Okay, granted, this Instructable is not going to change any lives or anything, but I'm allergic to this rubber coating anyway, and I was so happy with how these turned out that I decided to share the idea.
Step 1: Buy Them
For the retro, 1930's strongman look, choose the kind with round, bulbous ends. These are found pretty cheap at discount stores like Ross, TJ Maxx, and Marshalls.
Step 2: Peel Them
Use the box cutter to carefully cut through the rubber coating. Try not to scratch the metal underneath. You can tear the coating pretty easily, so you don't need to cut all the way through it all of the time.
Peel off the coating and discard.
Step 3: Wash Them
The casting process leaves very fine clay behind on the metal. This becomes trapped under the rubber coating.
We need to clean this clay off the weights before we can paint or clear coat them.
Take the weights to the sink and scrub them down with soapy water. The clay is so finely ground that it becomes sticky when wet, so you'll need to pick the bigger deposits off with something like a butter knife and then follow up with the soapy scrub brush.
The clay is hard to see against the metal when they're both wet, so feel for it with your fingers as you clean.
Step 4: Dry Them
Because these weights are made out of iron, they will begin to rust immediately from the exposure to water, so it's vital to dry them right away, and thoroughly!
The way I did this was to put them on the stove at about 40% of full heat and leave them there for 1/2 hour.
Watch out for deep pits which can retain pockets of water, as well as remnants of latex coating. I had to pick out the latex bits with a pin and then put the weights back on the stove for longer.
Step 5: Seal Them
Do this step quickly after your iron is dry. Don't let them sit around and start to rust (unless you're going for that kind of effect).
Now as the weights are iron, you could opt to slather them in lard and bake them for hours to achieve your classic cast iron seasoning, as one would with a vintage frying pan which one had accidentally run through the dish washer.
For myself, I opted to spray paint one set flat black and to clear coat the other with polyurethane.
The larger, 5lb, set turned out to have a rougher texture on the surface of the iron than the 3lb'ers did, so I used several coats of black spray paint to smooth that out. The smaller ones I clear coated to show off the natural patina of the iron. I used matte finish spray poly.
Step 6: Recolor the Plastic Stand
One of my stands was already black plastic.
The other was purple, so I spray painted it with the flat black paint.
Step 7: Enjoy!
Hope you like them!