Copper Fuses a "no-no"?
 

I've been told of the benefits of copper or brass tipped fuses for our cars, but they seem to think otherwise here...
http://mbca.cartama.net/showthread.php?p=74986

That's an interesting theory.

Can't condemn it as false out of hand, however.

The copper is also quite soft........whether it results in "significantly" less contact area would be questionable.

I'd have to see it to believe it.

I will condemn it out of hand. It's a crock. The copper fuses corrode badly. The"silver" type are solder coated (Tin/Lead) and don't corrode. All that talk about contact area with soft copper is meaningless with a non-gas-tight corroded connection.

You prefer the "silver" type fuses..........actually made from aluminum in many cases??

His argument may be valid if the aluminum deforms under the force from the brass, spring loaded terminal block.

I changed mine out to all new copper fuses a few years ago. They still look new, havn't needed to touch them since.

Tin coated fuses are not needed on cars, way overkill. Now talk to me about a bilge pump connector that spends 6 months out of the year wet with salt water.

All I know is my copper fuses were all oxidized and corroded. Power windows and radio were having issues. Replaced them with decent tin coated units (I don't think they were aluminum, color is obvious) and they've been working fine.

Just make sure the contacts still have good spring pressure.

Well, I've got all copper in the SD now. We'll see how long they go before they oxidize. Since copper is a fairly durable metal.........lasts almost forever in household plumbing..........I'll make a bet that I won't be changing them anytime soon.

Copper is a much better conductor of electricity than alluminum but more expensive. Alluminum is much cheaper and corrodes like crazy. Big industrial electrical cable is often alluminum due to it is much lighter and cheaper.

I like the copper fuses myself and never had a problem.

I gotta wonder about this one. I have seen too many problematic fuses of this style in old european cars and many were dissimilar metals and corroded.

Replacing aluminum fuses will continue to be a good idea. Tinned fuses may have their places.

The high amperage draw and contact area argument makes sense but I wonder if there is not another underlying problem causing the excessive heat.

Di-similar metals have enormous problems getting along. Like aluminum and copper, for instance.

Don't know about electrical
 

Don't know about electrical connections with dissimilar metals, but in plumbing you have what is called dielectric unions where one type of metal joins and different type.

The resulting action is the same as what you have in plating metal. Electrons flow from the metal with the higher atomic weight to the metal with the lower weight. This is also why water heaters have a sacrificial anode in them. I suppose this could pose a problem in electrical connections, too.

I beleive that you should always use the type and spec. fuses as called for by the manufacturer. Copper does corrode and oxidize. Ever seen a new penny STAY shiny? Tarnishing is the same as oxidizing, and that tarnish becomes a resistor electrically speaking.

For the dissimilar metal thing, google galvanic corrosion or stuff like that. It is a big problem on boats, read about the zincs ( sacrificial anodes? ) that are hung on the bottom of boats.

Calling the fuses copper is probably a misnomer, they are probably a copper alloy. The contacts in the fuse box are probably a harder copper alloy or they may be plated.

Almost all metals react to some degree, copper, aluminum and silver included. They call it by different names under different conditions and circumstances, annodization, tarnish, corrosion, rust, etc.

Pennies are not made of solid copper after 1982. Put a copper penny on top of your battery and it will corrode but the battery terminals will not. I have meant to find the explanation for this for years and have never done it.

Mercedes speced out there fuses 30 years ago, that leaves no room for technoloigical improvements in alloys and manufacturing processes. Some things are good to adher to, but you must be alert to progress in the industry. LOTS of things we have today was not even an option back when these cars were designed....like oil etc.

agreed.
have some minor corrosion in the box at the fuses,
and thinking copper will be better in the long term despite the tarnish issues. even seems more like stock.
AMSoil synthetics weren't around when these rigs were manufactured but man is that some sweet nectar.. :D