After years of use, the constant movement of dishes and water pressure inside a dishwasher can wear down the coating on dishwasher racks, leading to the exposure of the metal beneath. Once the metal in a dishwasher rack is exposed, the conditions inside the dishwasher commonly lead to rust, which may be dangerous to your health.
Dangers of Rust
When rust forms in your dishwasher, it generally stays in your dishwasher. While it is possible that rust may transfer to the dishes and pans washed in the unit, the amount of rust that generally transfers is undetectable. However, if the dishes in your dishwasher come out with noticeable quantities of rust, you should not eat off of those dishes without rinsing them well first. But the major danger of rust lies in the dishwasher itself. When rust comes off the metal, it may clog dishwasher components and make the unit stop working.
You can usually clean small areas of rust in a dishwasher, though you may need to cut away part of the coating on the dishwasher rack if it's in the way. Use a utility knife to make slits in the coating and pull just enough of the coating free to gain access to the rusted area of the metal. One to two inches of access should be sufficient. Clean the rusted area by rubbing it with steel wool or fine-grit sandpaper until the rust is gone.
If rust in the dishwasher is visible only on the tips of the tines of the rack, you can eliminate the rust by removing those tips. Since the tines are made of thin metal, you can generally clip the tips off with wire cutters. If an entire tine of the dishwasher has begun to rust, you can also remove the entire piece at the base where it meets the rack. You can also prevent tine rust before it starts. If you begin to see exposed metal at the tips of dishwasher tines, consider buying tine repair caps to cover the tines.
Resealing the Racks
Once you remove the rusted areas of the dishwasher, you should cover the holes that you created in the coating. You can do this by applying dishwasher rack coating, which can generally be found at home improvement stores. If you had to remove many tines of the dishwasher rack to eliminate the rust, repairing may not be your best option. You can buy replacement racks through the appliance manufacturer for a dishwasher with severely rusted racks.