Tarnished Fisher brass knobs: what is best to polish them?

monkboughtlunch

Super Member
What do folks use to restore tarnished brass knob covers on their Fisher 400,500B/C,800B/C series tube receivers? Is brasso a good choice?
 
Dremel with buffer wheel, and some Mother's mag polish. Just about any metal polish is fine. The more tarnished or corroded they are, the longer you leave the polish on (5 to 20 min) then buff it off leaving a shiny cover. The Navy actually banned Brasso back in the 50's for cleaning torpedo tube inner doors. Seems a few C.O.'s were making the Torpedomen shine the tube doors daily to the point the C.O could see his reflection at about 10ft. The problem was that Brasso is fairly abrasive, and the Inner doors were being worn down thinner and as such would not take sea pressure below periscope depth! So now they are polished in the manufacturing shop, and given roughly 20-25 coats of lacquer. The lacquer doesn't eat into the bronze, and it stays shiny with a damp cloth.

Ask any MARINE what the most reviled item in his cleaning kit is and he'll tell you BRASSO!
 
Newer Brasso also has a formula that includes ammonia, and you don't want ammonia on Bakelite knobs. Reasonably sure those knobs are Bakelite anyway. Ammonia is one of the few things that will damage it. If it smells like a cat's litterbox, thats the stuff it won't like.

I like the Mother's mag and aluminum polish. No ammonia smell.
 
A couple of days in vinegar water followed by 600 grit sandpaper and wire brush. Might want to remove the metal spring from inside before soaking.

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☝️I'm not an expert but l wouldn't use sandpaper.
Looking at my Fisher it has textured knobs and l thing sandpaper would be very harsh.
A bit like polishing vintage coins.
I'll stick with the patina look
Soft brass brush maybe okay
 
Gadget; as I recall Brasso has always contained ammonia. Bootcamp in San Diego 1973. The Admin bldg had a brass or Bronze 8-10ft. model of the Missouri. It got daily Brasso applications by members of the punishment details. Bunch of recruits would spend 6-8 hours bringing this monster to a hi shine. You could smell the ammonia from the brasso (literally buckets of the stuff) 100ft downwind when the front doors opened! GAWD AWFUL SMELL. Like 1000 cats pee'd on it!
 
Thanks for all the advice folks.
Where I'm stumped is: how do you polish the chamfered edges (i.e. the sloped brass edges) on these knobs without damaging the brown plastic of the knob? I've illustrated chamfers below with arrows.

Fisherchamfer.jpg
 
A couple of days in vinegar water followed by 600 grit sandpaper and wire brush. Might want to remove the metal spring from inside before soaking.

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Did you pry the brass off the plastic before soaking in vinegar? If not, does the vinegar eat at the plastic?
 
I have used Brasso on my knobs and they seem OK. I also polish the chamfered edges and then scrub off any Brasso residue with dish soap, warm water, and a toothbrush. To keep the shine on your knob brites, you might want to clean them and then remove them from the knobs so that you can spray a couple of lacquer coats on them. After the lacquer is dry, glue them back on. I lacquer the chamfered edges with a very thin brush.

Mike
 
Did you pry the brass off the plastic before soaking in vinegar? If not, does the vinegar eat at the plastic?

No damage to the plastic (as you can see in the photo). Looking back, the metal springs in the holes should have been removed, but no serious damage.
 
The glue holding the brass cap is not very strong and I've removed several from the plastic for better refinishing of the brass. I usually can push the brass caps off with a small screwdriver pushed up the shaft hole. If they don't come off easily I soak the knob in hot water for a few minutes and try again.
 
I usually take a qt measuring cup and fill with HOT WATER straight fro the tap, and add a Cascade or FINISH dishwasher capsule, and drop all of it in after the capsule dissolves and you mix it up. Let soak for 15-20 minutes, Rinse in HOT WATER and use a small brush to get the grains of the detergent that hasn't dissolved, out of the grooves. The wash water will be a dark brown from the nicotine, and breakdown of the dyes of the knobs (no UV protection). Then polish with Mothers Mag polish and a Dremel. The crud is washed off but the brass parts still need polishing.
 
A thicker glue or adhesive, 2 part epoxy, gorilla glue, Silicon RTV (Clear), contact cement, etc. Don't use superglue as it doesn't have the torsional strength. I use a dot of Silicone RTV. A SMALL DOT! or it will ooze out everywhere.
 
Agree with the comments to not use Emery cloth or similar. Even the finest is going to leave an irregular pattern. Easiest way is to apply metal polish of choice to your soft cloth on a flat surface and run the knob (or removed cap) back and forth (circular motion) until polished to your satisfaction.
 
What are thoughts on using Loctite?
That is a superglue as well (in my experience) and I agree that it may not be the best of choices as a knock could cause the glue to 'fracture' and the cap to fly off. I have used contact cement as Larry suggests with good results on these. Sure you could use epoxy but likely you'll never get the darn thing off again should you need/want to. The contact cement held well and I have little doubt I could remove it again if necessary and clean off the residual glue easily.
 
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