I just started using "CandleFlex" molds. After I've poured the wax and it's set up a bit, a thing like a sinkhole forms in the middle of the candle. I've tried pouring the wax very slowly, in small amounts at a time, and tapping the mold to release any air pockets, but it still happens, or sometimes the center just sinks down and makes the bottom of the candle concave. What am I doing wrong to cause this?
Which mold are you using? What temperature are you pouring the wax? Sometimes it has to do with how quickly the mold is cooling.
Some molds require you to poke holes (open up the little sink holes) and re-pour. When you re-pour, make sure your wax is pretty hot (I heat to over 170) and then fill in the holes and top-off the mold. This should create a seamless bond between the two different layers. Keep playing around. Each mold is slightly different and requires a slightly different technique, but once you have it down it goes pretty quick.
What type of candles (size/shape)are you pouring and what type of wicking. Why is the concave bottom a problem?
All candles will have this problem as the wax contracts when it cools down. If the bottom cools down fast because of the ambient temperature such as in an airconditioned room or when pouring candles in the winter time in an unheated room, the problem will show up on the side of the candles by becoming concave.
This concave distortion is more pronounced with rubber molds and long slender candles.
In order to circumvent this problem of the bottom sinking in and minimizing the problem of a concave side, I use an infrared heatlamp to keep the bottom liquid while the rest of the candle solidifies. For this I use an infrared lamp with grip and reflector. These lamps can be purchased at farm stores as these lamps are also used for raising chickens and pigs. Buy a 125 watt or a 250 watt bulb. Mount this light about one foot above the bottom of the candle, or if you are doing several candles you can hold the the lamp fixture in your hand and go from one candle to the others. Even if the bottom starts to set up you can go back and liquify the bottom again as the inside of the candle is still liquid. The result of this is that the bottom will remain level and does not need any further adding of wax, the candle will be about 1/8 shorter but so what. Most of the time the candle does not require any futher finishing.
Also Home Depot and Lowe's sell these lamp fixtures but make sure that the lampholder is porcelain as black lampholders are rated only for 60 watts, some have a switch in the holder, and the holders will burn up in due time as these are rated only for 60 watts.
The type of mold and/or wick have no bearing on the problem of the bottoms sinking in.
Also it is important that you pour the candle with one pour otherwise rings will form where you have stopped and a new pour has started.
Other uses for this infrared lamp are the following:
1) Use it to help melt your raw wax. Put the lamp about one foot above the wax pot and it will greatly speed up the melting process.
2) Once the wax in the pot is at temperature I will use the heatlamp in cleaning this liquid wax.
I use a double pot food warmer, each pot can hold 8 quarts. I put a colander or sieve over the empty pot and put some Bounty kitchen paper in the colander. I then pour the wax from the other pot into this colander and keep the heat lamp above the pot with the colander. Now it does not matter how cold it is in the room, the wax in this "filter" will not solidify and all the wax goes through very quickly.
3) When the ambient temperature is low such as in an airconditioned room, the top of the wax in the pot you will be working from will start to solidify although the temperature of the wax in the pot is at the right temperature. By keeping the heat lamp over the pot you are working from, this process reverses and you do not have to keep the wax too hot in order to keep the top of the wax at a desirable temperature.
4) As stated above, the pouring of a candles should be done in a continuous process. For larger candles, you can pour directly from the 8 quart pots. For smaller candles I recommend you use a pitcher and fill it with liquid wax. Again this wax will solidify quickly on the walls of the pitcher. In oder to keep this pitcher with its liquid wax content at the right temperature I put it on the colander with the heat lamp above it.
5) Real dirty wax can be melted in the colander with one or two layers of bounty paper and the heatlamp as the heat source.
6) Raw cappings wax and good wax retrieved from walls can also be metled using the heat lamp. I use a stainless steel honey filter sold by the Walter T. Kelley Co. This filter measures 6 inch round and 17 inches long, It has three legs and can be set on top of the 8 quart pot or and other device. I extended the legs so that the bottom of the filter sits above the container. Put a filter bag in this pot and fill it with cappings or chunks of honey. Put the heat lamp about one foot away on the side of this filter and it will do its work. First the honey will melt and drip into the container. Then the wax will melt and you will be surprised how clean this wax is. No overheating takes place because as soon as the honey or wax become liquid it wil go down in the container. Carelul examing of the residue in the filter will reveal that this is a dark substance formed by pollen and propolis.
It is important to realize that bees wax cells are made with raw bees wax and is mixed with propolis when the wax cells are build. Therefore in bees wax there is always propolis present. A carefull observation will reveal that with very gradual heating of the wax, the propolis will sink to the bottom of the pot. I do not use the last two inches without first putting it through the filter again. One can filter it many times and you will notice that a sediment will still form in the bottom of the pot. However you will never see the type of sediment that forms when melting raw wax in water. This sediment hangs under the block of wax and isusually removed by scraping the bottom of the wax cake. This sediment consits of mostly pollen.
A good support for the heat lamp is a tripod as used for a camera.
>The type of mold and/or wick have no bearing on the problem of the bottoms sinking in.<
Wicks I agree with, but the type and size of mold has a huge bearing on how quickly the wax cools which in turns affects cracking, sinking, holes developing, etc.. A cheepo Pourette plastic mold for example acts very differently than a comparably sized polyurethane mold.
>Also it is important that you pour the candle with one pour otherwise rings will form where you have stopped and a new pour has started.<
Generally speaking this is true, but there are many candles that require re-pouring techniques. Votives produced in metal molds for example require a re-pour. The timing and wax temp. are critical so that the rings don't form.
Of course molds have everthing to do with the problem due to the thickness and the way the candles cool in different molds. As to wick, Years ago when we 1st. started making candles we used zinc core wicking. Wax would seep through the wick where it passed through the mold, I assume because the wick slid on the core pulling it through the mold. Although I never associated it with anything other than annoyance it could cause a candle to concave on the bottom since the area at the top of the candle (botom of the flex mold) would harden last allowing the center wax content to recede. We use all braided wicks now and have no problems. All the light and camera tripod stuff sounds like alot of un-necessary work. I've found the less stuff around when pouring candles the less accidents, drops and spills. I like to keep things simple. I took an EAS Course years ago and the instructor suggested filtering through old T-shirts. Works great. He used an old deep fry with a thermostatic control for maintaing wax for pours and it worked perfectly. You can find them at the thrift stores for next to nothing. We've used paper towels but they will tear in handling which is a hassle. We pour several hundred candles a year this way and do just fine.
One other item I would mention is to make sure to never, ever leave wax while it is heating (especially if it is done in the house)for any reason for any period even to answer the phone or the door. Many honey houses and homes have burned processing wax. Even in a double boiler it's easy to get distracted once your away and for it to boil dry, over heat and ignite. Wax does not need an open flame to ignight. If you ever see a container of wax ignite it's like gasoline, water spreads it as opposed to extinquishing it and it burns very fast, large and hot. A fire extinguisher is a good candle making tool to have on hand, just in case.
I reccommend the use of a stem thermometer monitoring wax temps, it will keep your pours consistent and the wax below the flash point.
Most of all have a good time and enjoy your wonderful candles!
[size="1"][ December 08, 2005, 11:27 AM: Message edited by: Joel ][/size]
I consider "CandleFlex" molds to be of the highest quality. Well worth the money and they produce a very high end product. I have found none to compare.
The cooler the wax, the less sink you will have after the candle has fully set. I recommend between 165 and 168 degrees F.
If you pour the wax too hot, it will stick to the mold to some degree and it will feel as if you are ripping the two apart when removing the candle. A good temperature will not leave a poor finish and will not stick to the mold.
I often top off my candles afterwards. Sometimes a sink hole is unavoidable. Topping can be visible, but it is where no one will see it anyway. I finish the bottoms of my candles so they sit well. I want the end user to feel as if they have the best.