Almost blew up the lab

[soy327]

Eistein is a beautiful girl. So glad to meet her.

[Stella1952]

Even my stirring spoon was still stuck in there

GOTTA LOVE the spoon stuck in the mess!! :laugh2:

Einstein looks like a triplet to my twins, Gem and Ni.

you'll notice regular canning jars are NOT flat on the bottoms

...which is why they usually pop at the thicker, outer bottom edges. The thicker glass doesn't expand and contract at the same rate as the thinner sides and middle bottom. When that area experiences thermal stress, it cracks. They are designed that way because it's safer for the bottom edge to crack horizontally than for the side to shatter to relieve the stress built up in the glass. The other reason it's thicker in that area is because that's where the glass gets bonked most often when handling.

When one hears that distinctive "pop," remove the pan from the heat immediately and allow the water to cool before *carefully* removing the glass. Continuing to heat, adding cooler water, or removing the hot glass, (exposing it to cooler air) will cause the fracture to "run," allowing the whole dang bottom to separate and fall out as neatly as if one used a bottle cutter on it.

[cedar_lea]

You guys are able to remelt wax in the oven? Or do you mean just loosen it a little?

I had a couple candles accidently cool at an angle and decided to see if I could remelt them in the oven to straiten them. It worked, but my wax scalded or carmalised or something because they turned from green to brown.

[EricofAZ]

Stella,

Einstein concurs. The photo shows a very crisp line where the fracture ran around the bottom. There is a thin area in that location so it appears the container is designed to pop in that location.

That brings up a question. Would we be better off with containers like this or containers that simply cracked on the sides. Seems to me that a container designed to pop at the bottom is also designed to unload ALL of the hot wax within and I'm not so sure I like that idea.

Bottom is concave with a raised bump line around the contact area with the surface it is sitting on, like the mason jars.

[Stella1952]

One thing you never want glass to do is break in the middle because it will most likely shatter into wicked shards, which would cut Einstein's toesies. If it's gonna pop from thermal stress, best it should do exactly what yours did. The crack generally is small and doesn't leak much UNLESS it continues to run and separate... which is why you should never forget or ignore that *pop* sound!

Canning type glassware is one of the safest types of glass that one can use for candles. Pyrex (borosilicate glass) is way too expensive! Other types of glassware are not formulated to take the thermal stress of candles. Only glass that meets (or exceeds) the ASTM standard for candle glassware is suitable. The most common and inexpensive is canning glassware.

Candles usually are not liquid until the bitter end when they should be extinguished for safety's sake, so there's little chance of them dumping their contents if the bottom cracks.

You guys are able to remelt wax in the oven? Or do you mean just loosen it a little?

I had a couple candles accidently cool at an angle and decided to see if I could remelt them in the oven to straiten them. It worked, but my wax scalded or carmalised or something because they turned from green to brown.

What kind of wax? What temperature? What dye & what FO?

Just guessing, I'd say the oven temp my have been too high and/or ya left the candle in there too long. If you saw something "caramelized" looking, it may have been some impurity in the wax. I have seen stuff like that when remelting old wax out of spent containers and assumed it was debris, dead dust bunnies, etc. Can't say I've ever seen it in new wax, though...

When I say "oven," BTW, I am talking about a real oven, not a toaster oven or a convection oven or a portable roaster/oven (just in case that wasn't clear...). Be sure that the broiler in your oven does not come on when preheating... if it does, move the rack down, or wait to put the pan of candles in until it goes off. Put the candle on a cookie rack set inside a deep sided oven pan of some kind just in case something BAD happens... If you use the "disposable" aluminum baking pans, be careful when moving them 'cause they flex when full of heavy glassware.

When I remelt (yes, completely remelt, as in liquify) containers in the oven, I set the temp to no more than 180°F (if soy wax) or 200° (if palm wax). This is usually the "warm" setting on many ovens. Use an oven thermometer to be sure you don't get the oven too hot. I have salvaged many container and pillar candles which had messed up tops, frosting, crooked wicks or lack of crystallization by remelting and allowing them to cool in the oven.

I always use the oven to melt out the remaining wax in my containers so I can reuse them for testing and my own enjoyment. First I cut all the wax out that I can with a sharp knife and throw it in a used wax bucket (or save it to strain and reuse in a layered candle or votive), then I put the waxy glassware in the oven and heat it until all the wax is melted. Then I wipe out the containers with paper towels (have also used newspapers), pop off the wicktabs and put the glassware in HOT water (Dawn dishwashing detergent or Parson's Sudsy Ammonia) to wash, rinse in HOT water & air dry upside down in the dishwasher. HTH

[cedar_lea]

It was glass glow & I was reheating candles that were poured the day before. I think I uped it to 195 because I wanted to make sure I kept the crystals. The FO is my blend of about 5 different SOS scents & it totally kept it's scent throw. The dye was peaks hunter green liquid & I was a little heavy with it. I hadn't had a problem with the lowest oven temp so I'd figured it was just an issue with the heat. It's possible it could have been from the oven needing cleaned or something. It was strange because it was like the only thing affected was the color was browner. It also could have been from spilled wax on the baking sheet burning off. I don't believe I'd cleaned it before I noticed the candles were crooked.