Question about FMP

[pixie]

I have read that you are supposed to aim for a melt pool of one inch every hour. So for example, a container that is 3 inches across would take 3 hours to reach a FMP.

Does this generally change as the candle burns down? For instance, if I have a candle that is 2/3 of the way already gone, should I still aim for a FMP of one inch an hour or does it speed up because of heat building up in the 2/3 empty jar?

[Pristina]

Even though it's not supposed to be done (hehe) I have burned my candles all night long before because I know that there are some power burners out there, soooo I burn them for long periods to test for proper quality.

My melt pools will reach a 1/2" tops and stay at a 1/2" for hours and hours.

If my melt pool get's bigger than a 1/2", I wick down.

The jars I use are wider at the top so when they are first burned, they don't melt all the way across. There's a little hang up but nothing like some of the big gaping holes i see in leading brand candles....lol The hang up, catches up and the melt pool stays where it is supposed to.

Usually, at the beginning, I'll have 1/4" melt pool and once the candle burns furthur it will reach 1/2"

HTH

[EricofAZ]

I think the numbers are confusing. One inch in diameter per hour maybe, but as for depth once the pool reaches the container wall, I shoot for 1/4 inch depth only. That's enough to clean the sides.

And I agree, it is good to find a place to test burn for long periods because someone is going to do it by mistake.

I try to wick so that once a FMP is reached, the depth remains the same over time and hope that the candle does reach FMP well before the 4 hour mark.

To me, a great candle reaches FMP in about two hours and holds at 1/4 inch depth and wall to wall diameter for the life of the candle.

[Stella1952]

What wax are you using, Pixie?

Different waxes have different properties. Melt pool depth is not the same for all waxes nor do all waxes achieve FMP in the same amount of time.

To me, a great candle reaches FMP in about two hours and holds at 1/4 inch depth and wall to wall diameter for the life of the candle.

That would be absurd for a 3" soy candle or a 4" palm wax candle!

Yes, the heat WILL build up further down in the container. You should still test for the same period of time (1 hour per inch of diameter) to insure that the container does not become too hot, etc. The testing of the last half of a container is critical. One should "dial in" the wicking BEFORE attempting to powerburn. Taking shortcuts can result in skewed testing results which can mislead one into thinking their products are performing better than they really are. HTH

Edited October 12, 2010 by Stella1952

[Gucci]

I also totally agree on the powerburn test. Even on my pillars I'll start one in the morning and watch it alllll day to see what it will do.

But yeah, on my containers I prefer to have a meltpool that goes all the way across within a few hours and about 1/4+ deep depending on the container (8oz jelly jar seems to run a wee bit deeper than 1/4 than a wider jar but not much with my wick of choice) If after a 5 hour burn my pool is too deep than I wick down. HTH

[Candybee]

Stella's right. Each wax has its own type of melt pool and that may also vary depending on how far along down the jar it has burned.

Getting a full melt pool may not be exactly what you are looking for in some wax and jar combos. I find parrafin tends to burn down with the sides catching up while soy tends to develop a wider melt pool. Then GG palm tends to burrow into the candle leaving a roof and sides that later catch up as the candle reaches farther down into the jar.

The other point Stella makes about wicking for the bottom of the jar is also important. You want to test the whole candle and burn down to the bottom as the top and bottom may burn very differently.

Also, some wicks may get you a nice wide melt pool but a too hot to the touch jar. So for example you may have to wick down or find a cooler burning wick for some wax and jar combos.

[pixie]

For this candle, I am using C-3 btw. In the picture below you can see both candles. Number one does not hit a fmp until the three hour mark and has a mp of a little more than 1/4inch. Number two on the other hand reaches a fmp at the end of the first hour with a mp of half a inch. Im thinking of wicking up number one and wicking down number two. Does that sound right? Also, when you say ..the jar shouldnt be "too hot"...well how hot is too hot? At the end of a three hour burn, I could pick both these candles up and move them if I had to but I dont think I could just stand there holding them for 20 min or anything like that. They are both HOT but I could touch them if I needed to.

[coconut]

Too hot, my rule of thumb is that I can pick up the jar where the flame is burning, and carry it across the room and set it back down. Not recommended, of course, but if someone was to do that I don't want them to drop the jar because it is too hot.

[Stella1952]

Those containers are only half-full. This is a short cut that some people take because they don't think t makes any difference. I disagree. Start from the TOP and burn all the way down at 1 hour/inch of inside diameter. It can make a BIG difference!

Once you get the wicking dialed in, then powerburn that baby to see if it gets too hot at the end of the jar.

Do my eyes deceive me, or is the top of that C3 candle really frosted/cauliflowered? What's the white stuff in there?

Too hot, my rule of thumb is that I can pick up the jar where the flame is burning, and carry it across the room and set it back down. Not recommended, of course, but if someone was to do that I don't want them to drop the jar because it is too hot.

I totally agree. When I test candles, I may do lots of stuff that the warning label and common sense tell one NOT to do, but I want to be sure because so many customers ignore instructions.

Edited October 14, 2010 by Stella1952