This is very doable, just make sure you take the necessary steps to make sure it turns out good.
I've done a few of these and it is worth the time and effort. Sorry this is kinda long.
1) Clean up the wheel. There is 50 years of grime, grease, and oil from hands all over that thing. I use my bench top sand blaster to clean the wheel up and take all of the dirt off, but I hold the nozzle as far away from the wheel as possible using fast back & forth actions to not let the blast media hit one spot for too long. Dirt and grime will effect how well the primer/paint attaches. Don't worry about taking off the texture on the arms/spokes, you will deal with that soon. You may want to just sand the round wheel part to get it clean, make sure to get in all the areas where the finger grooves are.
2) What kind of cracks are you dealing with? Spiderweb cracking, cracks like 1/32"-1/64" in size, or chunks missing like 1/8"-1/4"? You must treat this like any other body repair. Sanding, epoxy or filler, sanding, putty, sanding, primer, sanding, sealer, and paint should all be involved. If you are only dealing with small cracks, then epoxy (preferred) or simple body filler (3M Platinum) and then a glaze/putty top coat (I use Evercoat Glaze) will easily fix those. If you have large cracks or chunks missing, you may want to get a small tin of short strand fiberglass filler, and use that before the primer & glaze. This will fill the larger spaces better, and is slightly flexible to move with the expansion/contraction of the part. But, again, epoxy is best.
If the cracks are on the "wheel" part where your hands go, it helps to tape around the wheel on either side of the crack, then use filler in the middle. This helps to isolate the filler in the cracks only. Makes for easier finish sanding too. If the cracks are on the "arm" parts that go from the wheel to the horn hub, you just need to get them filled in and sanded down a bit. This area doesn't have to be as pretty, because you will be re-texturing that part and it will hide your work.
3) Spray the first coat of primer. Just a rattle can primer from the auto store is okay for this, like Dupli-Color Automotive Series. Try to get one that is filler primer and is sandable. 2 thin coats is all you need for coverage. Check for runs when it's dry, sand them out if any are present.
4) Mask off the wheel part and apply texture to the arms. In the past I have used bedliner, undercoating, and trunk paint for texture. All of these are available from the auto parts store. Again, just spray can stuff is okay. The undercoating starts out with large texture, but will flatten down. The trunk paint has smaller bits of texture. Have a look at what your factory texture looks like, if you care about getting it as close as possible. Give this a full 24 hours to cure before you put on the next primer.
5) Primer the entire wheel. If you have a spray gun set up you can use epoxy primer just like you would on a door or fender. If not, you can use the spray can epoxy primer. 2 medium coats, take care not to go heavy and get runs. Light sand when dry, 400-600 grit.
6) Sealer or no sealer. Up to you.
7) Paint it. 3 or 4 coats, lightly. You want to avoid building up thick layers. The first coat should just be a dusting, to adhere to the primer/sealer, and offer a base for the next coats to stick to. Thick layers may come off in pieces if it gets penetrated.
Post #73 in this link for some pics. Only a few though, I forgot to get good before & after shots. Good luck!
'70 Duster - First MOPAR Build
