Prevent Rust Under Vise

[nova_robotics]

Tired of your mill's table turning into a pitted rusted mess? Place a piece of oiled paper between the table and your vise as a gasket. It works much better than sprays, oils and waxes I've tried.

[Frank S]

That's one of the bad things about leaving a set up semi permanently mounted to a flooded table. I'm as guilty as the next guy at that, once I go to all of the trouble to get something trammed and set just how I want it I'd almost rather amputate body parts than remove it

[Bony]

This works just with any paper and it doesn't need to be oiled. The reason the rust occurs is electrolysis between different metals in the presence of moisture and to prevent this any non porous material between the vice or other fixture and mill table should do the trick. It feels kind to add oil but the downside is the loss of some friction and therefore clamping force.

[nova_robotics]

This works just with any paper and it doesn't need to be oiled. The reason the rust occurs is electrolysis between different metals in the presence of moisture and to prevent this any non porous material between the vice or other fixture and mill table should do the trick. It feels kind to add oil but the downside is the loss of some friction and therefore clamping force.

I don't think that's correct. Paper readily absorbs water and makes an excellent ion exchange membrane. That's why they use it to separate the plates of electrolytic capacitors, lead acid batteries, other types of batteries... The vise is going to be electrically bonded to the table via the t-bars and bolts, so you'll have corrosion at all wetted surfaces of the paper. In order to stop the corrosion you either have to displace the electrolyte, or break the circuit between the vise and the table. If you had non-conductive hold-downs for the vise that would help. Or a plastic/rubber gasket instead of the oiled paper. But I'm pretty sure any old paper without any other surface treatment would cause pretty aggressive corrosion.

[Bony]

You make valid points nova_robotics and I don't intend, nor am I qualified to disagree with you. But ..... allow me to explain.
I used to work for a transport and earth moving company many years ago and although I worked in the office I spent a lot of time in the workshop and machine shop as I've have always been very interested in what those guys were doing and how they did it and I used to spend free time out there doing things for myself. The machinists had a big roll of brown paper, the sort that was once commonly seen in stores when purchases were wrapped up. This was rountinely placed onto the mill and shaper tables to prevent corrosion between table and fixture and some things were worked on for several days and remained wet with coolant without ill effect to the table or fixture.
I haven't tried this in my own workshop but surprisingly it worked for those guys. Unfortunately it's too late to find out the type of coolant they used.

[Frank S]

Butcher paper used to be popular at a local machine shop that I often did some, one off machining for, Butcher paper has a slight coating to resist absorbing blood.
I don't know what they were using if for though because they wrapped the machined parts in a brown oiled paper

[Toolmaker51]

Interesting discussion. I cannot explain what the effect is, but oiled paper does the trick; though it isn't permanent solution, just extended periods. Subjected to flood coolant, between a normal cast mill vise and table, looks different when removed, compared to a steel vise, such as sine or grinding vises.