Choosing The Correct Wick
By Bob Sherman
Selecting the correct wick is the most difficult part of candle making for most people. This guide will explain a bit about wick and how to determine the best wick for your candles.
PLEASE NOTE!! - Candle making can be dangerous if proper safety procedures are not followed. Please read these Safety Rules before attempting any candle making projects.
I Used The Correct Wick - Why Doesn't It Burn Right?
A common complaint among beginning candle makers is that they used the "correct size wick" for their mold, yet it burns poorly. Usually this relates to using a wick recommendation from a chart or mold instructions. The problem here is that mold size is only part of the equation and the wax formula also plays a major role in determining which size wick is needed.
To carry this concept a bit further, any wick size recommended will only be accurate if you use the identical wax formula as was used to develop that recommendation. This is a key concept and should always be kept in mind when choosing wick since there are virtually an infinite number of variations on wax formulas.
This also applies when changing wax formulas or using different waxes - any change will usually necessitate a change in wick size.
Small, Medium, Or Large?
Some suppliers who market to hobbyists don't even tell you the actual wick size and label them small, medium, large, etc... These are pretty much meaningless terms since there are well over 100 wicks sizes on the market (I have never bothered to count them all). I recommend avoiding wick sized this way.
Why Does The Same Wick Burn Differently?
This is a problem sometimes encountered when switching wick suppliers and although I have not seen it recently, it is something you should be aware of. Some unscrupulous candle supply companies have been known to label their wicks incorrectly intentionally. Their logic being that if you change suppliers and buy the same wick size it will not burn correctly. This is a really heinous business practice and the companies I know of doing this have all folded, but with the number of fly by night suppliers entering the market you should be aware of this possibility.
I Can't Tell My Wicks Apart
It is vital to keep your wicks well labeled since similar sizes look identical. Sometimes the only difference is the tightness of the braiding.
Which Type Of Wick?
The first step in choosing a wick is to decide on a wick type. There are three main types, and several subtypes as explained below.
- Square Braid Wick - This is the most popular wick type for pillar and novelty candles, but may also be used for tapers. Most beeswax candle makers prefer square braid. #10 is the largest and #6/0 the smallest.
- Flat Braid Wick - Popular for taper candles, but may also be used for pillar or novelty candles. Numbered by ply, the smaller the number the smaller the wick.
- Cored Wick - Used in jars, votives, and most floating candles - not recommended for other types of candles. There are several sub types, but the all have one thing in common - a core to hold the wick stiff. Common cores are zinc, paper, and cotton but I find zinc works best.
Flat and square braid wicks will curl into the flame causing them to burn cleaner. Cored wicks do not curl so they are commonly used where curling may cause problems such as deep melting jars or votives.
Experimenting with several wick sizes is the only accurate way to determine wick size for your wax formula / mold size combination. Luckily wick is the least expensive part of your candles and you should keep several sizes on hand. Your test candles may also be re melted so there is little waste or expense involved. It does require some patience, but you will be rewarded with great burning candles.
I use the following procedure to determine correct wick size:
- Choose a wick type.
- Look at a Wick Chart.
- Most wick charts show several sizes for any diameter. Select a wick size that falls in the middle, then one size larger and one size smaller.
- Make a candle with each wick. Make sure you label them by wick size.
- Trim wicks to approximately 1/4 inch (8 mm.)
- Test burn the candles.
- If none burn well, repeat with different wick sizes.
When test burning your candles place them apart so the heat from adjacent candles does not affect them. Things to look for when test burning:
- Suitable Size Flame - Not too small or too large.
- Substantial Melt Pool - A small melt pool may indicate a wick that is too large.
- Self trimming Wick - Flat and Square Braid only. A wick that needs trimming is normally too large.
- No Excessive carbon Buildup - Cored wick only. Excessive carbon is an indication of a wick that is too large.
- Dripping - A round candle that drips likely has a wick that is too small. Some dripping cannot be avoided on most irregularly shaped candles.
- Substantial Burn time.
With experience you will develop a knack for selecting the correct wick on your first try. This takes a lot of practice, but does come in time. By sticking with one formula it makes the process simpler.
Note that candle height normally has no bearing on this and a wick that works well in a 3 inch high candle will work just as well in a 12 inch high candle of the same diameter.
Shape usually has minimal effect as well - for example the wick you use in a 3 inch round will normally be the same size needed for a 3 inch square. The exception to this are extreme shapes such as figurines or pyramids. With extreme shape candles it is impossible to obtain a perfect burn throughout, so select a wick that burns the best over the bulk of the candle. For example any wick used in a pyramid will be too large in the beginning and too small at the bottom.
I have an entire troubleshooting guide available online which explains most burning problems in detail so I will not repeat that all here. See Candle Burning Problems Troubleshooting.
There is no magic chart that can provide you with the perfect wick selection every time and anyone who suggests that there is is a dreamer. By simple and inexpensive testing you can improve the quality of your candles tremendously.