Spitback is the frequent frustration of hot, splattering e-liquid propelled into the mouth during vaping. This phenomenon occurs when the e-liquid is heated rapidly on the coil but does not fully atomize into a vapor, resulting in droplets being propelled up the mouthpiece. The experience is often accompanied by a distinctive gurgling or popping sound. Spitback is a common mechanical issue that is almost always solvable through simple adjustments to technique, maintenance, or hardware selection.
Identifying the Sources of the Problem
The primary mechanical cause of spitback is coil flooding, which happens when the cotton wick within the coil becomes oversaturated with e-liquid. When excess liquid pools directly on the heating element, the rapid application of heat causes the liquid to boil unevenly and violently, similar to water hitting a hot frying pan. This oversaturation is often triggered by using a wattage setting that is too low for the coil’s resistance, meaning the coil cannot generate enough heat to vaporize the incoming liquid quickly enough.
Condensation buildup also contributes to the problem, especially in devices that use a long chimney or mouthpiece. As the vapor travels from the heated coil, it cools, and some of it reverts to a liquid state, collecting inside the internal pathways. This pooled liquid can then drip back down onto the coil, causing a sudden burst of spitback, or it can be inadvertently drawn into the mouth by the user’s inhale. A gurgling sound is a frequent indicator that this liquid has pooled in the coil or airflow path.
The physical properties of the e-liquid play a role in how prone a device is to flooding. E-liquids are composed of Propylene Glycol (PG) and Vegetable Glycerin (VG), and their ratio determines the liquid’s viscosity. Liquids with a higher percentage of PG are thinner and flow more quickly, increasing the likelihood of flooding the coil chamber. Conversely, higher VG liquids are thicker, which makes them less likely to oversaturate the wick, especially in high-power, low-resistance coil setups.
Quick Adjustments to Stop Spitback
One immediate way to resolve spitback is to manually clear the excess liquid that has accumulated in the device’s internal components. A simple method is to take a tissue or cotton swab and insert it gently into the mouthpiece to absorb any liquid collected in the drip tip or the chimney bore. This process removes the cooled condensation and pooled e-liquid that can otherwise drip back onto the coil and cause spitting.
Another fast technique is the “flick” method, which uses centrifugal force to clear the flooded coil. Hold the device securely, point the mouthpiece away from yourself and others, and quickly snap the wrist downward a few times. This action forces the excess liquid out of the coil and into the cotton or out through the airflow vents, quickly alleviating the oversaturation.
Adjusting the way the user inhales can prevent the problem from starting, particularly with mouth-to-lung (MTL) devices. Taking a long, slow, and steady draw allows the coil sufficient time to vaporize all the liquid being pulled into the chamber. Conversely, a sharp, forceful pull creates excessive negative pressure, which can rapidly suck unvaporized liquid directly from the wick and through the coil, causing spitback or gurgling.
Maintenance and Hardware Solutions
Ensuring the device is set to the correct power output is a preventative measure against coil flooding. Every manufacturer provides a recommended wattage range printed on the coil itself or its packaging, and it is important to operate the device within this range. Using a wattage below the minimum recommendation means the coil will not get hot enough to vaporize the liquid efficiently, leaving the coil saturated and prone to spitting.
Proper coil maintenance starts with the priming process for a new coil. Priming involves manually placing a few drops of e-liquid onto the exposed cotton ports before installation to ensure the cotton is saturated. Avoid over-priming, which immediately floods the coil and causes spitback upon the first use. Replacing old coils on a regular schedule is also necessary, as degraded cotton wicks lose their ability to hold liquid effectively, leading to oversaturation and poor vaporization.
The selection of e-liquid should be matched to the coil resistance to prevent flooding issues. High-resistance coils (1.0 ohm and above) are designed for lower power settings and work best with thinner e-liquids, such as those with a 50% VG/50% PG ratio. Low-resistance, sub-ohm coils, which require higher wattage, are better paired with thicker, higher-VG liquids (e.g., 70% VG or higher) because the thicker liquid wicks more slowly and resists flooding at high temperatures.
The integrity of the device’s seals and airflow settings must be maintained to regulate the internal pressure. The O-rings that seal the tank should be checked periodically for any tears or damage. A compromised seal can disrupt the tank’s vacuum, leading to uncontrolled flow of liquid into the coil.
Ensuring the airflow is set appropriately for the coil type helps maintain a balance. Too little airflow can prevent the coil from cooling effectively, while too much airflow can draw liquid into the coil too rapidly, disrupting the vaporization process.