Estimating Candle Burn Time

One question I occasionally get is, “How do I estimate how long my candle will last?” Here’s how!

Important Note

It is important to note that wax consumption will depend on the fragrance oil that is mixed in with the wax and also the wick’s capacity and number of wicks. This means that if you change fragrance, fragrance percentage, wax, or wick, you will need to re-test and recalculate your burn rate again. It’s easiest to do this during wick testing.

Step One: Gathering Data

During the wick testing phase, you’ll be testing for the ideal melt pool, hot throw, and vessel sturdiness. One more thing you can do while testing is record start and end candle weights.

  1. Weigh the candle: wick, wax, vessel, fragrance oils, decorations, and all. If your candle vessel has a lid, exclude it, don’t weigh it.
  2. When you start your test, record the starting weight and the time you light the candle.
  3. At the end of your test, blow out the candle. Weigh the candle again and record the ending weight and ending time.

Step Two: Calculations (with Example!)

The starting weight less the ending weight will give you the weight of the wax consumed during the burn. For example, I recently tested a candle that started the test at 498g and ended at 487g.

498g – 487g = 11g

We also need to figure out how long the candle burned. For example, the candle was lit at 10:15am and it was blown out at 12:10pm.

12:10pm – 10:15am = 1 hour and 55 minutes burn time

Now, take the weight of the wax consumed during the burn and divide it by the number of hours burned. (You can use minutes if you like.) This will give you a wax burn rate.

11g / 115 minutes = 0.096g/minute

To convert this to hours:

0.096g/minute x 60 minutes = 5.76g/hour

Step Three: Find Your Candle’s Burn Time

When you finally pour your candles, you should know how much wax is in each one. For the candle in our example, I decided that they would be 12.5oz each (not including vessel or wicks, but including wax and FO.) Since my burn rate is in grams, I’ll convert ounces to grams (it’s more accurate that way). Google makes it easy. 12.5oz is 354g.

Now I divide the weight of the wax (and fragrance oil) by my burn rate.

354g / 5.76 g/hr = 61.45 hours

Woot! We figured out that a 12.5 oz candle will probably burn for just under 61.5 hours. Since candles may burn faster or slower depending on where they are located (for example near a draft or in a still room) I like to couch the burn estimate in range, so I would then put the estimated burn time as 55 – 65 hours.

Priming/Waxing Raw Wicks

Most candle supply stores sell pre-cut, primed, and tabbed wicks, and most of the time those will be all the wick you ever need. Sometimes, however, you need a really long wick for a tall container. Or you need a particular size but no one has it in stock or sells it.

You can buy spools of raw wicking (and tabs). I get mine from Candlewic (I don’t have any affiliation with them, but I use them as a supplier for my business too.)

Spools of raw wick
Spools of raw wicks purchased from Candlewic.

Raw wicks on spools will look a little different from what you are used to when you buy pre-tabbed wicks. The wicks don’t stand up on their own because there is no wax to stiffen them. Likewise, because raw wick is literally braided and woven cotton threads, these will have air bubbles that will either be trapped in the wick or will create bubbles around your wick when you use them.

soft spooled raw wick
On its own, raw wick is just cotton threads braided together. It isn’t stiff and doesn’t stand up by itself.

While I could work with raw wick directly, I prefer to pre-prime my wicks. For this, any type/color of wax will work! The only thing is to make sure the wax you use has a higher melting point. I use white beeswax because I make lip balm and I always have some beeswax lying around.

Beeswax in a cup
I melt beeswax in a cup for wick priming. I don’t bother cleaning out the cup because I plan on doing more in the future.

First I cut the wicks to the length I want. Right now I am still testing wicks, so I cut them pretty long (I’ll cut them into thirds after they’re primed). I then drop the wicks into the melted beeswax and stir them around until I’m sure they’re soaked through. Then I pull on some poly/plastic gloves to protect my hands.

Raw wick vs primed wick
Raw wick from the spool next to wick that I’ve cut and waxed. (Note the bit of beeswax I didn’t clean off.)

I fish out the wicks with a skewer or with tweezers, and then lay them on parchment paper or wax paper. I have a very small window in which I won’t burn my fingers (from hot beeswax) and I quickly straighten and smooth out the wicks by pulling them between my fingers and laying them out on the wax paper.

If I work too slowly the beeswax solidifies on me and leaves me with a tangled mess, but if that happens I drop the clump back into the melted beeswax in my cup and it all melts down again. (I should have taken pictures during this process but was too busy to do so. Next time, I’ll do it and put up a TikTok video!)

Waxed wick
This wick has been waxed (aka primed) and it is nice and stiff and stands on its own.

It doesn’t take long for my straightened wicks to be ready for me to pack them up for future use. I bought tabs and I have pliers–I will use some of these in candles and tab them as I wick the vessels.

Primed wicks
Raw wick from the spool next to wick that I’ve cut and waxed.

I am going to experiment with dying the beeswax in the future. Just imagine: red wicks in green wax for Christmas, purple wicks in pink wax for Valentine’s Day, or red-white-blue wicks in a triple wick candle for Independence Day. The possibilities are endless…

Burn Testing

Most candlemakers ship their products with care cards or other such informational material that tell customers not to burn candles for more than 4 hours at a time, not to leave candles unattended, etc. Still, stories of cracked (or worse, exploding) jars abound. A chandler’s worst nightmare is hearing from a customer that their candle caused a fire.

Is there any way to protect against that? Proper wicking, of course… but most candles are tested under ideal conditions and following burn recommendations. And sometimes that slightly-larger wick is a bit too much for a vessel, but also throws amazingly and fills the room in an instant.

Less fragile materials (such as tin and concrete) are also popular. These materials have less of a tendency to crack or explode under extreme changes in heat, but they also just don’t have the same look that a glass jar does.

To help candlemakers decide if a vessel is safe or not, I abuse my vessels with over-wicked power burns and check to see how they hold up under intentional stresses beyond what a reasonable candlemaker would do. Here’s my latest power burn in the Marilyn vessel.

Notice how deep the melt pool is (1.5 inches–I measured). The outside of the thick vessel “only” reads 160F even though the inside is over 200F. The thickness of the vessel means that even under extreme burn conditions, this vessel will hold in all that hot wax and flame. Perfect if your customers like to burn their candles way beyond what their care cards say!

LAUNCH SALE

Hooray, our loan on Kiva has been fully funded! Thank you to every one who contributed and have supported us! This loan is only a small fraction of the funding needed to launch a vessel supply store, but it is vital and without it we would not be able to launch with the number of vessels we will be launching with.

In celebration, we are giving out an unprecedented 30% discount to EVERYONE who uses code THANKSKIVAF4 before the end of 2020. It is highly unlikely this high a discount will ever come again!

THANK YOU for your support, and I look forward to shipping all these vessels!

#soon

The container is packed and about to depart! It’s REALLY HAPPENING!

My manufacturer has finished stuffing the last boxes into the container and they are loading it onto a ship right now. I’ve filled customs power-of-attorney paperwork with my customs broker. The quicker that ship sails, the sooner vessels are distributed!

Right now, 26,000 vessels within this container (all Shadowfire and Marilyn vessels) are estimated to arrive, be sorted/checked in, and shipped in about:

Weeks
0
1
Days
0
2
Hours
0
1
Minutes
1
5

(Above information accurate as of January 12, 2021.)

When I founded Februaryfour Trading, I promised not to take pre-orders and make you wait months for vessels. However, at this point it’s only a matter of weeks, and some of you have requested that I begin reservations for these vessels. This company was made to serve you, the candle-making community, so your wish is my command. To assuage my conscience, orders will only be charged when they are about to ship.

If you are comfortable with an estimated ship date in January 2021, then please pre-order to reserve yours before supplies run out! I tend to over-communicate, and I will post updates on the ship’s progress as I get it. If you have any questions, as always please feel free to contact me!

We are live!

Welcome to Februaryfour Trading! We have been working since June to get to this point, but we can now launch with some of our vessels ready to ship right here from Highlands Ranch, Denver, Colorado. Please bear with us while the site is still under construction but ALL orders will be fulfilled immediately as soon as we see it!

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