How long until a full melt pool?

[hyeteck]

How long should it take for the candle to reach a full melt pool?

 

Here is my breakdown on a 3" diameter container.

 

25% pool: 3 minutes

50% pool: 12 minutes

75% pool: 30 minutes

90% pool: 50 minutes

100% pool: 80 minutes

 

Temperature range of pool at 100%: 165F(near wick) - 125F (at edge of container)

 

Do I need to wick up to get to a full melt pool faster or is this fast enough?

 

What temperature range does the fragrance get released from the melt pool?

 

Would stepping up on my wick size improve hot throw?

[TallTayl]

What kind of wax? what size container? How tall is the container.  What does the melt pool look like beneath the surface? What does it look like beyond the first hour? 

 

those measurements would be a red flag to me of that candle becoming far too hot to burn For any length of time. By the time that candle nears the midpoint, things really heat up.  By the bottom it reads as if it could become out of hand. 

[TallTayl]

There’s this myth perpetuated that hot throw comes from a hot melt pool.  Not sure where it started, but a wicked candle is not a wax melt. Too hot and your candle will smell nothing of fragrance and everything of burned wax. 

[pughaus]

What happens after 80 minutes?    An 80 minute test burn tells you.. not much at all that's relevant.

 

There is no formula for this:  No if X + Y + Z does this than use ____. 
 

So many variables: wax, container, FO chemistry, Fo%, wick type.. etc.. including uniquely odd candle making stuff like the fact that no 2 candlemakers ever get the same results no matter how identical their ingredients/conditions, are all factors.  
 

But first- why do you think you need fast "full melt pool"?  Have you seen what a candle you've made that has a FMP in under 1.5 hours looks like in the last 50% of its life?

 

If you are getting a 100% MP in 80 minutes, you have a really good opportunity here. I wish I'd done this when I started making candles.  Don't change a thing yet. Just test burn that candle- in 4 hr increments-  until the very end of it.  (in a fire-proof, well attended place- like in a pot that's in a bathtub - because it may get rather scary about 70% down the jar) Observe how it behaves in all burns- from the 1st  to the very last bottom- of- the -container burn.   You will save so much time and $ doing this and it will show you so much about candle making.   

 

FYI: In my experience, in a 3x3" tumbler- my best burning candles don't achieve an edge to edge MP until well over 4 hours and generally not until burn #2.  In a 3x4" tumbler, if I get a FMP (by that I mean edge to edge melted wax) in burn 1, I know I'm really overwicked and the candle will be hot, sooty dangerous mess by the last 1/3 of its burn, if not sooner.  That's with my wax- my own soy/para/coco blend.  YMMV but prob not by that much.  

 

Edited February 17, 2020 by pughaus

[pughaus]

@TallTaylwe overlapped but it took you about 2 lines to say what I did in my short essay/thesis.  LOL  well, good thing you're the admin of this site

[Forrest]

I have decided that a FMP not desirable in my candles. My goal is the smallest wick that will eventually melt all the wax. Of course that makes my wicking much harder.

[hyeteck]

Alot of good questions. 

 

The burn was my second burn for the candle.  The first burn takes about 2 hours to reach a full melt pool and even then its not really 100%.  There is a tiny ring around the edge that just doesn't have enough heat to melt.  As I burn the candle down to about 70%, i achieve a full melt pool within an hour and seem to have a better hot throw.

 

In terms of wax, i'm using my own coconut/soy blend.

 

The container size is 4" tall and 3" in diameter.

 

During my second burn, the depth of the melt pool varies. I have about 1/4"-1/2" near the wick and then it tapers down towards the edges where its barely 1/16" of an inch. When i get down to about 70% of the candle used, the melt pool is a bit deeper around 1/2"-3/4" at the wick and about 1/4" by the edges.

 

Also, temperature of the melt pool has less variance when the candle is burnt down to the. 70% mark.  It ranges from about 175F(at the wick) to 150F(near the edge).

 

The more I burn the candle, the better my hot throw becomes.  I was under the impression the higher temps of the melt pool are releasing the fragrance easier?  I'm using many of the popular Candle Science fragrances.

[Sarah S]

On 2/17/2020 at 11:05 AM, Forrest said:

I have decided that a FMP not desirable in my candles. My goal is the smallest wick that will eventually melt all the wax. Of course that makes my wicking much harder.

 

 

Ditto. My best, most fragrant candles still have some wax hang up even at the bottom of the jar. 

A full MP in the first couple burns equals a sooty, inferior throwing candle by mid point.

[pughaus]

2 hours ago, hyeteck said:

Alot of good questions. 

 

The burn was my second burn for the candle.  The first burn takes about 2 hours to reach a full melt pool and even then its not really 100%.  There is a tiny ring around the edge that just doesn't have enough heat to melt.  As I burn the candle down to about 70%, i achieve a full melt pool within an hour and seem to have a better hot throw.

 

In terms of wax, i'm using my own coconut/soy blend.

 

The container size is 4" tall and 3" in diameter.

 

During my second burn, the depth of the melt pool varies. I have about 1/4"-1/2" near the wick and then it tapers down towards the edges where its barely 1/16" of an inch. When i get down to about 70% of the candle used, the melt pool is a bit deeper around 1/2"-3/4" at the wick and about 1/4" by the edges.

 

Also, temperature of the melt pool has less variance when the candle is burnt down to the. 70% mark.  It ranges from about 175F(at the wick) to 150F(near the edge).

 

The more I burn the candle, the better my hot throw becomes.  I was under the impression the higher temps of the melt pool are releasing the fragrance easier?  I'm using many of the popular Candle Science fragrances.

the 4" tall jars create a nice little chimney effect down the burn -  that's why I love them.   The increased throw later in the burn  is often just the the wind effect going on in there - -the heat + air flow pushing the scent up and out.

So, the hotter MP isn't necessarily what's giving you better throw, it's the height of your container and the flame heat  pushing the air + fragrance up.. 

As TT said, the hottest  MP does not= the best throw. Too hot can kill the throw.  

 

[Forrest]

16 hours ago, Sarah S said:

 

Ditto. My best, most fragrant candles still have some wax hang up even at the bottom of the jar. 

A full MP in the first couple burns equals a sooty, inferior throwing candle by mid point.

I have a theory that the best HT comes from wax that is exposed to the air at the point of melting. A FMP prevents this from happening.

[TallTayl]

6 minutes ago, Forrest said:

I have a theory that the best HT comes from wax that is exposed to the air at the point of melting. A FMP prevents this from happening.

 

I have spent a lot of resources proving this theory in my own shop.

 

so much depends on the wax, doesn’t it? We have been fed this notion of FMP by craptastic wax pushers and equally mediocre fragrance sellers. Soy lobbyists, IMO, really ruined a lot for candles. 
 

to the OP: more of the candle’s performance emphasis should be placed on the burn than a small factor like the melt pool.  For example: a few things to record as your tests are conducted:

 

a) Does the user need to trim the wick super short each lighting? What happens if you don’t trim? (Let’s face it people won’t reliably trim, let alone to perfection).
b) does the flame “grow” as the candle burns past the ideal burn time? 
c) does the burn change with environmental changes, like from winter testing to summer testing? (This was an eye opener to me)
d) what happens during power burns?

(If someone left it burning accidentally over night, or when they left to run an errand what would they return home to?)
e) what temp does the container get to with each burn? with each power burn? During the very last inch? 
f) soot. How much soot gathers if the candle is not burned perfectly? 

G) you noted above it is a wax blend you made, how does the blend handle changes to environment? For instance, if it sits in a warm car or delivery truck to a customer, will the wax separate? 

H) I see a LOT of people mixing in “high melt point” coconut Oil into soy waxes to “improve the melt and burn” or “scent throw”. During winter months this “may” be OK, but when warm temps hit this coconut oil is just an oil. Most of waxes can only hold a limited amount of oils. When adding fragrance and coconut oil the combined total of oils will really challenge the emulsifying system in the wax. Without additional emulsifiers or gelling agents the warmed coconut oil fractions can, and do, melt out of suspension leaving puddles of oil throughout the candle. This can become a serious fire hazard if not careful.

I) continuing the coconut oil thought, in summer the coconut oil additions will be much softer than during winter tests. The wax will become much easier to melt, thereby easier to burn.  WHat does a power burn look like in that case?  I test in Illinois during winter and discovered a very big inference when burning those candles in Utah 🤪

 

[Forrest]

55 minutes ago, TallTayl said:

I have spent a lot of resources proving this theory in my own shop.

The next thing I'm going to try is twisting an HTP wick so that it rotates 360 degrees during the life of the candle. If I size it right the uneven melt pool could be a big advantage. and I won't need to trim the wick

[TallTayl]

45 minutes ago, Forrest said:

The next thing I'm going to try is twisting an HTP wick so that it rotates 360 degrees during the life of the candle. If I size it right the uneven melt pool could be a big advantage. and I won't need to trim the wick

In soft wax is that theory may prove unproductive. I twist my wicks in beeswax and Palm for that reason,  but the wax remains hard enough to hold the twist until that section of the candle.
 

Soft waxes have easily become untwisted as soon as the candle wax gets warm and softens. At least that’s my experience.
 

Likewise make sure your twist goes up the whole wick and not just at the base. I have to pre-twist along the length of the wick to ensure it’s not just twisting at the base Where the wick meets the tab. I had that problem when I pre-fixed the wick tabs and tried to twist. I could clearly see it was just at the base..

[TallTayl]

One more thing as it occurs to me. No matter how perfectly centered my wick is the natural air currents in the vessel will blow it off center until it gets to beyond the halfway point. Even rigid wooden wicks have off-center melt pools For a time just because currents blow in a certain direction.

[Forrest]

20 hours ago, TallTayl said:

Soft waxes have easily become untwisted as soon as the candle wax gets warm and softens. At least that’s my experience.

OK, my new idea is to use a zinc core wick and wrap it around a pencil.

 

[TallTayl]

17 minutes ago, Forrest said:

OK, my new idea is to use a zinc core wick and wrap it around a pencil.

 

I have had some early successes holding the wick on both ends, twisting, then heat gunning the wax coating to help “set” a twist. Then an over dip in high melt point wax can add to stability,  it is far from perfect, but may help at least a little for the exercise. 
 

flat wicks worked well in multi wick candles by facing the “V” in the direction I wanted the curl to face.  Helped to control the melt a little, but takes a bit of time to set up.

 

the bigger problem Of coreless/flat/curling wicks is that the curl weighs the wick just enough in soft waxes to cause them to lean as they burn.  Leaning wicks are a big pet peeve.  The lean makes the later burns kind of dangerous by a) exposing much more wick in the last burns as the lean was previously well beneath wax fuel, and b) pushing the flame closer to the glass. 

[Forrest]

On 2/20/2020 at 8:38 AM, TallTayl said:

I have had some early successes holding the wick on both ends, twisting, then heat gunning the wax coating to help “set” a twist. Then an over dip in high melt point wax can add to stability,  it is far from perfect, but may help at least a little for the exercise. 
 

flat wicks worked well in multi wick candles by facing the “V” in the direction I wanted the curl to face.  Helped to control the melt a little, but takes a bit of time to set up.

 

the bigger problem Of coreless/flat/curling wicks is that the curl weighs the wick just enough in soft waxes to cause them to lean as they burn.  Leaning wicks are a big pet peeve.  The lean makes the later burns kind of dangerous by a) exposing much more wick in the last burns as the lean was previously well beneath wax fuel, and b) pushing the flame closer to the glass. 

Using 4627 with a 7% FO load in 8oz tins I tried twisting two HTP wicks and spiraling a zinc core, yea that was a bad idea. The spiraling basically doubled the amount of wick in the wax, meaning I needed a much smaller wick size. I discontinued that test at 4 hours. I used HTP 92 and 72. After four burns of four hours each I can say that the HTP 72 looks like the right size wick, but one size down might be better. The twisting was slightly successful, the problem seems to be that when you twist the wicks they tend to bend less, however, the MP was slightly off center and over the 16 hours of burn time the bend of the wick has moved 180⁰.  I have an idea on how to better twist the wicks. If I heat the part of wicks that will be in the wax with a heat gun they will twist easily and get stiff again when they cool. The wick holder helps keep them from untwisting when I pour the wax. My other Idea is to drop down a size in the zincs and zig zag the wick a bit.