So let’s say that you’re rasping out some handles in a pine box. You hit a patch that feels a little funny, and then your sense of smell is overwhelmed by the crisp smell of fresh-cut pine. Smells like…victory! But then, as you continue, you notice that your normally very efficient hand-stitched rasp isn’t cutting very well and then ceases to work at all. Inspecting the offending tool, you realise (to your horror) that the teeth have been gummed up in gooey mass of pine resin and fine wood dust that has congealed and hardened around the rasp teeth. You can hear Bill Murray’s hangdog sigh in your mind’s ear: “He slimed me…”
Yuck! In disgust you reach for the brush that you normally clean your tools with and give the revolting muck a swipe…
It didn’t even dent the coniferous sheath that now surrounds your fine rasp! A few more swipes confirm the dim prospects for removing the gunk. So you resort to a very stiff brush…
Confustication and bebotherment! Now you’re really stuck. About the only thing stiffer is a wire-bristled file card, and you know that you shouldn’t use it on your rasp (they call it a “file” card for a reason), but you’re getting a little panicky at this point. What if this never comes off? Have you ruined an heirloom tool by using it on cheap lumber? What about fire? Could you, perhaps, gingerly touch the flame of a propane torch to the rasp and just burn out the–
No, burning out the residue will ruin the temper of the steel, just as burning out the stump of a broken off axe or hammer handle will. What we need is chemical warfare.
Easy there, Saddam! Put that mustard down!
If you get your rasp gummed up with resin, the only thing you need is a stiff nylon brush and a few squirts of mineral spirits. Spray, brush, wipe off the resultant sludge. Repeat as necessary. It will take only a few minutes to clean your rasp, and the teeth will be spared the onslaught of steel wires. Be sure to thoroughly dry and re-oil once it’s clean, and your rasps will carry on through many more years of service.