How do I get grease out from under my fingernails?

How-To

How do I get grease out from under my fingernails?

Grease under the nails is the last five percent that never seems to come out. You scrub your hands, they look clean, then you look down and there is still a black line under every nail. It is not dirt sitting on top. It is grease packed into the space between your nail and your skin, and regular hand washing does not reach it. Here is a method that actually works, without digging metal under your nails or soaking your hands in solvent.

1Why grease hides under your nails in the first place

Your nail is not flat against your finger. There is a small gap underneath called the hyponychium, and it is basically a trap. Grease, diesel, and metal fines get pushed up into that gap under pressure, when you are turning a wrench or pulling a part with your bare hands. Once it is packed in there, surface washing just glides over it.

Dry grime is actually easier to get out than fresh grease. Fresh grease is soft and spreads, so it wedges deeper into the gap every time you close your hand. That is why nails look worse at the end of a long job than halfway through it.

2The method that actually works

Step one, do not go in dry with a pick or a knife. Digging under the nail with something sharp can nick the skin underneath, and that is how you get an infection, not a clean nail. Skip anything metal and pointed.

Step two, soften before you scrub. Warm water for a minute or two helps, but grease does not dissolve in water alone. A cleaner built for grease, worked in dry first, breaks the grease down before you ever touch a brush. Our guide on getting grease off your hands without acetone covers why solvents and gasoline are a bad shortcut here, same idea applies under the nails, you are just trading grease for skin damage.

Step three, use a stiff bristle nail brush, not a toothbrush. A toothbrush is too soft and just moves grime around on the surface. A dedicated nail brush has bristles stiff enough to flick packed grease out of that gap without forcing anything under the nail plate. Work in small circles at the tip of each nail, then rinse and check.

Step four, repeat on stubborn nails. Thumbs and index fingers usually hold the most grease since they take the most pressure. Do not expect one pass to clear everything. Two shorter rounds beat one long, aggressive scrub.

3What to avoid

Skip the fingernail file or clippers as digging tools. They are not designed for it, and using them that way just widens the gap under the nail, which means it packs with grease faster next time.

Avoid soaking hands in gasoline, brake cleaner, or straight solvent to melt grease off. It works fast, but it strips the natural oil out of your skin and nail bed along with the grease. Do that often enough and your skin cracks, which is worse than dirty nails.

Hot water alone, used over and over, also dries skin out over a shift. Warm is fine. Scalding water does not clean better, it just irritates skin that is already working hard all day.

4After the nails are clean, protect them

Grease cutting and moisture go together. A cleaner with glycerin in it helps hold water in your skin while the surfactants do the work of lifting grease, so you are not left with that tight, cracked feeling after. Bentonite clay in a hand cleaner also helps by binding grease and pulling it away from skin and nail instead of just smearing it.

At the end of the day, work a little lotion or balm under the nail tip, not just on top of your hands. That gap under the nail dries out same as the rest of your skin, and dry skin there cracks easier, which gives grease an easier path back in tomorrow.

5Frequently asked questions