I have to admit, I am a detail freak. In my opinion, nothing makes or breaks a build like attention to the little things like fasteners and finishes. A few weeks back, I picked up these vintage Champion 6-Com plugs to use on my WWII period T modified. Based on Champion magazine advertisements, these plugs fit right into my era and date from approx. 1942-1946 (early plugs had a large brass ring on top of the insulator - '47 and later advertisements show a slender insulator with additional ribs toward the shell and smaller lettering). Although these plugs are NOS - they had some surface corrosion I wanted to address. Materials needed: 1. Evapo-rust 2. Small plastic container 3. Lacquer thinner or Acetone 4. Wax and grease remover 5. Gun bluing cream/paste (I prefer G96 over Birchwood-Casey) 6. Cotton swabs 7. Clean toothbrush (preferably not your own) 8. Light penetrating oil Step 1: Degrease - This step is probably the most critical of all to ensure a good finish. The chemical processes used in this tech depend upon thorough cleaning. I like to give the parts a good wash with lacquer thinner or acetone, scrubbing with a clean lint-free towel to dry. This is followed by the application of wax and grease remover and more scrubbing. I used cheap Rust-Oleum thinner and Dupli-Color wax & grease remover. Gloves are a necessary safety precaution and will keep your hands from imparting oils to the parts. Step 2: Rust removal - Fill your small plastic container with just enough Evapo-Rust to completely cover the plug. I submerged my plugs for approx. 4 hours. More or less may be needed - check early & often. Step 3: Degrease - Again, this step is critical to ensure a nice finish. Wash with thinner/acetone and scrub with a clean lint-free cloth. Apply wax & grease remover, scrub dry. Step 4: Bluing - In a well-ventilated area lightly swab the plug shell with gun bluing paste. I have found that q-tips work quite well for this and give more control than a piece of scrap cloth. Work slowly - aim for a light, even coat. Some 'scrubbing' may be required to get into the knurled portion of the shell. WEAR GLOVES - Bluing paste is acidic! Step 5: Rinse - By the time you've worked your way around the plug the first areas you swabbed will begin to develop a white/bluish-white haze. This means the chemical reaction is complete and the plug is ready to be rinsed. Carefully rinse the plug off in lukewarm water. While rinsing, scrub the shell with a clean toothbrush to remove any stubborn bluing paste. Blow dry with compressed air. Lightly polish the shell with cheesecloth. Step 6: Repeat steps 3-5 until a dark, lustrous finish is achieved. Typically it takes 2-3 degreasing-bluing-rinsing cycles to get a good finish. Step 7: Oiling - To preserve and protect the finish, give the plug shell a light coat of oil. I prefer to use CLP but any oil will work. If you're working in a cold shop, use a torch or place the plugs in an oven to warm them up a bit - this opens the pours of the steel and allows the oil to penetrate. Viola! Plug magic!! Hope this helps someone!
A couple things to note: Evapo-Rust does not harm the electrode. In fact, it has a nice cleaning effect, see below. I would also caution against using the bluing paste around the electrode...I stopped at the gasket seat.
gotta ask...couldn't I wire brush them on a bench grinder to get the rust off, then blast the electrode area/threads in my spark plug cleaning machine...then clean and blue them?...or do they have to be chemically stripped?
I don't see why that wouldn't work, only issues I see with a wire wheel is that you'd need to be careful around the insulator and you may end up polishing out the tool marks & some of the knurling. Soaking in Evapo-Rust was a lot easier, I could work on other things while it was doing its thing.
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