How to repair a rusty, chipped or enamel-damaged bath

What you need

• Hand sander or sanding blocks
• Plastic spatula
• Fine brush and mini foam roller
• Hairdryer
• Masking tape and protective paper
• Mask with an organic vapour filter and an FFP2
• Glasses and nitrile gloves
• Degreaser or isopropyl alcohol
• Wet and dry sandpaper in 120, 240, 400 and 800 grit
• Rust converter
• Epoxy filler (such as Plastic Padding Chemical Metal)
• Two part epoxy bath enamel, white (Leroy Merlin, Bricodepot)
• Anti-mould sanitary silicone

Step by step

1. 1

   Protect the bathroom and ventilate

   Cover the tap, plughole and tiles with masking tape and paper. Open the window or set up a fan that vents outside. Put on your mask, glasses and gloves before you start sanding.

2. 2

   Clean and degrease

   Wash the bath with water and soap, rinse and wipe over with isopropyl alcohol. Soap and limescale stop the filler from bonding. Dry with a hairdryer and wait an hour.

3. 3

   Sand back to clean metal

   With 120 grit, remove the rust and the edges of loose enamel until you reach bright metal. Feather the edges with 240 grit so there is no step. Vacuum the dust and wipe with alcohol.

4. 4

   Treat any remaining rust

   Apply rust converter with a brush on any spots where brown stains remain. Leave to dry for the time on the pack, normally 1-2 hours. Many people skip this step, and it shortens the life of the repair.

5. 5

   Fill with epoxy filler

   Mix the filler according to the pack and apply it with a plastic spatula, slightly proud of the enamel. Press it in so there are no bubbles. Leave to cure for between 4 and 12 hours depending on the brand.

6. 6

   Sand flush with 400 and 800

   Wet sand the filler flush with 400 grit and refine with 800 until you cannot feel a step with your fingertip. Wipe off the dust with a damp cloth and alcohol. Dry well.

7. 7

   Apply the first coat of epoxy enamel

   Mix the two part enamel in the ratio on the pack. Apply a very thin coat with a brush or mini roller, extending about 3 cm beyond the repair. Ventilate and wait 4 hours.

8. 8

   Apply the second coat

   Put on a second thin coat, again overlapping by 3 cm. If any area is still see-through, add a light third coat. Avoid thick coats that sag.

9. 9

   Remove the tape and leave to cure

   Take off the tape when the enamel is dry to the touch, after 2-3 hours, pulling at a low angle. Leave the bath unused for at least 72 hours and keep a sign on the bathroom door.

10. 10

    Finish the silicone and start using it again

    If the silicone around the edge is blackened, replace it with anti-mould sanitary silicone. When the 72 hours are up, air the bathroom for another day and use the shower with warm water the first time.

What damage your bath has and which repair it needs

Enamelled steel and cast iron baths have a layer of vitreous enamel. When a knock, a heavy object or years of hard water break it, the metal is exposed and rusts, and the rust lifts the enamel around it. That is why a small mark can grow within a few months if it is not treated.

Before buying anything, work out what kind of damage you have. A single knock the size of a coin is a touch up. Several spots around the plughole and the tap usually mean tired enamel, with a risk that the problem will spread. A hole right through the metal is a different story: water seeps into the floor slab and you need to consider replacing the bath.

DIY kit, professional re-enamelling or replacement: how to decide

The DIY kit is the way to fix isolated spots. Polyester or epoxy filler (such as Plastic Padding Chemical Metal) fills the hollow and two part epoxy bath enamel forms the finishing coat. They are sold at Leroy Merlin and Bricodepot, loose or in kits with sandpaper and a brush. If the finish is not perfect you will see a little relief and a difference in shine, but it does the job.

Professional re-enamelling is a different thing: the firm sands the whole bath, applies a bonding primer and sprays two or three coats of epoxy or polyurethane enamel. It lasts longer and the result is even. It is done by specialist firms and, because epoxy is toxic while it cures, the bathroom has to be kept closed to people for a while.

Replacing the bath is worth it when there is a leak, when more than 20% of the enamel is damaged or when you want to move to a shower. Swapping a bath for a shower tray costs €1,100-2,400 in Valencia and Alicante, coordinated by our partner renovation firm. The detail is in how much it costs to replace a bath with a shower tray.

If you are unsure, send us a photo of the damaged spot and of the bathroom as a whole on WhatsApp and we will tell you whether the kit is worth it or whether another solution is better.

Safety: epoxy is toxic while it cures

• Really ventilate. Open the window wide and, if the bathroom has none, use a fan that vents to the outside. Many holiday flat bathrooms in Benidorm and Torrevieja have no window: in that case leave the door open and work in stages.
• Mask with an organic vapour filter. A paper mask is no use. For sanding, add an FFP2. Glasses and nitrile gloves at all times.
• Do not use the shower while it cures. At least 72 hours in normal conditions, and up to 5 days if the bathroom is damp or cold. Put a sign on the door and tell everyone in the house.
• Keep children and pets out of the bathroom during application and curing. The fumes build up in closed spaces.
• Keep away from flames and sparks. The enamel solvents are flammable. Do not smoke while you work and unplug heaters.
• Do not mix the enamel with other products. Follow the maker's ratio and mix only as much as you will use within the pot life of the mix, normally one hour.

Common mistakes when repairing a bath

• Painting over the rust. The rust keeps spreading under the paint and the patch lifts within weeks. You have to get back to clean metal or treat it with a converter.
• Applying to a damp bath. Trapped moisture causes bubbles and poor adhesion. Dry with a hairdryer and wait an hour after cleaning.
• Using ordinary paint or synthetic enamel. It will not stand up to hot water, soap and knocks. Only two part epoxy or polyurethane made for sanitaryware.
• Putting on thick coats. They sag, run and take a long time to cure. Better two thin coats with the time stated between them.
• Not protecting the plughole, the tap and the tiles. Masking tape and paper all round the edge. Epoxy is very hard to get off chrome.
• Showering too soon. The enamel softens, takes a fingerprint and the spot soon opens up again.
• Forgetting the cause. If the rust is coming from the plughole, check the plug and the grille. If it comes from the water, consider a filter. We explain what is behind it in how to remove rust stains from a bath.

When to call a professional

Call us if the rust has lifted an area larger than the palm of your hand, if there is a hole right through the metal, if the bath gives underfoot, if there are damp patches on the ceiling below or if you would rather not work with epoxy in a windowless bathroom. In that case we assess from a photo what to do.

Small touch ups and resealing fall under the handyman hourly rate, €35-45 for the first hour and €28-35 for each hour after that, with a fixed price before we come. Full re-enamelling is done by a specialist firm and its quote is separate. For a bath to shower swap, the building work costs €1,100-2,400 and our part is fitting the screen at €90-170, changing the tap at €45-80 and resealing at €40-70.

You will find more in handyman by the hour and in handyman hourly rates. For the final seal, see how to remove old silicone from tiles and a bath.

Coastal climate: damp, salt air and hard water

On the coast, windowless bathrooms and high humidity make epoxy take longer to cure. In summer the best time to paint is the morning, with a through draught. In winter, with bathrooms at 12-15 degrees, the enamel takes much longer, so wait twice as long before you shower.

The hard water in Valencia, Alicante and Torrevieja leaves limescale on new enamel. Wipe over with a cloth and diluted vinegar every week and avoid scouring pads. Once it has cured, do not use neat bleach or abrasive products: they dull the shine and shorten the life of the repair.

In second homes in Torrevieja or Benidorm, plan the repair for a time when the house will be empty for several days, and leave the bathroom to air when you finish. It is the best way for the epoxy to cure without interruption.