Stopping rust?

I have a sheet of metal I’m cutting up to make a robot chassis but the surface keeps rusting up. Is there some sort of anti-rust paint/covering that I could apply to stop this effect?

Use aluminium or stainless.

I have a sheet of metal I’m cutting up to make a robot chassis but the surface keeps rusting up. Is there some sort of anti-rust paint/covering that I could apply to stop this effect?

What kind of “metal”?

Even if it was low-grade sheet steel, I wouldn’t expect it to rust (visibly) unless it is taking you a long time to build this chassis - or where you are working at is very humid.

To stop the rusting, you have to stop the moisture (I’m assuming you’re using steel here); you can clean the metal by sanding it, using steel wool, or sandblasting it to remove the rust (there’s also a really nasty chemical out there called “naval jelly” that is essentially an acid - but it removes rust well). Once you have clean metal, then paint it with primer, or coat it with a layer of grease. If you need to weld it or work on it in some way where you need metal contact, you’ll have to grind or otherwise remove the coating off, of course.

You might also try storing the chassis (after cleaning and/or coating) in a non-metal box (like a rubbermaid container or bin) or something (if it isn’t too big) with some desiccant, like silica beads - to remove the moisture; the cheapest way to get this without buying huge bulk at a chemical supply house is to go to the pet store, and purchase silica bead cat litter. Its basically the same stuff as what is in those little “do not eat” packets that come with electronics. Put the chassis in the box, then put the silica in a small container (a small jar with holes in the lid will work) with it. Close the box up.

If the chassis is larger, put the litter desiccant into a 5-gallon pail with holes in the lid, and put the whole thing in a room or closet with the pail. If the chassis is sitting outdoors, then wrap it in plastic sheeting or a large plastic bag. Put the desiccant inside an old sock or small cloth bag, and put it in the larger bag/wrapping with the chassis.

You can rebuild the chassis using aluminum or SS as AWOL, notes, but if you are doing any kind of welding on this chassis, both of those materials take some skill to weld (SS is easier, but you still need SS electrodes/wire, otherwise your welds will rust)…

Good luck.

:slight_smile:

Titanium’s good too.

Spray some etching primer on it, normal primer will do if you cant find any.

Even if it was low-grade sheet steel, I wouldn’t expect it to rust (visibly) unless it is taking you a long time to build this chassis - or where you are working at is very humid.

Forgot to write that it’s steel sheetmetal. And yes, my workshop is ridiculously humid. Will any primer do? (thegeekway mentioned etching primer) or is there a special primer for steel that I should know about?

EDIT: Found some at homedepot. Thanks for the help everyone.

Give the metal a good clean with a wire brush or something similar, then give it a coat or 2. Will be good to leave outside then :wink: