Tinning copper at home

[rotrax]

I used a 316 bolt to connect an anchor winch cable through a bulkhead, The resistance at the joint was sufficient to ignite surrounding woodwork.
Now replaced with brass.
It is interesting (and concerning) to check voltage drop across connection when under load.

When I get a problem, I shall, of course, be checking as you suggest. In the absence of any problems I shall continue to use my boat as usual. If it aint broke, dont fix it.

As an aside, when I fitted my used 8KW Westerbeke genset, I needed to extend the live and earth cables as the battery was 35mm shallower. I made two shaped connectors from 25mm X 2mm Stainless Steel strip. Each was about 70mm long. I connected them with 8mm S/S bolts and nuts. No discernable volt drop on my instruments when cranking the genny, never yet failed to start in 5 the years since fitting. There is no heat at my custom made terminal connectors either.

On the other hand, I am often criticised for tightening threaded fastners so others cannot undo them..................................

 

[Slowboat35]

Google is your friend...
Tinning Paste - 50g - 40% -Tin

 

[Neeves]

When I get a problem, I shall, of course, be checking as you suggest. In the absence of any problems I shall continue to use my boat as usual. If it aint broke, dont fix it.

As an aside, when I fitted my used 8KW Westerbeke genset, I needed to extend the live and earth cables as the battery was 35mm shallower. I made two shaped connectors from 25mm X 2mm Stainless Steel strip. Each was about 70mm long. I connected them with 8mm S/S bolts and nuts. No discernable volt drop on my instruments when cranking the genny, never yet failed to start in 5 the years since fitting. There is no heat at my custom made terminal connectors either.

On the other hand, I am often criticised for tightening threaded fastners so others cannot undo them..................................

I too have read that stainless steel is a poor conducted. This is of course relative to say copper. However I do note that most terminals are bolted together with stainless steel - so it does have its place - commonly the conductors might be copper - or as in your case large and short. I had assumed terminals on batteries were stainless....?

But then - there are many variants of stainless steel and the cautionary comments about stainless being a poor conductor refer to stainless as if it is a metal of one unique combination and 316, 304 etc are very different and have very different characteristics.

 

[Slowboat35]

Of course the bolts holding copper components together are not necesarily needed to be conductive at all, they are merely there to hold the conductive parts in close contact.
Terminals on batteries stainless? Not on any battery I've ever seen. They're a soft grey metal, I'd always thought it to be a lead alloy.

edit;
Google says a lead alloy with 2.75-3.25% antimony, 0.05-0.20% arsenic, 0.15-0.40% tin, 400-600 ppm copper, less than 30 ppm sulphur and less than 20 ppm selenium.

 

[Neeves]

Of course the bolts holding copper components together are not necesarily needed to be conductive at all, they are merely there to hold the conductive parts in close contact.
Terminals on batteries stainless? Not on any battery I've ever seen. They're a soft grey metal, I'd always thought it to be a lead alloy.

edit;
Google says a lead alloy with 2.75-3.25% antimony, 0.05-0.20% arsenic, 0.15-0.40% tin, 400-600 ppm copper, less than 30 ppm sulphur and less than 20 ppm selenium.

Or

Terminal Materials​

Diving Into Nickel-Plated Steel Terminals​

Nickel-plated steel is a commonly used material for lithium battery terminals due to its excellent conductivity and corrosion resistance properties. The nickel plating enhances the durability of steel terminals, making them ideal for long-term use in various electronic devices. Moreover, nickel-plated steel terminals offer good mechanical strength, ensuring reliable contact between the battery and device connectors for efficient power transmission.

 

[rotrax]

I have just been into my workshop where, hanging on the toolboard for electrical stuff, is my heavy discharge battery tester. Two pointed prongs with substantial wooden handles, pivoting in and out to reach different width terminal posts. Connected together via very heavy copper strip sandwhiched between what looks like asbestos insulation plates-it is 50 years old, asbestos was not a hazzard then-with a heavy duty voltmeter in parallel. When two terminals are joined with this device, it dont 'arf get hot! You read the voltage after shorting the terminalls for five seconds. It simulates a starter motor load on the battery. Below 10v on full discharge load, the battery is not fully charged or duff.

The specific thing I went to check was the material the prongs are made of. They have always been shiny. Scraping hard with a pointed spike shows they are not copper or brass that have been plated. The sparking and burning in use would soon burn copper or brass. No sign of rust, they have never been cleaned either. A magnet test shows they are not magnetic.

Surely not some type of Stainless Steel? I am told it is a bad conductor-nobody in their right mind would use a bad conducting material for such a device, would they?

Can anyone comment?

 

[rotrax]

Or

Terminal Materials​

Diving Into Nickel-Plated Steel Terminals​

Nickel-plated steel is a commonly used material for lithium battery terminals due to its excellent conductivity and corrosion resistance properties. The nickel plating enhances the durability of steel terminals, making them ideal for long-term use in various electronic devices. Moreover, nickel-plated steel terminals offer good mechanical strength, ensuring reliable contact between the battery and device connectors for efficient power transmission.

It is possible the bus bars on my Island Packet's are high nickel content solid steel. AFAIK, stainless steel has plenty of nickel in it.
They dont appear plated as they seem to have been cut to length to suit the spaces they are fitted in.

 

[B27]

I have just been into my workshop where, hanging on the toolboard for electrical stuff, is my heavy discharge battery tester. Two pointed prongs with substantial wooden handles, pivoting in and out to reach different width terminal posts. Connected together via very heavy copper strip sandwhiched between what looks like asbestos insulation plates-it is 50 years old, asbestos was not a hazzard then-with a heavy duty voltmeter in parallel. When two terminals are joined with this device, it dont 'arf get hot! You read the voltage after shorting the terminalls for five seconds. It simulates a starter motor load on the battery. Below 10v on full discharge load, the battery is not fully charged or duff.

The specific thing I went to check was the material the prongs are made of. They have always been shiny. Scraping hard with a pointed spike shows they are not copper or brass that have been plated. The sparking and burning in use would soon burn copper or brass. No sign of rust, they have never been cleaned either. A magnet test shows they are not magnetic.

Surely not some type of Stainless Steel? I am told it is a bad conductor-nobody in their right mind would use a bad conducting material for such a device, would they?

Can anyone comment?

Could be Tungsten?

OTOH the whole device is a resistor, there is no great imperative to use high conductivity materials.
You'd be looking for a metal that's reluctant to weld itself to the battery.
Tungsten was historically material of choice for sparking contacts like magneto points.
Stainless would probably be OK in this application, as in use, the insulating oxide layer would get broken.
Stainless can be a bad idea with small signals due to the oxide layer. The favoured metals tend to have more ohmic oxides.

There are dozens of metallic elements used in electrical alloys, many compounds have been banned under COSHH rules.

 

[PaulRainbow]

I too have read that stainless steel is a poor conducted. This is of course relative to say copper. However I do note that most terminals are bolted together with stainless steel

Terminals are indeed often bolted to busbars etc with stainless fittings, but the bolts do not carry any current.