I'm putting a swb/5 together from parts.
scored some fork sliders cheap at a friend's garage, they looked like crap.
now experimenting with making them look better.
scrubbing with brass brushes & scotch brite (green) in my parts cleaning tank got them 'clean'.
this one's the worst of the two, after cleaning.
I did some studying earlier.
reportedly, phosphoric acid gives good results and is not terribly toxic.
(Used in coca-cola, it can be sourced 85% pure food-grade from amazon.com.)
I shopped around and found this stuff which includes a fair percent of it.
^ these results were after three application at ~90 seconds each.
I then rinsed the slider in water with baking soda to neutralize the acid.
I'd say the results were better than it appears in the pic, but still those oxide freckles...
Here I've applied RnB pewter, obviously just in "quadrant of the cylinder" under the cast roundel.
below: same but with different lighting.
no RnB on the axle buttress, or left of the roundel.
for comparison we have here the second slider in the foreground, scrubbed and cleaned with solvent only (nice patina
Slider in back done complete in RnB pewter except for the upper, gaiter area.
in the pic below: foreground slider after etching with Aluminum Brightener (aka phosphoric acid).
IMO the etched slider would eventually oxidize to the pewter color.
I've not tried RnB "silver leaf" but it may closely resemble the freshly etched slider.
Same two as above, different lighting.
as seen below, I went ahead and waxed the second slider with the RnB.
(neither one was scrubbed, etched or waxed in the gaiter 'land'... that ~3 in. area at the top of the slider)
IMO it's a big improvement on these second hand parts. No way have they ever looked this good in this century.
from http://www.amaco.com/"Rub 'n Buff is made from imported carnauba waxes, fine metallic powders, and select pigments."
It contains a petroleum distillate which keeps it soft for application, and as this evaporates the wax hardens.
Easily removed with acetone, I like how it protects the aluminum from further oxidation while making it easier to keep the surface clean.
I guess it lasts about as long as a good wax lasts on patent leather shoes: depends on the duty.
Honestly, I'm not a 'cleaning' enthusiast and can't afford to spend a lot of time at it.
Having made the effort to get these castings clean, it's nice to keep them so while minimizing further effort down the road.
And I believe it will make the next owner happy as well.