1. Wire Brush
3. Chemical Paint Removers
Using a wire brush to remove the paint will usually only wear your arm out and provide you a mediocre surface for your primer coat. Obviously, we don’t recommend using a wire brush.
An electric sander is a decent option depending on how many layers of paint you are dealing with. Remember, you will be creating a lot of dust when sanding so you will want to be in a well ventilated area and you SHOULD HAVE A GOOD DUST MASK AND SAFETY GLASSES ON. You really should think safety - the paint you are taking off will likely contain lead (most old paints had lead in them). Start with a coarse to medium grade of paper and work your way down to a fine grit when you get to the cast iron layer.
Chemical paint removers are another option (if standard paint removers don’t work well, you can go to an auto parts store and ask for a stronger “Aircraft Stripper”). Chemical strippers are convenient but you need to exercise care when using them – they usually have a very strong chemical odors and harmful fumes. If you use chemicals, make certain to follow the safety precautions. I can tell you from personal experience – I got a glob of aircraft stripper on my arm and it hurt like hell. Needless to say, I am a lot more careful with chemical paint removers now.
Finally, you can sandblast the exterior. Sandblasting is the most thorough way of removing paint. If you decide to have your tub sandblasted, make certain to tape off the edges of the roll rim, drain hole(s) and any faucet holes with a strong duct tape. This will help prevent damage to the porcelain during the sandblasting process. Again, you really need to think safety here if you decide to do the sandblasting on your own. Remember, you will be blasting chips of paint from the surface of the tub with a sand frit (thus, the term sandblasting – clever, eh?) and you don’t want to get that stuff in your eyes.
Once you clean the surface, you need to get a primer coat down as soon as possible. This is particularly true with a sandblasted tub. Exposed cast iron can begin to show signs of surface rust within hours of exposure.
When choosing paints, find a primer that adheres well to metal and a top coat that stands up well to moisture. When it doubt, look up the paint manufacturer online or ask the staff at the paint desk at your local hardware store.
One last thing: I would always recommend having the claw foot tub feet sandblasted. They have so much detail that is so difficult to clean out and the results are almost always worth the extra effort to find a sandblaster. Again, make certain to get a primer coat on them as soon as possible to prevent rust from starting.
Painting Exterior Old Claw Foot Tub