When I started writing the pages of this site, more than twenty years ago, Candle Gel was a relatively new invention and was then rapidly growing in popularity. It was considered a true revolution in the world of candlemaking and many started to shun paraffin wax to concentrate on Candle Gel entirely. Today, the interest in Candle Gel seems to have died off, and you won't hear me complain about it...
A personal note before we move on: I don't hide the fact that I never liked Gel candles. Don't like the candles themselves, nor the process of making them. For the sake of this website and out of curiosity, I've experimented with it, created and documented a few Gel candle projects but I never got hooked on it, even though I must admit my Kriek Bellevue candle still makes me smile when I see it.
But that's just my opinion and a matter of taste and it's perfectly okay for you to disagree with me. This does not mean I won't talk about Candle Gel, its properties and specifics or its usage in candlemaking. Just don't expect dozens of Gel-based projects from me!
Candle Gel is actually paraffin (mineral) oil gelified using a specific polymer (from the Vybar family). What made the success of Candle Gel is its translucency and the fact it burns much slower than paraffin-based solid waxes.
It is Penreco (http://www.penreco.com), an American company active in the world of chemistry and bought by Calumet in 2007, that developed and still holds the patent on this polymer, the formulation of which is, of course, a well kept trade secret.
All the information that follows about Candle Gel characteristics apply to Candle Gel produced and distributed by Penreco under the name VersaGel™C.
You may find other brands of Candle Gel on the market whose characteristics can be fundamentally different. If you're planning on using another brand than Penreco, I strongly advise you to contact the manufacturer and inquire about important data like temperature of use, flash point, scent retention,...
In every article on this site, when I talk about candle gel, I will always mean Penreco VersaGel™C
Penreco markets its Candle Gel under the brand name VersaGel™C. VersaGel is available in three versions, called Grades:
As the description suggests, the main difference between the three grades is the percentage of polymer added to the mineral oil, resulting in a Gel more or less viscous (the higher the polymer percentage, the more "solid" the Gel will be).
Each grade has its own advantages and disadvantages, so choose wisely according to the type of Gel candle you're making.
If you're planning on making a Gel candle that's unscented or lightly scented (0 to 4% fragrance), Versagel CLP (Low Polymer) will do the trick perfectly. For a candle that will hold more fragrance (3 to 6%), use the CMP grade (Medium Polymer).
And if you want to "suspend" decorations in the Gel (non flammable decorations, obviously, stay tuned for the section about Candle Gel and safety further down this page), you will want to used Versagel CHP (High Polymer), the thickest of all three. Although it is not recommended to do so, it is technically possible to create a freestanding Gel candle with the CHP grade. That's not an option with CLP or CMP.
Be aware that the higher the grade (and the lower the pouring temperature), the more likely the formation of air bubbles in the Gel will be. It has been said that air bubbles are one of Candle Gel's most desirable characteristics and a big part of what makes it popular. If it is possible to limit the amount of air bubbles, know that it's not possible to avoid them completely.
The CHP grade, with the highest density of all three, re-gelifies more quickly than the others once poured, giving air bubbles less time to reach the surface and disappear. Remember this characteristic if you're planning to work with Versagel CHP.
Even though Candle Gel is made of 95% paraffin (mineral) oil, the differences with paraffin wax are important.
Candle Gel is viscous, jelly-like and has the tremendous advantage of being translucent. The latter makes it possible to create candles that feature intricate little sceneries.
Candle Gel does not melt as fast or easily as paraffin wax does. This is probably the only case where you shouldn't use the double boiler method, as it would take forever to achieve liquid form. Instead, use a saucepan (that will from that point be dedicated to your candlemaking activities) placed directly on a heat source.
Candle Gel not being a real "solid", we cannot talk about an actual melting point, like we do with paraffin wax. The more you heat up Candle Gel, the more viscous it becomes. When its temperature reaches somewhere between 180°F and 220°F, it is then fluid enough to be poured in a container.
Candle Gel, when burned in the context of a candle, generates more heat than a similar sized paraffin wax candle. The temperature of the melt pool can reach up to 281°F. In comparison, the melt pool of a paraffin wax candle generally does not exceed 180°F. This means that you have to be very cautious when you select the glass container to use. You should use exclusively glass containers with thick walls that explicitly mention they are heat resistant.
Just like regular paraffin wax, Candle Gel has a flash point of about 392°F.
The complicated answer to this simple question can be found in the article Fragrance Oils and Candle Gel.
One of the most important aspects of safety when working with Candle Gel is the addition of fragrance oils. This topic deserves a full article, so please read Fragrance Oils and Candle Gel for more information.
As I mentioned earlier, one of the main selling points of Candle Gel is the possibility to create little sceneries by placing small decorative items in the candle.
As a candlemaker, you have to be very cautious and aware of the risks when choosing the items used as decorations. Never use anything that is potentially flammable, like dry or artificial flowers, items made of plastic, fabric, spices or cereals...
On the other hand, let your imagination run wild with glass figurines, (non-porous) stones, shells, ceramic items or even items molded in paraffin wax (fruit-shaped wax castings are very popular. If you make them yourself, use the highest melting point paraffin wax you can find).
Whenever possible, use the double container technique, as shown on the image below. The wick is placed in an inner glass container whose size it matches, and any decoration is placed between the inner and outer container. Both containers are filled with Candle Gel, or only the inner one is, depending on the fit of both containers.
The topic of wicks to be used with Candle Gel is so vast it will be discussed in a separate article, but it's worth mentioning already that you will need to use another type of wick sustainers than you would with paraffin wax container candles. The neck of the sustainers used in Candle Gel must be longer, about half an inch long. This is necessary to make sure the flame cannot reach the bottom of the candle where the little quantity of Gel left combined with the high temperature of the melt pool could cause the whole thing to catch fire.
An alternative to long neck sustainers is to pinch a small metallic tube around the last half inch of the wick; this should cause the wick to go out when it reaches that level. You will get the same result by threading two or three glass beads (glass only) onto the wick.
My role here is to make you aware of any potential danger inherent to the use of any type of candle, but specially Gel candles (often seen as harmless novelties), so that you have all the information you need to hopefully avoid these dangers. Your role as a candlemaker is paramount too as far as sharing safe usage information goes, whether you're gifting your candles to your grandmother or selling them to actual customers.
Draw their attention to the fact that a candle, whether it is made of Candle Gel or paraffin wax, should not be allowed to burn for more than three hours in a row and that a candle is like a baby: you never leave it unattended.