How to Refinish a Claw-Foot Tub | This Old House

This Old House plumbing and heating expert Richard Trethewey shows how to save an old, but elegant, cast-iron bathtub.
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Cost: About $400 to $600
Time: 4 to 6 hours
Difficulty: Hard. This is a job best left to a professional tub refinisher
Steps:
1. If the outside of the tub has been painted, use a paintbrush to apply a thick coat of paint stripper to the surface.
2. Once the stripper has softened the paint, scrape off the paint and stripper using a 3-inch-wide putty knife.
3. While wearing a dual-cartridge respirator, brush a thin coat of hydrofluoric acid over the entire interior of the tub. The acid will etch the surface, ensuring a good bond with the new epoxy finish.
4. While waiting for the acid to etch the tub, use small files, dental picks and sandpaper to clean all paint and grime from the tub's claw feet.
5. About 30 minutes after applying the hydrofluoric acid, scrub clean the interior of the tub with lots of water and paper towels.
6. Repair chipped enamel by first using a rotary tool fitted with a grinding stone to grind away any black carbon stains and to rough up the enamel around the perimeter of the damaged area.
7. Wipe the repair clean of all dust, and then fill the chipped area with auto-body filler.
8. Allow the filler to harden, then sand it smooth with 220-grit sandpaper, followed by 320-grit sandpaper.
9. Use a high-velocity, low-pressure (HVLP) paint sprayer to apply three coats of epoxy primer to the interior and exterior surfaces of the tub. Wait for the primer to dry completely before proceeding.
10. Use the HVLP sprayer to apply an epoxy topcoat to the interior and exterior of the tub. Allow the epoxy to fully cure before moving the tub or installing the faucet, spout and other hardware.
About This Old House TV:
This Old House is America's first and most trusted home improvement show. Each season, we renovate two different historic homes-one step at a time-featuring quality craftsmanship and the latest in modern technology. We demystify home improvement and provide ideas and information, so that whether you are doing it yourself or hiring out contractors, you'll know the right way to do things and the right questions to ask. Our experts Norm Abram, Tom Silva, Richard Trethewey, Roger Cook and host Kevin O'Connor give you the tools you need to protect and preserve your greatest investment-your home.
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How to Refinish a Claw-Foot Tub | This Old House
/ thisoldhouse

[@CurlyQLink]

I have a 6 foot long claw foot bath tub that I salvaged from a house in Northern Illinois 20 years ago. On the bottom of the tub is a 6-1923 date stamp. The tub's exterior and especially the porcelain interior are in great condition. The porcelain finish on those old claw foot tubs lasts forever.

[@Bettymassie]

How much

[@GILLEBRATH]

Thanks for the demo and info. I have to refinish my tub and now know how. Porcelain would I believe be a much involved job and this epoxy finish suits me , I'll do it again in 10 years .

[@Boginia00]

Hi, did you refinish yours like this video shows or do you have other options? TYA

[@Streborp01]

HVLP doesn't mean high velocity, low pressure, it means high volume, low pressure.

[@davidmartinez-ip3me]

Cmon guys get over it! You can´t beat it for the price!

[@marmoleriaalba7018]

This little kzbin.infoUgkxVoi3B4CB6Oygq1-vo4OTL1M_M5JkrXif tub works perfect in our 6 x 6 shower and is easy to get in and out. Also easy to drain.

[@Ixapter]

I didn't know that's what this type of tub is called (I used to call it "old-fashioned"). Learn something new (almost) every day.

[@samuelraskin9550]

Can anyone provide a link for the type of primer and top coat I should use for this project?

[@PatsGoTheDistance]

Is there a link to the HVLP spray gun set up? OR something very similar?

[@bmuscotttybmuscottty4542]

What percentage/ strength was the Hydrofluoric acid being used at here? Or does anyone know what's typical for the application in stripping these old enamel baths? I don't want someone who watches a lot of KZbin give me a guess, or what they figure might work, I'm asking for an answer from someone who actually 'knows' by using this acid a lot. It's deadly stuff and I aim to not take risks where I don't need to.

[@paullujan9729]

I can't tell you % I can tell you it comes from Napco ltd or Hawk Labs specifically for etching bathtubs. It's STRONG, and the safest way is to wear a fresh air system not just a respirator mask. While This is a standard method of preparing the surface, there are adhesion promoters and bonding agents that prepare the surface without etching that work very well without using acid.

[@bmuscotttybmuscottty4542]

Cheers :-)

[@garygraham4679]

+bmuscottty bmuscottty: I've used it and seen guys get real screwed up from it. Don't know the concentration but the stuff we used would burn through a glass bottle overnight and yes I found out the hard way. This stuff is so nasty you don't want to get near it let alone have it in your house or pipes. Now days there are far better coatings and ionic bonding agents that work even better IF you take the time to prep. the tub well.

[@TheSubpremeState]

bmuscottty bmuscottty RIP

[@Chungustav]

Gary Graham yes never store HF acid in glass

[@teresamartini10]

Hi, I bought a used cast iron bath. It had a horrible red paint on it. My builder recommended I applied an undercoat using a white paint he used to paint a steel RSA which protect the steel from fire. I did, but that paint is water-based and I'm seeing now online that everyone is recommending painting the exterior of a cast iron bath with oil-based paint. Is it now a problem if I apply oil-based paint on top of this water-based undercoat? Many thanks!

[@eh238]

should not be a problem, the expansion and contraction of the tub is minimal unlike exterior wood siding which is a problem to do that combo, i would say go for it, if it does cause problems strip all the paint and start over.

[@donnimetropolis9899]

How smart is it to use hydrofloric acid with no face goggles

[@seriousbutfunny2]

I have a brand new WHITE cast iron clawfoot tub. Where can I find video on how to paint the exterior myself?

[@AngelaCoffman]

The exterior can just be painted. We used wall paint on ours and since it has minimal contact with water etc, it holds up great. The inside is what is so tricky to refinish.

[@vampirecalligraphyvc6475]

1920 Cast Iron Antique Tub

[@brettgratton]

Some of the problem areas should have been sandblasted . I did my entire bathtub down to the bare metal . Now time to decide on paint or powdercoating .

[@steveweber9820]

Powder coating with proper maintenance could last forever , maintenance is reg cleaning with soapy water no abrasive tools(Steel wool , stone)_ and it's not a easy process the surface has to be perfect or you will see it , it can bubble. It took 5 sinks to figure proper temp , what to use to patch the bad spots, and you need a big oven . I do the repair work and a professional of 20 years shoots it , he never did one till I asked him to try one in 2 years we have done over 100.

[@julesjaay822]

Steve Weber I need to know where to get this done!

[@MRrwmac]

I thought the original was a porcelain coating. Why only an epoxy refinish and lasts only 10 years? I've seen porcelain tubs from 50+ years ago still looking good. That's why I wanted to know why not re porcelain?

[@stuartgreen1376]

porcelain has to be heated to a high temp at which point you need to call the fire department. epoxy is great at bonding but should be finished with acrylic polyurethane for a beautiful high gloss finish. Finally, I use a fresh air delivery system instead of just a mask with filters for spraying and acid washing.

[@JAG77productions]

MRrwmac.

[@steveweber9820]

I resurface sinks and tubs , more like 5 to 10 depending on usage ,and there is 1 company that does porcelain in the USA so the waiting list is a year and the price is $$$$ I do my sinks with powder coating it is amazing could last a lifetime

[@tkjazzer]

@@steveweber9820 what company does porcelain?

[@nateintx4098]

@@steveweber9820 What brand of powder coat do you recommend for these claw foot cast iron porcelain tubs? I have one that I have sanded down and it needs to be refinished inside and out and we don't want to cheap-out on it. If re-glazing is outrageous and unrealistic, and you say that powder coating is the next best process, what is the best brand and process for that? Our tub is sitting in the garage waiting to be fondled.

[@johndavies7180]

Anyone know how i can cheaply repaint a clawfoot tub without removing it. Do i ruff it up with sandpaper and can i use cans of enamal spraypaint?? Not looking for great results but would like it to be halfway decent

[@saintejeannedarc9460]

Did you do it? If not, use the proper paint, otherwise you'll have paint chipping and render it useless until it's done properly. We bought a house and I was so excited about the original clawfoot tub. Didn't notice until we bought it and cleaned it up that mere cleaning made paint come off inside. So now I will probably replace it. I'm too allergic to paint to have it done in the house.

[@brendathompson2288]

@John Davies You've asked the same question that I need an answer to. Someone painted the old claw foot tub in my home with what appears to be wall paint. Every time I clean the tub; paint comes off.

[@coasterbrookie]

@@brendathompson2288 strip with paint stripper

[@krisweaver3885]

Water does not neutralize acid.

[@jays1752]

It absolutely does. Adding water to HCI breaks it down into positively charged Hydrogen atoms and negatively charged Chloride ions. But don't go drinking a HCI and water smoothie.

[@coasterbrookie]

@@jays1752 Nope. Dilution. The amount of H2O required to "Neutralize" HCL is extremely significant. You're simply adding enough water to dilute the pH to a less acidic level.

[@jesuiscequejesuis2267]

You're right, water doesn't neutralize acid, it only dilutes it. You need something alkaline to neutralize acid.

[@carbar9752]

I was going say something along the lines of it probably has baking soda in it. But then he said it was only water and I realize I need to shut my mouth. Lol

[@Kaixo-Zemouz]

Fantastic quality video, thank you

[@DragonBuilds]

0:47 Did he just say HYDROFLUORIC ACID? That stuff is so dangerous!

[@iasimov5960]

I guess you'd better avoid such an endeavor as reglazing a tub.

[@jesuiscequejesuis2267]

I thought he said hydrochloric.

[@AquarianNomadic]

Call a pro.

[@technicjeff]

"High-Velocity Low Pressure"? Try "High-Volume Low Pressure". Idk what they think velocity has to do with anything, but whomever is explaining this doesn't really know what they are talking about. Secondly, a primer is not needed when using the proper material. A wipe on powerband is FAR more effective.

[@AquarianNomadic]

Use both for extra adhesion.

[@TheSubpremeState]

Ok so he's using a wet rag and light gloves to wipe of HYDROFLOURIC ACID OMFG

[@miracleblk]

It becomes inert once the product dries.

[@gangisspawn1]

You're familiar with hydroflouric acid?

[@TheSubpremeState]

@@gangisspawn1 familiar enough to stay away from it. A teaspoonful of that on your skin is enough to kill

[@coasterbrookie]

This "contractor" is an utter moron. HVLP has nothing to do with "Velocity", Not sure what the HF concentration is (likely 10:1 DI:49%HF) and how they are handling it and whimsically using it is absolutely going to get someone badly injured over time. These "Experts" are not experts whatsoever! I've handled HF/HCL/Nitric/Sulfuric/Phosphoric/BOE for 30 years (semiconductor manufacturing) and anyone that believes this guy is an expert is in trouble. And the "fresh Air Intake" right next to the exhaust is an utter joke. OMG!

[@coasterbrookie]

@@miracleblk far from the truth. it absolutely does NOT become "Inert" as it dries. Besides, once they have wiped it with water, it again becomes very mobile. You neutralize HF with Sodium Hydroxide or any other strong base.... and that is a whole other hazard!

[@tkjazzer]

If Hydrofluoric acid bad for the environment?

[@rockypettyjohn1144]

It will melt your skin bones and your everything. It is what's in your stomach.

[@coasterbrookie]

Extremely bad. Extremely bad for living tissue as well.

[@somewhatfast]

any notice that wasn't an hvlp spray gun and that's what he called it.

[@JoAspirin]

Nick Richardson it's an hvlp turbine.

[@bignizzle6973]

Nick Richardson it is HVLP. Look at the big air hose.

[@cmnieman1]

is that really a one day job?

[@saintejeannedarc9460]

Professionals say it's about a 5 hr or so job for the interior. This looks like it would take all day, at least. Can three coats of primer dry in a day? Then the enamel after?

[@alisonisaac5400]

Why can't i just paint over the old paint on the outside?

[@JoAspirin]

Alison Isaac you can. Just make sure you send it flat and make sure whatever you are painting it with won't react with the old paint. You don't need epoxy nor polyurethane on the outside. You can go straight ahead with waterborne metal paints or oil base, it doesn't require to be water proof since there should be no water contact on the outside.

[@alisonisaac5400]

Also, how necessary is it to use that hydrofloric acid to etch the inside of the tub? Can I just go ahead and use a tub and tile refinishing kit? I want to use as few chemicals as possible because i have to do it inside. :(

[@JoAspirin]

Alison Isaac If the bathtub is already painted on the inside and you see that it still holds properly you can sand it with a sand paper but if it has never been painted you need to etch it (I personally strip them all to the original porcelain and then etch). Also stay away from these refinishing kits they sell at the hardware store. They are crap and non of them work. Send me an email to [e-mail] and I'll show you something better, less toxic then all these refinishing crap they sell and you'll be able to achieve great results if following the instructions right.

[@icecoldusa]

@@JoAspirin can u please tell me wht products do you use?

[@saintejeannedarc9460]

@@icecoldusa The refinishing kits must be crap. I think that's what someone used on the beautiful clawfoot our house came w/. I likely have to replace it now. Paint chips when you just rinse it, so can't bath in it.

[@verdatum]

Why would you paint a claw-foot tub blue?....Why? WHY?

[@granjmy]

Because they were out of purple? ;))

[@melibadeli]

Because it's a cheap and easy way to give an old, dated house a new look. Painting over EVERYTHING, as annoying as it is, is really common among old, low-valued houses. My boyfriend recently bought such a house and he's renovating it. The house has copper-plated door-hinges, copper-plated grates for the ventilation, ornate vintage door handles, solid-wood window frames and floorboards, and all of these beautiful features are hidden under layers and layers of paint. Thankfully, our claw foot has been spared.

[@animalfarm7467]

Does the contractor understand that even in low concentrations the weak HF acid vapor will easily penetrate the skin and cause destruction of deep tissue layers, including leaching calcium from bones. Well, at least poor workplace health and safety standards will improve the bottom line of the company and keep the the Medical Industrial and Insurance Complex busy and profitable. Maybe he could select a less aggressive (glass etching) compound and save himself and his family a lot of future pain.

[@julesjaay822]

I wish wish a new baked-on porcelain could be done instead of a paint job.

[@normbograham3]

I understand, to do a powercoating finish, all old porcelain needs to be removed. One nearly unnoticeable spec, not removed, ruins a man month worth of work.

[@julesjaay822]

norm graham That’s bad. I can’t find anyone anywhere who does it so it must really be unviable. Shame, there’s so many cool vintage fixtures out there that could have new life.

[@00Lauren00]

There are some places that can sandblast down to the cast iron and rebake a new porcelain interior on it- one is antiquebaths.com.au here in australia. I don’t really know how I feel about bathing healthily in a painted tub even if it is automotive paint 🤷🏼‍♀️

[@nateintx4098]

If the tub is removed from the house and needs to be refinished inside and out, what is the best way? I heard that Hawk Labs makes the best products but when I called them, they only sell to professionals like Miracle Method, not to home owners. I am quite capable of taking precaution to the chemicals used in the process but they don't want the liability I guess. I'm disappointed with them for this. I know the products in the stores is junk and a waste of time. I have never been able to find a worthy video or website that gives an explanation of different methods with a proper thorough step by step process of how to do this. I would like to see a video that is done by an vigilant individual that shows and explains chapter by chapter detail with how temperature, humidity, dry time, priming, number of coats.......EVERYTHING CONSIDERED on a proper job. I see so many people saying re-glazing a bathtub when they are not re-glazing, the video they post is them re-coating a tub with epoxy and not actually re-glazing. There has been misinterpretation of processes and nobody giving information as to the pros and cons and costs of these different methods. I would like to see somebody provide information on being able to powder-coat a tub if it is removed from the house along with the average longevity verses a typical epoxy brushed or sprayed method. Somebody needs to provide a comparison chart with manufacturers products and warranties along with price so we as consumers can rule-out the cheap crap products. People must also understand that the products can be the best on the market, but if the person doing the work did't consider the temperature and humidity of the work environment or used just one inferior product that affects the quality of the adherence of the quality product, that will ruin the entire job. A chain is as strong as its weakest link. If somebody can reply back to this comment with informative answers, you will be honored and respected among the all inspired search for answers community! Thanks much for hearing me out on this rant that is in hopes of an answer.

[@miracleblk]

If you insist on trying this yourself, I can tell you the answer to any question you have about these procedures. I assure you that no level of explanation will guarantee proper application. Each step is surprisingly logical but the tooling up for a single use is cost prohibitive. Feasibility occurs at volume as with most industries. Hawk research sells fantastic materials but you may have great success with Imron or European Coatings. The later is very high grade but all of them contain high concentrations of Isocynates.

[@laurenhorning4401]

Disappointed that it didn't show the finished product.

[@raywood8187]

This isn't a how to so much as a how to hire someone to professionally do it. Can't learn much from a 3 minute video anyway.

[@dreamingcode]

i bet for whatever he charged you could just buy a new tub

[@PhotoLabMP]

dreamingcode Yes, but there's character with those old wrought iron tubs. Especially if you renovate a house from that era.

[@vilveyachke5103]

you can get a 6' claw foot tub, new, for under $1,000. and it's real porcelain.

[@kingkoopa7481]

I'd refinish the same tub for 600$ and it will be perfect. I just did one that was 90 yrs old. You can't buy sentimental value

[@crash4dafun]

@@kingkoopa7481 Yeah man, I have one from 1913 I'm refinishing by myself. I use an old up-side-down rug to slide it on the wood floors to move it through the house, it's a little heavy. lol

[@saintejeannedarc9460]

@@crash4dafun Were you just sliding it on the same floor or did you need to get it down or upstairs? I'm wondering how many men to get a large one (65 inches) down the stairs?

[@donaldkissick4549]

Tired of seeing another halfassed video to properly refinish a clawtub from sanding to painting.

[@thatlady7413]

Resurfacing or Refinishing a bathtub is nothing but a very expensive and toxic PAINT job. Because it is a very strong type of paint, it will take 6 weeks to cure. Afterwards it will begin to crack and peel. the homeowner will need to begin paying for yearly tub maintenance. which will include fees of monthly service calls to repair peeling or pay for a new resurfacing of their tub every 6 months. resurfacing jobs do not last 1 to 10 years. If the tub is used daily, the resurfacing job will barely last 6 months. a homeowner will be spending $1200 to $1500 yearly in tub maintenance fees. Just buy a new tub that never needs to be resurfaced.

[@miracleblk]

Unfortunately, and I mean this with whatever respect is due... your response to this video matches the technique demonstrated in it.

[@kingraiderr]

It's not worth it, just buy a new tub.

[@GoatzombieBubba]

dumbass

[@saintejeannedarc9460]

Not everything is so easily disposable. These old tubs are amazing and will last several lifetimes.