What substance can I use for cleaning the metal cahssie at old tube radios?

Hi, it depends on what is wrong with the chassis; is it just dirty, or greasy, or is it rusting?

For dust and dirt, use a small paint brush and try to brush as much of the dry dirt away. If it is still dirty, rub a damp cloth on a small section and then immediately wipe with a dry cloth.

Waterless hand cleaner is good to use, the kind that mechanics use to get grease off their hands. Spread some on the chassis, wait a few minutes, then wipe off with a dry cloth.

If the chassis is rusting, again it depends on how bad it is. For small areas of rust, rub with fine sandpaper and brush off the dust. Then, for a silver colored metal chassis, brush on some aluminum paint over the rusted area, with your brush almost dry. This often looks pretty good if you use an almost dry paintbrush and blend in the paint at the edges so that it almost looks like the unrusted part of the chassis.

If you have a VERY rusty chassis, there are other methods that could be discussed. :)

Good luck with your projects,

Reece