Testing For Proper Wick Size in Candles

Candle makers often talk about test burning candles..Remember the trapped heat? You don't want your
It seems like common sense that a candle makercandle to burn all of the way out to the edge until
who sells a product would know how their candlesthe candle is about 1" down. Otherwise it will be way
burn. It is a bit surprising that few candle makerstoo hot by the time it gets to the bottom of the
actually have a system that will generate repeatablecandle. This notion is generally held mostly for
results. A lot of candle makers have different ideascontainers. There are some exceptions to this rule.
about test burning. But what exactly does "test burn"Very shallow containers (less then 2" deep) should
mean and how do you go about doing that. Theseget full melt pool on the first burn.. Pillars on the other
guidelines are created to help better understand whathand will start to consume their edges once they
a productive test burn involves in order to achievestart to get about 1" down. If they are too hot they
reproducible results. The important thing to takewill blow out the sides.
away is that repetition is needed.The following details are for how a container candle
Simply put, the test burn is used to understand howshould burn. Pillar candles burn the same after the
a candle burns. Pillars, containers, votives and teafirst inch. Whereas container candle have different
lights all burn differently even if the same wax, wickburn zones.
and additives are used. Size (diameter and depth) andIn the first zone the candle should feel warm on the
container (metal, glass or none) greatly affect howtop portion and should burn out to within ¾" -
each candle will burn. Each candle type must be test1" from the edge within it's given time period. (One
burned to insure accurate performance. For instance,inch per hour). When the candle reaches the second
the taller the container candle, the greater thezone the top wax "hang up" will start to melt. When
trapped heat factor. Trapped heat is the heat that isthe candle has reached it's full burn time (2 hours for
trapped in the jar as the candle burns down. Thea 2 inch diameter, 3 hours for a 3 inch diameter
further down the candle burns the more heat thatcandle) in zone two it will leave very little wax on the
builds in the jar. Containers will have more trappededges. The melt pool may get as deep as about
heat and tea lights will have the least. This is½". In the third zone the side hang up will
important to understand. A candle that seems tocompletely melt within it's proper burn time (one inch
burn well at the beginning of its life could become aper hour of diameter) and the melt pool may get as
flamethrower as the wick nears the bottom of thedeep as 1".
candle. It is also important to understand, as theThe deeper the candle the more exaggerated the
candle burns down the diameter burns out. Thiszones. In a 6" deep candle the first zone may extend
generates more trapped heat. This will be discusseddown 2" or more. Different depth candles will have
later in the paper.different zone depths and it will take some
Do your research! I can't say this enough. If you planexperiments on your part to determine where the
on selling a product you should know that product!transitions occur.
Here are some things to consider when test burningRecord your information-I can't say this enough. Keep
candles.very detailed information on everything that you do
Many wick sizes and types. When you have an entireto make your candles and while test burning. You will
line of candles it is usually not a good idea to try andthen be able to reproduce them. You won't be able
use just one size or type of wick. There are manyto "remember" all the steps.
different families of wick on the market today andEven the best minds get a bit hazy when dealing
each type is designed to perform best under specificwith a bunch of candles.
circumstances. Braiding tension, type of material used,Some of the information that is important to note
possible inner core or flame retardant treatment allwhen pouring your candles; Room temperature,
contribute to the burning properties of the wick.humidity level, temp you add your scent and
Families of wick are HTP, CD, CDN, PK, RDH, Eco,additives, temp you pour your candles, amount of
square braid, etc. Each type of wick should havedye, amount of scent, amount of wax, and amount
application information. When testing choose manyof additives.
wick families that you think will work best with yourFactors that should be recorded when test burning.
candle and go from there.1) Initial weight of candle (you can weigh the jar with
All wicks are not the same. When you test 5the candle in it since you will be using the change
different wicks from different wick families that areover time to determine how your candle burns)
supposed to perform well in the same wax and burn2) Weight after certain time periods (we do ours
the same diameter they will not perform the same.every ½ hour)
That is why test burning is so important. Different3) Flame height
families of wick burn better in different wax/scent4) Melt pool depth at different times, melt pool
dye combinations. For instance, that HTP 1212 maydiameter at different times, when does the candle
work wonderful in a 4" EL soy container jar withget a full melt pool, when do you have to trim the
Serendipity scent and Scarlet Fever dye crystals butwicks, is the candle smoking (sooting) and does the
it will fail when you use it in a 4" EL container jar withjar get excessively hot.
Patchouli Dreams and Midnight dye diamonds.5) Another good thing to look at is first ignition. (How
All waxes are not the same. Just because twolong does the flame stay up when it is lit for the first
different waxes are 100% soy does not mean thattime at the beginning of every burn? If more than
they will burn the same, have the same scent throwone minute the wick capillary action is probably too
abilities or even the same dying abilities. The soybeanstrong. Steadiness of flame is another factor to
can be taken apart to form many differentstudy. (Does it bounce around?) The more stable the
compounds. I'm sure that you are all familiar with tofuflame the less soot and mushrooming.
or soymilk. Both of these are from the soybean. Now6) And finally record the final weight of the glass
can you see burning either one of them? Somewhen the candle has fully burned.
waxes will be easier to burn then others. Some willYou may find in your own testing that there are
have better scent throw then others. And some willother factors that you may want to include. My list is
change their burning properties whenever somethingby no means all-inclusive.
is added.Determining the winner.-With all of your testing
All fragrances and additives are not the same. Theseinformation it is much easier to determine the winner.
are the factors that will have the most variability.Which one did the best overall? You now have plenty
When testing you will want to hold them constant asof information to compare to wick manufacturer
you test for wick size. Use the manufacturersspecifications and your own guidelines. Little soot,
recommended about of scent for your testing. Justgood melt pools, jar not too hot, short initial burn
because a wax can hold 10% oil doesn't mean thatflare-ups, no bouncing flames, flame height the
you should use that much! In fact, sometimes usingcorrect size (check manufacturer's guidelines), few
too much scent can "lock up" the scent or changewick trims needed, etc.
the scent as it is burning. Also, super concentratedAfter we have determined which wick to use we
scents need very little scent because there are moremake a couple of candles and give them a torture
raw materials in their composition and less filler. Filler istest. The torture test is to let them burn all day,
cheap and will often be used in inexpensive scents toabout 6-10 hours. We can then see what they will do
keep the price of a pound of wax low. But you justif a customer lets them burn too long. If they don't
end up using more oil to get any scent throw.need an excessive amount of wick trimming and the
After you have picked out wicks, wax, additives andjar does not get super duper hot I feel much more
scent it is time to start testing.confident about my results. After a good torture test
Burn multiple candles with the same wick.-Anotherwe then alternate between normal burns and torture
important component of testing is to make sure thatburns. A normal burn is when you give your candle
you can duplicate your results. Make sure that youone hour of burn time for every inch of diameter. So
have at least two of all of your wick sizes/typesa four-inch candle gets four hours. You will notice
that you are test burning. This helps to insure thatthat the candle will consume the first inch of
your results are accurate. Any number of problemsdiameter much faster then the last inch. That is why
may affect an individual wick. You may get anit needs the full burn time for a good test. Your
unreliable burn if the wick was not primed correctly,candle may get all of the way out to 2" (for a 3"
something got into your candle, the wick incorrectlydiameter candle) in the first 30 minutes and then putt
labeled, braiding tension was faulty, etc. Thus, if youalong for the next 1.5 hours to reach the outer
have two or more of the same wick/wax/scent/dyeedges. The closer the flame is to the wax the
combinations and they are burning the same you canquicker it will melt and the further away from the
be more assured of the accuracy of your results.flame the longer the wax will take to melt.
Other things to be cautions of while test burning areThe final burn-One last step. Now that you have
improper wick priming, trimming the wick too short,determined which wick that you want and given the
not trimming enough, pigment in the color cloggingfinal torture burns it is really a good idea to make up
the wick, drafts, etc.two more jars with your chosen wick, wax, dye,
Example--When we test our 4" diameter jars we use.scent combo and burn them like it says on your
We use EL soy container wax. We use about 6instructions. Again, one inch for every hour the candle
different types of wick and many different sizes. Inburns. You can go a couple of extra hours some
all we have about 20 - 24 jars burning at a time. .days but don't give them any torture tests for this
That is 10-12 (wax,wick,scent,) jars with a duplicate.one. Then when the candles are finished burning
For example, 2-CD18, 2-CDN18, 2-CD20, 2-CDN20,evaluate how they did. If they burn out nice and
2-CD22, 2-CDN22, 2-#2 square braid, 2-#5 squareclean you are ready for production. If you have
braid, 2-HTP 1212, 2-PKN15, 2-PKN20, 2-RDH 15,problems it is back to the drawing board. Look at all
2-RDH 17of the components and see what you did differently.
Also, make sure that you burn all of the candles atYou may have even mislabeled something. You may
the same time. You will be able to see how each isbe tempted to skip steps and cut corners because
doing compared to the others throughout the entireof all of the materials involved but remember you are
test. Remember not to put the candles too close tocreating a product that someone will be burning in
one another or their heats may affect each other.their homes! You should really know the candles that
Burn the entire candle. Candles burn differentlyyou are selling.
throughout their life. As a candle burns downEnjoy the trip-- Try not to feel bad if you do need
vertically it will burn further out horizontally. This isto spend more time on evaluations and further burns.
due to the heat of the flame creating more trappedThis is what being a candle maker is all about. If
heat as the candle burns down. Containers hold thiseveryone could make a candle there would not be
heat more drastically then pillar candles. This trappedany reason for candle makers. And don't forget that
heat helps to burn the sides of jars and pillars. Theretesting and knowing your candle will really set you
is little trapped heat until the candle burns about 1"apart from hundreds of other candle makers out
down. It could take many hours to get to this point. Ithere. Which in turn will help you sell your candles!
will call this zone one. When the candle is about 1"Think of all of this testing as an investment.
down the flame will start to melt more of theOne last word on test burning. Legal issues. Insurance
"hang-up" on the sides of the candle. This will be zoneiis not enough. If you document the fact that you
two. As the candle burns down and the flame nearsknow how each one of your candles burns you will
the bottom of the candle the trapped heat is thebe in a much more stable place if there is ever a legal
greatest. This will be referred to as zone three. Ifquestion. Keeping your test burning records along
the wick is burning too hot it can cause excessivewith giving burning instructions make it much more
sooting or it can shatter glass.difficult to indicate negligence on your part. How could
How the candle should burn. The general rule ofyou be negligent if you took the time and effort to
thumb is that for every inch in diameter that a candleknow your candles! The burden of proof them falls
measures, it should take about 1 hour to burn. Aon the customer to show their burning records.
three-inch diameter candle should take about 3 hoursAnd most of all have fun! I hope that you enjoy a
to burn as far as it is going to burn. The burninglittle of the science of candles as well as the
diameter will expand as the candle burns down.aesthetics.