To date, I have never had any luck with any tire paint.....I've tried three times to paint the tires on my Dad's 30 Reo - it either turns brown, or cracks and falls off....
Someone mentioned the need to wash the tire (with what I don't know) several times to get the oil out of the rubber before painting. Otherwise the paint won't stick well and will discolor.
Unfortunately nothing looks as good as a real white wall.
Painted ones don't last. Even with "Real" tire paint they just don't hold up and they realy need some specific prep to make the paint stick. Lately though there are some that are claiming great success with Krylon Satin white spray paint
Grinding is a better option. With a good eye and a steady hand good results can be had. But be aware that if you were to buy new tires and ground them chances are all warrenty bets are off.
Port-a-walls are stiil out there but can be pricey plus some times there is problems with the tire bead sealing as well as the port-a-walls themselves flapping in the breeze at higher speeds. People tend to forget that when things like Port-A-walls and visors,ect. came out originaly the cars did not travel on the interstate systems and many never went above 45 or 50 MPH.
I know that this isn't the type of answer you were hoping for but sometimes you just got to buy the real thing.
Torchie.
Ok... don't laugh but I've always used off-white house paint! Works great but don't scrape the curb!!! I've always been too afraid to scrape the sidewall down to the white!
Bob you're a chicken. Ok, maybe the way you drive, you should keep all the rubber you can. You only take off a 1/16" generally to get to the white wall.
the true white wall paint will last and stay on. It takes a while to lay out a perfect circle but can be a cheap way to get alot of whitewalls out of a small can of paint. It will flex with the tire also.