How to paint a rusted cast iron bath?

[Michney]

Wanting to paint the OUTSIDE of a cast iron bath that has rust.

Inside is fine.

Thank you.

[EricL]

Hello @Michney 

Welcome to the Bunnings Workshop community. It's fabulous to have you join us, and thank you for sharing your question about painting the outside of your cast iron bath.

Generally, I would recommend using the White Knight Rust Guard system. The steps to repair include sanding, cleaning and removing as much of the rust as possible. Once you've done the cleaning, I suggest washing the tub in water and detergent to remove all the sanding dust. I propose applying White Knight Rust Guard Solvent Cleaner Paint Thinner - 1L, followed by the White Knight 0.125L Rust Guard Rust Converter.

Once the rust converter cures, you then apply the White Knight Rust Guard Medium Grey Metal Primer Paint and then followed by the White Knight 1L White Gloss Rust Guard Quick Dry Advanced Enamel Paint tinted in your preferred colour. 

Please remember to give each new coat enough time to cure before applying any new coat.

In order to give us a better idea of the condition of the bath's exterior, would it be possible for you to post a photo? This will give our members a chance to assess its condition. We can the make recommendations if you need any extra steps to painting the bath.

Please remember to wear personal protection such as gloves, goggles and a mask when working on your bath restoration.

If you have any other questions we can help with, please let me know.

Eric

[Michney]

 

  

[Michney]

Thank you Eric. Initially, any loose previous paint was removed & sanded back to remove rust. It was then painted with the paint pictured (which was recommended) but the rust appears to have bled back through again.

[EricL]

Hello @Michney 

Thank you so much for posting photos of the bath. The little bits of rust spotting are from the rust residue left on the surface of the tub when you were sanding it clean. It got trapped in the paint and is now slowly rusting through. How old is the paint on the bath? This will give us a rough idea of how long it takes the rust to travel through and stain the surface of the paint.

In order to accomplish an in-depth repair, it will be necessary to sand off all the paint and prep the steel properly. But if you are after a quick cosmetic fix, I propose sanding all the rust stains as far as you can until they are all gone and then recoat the bath with the epoxy enamel. Please make sure to wash the bath so that all the sanding dust has been removed before you start painting.

Please make sure to wear gloves, goggles and a mask when repainting your tub.

If you have any other questions we can help with, please let us know.

Eric

[Michney]

Thankyou again Eric for your suggestions. 

The bath came with a property we purchased. 

From what we can gather, it was refurbished 40 years ago and the outside painted green. We are now changing the colour to white. The white paint was done about a week ago.

[EricL]

Hi @Michney 

Did you post another set of photos of the bath? Can I please request that you post them again as it did not come up on your response.

Eric

[Michney]

Did not post more, but can do so tomorrow if you think it will help.

[EricL]

Hi @Michney 

The photos you posted are sufficient. If it has only been a week since it was painted, it's likely that rust got left behind on the surface. 

If you require more advice or information, please let us know. 

Eric