Cleaning tools or really preventing problems

[Planeiron]

What do you use to clean tools? Usually I have a rag with WD-40 oil and that does the trick but I was working with very green poplar and couldn't wipe away the residue from the wood even straight away. Presumably this is oxidation reaction from sap? Steel has gone black but from what I can see the steel seems ok.

I've only really ever used light oil on tools to keep them in good shape. Suppose I'm asking what people use to prevent this as the WD-40 was pretty useless.

[TreefarmerNN]

For me it depends on the tool and where it's stored.  My wrenches, screwdrivers etc. are mostly inside in a tool box.  A quick wipe down with any oil is sufficient for them as they aren't exposed to high humidity or moisture.  Most of the time I'm wiping oil off the wrenches as they pick it up from lube on bolts or whatever I'm working on. 

Tools that are stored in other conditions might get Fluid Film, a brush down of used motor oil or even RIG (Rust Inhibiting Grease) depending on what they are and how often I use them.  A shovel might get the used motor oil while a chisel will get Fluid Film.  The WD-40 gel seems to be better at rust prevention than the regular version.  I keep both as well as Fluid Film on hand but will pick up cans of other stuff to try when I see something that looks interesting. 

[Old Greenhorn]

Did that happen in one session or over a period of time. The chisel in the photo appears to be older than 'new'. Were they shiny before you worked on the poplar?
 I can't see any residue in the photo, just discoloration. Is that accurate? Yes, I agree, that discoloration appears to be a chemical reaction between the steel and what ever you are working on, almost like a light acid etch. I think the only way you can get that off is with something like a scotchbrite pad in conjunction with WD40. I use that on machine tables that get a slight fine rust and it shines them right up.
 Best of luck.

[Planeiron]

Thanks both. Been using that chisel from new for 5 years. Wiping it down with light oil worked previously on green oak and seasoned wood. The poplar has just been felled and used the chisel to remove some bark as didn't have anything else to hand at the time. That seemed to happen overnight. I wiped it down on the day but must not have spent enough time on it. Have had overnight flash rust on the iron top of a bandsaw when i forgot to wipe down before but this seems different.

[beenthere]

I also spray WD-40 and wipe off excess. 

[Magicman]

The Tannic Acid in hardwood, especially Oak, will blue stain any tool with a "heavy" Iron content.  Same as Iron will cause blue stain in Oak, etc.