Rust removal from surface plate

[Balders]

Don't waste too much time, effort or cash.

Citric acid it (cheap, not much time spent). Wipe then try it. If it's fubar, use it for bashing/welding

 

[graffian]

Yes a Blanchard would make a nice job of it. I thought about suggesting it but figured the cost would be prohibitive.

Maybe not if you knock on the door of the grinders and ask. I got a surface plate on ebay for a quid! I was really surprised when I went to get it, it looked freshly ground. The bloke had taken it to a local grinders and had it ground, he said it didn't cost a lot. I guess he bought it looking like yours.

 

[fluxcored]

I picked up a set of solid, beautifully made old English squares some time ago that had some surface rust on it.

I wrapped them in a cloth soaked in vinegar for a day which removed all the surface rust and I washed them thoroughly with water and oiled them properly.

But as stated removing the rust will not improve the accuracy of the plate.

 

[awemawson]

Buy some citric acid crystals off ebay - 1kg will do - dissolve in warm water and leave the plate in the solution over night. The citric acid (lemon juice is mainly c.a.) is safe to use and very effective at removing rust. The rust is converted into iron citrate which is water soluble - you will end up with it in the solution, which can be safely poured down the drain. Phosphoric acid which is often used on rust forms iron phosphate which is not water soluble and stays on the item being treated.