Thread: WD 40 and RUST

I just got reminded of my experience with WD40 and rust. See the post from dullvinci with the pics of owners lathes "as is". I was living in Jacksonville, Florida at the time, so the humidity in the shop was pretty high, but I swear that the WD 40 made the drill chuck on my drill press rust up overnight! I had cleaned it off with a wire brush because it was starti9ng to show signs of slight rusting. Then I sprayed it down heavy with WD 40 to keep it from rusting. Big mistake! When I came back the next day it was solid brown like it had been left out in the rain for a month. There was no protection left and the surface was dry and crusty!

So I sent in a comment to the Home Shop Machinist magazine reader's forum. I wanted to warn the other readers too. They printed it in the next issue, but somebody must have complained, because a month or two later they printed a disclaimer saying that "the comments in the reader's feedback are in no way the opinion of the Home Shop Machinist magazine." or something to that effect. WD 40 is ok for loosening things up if that's all you can get, but I don't leave it on the steel parts if I'm trying to keep them from rusting. Especially not a lathe.

I just hauled home a SB 10L lathe a few weeks back. It got a 6 hour washing in the rain on the way home. When it started raining i sprayed the entire lathe down with WD40, it was perfect when i got it unloaded and wiped off and the correct oil put on the ways and shiney parts. I also use WD in my welding shop to keep the parts from collecting slag and bb's it also coats the parts with a film until they can be delivered to the powder coaters. Regular anti splatter will rust the parts within hours.
I know about leaving it on lathe parts, i spray my chucks and shiney parts down with it when i am away for weeks at a time and have never had a problem, but i use the liquid WD in the gal and not the spray can stuff. I did one time see a discoloration on a lathe chuck where there was a drip from the WD but it was otherwise perfect, and they are still shiney fter 3 years of sitting. Just my .02 ....Bob

Here in New Endland the humidity swings are huge, especially overnight. I don't keep my heat on in the garage 24/7 for obvious reasons. I have actually seen water sitting on the ways of my stuff in the morning with developing rust! I don't have a lot of time so I find that giving the stuff a good shot of "water displacing" 40 does the trick. When I get home at night a quick wipe rids the rust and moisture. Your right tho, the metal is darker than it usually is... a patina [img]smile.gif[/img]

WD40 is a lousy lube, but pretty good against water IMHO.

I use 631 Rust lick on everything. I have cylinder heads sitting on the shelf for 10 years sprayed with this and look as good as the day they were bagged.

I've read a lot of negative comments on WD-4o, but never personally experienced any problems with it.