The dreaded Rust - How to get rid of it!!!

[92220]

I have recently bought some spring steel strip for my tender springs. Previous purchases, from the same source, have always been clear of rust. This time I've got 7 mtrs of very corroded strip. It does appear to be only surface rust so I investigated rust removal. I have a phosphoric acid bath which would  convert the rust to iron phosphate but I didn't know what effect the heat treatment would have on it. I also didn't want to sand blast as this would damage the surface.  

Roger suggested trying vinegar. I had heard of this before but hadn't taken much notice of it, so had forgotten about it as it seemed like an 'old wives tale'. Anyway, nothing ventured nothing gained, so I pinched the bottle of Sainsburys White Wine vinegar that we had in the kitchen cupboard. I cut a short piece of rusty steel from a strip and dropped it in the bottle. I left it for 3.1/2 hours and then removed it from the vinegar. It didn't look much different - until I wiped it with a piece of paper towel. The rust just wiped away, leaving a grey, rust free, surface on the one side, and a slight rusty discolouration on the other. I put it back in the vinegar and left it overnight. This morning I took it out and both sides are completely rust free. I've tried to photograph a piece of rusty steel and the treated piece to show the difference. I hope it shows up OK on here.

The result is a smooth, clean strip that can be polished with 1200 wet n' dry before heat treating.

Bob

[Jim]

I've also used strong black tea with similar success Bob. The rust turns to a black sludge as does the tea so don't drink it but it does work.
White vinegar mixed with a spoonful of salt also cleans metal, especially copper.

Jim

[Lisa]

"MrPete" on youtube recently did a series on several rust removal methods (including vinegar). I haven't watched it yet, but it looks interesting.

Part 1: www.youtube.com/watch?v=zCuQquR-rzo
Part 2: www.youtube.com/watch?v=ljiauwNVjzs
Part 3: www.youtube.com/watch?v=NNxyFAsxWW0

[Jim]

A dip your fingers in your tea Paul, no milk of course and very quickly if hot. I'm always here to help.

Jim

[donashton]

If you persuade rust, whatever colour/sludge you throw away, to leave the surface then logically there is a loss from the original strip. The result is usually akin to a crater and an eyeglass will confirm. There is no such thing as surface rust. Getting rid of the bulk of the problem usually means chemically treating the small craters and rather wastefully treating those which you throw away!

Don.

[masterdrain]

Coca-Cola (really a dilute solution of phosphoric acid) is quite effective - cleans up all sorts of things. Goodness only knows what it does to your stomach!

Iain