Thread: RUST REMOVAL - CLR?

Don't waste your time with CLR.

In no particular order - phosphoric acid, citric acid, evapo-rust, vinegar, oxalic acid, molasses, electrolysis and mechanical removal.

Phosphoric acid is the active ingredient in most commercial derusting solutions; cheapest way to buy it that I have found is the Chemtech Rust-off from Bunnies ($15/litre).

Originally Posted by jim47

Has anyone tried removing rust stains from machinery using CLR?

For clarification - are you talking about the rust itself, or the darker stain on the metal that will be left behind after the rust has been removed (by any one of MS's suggested methods). Cheapest I have found is bulk Citric acid - at $5 per kilo that will make ten litres.

Short of an abrasive to get through to new metal (which might create an undesirable depression) there's not much you can do about the darker stain.

Thank you all, for your very prompt replies.
I have some vinegar so I will try that first.
Citric acid (which I don't have) being cheap will be my second option.
I will try each of your suggestions until I obtain results.
My appreciation for your help.

I heard 50% white vinegar / 50% bleach works. Apply and let sit for a short while and wipe off. Have not tried it myself though.

G'day Jim,
Unless you are trying to minimise damage to a painted surface I wouldn't waste time on messing around with chemicals.
Just like your mouse pee, liquids have a habit of getting into places where you don't necessarily want them to and the next thing you know the rust has spread to more critical and hard to get to places.
Just get a wire cup brush for a drill or an angle grinder and have at it.
Cheers,
Greg.

I swear by evaporust.

Make a little dam surround with hot melt glue and pour it in. It's amazing.

After its done it's work, I use the ROS with an 120 grit pad. This cleans it up nicely. Then I put a green scourer pad under the ROS and use some Brasso. Comes up a treat.

I recently redid my TS for the once yearly do-over and it came up very shiny.

I use pieces of left over lino cut to size as a moisture barrier when lablesaw etc aren't being used
seems to work well

I'd be very hesitant about using any solutions containing chlorides (bleach, ie sodium chloride) as chlorides have a tendency to introduce rusting in ferrous metals as they are very electronegative.

Having said that, I also happily use hydrochloric acid as a rapid deruster, but it's so quick it's not a set and forget process, it's typically faster than waiting for a cup of tea to brew.

i found vinegar to be best for 'scrubbing'
and citric acid best for 'soaking'

and when I use these I'm not looking to get back to showroom shine rather just remove that dirty surface rust that gets on everything and of course it'll need some type of seal coat afterwards otherwise it's just gonna rust again ....