The Brookfield....one side is embossed Brookfield 45 Cliff st. NY...Any one have any idea how to get the black residue out of the base? Can insulators be tumbled like bottles are?
The Hemingray-42 is a CD 154, the insulator with the black residue is a Brookfield CD 145.
Getting the black residue, "train smoke" as alot call it, off the base can be tricky.
Most collectors use Oxalic Acid, also known as wood bleach. Wood bleach is very safe to use as far as acids go, but I always tell people to use goggles and rubber gloves.
Many collectors also use Lye, which is a little more dangerous. There are other acids you can use, but the stronger the acid, the more PPE you need to wear.
As far as tumbling, yes, some people tumble insulators, but not to clean train smoke off. Normally tumbling of insulators is used to get rid of glass sickness.