Cast iron sinks bring back a bit of the past to your current décor. They are a heavy-duty way to decorate and remind you of your childhood days. However, along with the beauty comes the maintenance required to keep them looking that way. If the sink becomes beat up over the years, you will need to refinish it to restore it to its original charm.
Cleaning the Surface
Debris including much of the stubborn grime that collects on sinks can be made much easier to remove if chemicals are used. An alkaline solution called trisodium phosphate (TSP) is a water-soluble compound used as a cleaning compound.
Before refinishing, it is essential to remove all of the original paint applied on the sink. Using a paint scraper and a heavy-duty steel wool will aid in the process. You can also use a mixture of paint thinner and alcohol to break through the tough exterior. If one application doesn't work, you may need to reapply several times to remove all of the surface paint.
Use a thin layer of oil-based waterproof paint with a dry brush. The paint will need to fully dry (preferably overnight). The next day, sand the surface and wipe down with a tack cloth. At this point, you can add another thin layer of paint.
After this dries overnight, repeat the process with a thick layer of paint. Allow this to dry thoroughly and place a paint sealer on the sink. You should not use the sink for several days to ensure the surface has setup effectively.
If the surface has a few dings, an auto-body repair person suggests using a putty of fiberglass to patch the areas just as you would do to a car's surface. If the whole sink is damaged, you will putty the entire area. After it gets hard, you sand the surface to even it.
Use a polyester glazing putty for any blotches left on the surface, and resand it the same way. Wipe any dust away with a tack cloth and use a cloth of bonding adhesive for the acrylic urethane enamel to stick to the surface. You may want to rough up the surface before you place the enamel on the area.
Use some citrics of acid to remove the acid before it goes down into the pipes. This will eliminate damaging the pipes.
These suggestions should allow you to refinish your sink and enjoy it for many years to come. If you are unsure of the process, it may be time to call a professional like Qualtire Plumbing & Construction for the job.