If your candle has wet spots, consider using a heat gun to resolve the problem. The application of heat will assist in smoothing out the wax surface and concealing the wet spots. Be sure to heat the candle uniformly to prevent frosting. Additionally, monitor the room temperature and humidity to ward off any wick-related issues with the candle.
Seasonality
There are a few reasons why your candle may be sinking to the center of the glass. One common reason is that it’s too cold and is causing the wax to shrink. This is normal. However, you can reduce the shrinkage by pouring the wax at a lower temperature or by heating the container slightly. This will help your candle burn more evenly and will minimize smoke.

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Humidity
Your candle may be getting wet spots on the inside. This happens when air gets trapped inside the container while the candle cools. The problem can also be caused by unclean surfaces inside the container. Luckily, there are ways to fix this problem. Pouring your wax at a lower temperature and keeping it out of drafts are both good ways to avoid wet spots. You can also use a heat gun to re-melt the wax and encourage the air to disperse. Lastly, try elevating your candle on a wire rack to ensure it cools evenly.
The reason your candle may be getting moist and dislodged from the glass is humidity. This is not a defect of the product, but it can be an eyesore for the customer. Clear glasses are less visible and will also add a touch of class to your candle. Clear glasses outsell frosted glasses two to one.

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Room temperature
The temperature of your candle may be causing the problem. You may be pouring the wax at a temperature below the suggested amount. Or, the wax may be melting too quickly, causing your candle to sink. In any case, you need to monitor the temperature of the container and the wax to prevent these problems. To avoid these problems, you need to ensure that the mold is room temperature before pouring the wax. Natures Garden suggests two methods of prepping your mold.
When pouring wax, the candle must cool gradually to avoid it from cracking or leaking. When pouring, it is best to use a wire rack to prevent heat loss. It is also a good idea to gently tap the glass jars to get rid of any air bubbles.

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Wick size
The first thing you need to do is check the wick size. If it is too long, your candle will have a difficult time staying lit and may end up burning too quickly. If it is too long, you will need to trim it to a reasonable length of 3/8 inch before each burn. You can use wick trimmers or a pair of Joyce Chen scissors to do this.
Another cause of a clogged wick is using too much or too little wax. Too much wax can cause the candle to tunnel. It can also result from too much fragrance oil. You should make sure you use the correct wick size based on the diameter of the candle. To find the correct wick size, just look at the wick size tab found in the wick listing.

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Preheating the glass before pouring
Before pouring candle wax, it is important to pre-heat the glass container. This step will prevent air bubbles from forming, which can be problematic when the candle is burning. Using a hair dryer or heat gun to pre-heat the glass container will help minimize the amount of difference between the glass and the temperature of the room. Alternatively, you can place the glass container in the oven.
Preheating the glass before pouring candle wax will also help prevent wet spots. These spots appear when the wax is not adhering properly to the glass. There are several causes of this problem. One of the most common is the temperature differential between the candle wax and the candle jar, which can lead to poor adhesion. Another cause of adhesion issues is oil on the inside of the jar. In addition to avoiding this problem, it is also recommended to clean the candle jar before pouring the wax.
Tunneling caused by wick
Tunneling, also known as candle rings, is caused by the wick not burning long enough. It usually occurs when the wick is too small for the candle’s container, or when it burns for a long time in the first place. Once tunneling starts, it’s very difficult to reverse.
There are a couple of solutions to tunneling. First, try burning the candle for a longer period of time. This will help melt the wax off the sides and can help prevent minimal tunneling.