Lisa and Glenn:
In my view, a powder coated tub will stand up much better than any field cured coating like the two part acrylic polyurethane that's being offered by others. The question is: How is he going to bake that tub at 400 degrees without removing it from your home and replacing it, and if he does that, it makes more sense to just install a new tub, doesn't it?
Also, if he's going to sand blast the tub anyway, WHY NOT sand blast all of the old porcelain off and powder coat the whole tub? I my opinion, the existing porcelain will not be powder coated (or powder coated very thinly).
Powder coating will give you a more durable coating than refinishing the tub, but I don't see why he can't remove all the porcelain (at least on the inside of the tub) and powder coat the whole interior.
Maybe keep looking. You SHOULD be able to find plenty of shops in Tennessee that do porcelain enamel coatings.
Your local powder paint man is the best finish you can get in retro, but tubs and all bath fixtures should not have bleach, abrasive cleaners, steel wool or even tile cleaners used on them. Each use of these things breaks down the porcelain a little more. Even the toilet will show signs of dulling after a few years of strong cleaners.
While I'll agree with you on the abrasive cleaners and steel wool, I have to take exception with the bleach and tile cleaners.
I own a 21 unit apartment block in Winnipeg, Manitoba, Canada and have been using bleach to remove stains from linoleum, 100% Olefin carpets, and plastic laminate for over 20 years now. I REGULARILY clean mildewed silicone caulk after tenants vacate by having it in contact with a bleach/talc slurry for several days. I have never noticed any deleterious effects on the olefin carpets, linoleums, laminates or porcelain enamels as a result of using bleach on them, even for extended periods.
I also clean stains out of the acrylic floor finish on my vinyl composition tile floors using bleach. The bleach will clean the stain off the acrylic floor finish without dulling it's gloss. It seems to me that if the bleach was harming the floor finish, the first thing to go would be the gloss.
And, of course, I've remove heavy nicotine staining from latex painted walls using bleach, without harming the paint. I simply rinsed the bleach solution off the walls, allowed time to dry and painted over them. (I don't know how many "paint people" there are in this forum, but good quality latex paint is made out of acrylic plastic. That is, good quality latex paint and good quality grout sealer are both made out of the same plastic we call "Plexiglas".)
The reason why phosphoric acid is commonly used as a general purpose bathroom cleaner is that it cuts through soap scum like a knife, but won't attack chrome plating. In my case, all of my bathrooms have ceramic tiled walls around the bathtubs, and the grout lines are sealed with an acrylic grout sealer. When tenants vacate, I use a phosphoric acid based toilet bowl cleaner on the ceramic tiling around the bathtub to clean the soap scum off of it, and I have been doing that for over 20 years now.
If it did any harm to either the tile, the tub or acrylic sealer on the grout lines, I wouldn't do it.
Sorry, but we're going to have to agree to disagree on this point. "Strong chemicals" that may dissolve and discolour some materials often have no effect whatsoever on other materials. This is why you can buy muriatic acid in plastic jugs. The plastic the jug is made of is unaffected by continuous and prolonged exposure to hydrochloric acid. And, before the world was flooded with plastic, hydrochloric acid was stored in glass bottles:
If hydrochloric acid doesn't harm the glass bottle, I expect it wouldn't harm real porcelain like a toilet, bathroom sink or even glazed ceramic wall tiles. It might dissolve the grout between the wall tiles, but it shouldn't harm the surface of the wall tiles.
Despite how "strong" some chemicals are, it doesn't stand to reason that they harm everything they come into contact with. Often, they have little or no effect on materials.