C-3 Issues

[smellylittlemonkeys]

I have not posted in awhile as I have been REALLY busy with school but I have started trying to pour again. I am having issues with C-3 and sinkholes as well as the circular crack. I was wondering if anyone had any tips or suggestions for me to try.

Like I said I am using C-3 in 8oz Mason Jars. I am adding UV and USA, heating to 185 and pouring at 165 with liquid dye and 1oz pp FO. I warmed the jars with a heat gun, filled to the neck, set on a wire rack on top of the stove and poured and then covered with a styrofoam cooler. The cooler did not go all the way down to the stove, it sort of sat on top of the wire rack. By the way, they are wickless. Room temp was 72F. Should the cooler go all the way to the stove? Should I fill just below the neck?

It looked as if they were cooling from the bottom, I could look up under the cooler to the bottom of the rack. I got the circular crack, which I think I've read that could be rubbed out, but I also got a sinkhole. I would like to figure out how to avoid the sinkholes but if I get them what is the best way to fix it? I tried zapping them with the heat gun but then I would get air bubbles (I poked holes with a skewer).

[Stella1952]

Sounds like the candles are cooling too quickly. Be sure they are sitting on an insulated surface or wire rack (countertops, etc. get pretty cold in the winter!) and that the box or cooler you place over them goes all the way to the countertop. You can also cool in the oven preheated to 170°-180° then turned off when the candles go in.

As far as the height to fill them - that's pretty subjective, but I would fill them to the shoulder and leave some headroom.

You can either second pour sinkholes or heatgun to fill the depression; however, best defense is no be there, so try to let the candles cool more slowly and evenly to eliminate the depression.

I do have a question... you are making wickless candles in regular 8 oz. mason glass jars, correct? Are these to be heated from above (indirect heat) or below (direct heat)? The reason that I am asking is that I would worry about the safety of a wickless candle of that size/shape heated from underneath... If heated from below in a cold room, the candle could build pressure underneath the unmelted wax and cause the container to crack or the wax to spew suddenly... The shape of the container you are using (taller than wide) would exacerbate this problem whereas an 8 ox. widemouth container would be slightly less likely to do a volcanic spewathon because of its squatter shape...

Unless heated from above, I tend to shy away from glassware for wickless candles and use tins instead. Some folks believe heat tempered canning glass is safe enough for this kind of function, but it was not designed to be used in this manner (direct heat). I have had many canning jars unexpectedly "pop" in a waterbath while sitting on a rack (no direct heat contact) so I personally would worry about the safety issue... Just a thought...