Does anyone know what kind of plate this is?

[RVonse]

Please look at the picture I have posted.

I have a few of these pot metal based switch covers and some are starting to get black. Was wondering what kind of plating covers the pot metal and whether it could be easily reproduced.

[CarWiz]

It appears to be brass or bronze with antiqueing highlights. Are you sure it's "pot metal" base material?

[RVonse]

CarWiz thanks for your help.

I have no idea what kind of base metal it is other than the fact it appears white/grey in color and that it is definately die casted. I am thinking it is zinc die casted but I really do not know for sure. Do you have any suggestion on how I might be able to tell for sure?

Is plating brass or bronze with antiqueing highlights something I might be able to accomplish? Any suggestions on how I can come up with that process? These plates have not been manufactured since 1976 and are getting very rare to find. Like I said before, most of them I have are starting to get blackened and polish doesnt seem to bring it back.

[lcaswell]

The test for die cast is a two part process:

1. Put a magnet to it. If it sticks, it's not die cast or aluminum.
2. Have some water handy. Take a drop of battery acid and drop it on the part in an inconspicuous area. If it bubbles, it's pot metal (die cast). If it doesn't, it's aluminum. Drench with water to stop the acid attacking the metal further.

To get an antiqued look, you can replate die cast with our Flash Copper Kit, then use one of our antiquing solutions on the copper plate. You can also brass or bronze plate it, after copper plating.

See Plating Kits Chrome Plating Kits Aluminum Anodizing Kits Electroplating Kits - Caswell Inc.

[RVonse]

Originally Posted by lcaswell

The test for die cast is a two part process:

1. Put a magnet to it. If it sticks, it's not die cast or aluminum.
2. Have some water handy. Take a drop of battery acid and drop it on the part in an inconspicuous area. If it bubbles, it's pot metal (die cast). If it doesn't, it's aluminum. Drench with water to stop the acid attacking the metal further.

To get an antiqued look, you can replate die cast with our Flash Copper Kit, then use one of our antiquing solutions on the copper plate. You can also brass or bronze plate it, after copper plating.

See Plating Kits Chrome Plating Kits Aluminum Anodizing Kits Electroplating Kits - Caswell Inc.

Thank you.

It is not magnetic but I still haven't checked for acid.

I have a further question about the antiquing solution. Will that cause all of the brass plating to darken evenly? Because it looks like the low spots where the lettering is embossed in the plate are supposed to be much blacker than the rest.

[KCV6]

With the acid test, be aware that poorer grade cast aluminium will fiz if you put hydroclauric (pool acid) on it, however once rinsed the patch where the acid was will be silver to light grey. Pot Metal or zinc die cast will fizz harder and the spot will be dark grey to black.

Cheers

Mark

[RVonse]

Originally Posted by lcaswell

The test for die cast is a two part process:

1. Put a magnet to it. If it sticks, it's not die cast or aluminum.
2. Have some water handy. Take a drop of battery acid and drop it on the part in an inconspicuous area. If it bubbles, it's pot metal (die cast). If it doesn't, it's aluminum. Drench with water to stop the acid attacking the metal further.

To get an antiqued look, you can replate die cast with our Flash Copper Kit, then use one of our antiquing solutions on the copper plate. You can also brass or bronze plate it, after copper plating.

See Plating Kits Chrome Plating Kits Aluminum Anodizing Kits Electroplating Kits - Caswell Inc.

Ok after further investigation, the metal is definitely die cast zinc. It is non magnetic and it fizzes with acid turning dark grey/black. But...that is only if I scratch off the surface on the back with a screwdriver to get into the white color die cast metal. Otherwise, it appears to be a pretty good layer of brass looking plating. But somehow over the years the original antiquing has gone bad I think which has caused the plate to turn black. Now if I clean with alcohol or paint thinner nothing comes off. But if I buff real hard I get a black rag and a bright and shiny brass underneath. Not the goldish color you see in the picture but a completely different brass color that is much shinier.

So here is what I am wondering if would work:
1. Buff down to bright shiny brass
2. Then use a new antique solution on the brass?

What do you guys think? Can I forget about the flash copper since the existing brass will protect from a reation? I am also wondering if the Caswell antique solution will offer the finish I am looking for. In particular the inscribed writing needs to turn out much darker than the rest of the plate.

Thanks for your help.