflynn said:

Should I fit a cratch cover or a composting loo?

Needs a pram hood.

[Murflynn]

1 hour ago, Alan de Enfield said:

It wouldn't then be a realistic model.

It is thought they would drop their kegs, reverse out between two shileds, hang onto the shields whilst straining, then pull themselves back inboard.

 

On some archeology programme I was watching they had found 'staining' on the side of the viking boat and analysed it and found it was 'poop'.

 

Maybe to be fully authentic you could paint similar onto your model ?

I love the seats of leisure on Arab Dhows.

 

 

 

 

The "heads" of course originate from the days when the crew went forward over the bow and held onto ornamental timbers where the bowsprit projects, known as the heads of the ship, to do their business.

 

 

 

[Onewheeler]

13 hours ago, Captain Pegg said:

No logic in that. Steel piling isn’t going to create a galvanic cell with a steel hull.

When I used to moor against steel piling, I did consider fitting active cathodic protection to rot the piling in place of the boat. Wonder if anyone has tried it.

[Alan de Enfield]

Just now, Onewheeler said:

When I used to moor against steel piling, I did consider fitting active cathodic protection to rot the piling in place of the boat. Wonder if anyone has tried it.

A lot of piling is actually galvanised so is effectively a big Zinc anode - shame that zinc is not particularly effective as an anode in fresh water - maybe Inland waterways should use Magnesium coated piling ?

[Captain Pegg]

7 minutes ago, Onewheeler said:

When I used to moor against steel piling, I did consider fitting active cathodic protection to rot the piling in place of the boat. Wonder if anyone has tried it.

9 minutes ago, Onewheeler said:

When I used to moor against steel piling, I did consider fitting active cathodic protection to rot the piling in place of the boat. Wonder if anyone has tried it.

My point was that there is no competition between the piling and the boat. They are made of the same material.

Edited December 7, 2020 by Captain Pegg

[Captain Pegg]

10 minutes ago, Alan de Enfield said:

A lot of piling is actually galvanised so is effectively a big Zinc anode - shame that zinc is not particularly effective as an anode in fresh water - maybe Inland waterways should use Magnesium coated piling ?

The galvanising isn’t really used to protect against galvanic corrosion in that instance. It’s a barrier that works as a galvanic coating when damaged.

[Alan de Enfield]

7 minutes ago, Captain Pegg said:

The galvanising isn’t really used to protect against galvanic corrosion in that instance. It’s a barrier that works as a galvanic coating when damaged.

I realise that - it is simply 'a paint' to assist in reducing corrosion.

Unless you are physically bonded (joined electrically) then you won't get any anodic effect by mooring next to it.

 

On my GRP boat each of the thru-hull fittings (cooling water in, exhaust out, toilet flush in etc etc) are individually bonded by electrical cable to an anode. (Anodes are bolted thru the hull)

[blackrose]

17 hours ago, matty40s said:

The hire boat fleets are never hooked up to landlines, out cruising for 9 months of the year, so dont need the protection that boats predominantly hooked up to landlines need.

But as you know, protection for boats hooked up to landlines should take the form of a galvanic isolator or isolation transformer rather than anodes. If a boat had no galvanic isolation on the mains earth cable and was suffering from galvanic corrosion then for sure the anodes would be the first to go and they'd probably go pretty quickly.

15 hours ago, Arthur Marshall said:

I had anodes fitted about twenty years ago. When I got rebottomed a couple of years back they were still good as new.

Then they're not working. I'd be just as concerned about that than if they were eroding too quickly.

[blackrose]

16 hours ago, ditchcrawler said:

I was under the impression that the anodes only have an effect over about 6 foot This is the underside of Harnser and the anodes are on the side of the hull by the bostock 

But the anodes will only work on the plate that they're attached to, not the plate around a 90deg corner. It's difficult to see how bad the unpainted baseplate corrosion it's from your picture. It looks a bit like mine and last time I looked it was just superficial surface rust.

Edited December 7, 2020 by blackrose

[blackrose]

14 hours ago, Captain Pegg said:

No logic in that. Steel piling isn’t going to create a galvanic cell with a steel hull.

If the boat is on shore power and doesn't have any galvanic isolation then it will, but if it isn't on shore power then it would need to be rubbing against the piling with the paint scraped off.

1 hour ago, Captain Pegg said:

My point was that there is no competition between the piling and the boat. They are made of the same material.

But there is always a small difference in the nobility of different steel. Different grades or just from different production. That's how galvanic cells can be created between different steel boats connected to earth on shore power, or steel boats and steel pilings.

Edited December 7, 2020 by blackrose

[ditchcrawler]

27 minutes ago, blackrose said:

But the anodes will only work on the plate that they're attached to, not the plate around a 90deg corner. It's difficult to see how bad the unpainted baseplate corrosion it's from your picture. It looks a bit like mine and last time I looked it was just superficial surface rust.

Dont they go round corners then, just the flat bit they are welses to?

[Captain Pegg]

18 minutes ago, blackrose said:

But there is always a small difference in the nobility of different steel. That's how galvanic cells can be created between different steel boats connected to earth on shore power, or steel boats and steel pilings.

A true galvanic cell is spontaneous. Very similar metals in a poor electrolyte shouldn’t be a concern to boaters in terms of creating a galvanic cell due to dis-similar metals.
 

[Captain Pegg]

1 hour ago, Alan de Enfield said:

I realise that - it is simply 'a paint' to assist in reducing corrosion.

Unless you are physically bonded (joined electrically) then you won't get any anodic effect by mooring next to it.

 

On my GRP boat each of the thru-hull fittings (cooling water in, exhaust out, toilet flush in etc etc) are individually bonded by electrical cable to an anode. (Anodes are bolted thru the hull)

I don’t understand then why you asked if the piles should be galvanised with magnesium. Most zinc galvanised products probably don’t spend their lives submerged in any electrolyte let alone a poor one, and nor are they bonded to any other metals.

[Alan de Enfield]

16 minutes ago, Captain Pegg said:

Most zinc galvanised products probably don’t spend their lives submerged in any electrolyte

Sheet piling does (Armco)

 

Galvanised cable tray spends a considerable time in the 'splash zone' on offshore rigs - we had to supply stainless steel cable ties with a macropol coating to stop crevice corrosion and problems due to dissimilar metals and 'salty-splashing'.

In Saudi, Galvanised cable tray would suddenly fall apart - the zinc coating was perfect but the steel under the coating just crumbled

 

It is quite a complicated subject which was above my understanding but we had to do what the scientists advised to avoid corrosion problems.

[Murflynn]

11 minutes ago, Alan de Enfield said:

Sheet piling does (Armco)

 

Galvanised cable tray spends a considerable time in the 'splash zone' on offshore rigs - we had to supply stainless steel cable ties with a macropol coating to stop crevice corrosion and problems due to dissimilar metals and 'salty-splashing'.

In Saudi, Galvanised cable tray would suddenly fall apart - the zinc coating was perfect but the steel under the coating just crumbled

 

It is quite a complicated subject which was above my understanding but we had to do what the scientists advised to avoid corrosion problems.

in the UAE there was a revolution in building and civil engineering in the 80's when it was decreed that all reinforcing steel bars for buildings over 3 storeys high must be epoxy-coated by electrostatic means.  The bars had to be coated after bending to shape otherwise the coating would just crack and peel off. 

[Alan de Enfield]

10 minutes ago, Murflynn said:

in the UAE there was a revolution in building and civil engineering in the 80's when it was decreed that all reinforcing steel bars for buildings over 3 storeys high must be epoxy-coated by electrostatic means.  The bars had to be coated after bending to shape otherwise the coating would just crack and peel off. 

Pretty much what we had to do (same time period)

Standard polyester and epoxy coatings were V2 fire rated (they burnt rapidly and sprad the fire) and we found a company who had developed this 'polyester' type material that could be electrostatically applied and was Vo rated (wouldn't burn or support fire)

 

Stole a good few years march on our competitors who were using Nylon 11 & Nylon 12 coatings that were V2 rated and dropped flaming drips onto the cables below spreading the fire.

 

Not a good feature on oil-rigs or ships.

 

During the Falklands war, more sailors were killed by smoke inhalation as they could not exit the ships due to fallen cables blocking escape routes, that were killed by the missile hits.

We went onto develop metal cable fixings for ships and subs that were Vo rated AND could withstand the very high G-Forces of a missile hitting the ship without allowing the cables to fall. Witnessing the testing (to enable lloyds approval) was extremely interesting - a 150G force 'rocks the building'

 

Spent many unhappy hours crawling about in part-built submarines at Barrow. I'd never realised how big the things were.

 

Happy times.

Edited December 7, 2020 by Alan de Enfield

[Arthur Marshall]

2 hours ago, blackrose said:

 

Then they're not working. I'd be just as concerned about that than if they were eroding too quickly.

I thought that, and every time the boat got blacked I asked someone's opinion. As far as we could see, they were made of the right stuff and bolted on properly (they were put on by Chas Hardin, who knows what's what). But they didn't decay, and nor did the boat, much. It did get a bit thin in places, but those bits were at least fifty years old, so  I think they were entitled to.

[Dave Payne]

22 hours ago, aristorias said:

I have been looking at some secondhand Viking hire boats. They seem to be without sacrificial anodes. Has anyone seen this on other hire boats and would the hulls be ok if just blacked by the hire fleet every season? If so after the survey I would have a new set of anodes fitted.

 

I purchased an ex Vikings afloat boat five years ago, it had Anodes on it, still got the same set on to be honest as not needed new ones.

[Alan de Enfield]

34 minutes ago, Arthur Marshall said:

I thought that, and every time the boat got blacked I asked someone's opinion. As far as we could see, they were made of the right stuff and bolted on properly (they were put on by Chas Hardin, who knows what's what). But they didn't decay, and nor did the boat, much. It did get a bit thin in places, but those bits were at least fifty years old, so  I think they were entitled to.

If it had zincs put on it (either by mistake or intentionally) they will last for many years in fresh water before they start to show signs of erosion.

 

Take a boat with mag anodes onto salt water and they are gone inside a week.

 

Check you are using the right ones in the right application. Even boat yards can make mistakes.

[ditchcrawler]

1 hour ago, Alan de Enfield said:

 

 

Not a good feature on oil-rigs or ships.

 

During the Falklands war, more sailors were killed by smoke inhalation as they could not exit the ships due to fallen cables blocking escape routes, that were killed by the missile hits.

We went onto develop metal cable fixings for ships and subs that were Vo rated AND could withstand the very high G-Forces of a missile hitting the ship without allowing the cables to fall. Witnessing the testing (to enable lloyds approval) was extremely interesting - a 150G force 'rocks the building'

 

 

We ran all cables on top of galvanised tray not face for that reason unlike some others I saw.

[Captain Pegg]

3 hours ago, Alan de Enfield said:

Sheet piling does (Armco)

 

Galvanised cable tray spends a considerable time in the 'splash zone' on offshore rigs - we had to supply stainless steel cable ties with a macropol coating to stop crevice corrosion and problems due to dissimilar metals and 'salty-splashing'.

In Saudi, Galvanised cable tray would suddenly fall apart - the zinc coating was perfect but the steel under the coating just crumbled

 

It is quite a complicated subject which was above my understanding but we had to do what the scientists advised to avoid corrosion problems.

It is a complicated subject and I think as a result the forum gets confused between requirements relating to protection against corrosion through ordinary rusting, those for preventing corrosion due to the galvanic action of dissimilar metals in an electrolyte, and those for protection against corrosion caused by stray currents.

 

Armco is the name of a barrier rather than a sheet piling product. Presumably it’s use as a waling with sheet piles is where the use of the term in a marine context is derived. It’s a galvanised product that is not primarily intended to be used underwater. There are many that are, and many that aren’t.

Edited December 7, 2020 by Captain Pegg

[cuthound]

1 hour ago, ditchcrawler said:

We ran all cables on top of galvanised tray not face for that reason unlike some others I saw.

 

Likewise in data centres. On vertical runs cables were secured with stainless cable ties

[aristorias]

Thanks to all for the advice (and jokes) I think it will be a case of checking over the hull which would be usual in any case. Several replies indicated that the viking afloat hireboats are well maintained, which is a good starting point.

[Jen-in-Wellies]

On 07/12/2020 at 14:29, Alan de Enfield said:

If it had zincs put on it (either by mistake or intentionally) they will last for many years in fresh water before they start to show signs of erosion.

 

Take a boat with mag anodes onto salt water and they are gone inside a week.

 

Check you are using the right ones in the right application. Even boat yards can make mistakes.

Weird question, asked just out of curiosity. On the River Weaver, around Northwich, is the water salty enough to make zinc anodes work? How long do Mg anodes last there? Is there much salt in the water from the salt beds these days?

 

On 07/12/2020 at 15:50, Captain Pegg said:

Armco is the name of a barrier rather than a sheet piling product. Presumably it’s use as a waling with sheet piles is where the use of the term in a marine context is derived. It’s a galvanised product that is not primarily intended to be used underwater. There are many that are, and many that aren’t.

I call it crinkle cut piling. Inland boaty types know what I mean. ?

Jen