I found this on FB, wet spots are trapped air?

[ChandlerWicks]

Wet spots are simply air that was trapped in your wax once the candle was poured. Over time the air will escape from the wax (much like fragrance will do if you add to much) and will appear as a spot that looks wet on the side of the jars.

How to prevent them. Like frosting, this is not going to be something you will tot...

ally be able to eliminate. If you look most candles (even Yankee and other larger producers) you will notice most of their candles have this as well. Once again, you are going to be your own worst critic. To help prevent them is simple, you want to limit the amount of air that is put into the wax. This is done by two way. First, when you add your fragrance and dye make sure that you stir slowly and avoid splashing or anything to can add air to the wax. Second, pour slowly and try to minimize slash. Think of it as trying to pour a Coke without having it fizz. The slower and more gently you pour the less fizz you get. Thus is the same with the wax. Other things that can help is letting your wax sit for a few minutes after stirring in your dye and fragrance, limiting airflow in the room (fans and air units), and even heating your jars can help some to limit this.

[rjdaines]

I thought wet spots were place where the wax separated from the glass, poor adherence. I don't think it has anything to do with air in the molten wax.

[Judy, USMC]

I've been pouring the same way for over 15 years. I've used soy (CB-135) with no noticable wet spots. I also use paraffin (4786) which is a 2-pour wax; it naturally "shrinks" when it solidifys. With this paraffin if I forget to pre-heat the jars I'll get wet spots. I can pour in a facility that is 75 degrees and have good glass adhesion. But if the store is only 70 degrees wet spots will develope. I can only assume that it is the wax separating from the glass. So I agree with rjdaines.

It's an interesting theory - and sounds plausible - but in my experience (especially with the paraffin) it's not the reason wet spots appear. Yes it is trapped air but I don't believe it's coming from air in the wax; I think it's trapped because the wax surrounding the air is more adherent.

Sounds like something MythBusters should investigate. @ Chandlerwicks - may I ask where that bit of info came from?

Edited September 11, 2012 by Judy, USMC

[ChandlerWicks]

Of course, Aztec on FB.

[rjdaines]

When I fist melt my wax in a Presto Pot I do seem bubbles but never after that. Taking a fresh piece of slab and putting it into a pouring pot "might" give you some residual bubbles but one would have to add FO and whatever and pour really fast. Not realistic. Differential shrinkage is the answer, the wax contracts more than the glass. This is why people put votive candles into the freezer to release them from the glass holder.

[ChandlerWicks]

Thanks for your answers!

[chuck_35550]

Hot wax shrinks as it cools. Most blends are formulated to shrink less (single pour wax) and maintain adherance to the jar wall. Slow cooling is one way to avoid wet spots but some wax formulations don't require anything (6006) and can cool on the open counter. Some fos are heavy on vanilla, cinnamon or other ingredients that effect the adherance and result in pulled away areas that look like wet spots. Changes in temps, humidity and other variables will eventually interefere with adhearance over time but I have some really old candles that have never developed wet spots. Containers are the last item to consider as square jars are difficult for wax to make a full bond with the wall or jars with hour glass shapes can be difficult. I think most of us embrace the wet spots because most customers never even notice wet spots (they only care if it smells good all over the house and part of the neighborhood). HTH

Steve