[TheForge] Re: Dielectric connections

[Andrew Vida]

What you're describing isn't a dielectric, but an anode.  THey weld 
large zinc blocks to ships hulls to prevent galvanic corrosion.  The 
zinc node is sacrificed over the course of years.  When the vessel is in 
drydock for paint, new anodes are put into place.

ries wrote:
> We are not talking about ALL electrical connections here- the bronze 
> fitting Jerry is referring to is made, and sold, to solve a specific 
> application between two metals.
> When plumbing, you often come up with a situation where you need to 
> connect black iron, or galvanized iron, to copper. These two metals are 
> far enough apart on the galvanic corrosion chart that there may be, 
> depending on the presence of salts in your water, corrosion if they are 
> connected directly.
> Bronze connectors are used, as they are about halfway in between steel 
> and copper. Split the difference, and minimise the chances of failure.
> 
> This has been a time honored plumbing trick for probably 50 years or more.
> 
> No, it does not apply to capacitors, or to insulating 240,000 volt 
> lines, or to other real electrical uses- but it is very common, and 
> works quite well, to prevent galvanic corrosion in common plumbing apps.
> 
> Ries