[SIX8YAK]

POR-15 seems to be the ticket for stuff like that, especially with a little surface rust. I have a friend who is using a cheaper somewhat similar version called Chassis Saver.

[JamRSW6]

From what I recall, this product was not a opaque coating like POR-15. More like a clear/transparent coating. I want it to go on various surfaces but not have the underside of the car just all black. I want the original finished protected but not altered from their original color. I apologize for not remembering where I saw the thread. Jimmy

[64-3Deuces]

You might be referring to wool wax, a lanolin by-product of shearing sheep wool. Discovered in WWII that applying this lanolin kept Navy ship ballast tanks and anchor chains clean and rust free. Good article about this stuff in the January 2018 issue of POCI Smoke Signals. Can be sprayed, brushed, or rolled on and is more or less clear. The commercial name is Fluid Film and available through NAPA and I suspect other auto places as well. Do a search for Fluid Film Napa and all kinds of links come up.

[SIX8YAK]

Originally Posted by JamRSW6

From what I recall, this product was not a opaque coating like POR-15. More like a clear/transparent coating. I want it to go on various surfaces but not have the underside of the car just all black. I want the original finished protected but not altered from their original color. I apologize for not remembering where I saw the thread. Jimmy

Missed reading "not undercoating", woops!