Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion Rust on porcelain signs

I have a 6' sign that is in pretty good shape but there are a few spots that are chipped and down to the metal......and rusty. Has anyone had any luck removing the rust so it's bare metal. The sign is inside so I'm not too concerned about it rusting again. I dabbed on some muriatic acid in one spot but it didn't seem to do much. Maybe I should just leave the rust as it adds character to the sign??

There is a product used in body shops call Rust Mort. Lay the sign flat and fill the chip with liquid, let stand according to instructions. It will neutralize the rust in the chip and the rust will turn black. Clean off with a scotch brite or small wire brush. It can be used for shorter periods with a scotch brite to remove rust on old painted surfaces and bring paint color back out and kill rust.

Follow ALL Safety Instructions for body and lung protection. This is an industrial strength product and can be harmful to skin and lungs.

In the US, there is a product called Evaporust and it removes rust without eating the metal like acid does. It has the consistency of water so you would have to soak a paper towel and let the wet towel sit over the rust spot or spots until the rust is gone. It works best by immersing the piece in the liquid. Go to your local auto parts store and ask for naval jelly or the equivalent. It is a jelly-like liquid with phosphoric acid in it. You can paint it on the rust spots and it stays in place. You will have to reapply several times as the process degrades the acid.

I've had great luck with porcelain toilet bowl cleaner that you can get at any plumbing department shop. Pour some on the spots, let stand, rub with a small brass brush and "rust be gone". The great thing with this is that there is only a small amount of muratic acid in it so it will not harm the surrounding porcelain and it does the trick. hose it off and you're done. Remember to stand up wind of the fumes while working with the stuff

Thx for all the tips gents. I'll let you know how I make out.

...you might be right...can you post a picture of the sign in question?

Over the counter Muriatic acid is not a wipe on/wipe off type of treatment. For metal it needs time to eat the rust, I use it on toys in an immersion bath and it can take several hours to days depending on the rust level/% of acid. And the area will start to rust immediately after treatment ends so be prepared to treat the area with a covering product.

Naval Jelly will eat rust away, you need to neutralize the area after treatment to get rid of all the product.

Household Baking Soda w/ water will neutralize the Muritic acid, rinse w/ clean water, Propane torch dry. Bead/sand blast & primer area to stop Oxidation.
Over the counter Muritic Acid is the same as used in Pool Treatment.

Thx again guys. I'll post a picture when I return from holidays and can take a photo. I might be on holidays but still check in a few times a day with old gas...lol!