Product review (5 stars): Magical, inexpensive answer to an expensive problem
I just saved the cost of a new dishwasher - hooray!  I installed our Kitchenaid dishwasher in 1971, over 40 years ago.  It still works fine, but the vinyl covered racks had numerous places where they were rusting very badly. Obviously, racks are no longer available for such an old machine, but even if they were, they'd be too costly to justify instead of just biting the bullet and replacing the dishwasher.

In some spots, the wire was rusted more than halfway through.  Some of the spikes were an inch or more shorter than original because they'd rusted away.  In short, the racks were in HORRIBLE shape.  I found a bottle of ReRACK at a hardware store and since it was only 7 bucks, I figured there was not much to lose.  The only color in the store was white, I later found out Performix also makes gray, but it didn't matter since my dishwasher racks are pale blue.  White looks way better than rust!

There were so many rusty spots, I decided to sandblast the racks.  If you don't have access to sandblasting, you could start with 50 grit sandpaper, and move to 120 to finish, or you could use a grinding wheel in a rotary tool.  After getting rid of the rust, clean the surfaces carefully twice with lacquer thinner to completely degrease.  This is a better solvent than the rubbing (isopropyl) alcohol they recommend.  Most rubbing alcohol is only 70%, meaning 30% is water, which is a lousy grease cutter.  If you use rubbing alcohol, try to find 90% which is a better solvent for grease.  Use clean paper towels and Q-tips for this job.  Let dry thoroughly.

Apply several thin coats of ReRACK, letting it dry between coats, approximately a half-hour or more.  For the worst spots on my racks, I put 5 coats on, so it requires some time and patience.  Tilt the rack using some blocks of scrap wood to allow even application.  You'll find you need to reposition the rack several times to gain good access to all spots needing repair.

Our bottom rack needed about 120 spots repaired, the top rack only about 30.  One bottle did the job but there was very little left over.  The solvent (mostly acetone) evaporates very quickly. If your product thickens up, you can thin it with acetone or with Plastic Wood Solvent, which contains acetone, methyl ethyl ketone and toluene.  Add just a little solvent (less than a cc), replace the cap, and shake thoroughly.  Do this until you have the consistency you want.  If you over dilute, you can just let it sit for a while with the cap off because the solvents are very volatile.  Make sure you replace the cap tightly while you are examining the rack for more areas to repair, and also while you are repositioning the rack to get access to all repair areas.

Some people will object to the odor.  I didn't think it was as terrible as some others.  If it bothers you, do this job outdoors, or in the garage with the door open.  I did it indoors but had a fan on low to blow fresh air past me.

After curing in a warm dry place for 24 hours, the racks can be returned to service.  Our dishwasher is working great and no more rust. The repairs were done several months ago and are holding up perfectly.  After a month, I did find a few tiny spots where rust was starting to bleed through.  I simply cleaned those areas with solvent, let dry, and reapplied a couple more coats.  Worked great.  Couldn't be happier with the results.  This stuff is amazing.  Just remember to read and follow the directions carefully.  Lots of people don't and you don't want to waste your time to get poor results.  Do it right and you'll be delighted and save a lot of money if your dishwasher is working fine otherwise.