What happened to the melt pool?

[Cait]

First, I want to apologize in advance if someone has posted a similiar topic before. I just came across this forum and have been overwhelmed with so much new information (that's a good thing, though) that I might have missed something.

I am really used to making my candles in tins/jelly jars. However, I am testing a new jar and I found that on the 3rd burn, I couldn't achieve a FMP like I did on the 2nd burn. Is this normal? Here are some details on my tests:

Wax: GB 464

Wicks tried: ECO 14 and ECO 16 (yes, I do have to try different wicks but am waiting for another shipment of samples to come in).

FO and Amount: Pumpkin Souffle (CS) - 3%-6%

Jar: 12 oz Square, 3.5 diam. - 10 oz of wax used

First Candle Test

Pumpkin Souffle, 3% FO, ECO 14 wick

1st Burn: after 3.5 hours, FMP not achieved, hang up in corners, HT okay - not great, some mushrooming

2nd Burn: after 3.5 hours, FMP achieved, no hang up, HT still okay, some mushrooming

3rd Burn: after 3.5 hours, same as 1st burn but alot of hang up in corners

4th Burn: after 3.5 hours, same as 1st burn

Second Candle Test:

Everything was the same except I tried 6% FO and it helped with HT.

I stopped test burning for now until I could figure out the whole MP thing.

I tried using the ECO 16 wick using both 3% and 6% FO and I had a FMP within 45 minutes, alot of soot, major mushrooming and flame was really high everytime. Needless to say, I am uncomfortable using that wick.

So, aside from all those tests I have done so far, is there a reason why I would stop achieving a full MP after the 2nd burn? I have never experienced this with my other containers, so I'm thinking this jar is just a real bugger to wick? Please feel free to tell me if I am doing something wrong or if there is anything else I need to look out for in general. Thanks!

Edited August 22, 2009 by Cait

[topofmurrayhill]

Square containers can be buggers, especially as a lot of them have thick glass that's hard to melt the wax down from. At this diameter, my instinct would be to stay away from this container with soy wax.

On the other hand, it doesn't sound like you're doing too badly at all. Why not just burn it down and see how it ends up? Nothing says you have to get a full melt pool on every burn. If you don't have a big flickering flame, the candle smells good, and the wax is used up by the end, it could be a perfectly good design for an attractive container.

As far as the hot throw is concerned, use the amount that works. With a lot of FOs I think 6% is the minimum for soy wax.

[chuck_35550]

I feel like my candles are much safer if they don't obtain a full melt pool right off the bat. As long as you have a pool of wax that is accomplishing the job and your container is staying warm and not red hot; then you have nothing to worry about the safety of your product. The candle should catch up about half way down and hopefully won't over heat by the end of the burn. I notice that Walmart candles appear to have a core that looks like a pillar with an overpour. It certainly burns that way too. Those guys use very heavy glass to insulate heat and the wax system burns slowly and safely.

[Stella1952]

Is that 3.5" from side to side or corner to corner? How tall is the container? Photos would be helpful...

I recommend CDN wicks and would start with an 18 (but have a 20 ready, just in case). As Top pointed out, that shape jar is tough to get a perfect burn into the corners because melt pools are round, not square! The square ones I have made do mostly catch up by the end of the jar, but a little residue in the corners is NOT a bad thing nor is it unusual. On smaller square containers, I totally ignore FMP on the 1st & 2nd burns. On large diameter square candles, I even ignore it on the 3rd & 4th burn. I have found that very often, once the candle burns down into the container, it seems to stay the same for a while, but then I notice the corners slimming down - kinda like watching someone lose weight! As the container starts heating up, the hangup begins to melt.

Personally, I think you should continue your testing to see what happens during the last half of the candle. HTH

[Circle]

As long as your wick doesnt drown and your wax is used up towards the end, that is good. I think a full melt pool on first and second burn can be a bad thing later on when the glass becomes too hot

[Cait]

Thanks for the replies and any advice! I finished burning the candle with the ECO 14 wick and it burned nicely the rest of the way. Even if there was hang up, it all melted on following burns. I still want to test different wicks to see how they perform in this jar.

[Stella1952]

Even if there was hang up, it all melted on following burns.

This is typical. Now you understand why we encourage folks to burn the candle all the way to the bitter end before they decide a wick just ain't gettin' it.

[Cait]

This is typical. Now you understand why we encourage folks to burn the candle all the way to the bitter end before they decide a wick just ain't gettin' it.

Yeah. I think I jumped to conclusions out of frustration, assuming that this jar was going to be a complete hassle to wick before I gave it a chance. :embarasse

[Stella1952]

It's very difficult to be patient - easy to say but hard to do!