Disclaimer: If you do not own, or have an aversion to "steelies" then this thread is probably not for you...
For those of you that have steel rims, whether you use hubcaps or not, you might begin to notice some rust on them ... especially if you use them as your winter wheels. Some people dont care, which is fine - you can let them rust ... but others want to keep them looking fresh & black like their tires, and this was my solution:
Supplies
+ Bucket for Soapy Water
+ Abrasive Pad or Sponge
+ Dry Cloth or Shop Towels
+ Sand Paper (a medium grit like 150 or 220 should do)
+ Index Cards (one large pack, just to be safe)
+ Newspaper
+ Paint of Your Choice [discussed below]
+ All necessary tools to remove wheel from car
How-To
Step 1: Jack up corner and remove 1 wheel from car
Step 2: Clean steel rim with soapy water & abrasive pad
Step 2.5: Dry rim thoroughly with cloth or towels
Step 3: Sand rim until seemingly grey (doesnt take a lot of effort)
Step 4: Clean rim again to remove any debris from sanding process
Step 4.5: Dry rim again - make sure there is no water in any crevice or dimple
Step 5: Mask off tire area with index cards - they should stay fine if pressed in firmly, as long as you are not painting on a very windy day ... some people also say to use some duct tape to mask off the valve stem (which i did)
Step 6: Apply very light coats of your base paint - waiting a few minutes between coats
(Optional) Step 7: Apply 2 full coats of secondary paint [discussed below]
(Optional) Step 8: Apply 1 or 2 light coats of clearcoat
... and then youre done! Allow the wheel to dry while you work on the next 3 - and try to keep them out of wet areas for at least 24 hours!
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Optional Paint Ideas:
I painted my front wheels two different ways at first to experiment with finishes, and then decided and repainted them to be the same ... this way you wont have to worry about what it will look like if you try this!
Version 1:
Use Rustoleum High Heat black spray paint for Grilles - this will give a deep grey finish (dark gunmetal). If you apply clearcoat, it will give you a deep matte grey with somewhat of a sparkle due to the clearcoat.
Version 2:
Use the process above, but use Duplicolor Semi-gloss Black for the secondary coats (using the rustoleum high-heat almost like a primer). This will give you a true flat black color.
Version 3:
Use the aforementioned Duplicolor as the base paint, applying a light clearcoat afterwards. This will give you a finish that is almost exactly like the OEM paint on the steel rims.
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Before:

After (Version 2):

After (Version 3):

Paints Used:

Hope That Helps! 