Oil Leak – What is it in Vaping?

Definition

Oil Leak is the unintended escape of e-liquid from a vapetank, pod, or cartridge onto the device body, battery housing, or user’s hands. In Australian vaping slang it is sometimes called “juice weep” or “tank spit.” Leaks occur when the vacuum seal inside anatomiser is broken, allowing vape juice to seep through airflow holes, open system joints, or coil base threads. While a small amount of condensation is normal, persistent oil leaks waste liquid, damage sensitive electronics such as the OLED screen, and can deactivate overheating protection circuits by coating sensors with sugary residue.

Technical Details

Most tanks rely on balanced internal pressure and surface tension of organic cotton wicking to keep e-liquid contained. When a sub-ohm coil drops below 0.3 Ω, faster vaporisation can draw more juice than the cotton can re-absorb, creating a positive-pressure pocket that forces liquid out through the path of least resistance—usually the 1.2 mm–2.0 mm airflow channels. Variations include:

• Top-fill leak: appears under the DripTip“>drip tip when an O-ring is nicked or swollen.
• Bottom-flow leak: pools under the tank, often caused by cracked Pyrex or cross-threaded 510 connector.
• Centre-pin leak: juice travels down the positive pin and enters the mod’s chipset, tripping over-current protection.

Glass thickness, coil-head tolerances (±0.1 mm), and ambient temperature swings above 30 °C all influence leak severity.

Usage & Tips

Preventing oil leaks starts with assembly: hand-tighten only until snug—over-tightening slices O-rings. Close airflow when refilling to maintain negative pressure, then open gradually. Use 70 VG/30 PG juice in high-wattage sub-ohm tanks; 50/50 liquids are thinner and more prone to weeping. Check coil ohm reading after every replacement; a 0.15 Ω coil reading 0.10 Ω can signal internal short and flooding. If you find juice under the tank:

• Disassemble, rinse with warm water, dry thoroughly.
• Replace any O-ring that feels brittle or stretched.
• Prime new cotton with 3–4 drops only; oversaturation is the #1 leak trigger.

Never vape a visibly leaking device—escaped liquid can short the battery and bypass overheating protection.

History & Context

Early 2010 clearomisers leaked constantly because silica wicks could not match modern coil speeds. The 2014 introduction of vertical organic-cotton coils and adjustable juice flow reduced leak complaints by roughly 70 %. Today, top-airfeed mesh tanks and closed pod systems continue the arms race to deliver flavourful clouds without the dreaded oil leak.