Penetrating oil is a thin spray or liquid that creeps into rust and tight joints to free stuck bolts, nuts and axles.
What it does
It soaks into the gap between a seized part and its seat, so the part turns or slides more easily. Some also draw water off a wet part.
When to use it
- A bolt, nut or axle that will not move.
- Parts on a bike that has stood for a long time.
What to know when buying
- Choose a penetrating oil that says it frees rusted parts. Several brands work.
- A general water-displacing spray frees parts, but may leave a hard residue and is not a good lubricant. Free the part with it, then lubricate with a normal oil.
- A light general-purpose oil stays where you put it after the part is free.
Using it
- Spray, wait, then try the part. Work it back and forth: Free a rusted or glued part by working it back and forth.
- Penetrating oil disappears after a day or two. Relubricate with normal oil.
- Keep it away from brakes, tyres and clutch plates.