Refinishing a Cast-Iron Tub

LESLIE: Well, painting a room, painting a floor or even painting your kitchen cabinets are all a can-do, do-it-yourself project. But painting your bathtub is not.

TOM: Absolutely right. You know, refinishing a cast-iron tub is something that can be done by a pro who, with the right tools, can deliver a finish that will last for many, many years. With details on how this project gets done is Kevin O’Connor, host of TV’s This Old House.

Welcome, Kevin.

KEVIN: It’s great to be here, guys.

TOM: And this is one of those projects that many DIYers have tried but few have ever achieved a good result. But there is a big difference, though, when a project like this is approached by a pro, correct?

KEVIN: Well, there certainly is and I can understand why so many people want to try to do this themselves because these old tubs, well, they can be beautiful. They’re great historic pieces – whether they’re built into the wall or if they’re these gold, claw-foot tubs – and a lot of people want to save them. But it is definitely a project for a professional and I think you’ll appreciate that when you understand the steps that are involved.

TOM: Alright. So where does it all begin when the pros come in?

KEVIN: Well, if it’s built into the wall, if it’s part of the tile surround – tub surround – you want to remove the caulk that goes around the perimeter first. That’s the easy part. But then after that, it starts to get a little bit more difficult.

Next, you have to clean the tub and you’re going to do that with an acid-based, commercial cleaner. Now, it can be a very dangerous product, so you’ll see the pros who use it, they wear a full face mask and a respirator to make sure that they don’t breathe in the acid or get any of it into their eyes.

LESLIE: And Kevin, these are products that a do-it-yourselfer can’t get their hands on, so you really do need to go to a pro for this, right?

KEVIN: Well, you know what, Leslie? Even if you could get your hand on these things, you don’t want it in the hands of an amateur, because they’re just dangerous. So, it really shouldn’t even be considered.

TOM: And that’s not the only acid step. Isn’t there an etch process after that?

KEVIN: Well, that’s the next step. And so once you have it cleaned, you actually have to etch up the tub so that the paint can actually adhere to it. And so there is an acid etching paste that really digs into the old finish and it gets it ready to accept the primer coat, which is the third step.

The primer is applied using a paint sprayer and this helps to make sure that the paint goes on smoothly and easily. And if you’ve ever used a paint sprayer, it really takes a fine touch to get that nice and even, so that’s another project for a pro.

TOM: Right, with no drips whatsoever. So the adhesion really is what I’m hearing is the absolute key here. And then, of course, after the primer, there’s a top coat that looks just a bit like the original enamel finish?

KEVIN: Well, it’s a top coat. It’s also put on with a sprayer and is a combination of paint and polyurethane. And when it dries, well, it delivers this beautiful shine that looks very much like the original, porcelain enamel once did. And it can be a fantastic finish.

LESLIE: Kevin, there’s so many steps. How long does this process take?

KEVIN: Well, the good news is a professional could do it all in one day.

TOM: Wow.

LESLIE: And then how long will that last for?

KEVIN: Years. Decades, if it’s done well.

LESLIE: Really?

KEVIN: Yeah.

TOM: Wow. Definitely a great project and a way to really preserve a piece of history in your very own house.

KEVIN: But a job for a professional.

TOM: Absolutely. Kevin O’Connor, host of TV’s This Old House, thanks for stopping by The Money Pit. Great advice.

KEVIN: Great to be here, guys.

TOM: And if you’d like to see a video of how this is done, you can visit ThisOldHouse.com.