Plastic vape tanks are by far one of the most popular choices with choosing a tank to vape with. They are inexpensive and widely available. Plastic tanks are used in a vape system to hold the e-liquid and restrict the amount of liquid that comes into contact with the conductor or coil. They are good for beginners as they are fairly inexpensive and easy to get. One major concern with the plastic tanks is cracking, which will render them useless.
The first and most obvious reason for having a tank crack is carelessness. If a MOD or personal vaporizer is being used with a plastic tank, it is important that the vaper treat the device with care. If a vaper places the device and tank inside a pants pocket and sits down on top of the tank, the applied weight and pressure will, usually, serve as enough to crack the plastic reservoir of the tank, which, unfortunately, makes it useless. To avoid this or lessen the likelihood of it happening, be aware at all times where your vape is located.
Plastic tanks are also more prone to cracking with more concentrated and 'acidic' e-liquids like orange, lemon, lime, and grapefruit flavors, as well as cinnamon, licorice, and wasabi flavors. If you choose to use these flavors with your plastic tank, it can often result in a cracked tank. The acidity of the e-liquid will eat away and weaken the tank walls over time, some take longer than others but some can crack a tank after only a few uses. These tanks are usually made of poly-carbonate plastic and that is the culprit here as it simply can't hold up to the strong bases or acids in these e-juices.
Large or extreme temperature changes can also be a culprit of cracking and cracked plastic vape tanks. If you don't maintain your system properly, this includes regular cleaning; and don't use the correct batteries it can result in excessive temperature change. Leaving a vape system unattended in a can in the summer months can result in excessive heat, and winter months can result in excessive cold, vapers will often come back to find their tanks cracked and the e-juice has leaked all over the surrounding areas. To prevent this from happening, take your vape with you or leave it at home, just don't leave it unattended in your vehicle no matter what time of year it is as it can change quickly.
E-cigarettes are generally used by beginners and/or light vape users. No hassle and no set up. However, you cannot adjust the nicotine levels, and usually can’t swap out parts to customize the e-cig to your specific tastes. The tank can corrode with certain flavors, but these are inexpensive to replace. MODs are more customizable and are favored among experienced vape users. You can switch out parts to get a more personally customized experience.
To summarize, plastic vape tanks can crack by mishandling or accidents, structural weakening and cracking depending on acidity of the e-liquid, and extreme temperate changes will play a role as well. They are inexpensive to replace however, and this makes them a favorite among vape users.