Really dumb electrolysis question. Really, it's like a sign saying "low season"...

[Greenheart]

Really dumb electrolysis question. Really, it's like a sign saying "low season"...

I managed to prevent the top swivel of my genoa furler from hanging off-centre under tension - the top boltrope thimble had been too narrow to sit centrally in the space on the swivel, so I drilled 4mm holes in two penny coins, to fill the space either side of the thimble on the stainless bolt. Terrific...a neat two-pence solution...

...but which of these metals will degrade, if the swivel is left in the damp dinghy after sailing? Or, must the adjacent metals be submerged to suffer?

 

[Tranona]

You need an electrolyte (seawater) for any galvanic action.

Will bake you a cake with a file in it for when you get banged up - defacing the sovreign's coinage!

 

[alahol2]

I managed to prevent the top swivel of my genoa furler from hanging off-centre under tension - the top boltrope thimble had been too narrow to sit centrally in the space on the swivel, so I drilled 4mm holes in two penny coins, to fill the space either side of the thimble on the stainless bolt. Terrific...a neat two-pence solution...

...but which of these metals will degrade, if the swivel is left in the damp dinghy after sailing? Or, must the adjacent metals be submerged to suffer?

You mean you fabricated two washers

 

[Greenheart]

It's true, I basically made two washers. Although, all the other bits at the bottom of my toolbox were the wrong size or thickness - pennies were spot-on.

Apologies to the Treasury, but I doubt I could have bought washers, more cheaply.

I suppose I'd have to be tragically unfortunate to suffer an electrolysis problem on metals which live high up the mast...weeks on end, continuously capsized.

I said it was a dumb question. Thanks.

 

[macd]

You don't need any electrolysis: a British penny is steel. It'll rust.

 

[AngusMcDoon]

...but which of these metals will degrade, if the swivel is left in the damp dinghy after sailing? Or, must the adjacent metals be submerged to suffer?

The rule is that it is always the metal that the more expensive component is made of that corrodes.

Doesn't need to be submerged; damp will do it.

 

[nigelmercier]

You need an electrolyte (seawater) for any galvanic action.
Will bake you a cake with a file in it for when you get banged up - defacing the sovreign's coinage!

So called "copper" coins are electroplated steel, so they will rust. Even so, damp can cause electrolysis.
The defacement law was removed over 30 years ago.

 

[macd]

So called "copper" coins are electroplated steel.

Not necessarily so, but as true of a modern British penny now as it was at 0555 UK time

 

[oldsaltoz]

If your tender is aluminium, ant copper object will put a hole in aloy.

Good luck.

 

[VicS]

I managed to prevent the top swivel of my genoa furler from hanging off-centre under tension - the top boltrope thimble had been too narrow to sit centrally in the space on the swivel, so I drilled 4mm holes in two penny coins, to fill the space either side of the thimble on the stainless bolt. Terrific...a neat two-pence solution...

...but which of these metals will degrade, if the swivel is left in the damp dinghy after sailing? Or, must the adjacent metals be submerged to suffer?

Copper and copper alloys (bronze, brass, cupronickel etc) will be fine in contact with stainless steel.

However, as stated, modern 1p coins have a steel core. This will rust once exposed and being in contact with the stainless steel and the outer coating will suffer from galvanic corrosion in seawater. They have been like this for over 20years and I doubt if any old type are still in circulation.

If you cannot find any of old ones a couple of 20p coins might do the job, but a couple of stainless steel washers would be cheaper!

 

[davidej]

Its a crime to deface coins of the realm

Plod on the way - once they have finished stitching up andrew mitchell

 

[nigelmercier]

Its a crime to deface coins of the realm...

No it isn't, try to keep up at the back.

From Wikipedia (and other sources):

In the UK, the Coinage Offenses Act 1936 prohibited the defacement of any current coins. This was repealed in its entirety by the Forgery and Counterfeiting Act 1981, thus removing the prohibition on coin defacement.

 

[lw395]

.....I doubt if any old type are still in circulation.

.....!

Does lurking in the bottom of a toolbox count as 'in circulation'?

I'd either use stainless or plastic. Perhaps grp, a bit of batten or circuit board?

 

[Greenheart]

Thank you gentlemen. Actually there's no shortage of 1970s "copper" coins around, if indeed their metallurgy is better suited to surviving alignment with stainless steel.

Other UK coins are two thick. I have some euros around... I could trawl the tool-box for bits of plastic which are similar in thickness, but nothing will look neater than the pennies.

 

[VicS]

1992 was when the change to copper plated steel coins was made apparently, so any prior to that date will be suitable.

From the Royal mint website:

What are 'bronze' coins made from? Why are some magnetic and some not?

Traditionally bronze coins were made from an alloy of copper, tin and zinc. Since September 1992, however, 1p and 2p coins have been made from copper-plated steel. The change was made because of the increasing price in world markets of base and non-ferrous metals. The copper-plated coins are the same colour, weight, diameter and design as those struck in bronze and circulate alongside them. There is one notable difference. Copper-plated coins are attracted to magnets because of the iron content of the steel core, whereas bronze coins are not magnetic.

In 1998, 2p coins were struck in both copper-plated steel and bronze. We may decide to do this again because, by having this flexibility to produce in either material, the Royal Mint can better meet customer needs promptly and cost effectively.​

Id hardly describe them as being the same colour though!

 

[Greenheart]

Thanks for that Vic. So can I assume that a couple of copper/zinc/tin pennies from the 'eighties will be safe from galvanic corrosion over time, left in the damp of the boat's cockpit?

 

[AngusMcDoon]

Thanks for that Vic. So can I assume that a couple of copper/zinc/tin pennies from the 'eighties will be safe from galvanic corrosion over time, left in the damp of the boat's cockpit?

It's not the pennies that you have to worry about - they are cheap and at the noble (least likely to corrode) end of the scale. It's what they are next to that you need to be concerned about. If they are in contact with aluminum and you use the setup in salt water you will destroy it in short order and the cost will be much greater than 2p. If you are using any metal in contact with aluminum, you need to do it properly with proper materials and preparation.

 

[CreakyDecks]

I'm not sure electrolysis would be a problem. When I recently rebuilt my old push bike, the aluminium wheel rims were perfect but the (presumably once chromed) mild steel spokes had rusted to almost nothing. Electrolysis would have done it the other way round. Mild steel doesn't need electrolysis to rust.
PS. Differentiating copper pennies and steel ones is easy, use a magnet.

 

[bedouin]

Not really relevant to the OP, but I had assumed the core of the 1p was the same metal as the 5/10p etc - so wouldn't rust

 

[CreakyDecks]

Not really relevant to the OP, but I had assumed the core of the 1p was the same metal as the 5/10p etc - so wouldn't rust

I think they are mild steel as well now. The country is going to the dogs!