"How can I refinish the dull, chipped porcelain enamel on my bathtub without removing the tub and sending it out to a professional refinisher?" is a common query.
There are two solutions. First, some porcelain refinishers now have a process that allows them to do work in your home. This eliminates the mess and expense of removing the tub for transportation to the refinisher's shop. Check the Yellow Pages under "Porcelain Repairers and Refinishers," and a quick phone call should reveal whether in-home service is available.
If you can't find in-home service in you area, the other solution is to refinish the tub yourself with a special, two-part epoxy enamel. This is not a porcelain enamel, it's a paint, and won't give the durability or hardness of true porcelain. After all, porcelain is essentially a fused glass surface.
Still, epoxy enamel is tough stuff and will outwear an ordinary high-grade paint about five to one. So if you're willing to accept its somewhat limited durability, it does a good job. And at a good price: around $10 for the average tub.
For maximum adhesion an durability, apply the epoxy over a clean surface. Start with an abrasive cleanser. Rinse thoroughly, then follow up with 120-grit waterproof sandpaper, used wet. To do a first-rate job remove faucets and other hardware to clean and enamel under them.
Fill any chips with an expoxy steel paste. Let it set up hard, then sand smooth with that same 120 paper. Rinse again and let all surfaces dry completely.
To apply the enamel, mix the two components in the kit thoroughly. Let the mixture set about an hour while the two chemicals interact. Then brush on a smooth coat, using a bristle brush. Stay away from synthetic bristles - the solvents in the enamel may attack them.
You'll probably need two coats for a super-smooth finish. The second coat should go on no sooner than 12 hours and no later than 36 hours after the first. If you apply the second coat coat too soon, it may soften the first coat; if you wait too long, adhension between the two coats will suffer. Scuff-sand the first coat lightly before applying the second.
Flow the second coat on as smoothly as possible, but don't overbrush it. Too much brushing may start to soften the first coat. After the second coat is on, let the finish cure for five days before using. The enamel may seem dry before the end of five days, but the chemical cure will not be complete. Don't rush things.
These epoxy enamels come in variety of colors and do a good job on sinks and kitchen appliances as well as tubs. You can also use them on tile (porcelain, not plastic) and to waterproof the walls around tub and shower.