Leaded reels & nonsense.
Leaded aluminium fly-fishing reels first appeared near the end of the 19th century. The bronzing and leading methods were closely guarded by the different makers, but are all basically similar.
The “bronzing” consists of a number of noxious compounds and strong acids [I won’t reveal the formula because I’d hate to be responsible for the irresponsible] Suffice to say that some are highly toxic and others highly corrosive.
These were applied and removed in accordance with each maker’s procedures ~ this is what creates the lovely bronze/gold tint on some old aluminium reels.
The “leading” was simply the application of a layer of graphite over the bronzing. Some say they used pure carbon, some say they used a proprietary fire-grate paste . . all I know is that they created the lovely dark grey colour named after darkly oxidised lead.
The leading wasn’t complete until they varnished/lacquered the carbon coating to give that lovely sheen of mint pre WW2 reels.
One of my biggest groans these days is seeing so-called experts, usually on the internet, advocating some wonderful petroleum based oil/wax magic brew for “saving” your old reel.
They have absolutely no idea what the reel lacquer is, or how it will react to petrol based concoctions. I’ve used petroleum spirits to remove varnish in the past . . . ???
As for how it will react with the compounds contained in the bronzing solution . . . .
[The same logic applies to soaking old leaded reels in an acetic acid solution . . . really?]
Just say “No” to exotic chemicals. Soap and water and a soft cloth, occasionally – save the tiny drop of oil for the pawl and the spindle only.
You have to wonder how many reels, which had survived for a century, have been ruined as a result of these clowns' ignorance.