Thread: Rusty Ball Screws

Unless they are really long and you like a challenge, with the price of the Chinese ballscrews I wouldn't bother.
Method would be to soak the nut in WD40 and see if it frees up. Don't use abrasives to clean the screw - just use one of those non scratching (Nylon) dish scourers and WD40 and see if that will lift it. You could also try a cloth buff on a grinding wheel. If either of these methods don't work chances are the rust is worse than you thought. Look under magnification and it should tell you what is going on.
If the nut doesn't move then you might have to lift the bearing out is situ (if you can) and slide the nut off.

A good way to clean them is a citric acid bath. It is a common way to clean some metals with rust. Again length and quantity of acid are the factors. Standard food grade citric acid and warm/hot tap water works great. Bath them for 24 hours, giving the parts are rub down 2-4 times depending on how much rust. Towel dry them when done and also heat them to make them 100% dry and then apply machine oil to the parts.

I found it while i was trying to sort out a rust problem myself, funny thing is i only had a small amount of surface rust and i ended up just making a small batch and soaking a rag and wipped it on and left it, rubbed back slightly after 10min and it worked well, repeated 2 more times and the old lathe was good again. Too bad i had to give it back.

Other acids work but are toxic and hard to get rid of. Citric acid when used is safe and can be poured out in drains etc but i do recommend gloves and glasses and a not so important garden bed/grass for discarding.

Just an extra option, it does depend though on how much rust.

Daniel
P.S Dont be scared when the mix turns a really bright yellow. It is just the reaction to rust. When i did it scared the c**p out of me.lol.

Originally Posted by twistedfuse

A good way to clean them is a citric acid bath. It is a common way to clean some metals with rust. Again length and quantity of acid are the factors. Standard food grade citric acid and warm/hot tap water works great. Bath them for 24 hours, giving the parts are rub down 2-4 times depending on how much rust. Towel dry them when done and also heat them to make them 100% dry and then apply machine oil to the parts.

I found it while i was trying to sort out a rust problem myself, funny thing is i only had a small amount of surface rust and i ended up just making a small batch and soaking a rag and wipped it on and left it, rubbed back slightly after 10min and it worked well, repeated 2 more times and the old lathe was good again. Too bad i had to give it back.

Other acids work but are toxic and hard to get rid of. Citric acid when used is safe and can be poured out in drains etc but i do recommend gloves and glasses and a not so important garden bed/grass for discarding.

Just an extra option, it does depend though on how much rust.

Daniel
P.S Dont be scared when the mix turns a really bright yellow. It is just the reaction to rust. When i did it scared the c**p out of me.lol.

Thanks for the info Rod & Daniel,
I will grab them and try to clean them up.
Will post results, good or bad.

Good tip with the citric acid, my mill bed has a bit of light surface rust I might try it on that.

BTW if the balls are buggered you can buy some new ones pretty cheap at any bearings or engineering shop. I bought some from CBC Bearings in Minto, NSW when I was repacking my linear slides and found the chinese didn't pack all the balls.

I believe I ordered 1/8" balls and have some left over if you want them.