The Compete Guide to Creating Bubbleless Gel Candles with the BBB2 Vacuum Bubble Buster Deb Puerini Gel Candles by Deb E. Providence, RI Steve Hansen the Bell Jar Amherst, NH
The Genesis of the name BBB (Boyle's Bubble Buster) Boyle's Bubble Buster is our nickname for the Gel Candle Debubbler. It is named in honor of Robert Boyle (1627-1691). Boyle was a chemist and a natural philosopher. He was noted for his pioneering experiments on the properties of gases and his views of matter. His work led to the modern theory of chemical elements. While at Oxford Boyle collaborated with Robert Hooke in constructing an air pump with which he conducted the experiments leading to his publication (1662) of the relationship, now known as Boyle's law, that at constant temperature the volume of a gas is inversely proportional to its pressure. The complete story of the origins of the BBB can be found in the article Bubbles and Gel Candles which can be found on the Web at http://www.belljar.net/034gel.pdf. Later on in this instruction manual you will also find information on the theory behind the BBB. Page 1
A Note on Safety Working with vacuum can be dangerous. Please read this entire manual before attempting to use the BBB. If you have any questions, please do not hesitate to contact either of the authors before proceeding. Your vacuum chamber is designed to work safely under full vacuum as long as it is undamaged. Check it frequently for deep scratches or chips. A damaged chamber should not be used. Any vacuum device will implode if it fails. To protect yourself it is best to wear safety glasses whenever the unit is operating. Keep as much of your body covered as possible. Melted gel is hot. Use suitable insulated mitts when handling hot gel. Never leave the apparatus under vacuum for extended periods or when unattended. Whenever the pump is turned off, immediately vent the chamber to atmospheric pressure (0 on the gauge). The pump's exhaust will emit a fine mist of oil vapor. Your work area should be well ventilated. For normal use just placing a cloth rag over the pump s exhaust will collect virtually all of this vapor. Don't put any living critters in the debubbling chamber. Also don't put in any water, solvents or toxic materials. Some materials will react violently when placed under vacuum Page 2
Getting Started with your BBB Vacuum Debubbler Congratulations on your purchase of the original BBB which has been developed specifically for maximum elimination of bubbles in gel candles. Nothing works as well and as dependably. Vacuum debubbling is a standard technique in industry for eliminating bubbles in plastic moldings and potted assemblies where the presence of bubbles could cause anything from performance problems to catastrophic failure. The wide use of vacuum debubbling is a testimony to the efficiency of this method. While other techniques can work under some circumstances, only the application of vacuum technique can assure consistent success and productivity The team of Deb Puerini and Steve Hansen have developed a simple to use system, the BBB, that will make the production of beautiful, clear gel candles an easy and relatively straightforward task with immediate results and no guesswork. Unpacking When you receive the BBB you will find two major items: the vacuum pump & manifold and the plastic debubbling chamber. Other parts with the kit include: Vacuum pump fluid (oil) with Material Safety Data Sheet (MSDS) Pyrex glass beaker Operating manual for the pump These instructions Carefully unpack the items and place them on a table where you can become familiar with the bits and pieces before actually assembling and operating the system. What's All that Stuff on the Vacuum Pump? The vacuum pump is a precision machined device that is capable of achieving very low pressures. It's properly called a two-stage oil-sealed rotary vane vacuum pump. In brief this means that the pumping mechanism has two parts (stages) arranged in series with everything immersed in oil. The oil serves as both a lubricant and as a sealing agent for the sliding vanes. The oil must be clean (change it regularly) and of sufficient quantity to do its job. Too little oil and the pump will not work properly and will, in fact, seize up. Dirty or contaminated oil will result in a poor vacuum and corrosion of the pump parts. Set the pump on a table and read the following to get familiar with the various parts of the vacuum pump. Page 3
The rear portion of the pump is the motor (see Figure 1 below). At the very back end are the 3-prong power cord and on/off switch. You will probably have to use an extension cord. Make sure that your cord is grounded (3 prong). Do not use a 2 prong ungrounded cord. Figure 1 - Rear of vacuum pump showing power cord and on/off switch. The business part of the pump is at the other end (see Figures 2A and 2B). At the very end on the pump housing (bell) is a clear window (sight glass) which is used to check the oil level. Just above and behind that on the top of the bell is the vent. This is where the pumped air gets expelled from the pump into the air. The vent is also where you add oil to the pump. There is a fitting (either a brass hose connector or vented cap) in this vent opening. Remove the fitting or cap to add or drain the oil but put the fitting or cap when the pump is actually being used. Under no circumstances should this vent port be plugged as damage to the pump will result. At the rear of the bell is a little screw plug called the gas ballast. This is normally used when pumping very moisture laden air but we will not use it in the BBB application. Check to be sure that it's tight (fully screwed in) and leave it there. If you are curious about when the ballast is used and how to use it, check the pump manual. Vent Vent Sight Glass Gas Ballast Figure 2A, 2B - Business end of vacuum pump. Page 4
The part that you will work with mostly is the brass manifold assembly that is connected to the inlet of the pump (see Figure 3). This manifold is for the most part made of brass plumbing fittings, all screwed together and sealed with a vacuum-compatible adhesive sealant. (Do not attempt to take any of these pieces apart as you will break the adhesive seals and you will no longer get a good enough vacuum for efficient debubbling.) Pressure Control/ Relief Valve Figure 3 - Manifold Assembly Gauge Inlet Hose Connector (Behind) The three parts of the manifold that you will be interested in are the inlet hose connector fitting, the pressure control/vacuum relief valve, and the vacuum gauge. The inlet hose connector attaches to a short length of 3/8 inside diameter clear plastic tubing which is supplied already attached. Take care when using the pump that excessive amounts of dust or dirt are not drawn into the pump as these will cause the pump to wear or seize. The pressure control/vacuum relief valve is simply a small plastic or metal cap with a rubber o-ring inside. When the cap is fully tightened and the pump is connected to your debubbling chamber, the pump will produce the best vacuum that it can. By slightly loosening the cap you can regulate the pressure in the chamber anywhere between full vacuum and no vacuum. When you have finished a debubbling operation, you turn off the pump and fully loosen the cap to let air into the chamber. The vacuum gauge is a simple dial-type gauge that gives you a good idea of how good a vacuum is being produced (more on this later). The debubbling chamber (see Figure 4) is a commercial plastic desiccator to which we have added a length of plastic vacuum-compatible hose. Figure 4 - Debubbling Chamber. This consists of a clear plastic top, opaque bottom with o-ring seal and connecting vacuum hose. Note the safety placard. Page 5
Examine the debubbling chamber. You will see that the lower half has a rubber o-ring that is used to seal the two parts together. Be sure that this is kept clean and dust free. Dust, hairs, etc. on the o-ring will cause the seal to leak and will result on a poor vacuum. Now find a good location for your BBB. Everything should be at table height and the platform should be stable. You may want to have a small metal tray under the pump to catch any small dribbles of oil. Once you have situated your BBB connect the loose end of the vacuum tubing that is attached to the debubbling chamber to the barbed inlet fitting on the slightly smaller tube that is attached to the pump's manifold. This should slide on with just a moderate amount of force. It should not be loose. For best results the tubing should have as few bends as possible and definitely no kinks. Avoid any tendency to add more tubing as that will impair the performance of the pump. Figure 5 shows a good installation. Figure 5 - Pump and Chamber Connected. Note that there are two pieces of slightly different diameter hoses that are connected with a plastic adapter. The hose clamp on the chamber's fitting should be tight enough to secure the hose but not so tight as to stress the plastic. Now add oil to the pump. Remove the cap or fitting from the pump's vent and, with a clean and dry funnel, add oil slowly until the oil level is half way up the sight glass. Not much more, not much less. If you add too much simply pick the pump up and invert it to drain a bit of oil. Now replace the vent fitting. Page 6
Science Stuff: How Vacuum is Measured To successfully run the BBB you need not be able to express pressure in Newtons per square meter or to be able to convert millibar units to Pascal. However, you should understand a bit about what the vacuum gauge is telling you. At sea level our atmosphere exerts a pressure of about 14.7 pounds per square inch (psi). Pressure can also be measured in units that are derived from the weather barometer. That 14.7 psi ambient atmospheric pressure will support a column of mercury that is about 30 inches high (inches of mercury or inhg). When you listen to your local weather guy (or guyess) he (or she) may say that the something like "the barometer is 29.30 inches and rising." That doesn't mean that the barometer is levitating but that the reading (which is stated in terms of a barometer's mercury column) is some value and increasing. What that means is that the 30 inhg is just a typical value and can vary by weather conditions or by height above sea level. (Denver is normally about 26 inhg because they are a mile above sea level. A barometer would read zero inhg in space because space is a really good vacuum.) The gauge that is supplied with your BBB reads 0 to 30 inches but you will note that when the BBB is not running the gauge reads 0. As the pressure goes down (more vacuum) the reading increases. This is opposite what barometer readings are just because that's what all the pump manufacturers do. Just keep in mind that normal pressure is zero and full vacuum is 30. And, of course, if you are at a high elevation (Denver, Albuquerque, etc.) full vacuum is going to be something less than 30. Don't worry too much about this as what we'll be doing for the most part is looking at what's happening in the chamber, not what the gauge says. However, the gauge readings will provide important reference points as we'll see later. If you really want to get the lowdown on vacuum measurement units, check out http://www.belljar.net/units.htm. Doing a Trial Run For anyone who has never dealt with vacuum apparatus, it can all seem quite daunting. However, the equipment is fairly simple and easy to use. Before we actually try to use it do debubble gel, let's get familiar with how it works. Make sure you have everything connected, oil to its correct level, nothing in the debubbling chamber and safety glasses on. Place the lid on the lower half of the chamber. Apply a bit of pressure with your hand to make sure that it is closed tightly. With the screw cap of the pressure control/vacuum relief valve partially open, turn on the pump. You will hear a gurgling sound as air bubbles through the pump's oil bath. Page 7
Look at the vacuum gauge. It should be reading some value more than zero indicating that you have a partial vacuum. Once you have a reading of more than about 5 inches you should be able to let go of the chamber's lid. The pressure from the atmosphere will hold the lid on. Start to close the pressure control/vacuum relief valve's cap in tiny increments (turn clockwise). You should see the gauge reading start to increase even more. Try to set the pressure at 20, 25, 28, 29 by varying the tightness of the cap. Close the cap fully and see what the gauge reads. At sea level it should read about 30 but don't worry too much if the reading is a bit different. Let the pump operate for 10 to 20 minutes. You will note that the gurgling sound pretty much disappears (if it doesn't you may have a leak) to be replaced by a sort of clicking sound with maybe some intermittent gurgles. The clicking sound is the pump's exhaust valve and this is normal. Make a note of your final pressure reading. This is called your base pressure and is your reference for a full vacuum. When you are ready to turn the pump off first open the vent screw cap to let some air in and then shut off the pump. Immediately open the vent screw cap fully to bring the gauge reading to zero. It is important to quickly vent the system once you have turned the pump off. If you don't, some of the oil in the pump will get sucked back into your lines and chamber making a real mess. (If this does happen, don't despair. Raise the chamber so that the oil in the tubing can go back into the pump when you turn it on briefly. Then clean any residual oil that may have gotten into the chamber with a solution of water and a mild soap (e.g. Ivory). Dry with a lint free towel and check the level of oil in the pump.) A Nifty Experiment Deb really likes this one and it's a classic vacuum demonstration that shows how the debubbler works. Place a marshmallow (preferably one of the big ones) or a marshmallow Peep (this is really sadistic) into the debubbler chamber. Close it up and apply vacuum as in the above section. Note the size of the marshmallow as the pressure drops. It will get quite large. This is because the marshmallow is composed of thousands of air cells. As the pressure drops (gauge reading goes up), the bubbles expand. The amount that the bubbles expand is directly related to the change in pressure in the vacuum chamber. When the pressure is 29 inches the bubble will expand by a factor of 30. As noted before, this relationship between pressure and volume was discovered by Robert Boyle and is referred to as Boyle's Law. Now turn off the pump and vent the chamber back to atmospheric pressure. The marshmallow will literally collapse because the bubbles, in their expansion, also broke. This is what you will be doing with the gel when you debubble it. Figure 6 on the next page is a picture of a marshmallow Peep that is under vacuum. Page 8
Figure 6 - An Expanded Marshmallow Peep under Vacuum. Poor thing. (Don't try this with your gerbil.) A Debubbling Test with Real Gel Now prepare a small container of melted gel. Don't use too much as we are still trying to get familiar with this whole vacuum thing. Put the container of melted gel in the debubbling chamber and close the lid. Turn on the pump with the vent valve cap partially closed. Quickly start to reduce the pressure (gauge reading goes up) to about 20. Then continue to drop the pressure by gently closing the vent cap in small increments. Go in increments of 1. At some point you will see the bubbles start to get bigger. Then you will see them start to rise more quickly to the surface and then break. As the vacuum gets better and better the bubbling will become more energetic. This is where it is more important to see what's going on rather than watching the gauge's reading. You don't want the action to get too out of control as the gel may actually froth and overflow. No big deal but that's messy and you will have to clean spilt gel out of the chamber. Just imagine what a real candle would like. For people who are at sea level, the bulk of the action happens at gauge readings somewhere between 29 and 30 inches. Figure 7 shows debubbling in progress. Figure 7 - Air bubbles dutifully obeying Boyle's Law by expanding like crazy and rising to the surface whereupon they break and are never seen again. Page 9
A Full Run and Other Hints from Deb Please familiarize yourself with all of the basic aspects of gel candle making before attempting to use the BBB. We want you to be successful and a piece of equipment, no matter how good, won't get you there unless you are knowledgeable of the basics. We strongly recommend the ebook How To Make Gel Candles That Sell Like Wildfire which is available as a download from http://www.howtomakegelcandles.com. Read this book cover to cover at least twice, it is our "bible" and, in the opinion of many, the BEST gel candle making book EVER. As you can see in Figure 8 below, I have two separate melting pots - one for regular, unprocessed gel and one for the debubbled gel. I go on debubbling jags and try to fill the debubbled pot up so I can have it ready when the mood strikes. I got the one on the right in Walmart's housewares department, It's called a Presto Kitchen Kettle. They are about $20.00 around here. The other one is a deep fryer with incremental temperature control (not just low, medium, high) that I got at a thrift shop. The most important attribute of a good melting pot is that it has incremental temperature control. The most important accessory is a candy thermometer for each of your melting pots since the controller on the pot won't give you an accurate indication of the real temperature. Figure 8 - Melting pots for raw gel and debubbled gel. Note the candy thermometers. Now, what temperature is the best for debubbling gel? The hotter the better, but not too hot or you will scorch the gel. My general rule of thumb is at least 250 degrees F but not over 275. I use a 1 cup metal measuring cup to transfer the hot gel from the melting pot to the beaker to be debubbled. But you can experiment to find what works best for you (raid your kitchen for tools!). Another good idea is to get an electric griddle (the bigger the better) on which to set your smaller pots of already melted gel, ready for scenting and/or coloring. This will keep them nice and warm. I just have a small one but it does work well if you have a lot of little pots of different scented and colored gels. Page 10
If you want to color and/or scent, I suggest you do that first before debubbling, as doing it later will reintroduce air to the gel. Just put your scented/colored gel onto the griddle or on the stove for a bit to get it hot again (don't forget the thermometer and NEVER let it leave your sight). With the gel container in the vacuum chamber, turn on the vacuum pump and let it go at full vacuum for about 3 minutes (remember, if it looks like the debubbling is getting too wild, raise the pressure just a bit (probably just 1/2 inch will do) until things slow down and then return to full vacuum. It will still look as if there are tons more bubbles to get out, but don't worry, this is just fine. Keep your eye on it, you can jiggle the chamber just a bit if the bubbles don't seem to be going as fast as they did at first. I put some rubber material in the bottom so the beaker won't slip and in case some gel bubbles over, it will collect on the rubber mat and not stick the beaker directly to the chamber (it happened to me and I didn't have that rubber underneath it and it was really hard to get the beaker out). When it's done debubbling, you can now pour directly into your candle, let it sit on the griddle, or pour it into your "debubbled" melting pot for later use. Don't worry about a lot of leftover gel in the beaker. Let it cool off and it will just peel out and you can drop it in the debubbled gel pot. I encourage you to try to find a better beaker to put gel in to debubble. Because of the size of the chamber, it is hard to do, and the beaker that is provided is the best I could find. You do need a handle (as you will see after trying it for the first time) and handled beakers or pitchers of the right size are really difficult to find. (If I find a better one, I'll let you know. If you find a better one, let us know!) Tips for Minimizing Bubbles that come from Embeds The warmer everything is the better. And the slower you pour the better. If you can break the fall of the gel with something (like an embed) that is better. If you have sand in the bottom of your candle, be sure to pour a thin layer of gel to cover the sand and then let it completely cool off. Otherwise you will get big air "blurps" from the air in the sand. Mostly, have fun and experiment! You will find your own way of doing things, and if you find a cool tip be sure and share it with us at the Yahoo gel candle groups!! Remember, don't hesitate to email me about gel and Steve about vacuum. We're here to make this experience a GREAT one!! Regular Maintenance of your BBB Your BBB requires very little maintenance. Just keep all of the parts clean with an occasional wiping with a clean, dry, lint-free cloth. For a more thorough cleanup, if required, you may use warm water with a mild, pure & unscented soap (e.g. Ivory dish detergent). Do not use solvents as these may attack the seals or plastic surfaces. Under no circumstances should you use any abrasives such as scouring Page 11
pads. If water has been used for cleaning, make sure all surfaces are dry before using with the vacuum pump. Water will contaminate the pump oil instantly. The most important part of maintenance is keeping the pump oil clean and at the proper level. Before each debubbling run make sure that the oil level is midway in the sight glass. We recommend that you change your oil on a monthly basis or more often if the oil appears darkened (dirty/contaminated) or milky (a sure sign of lots of water content). To change the oil take the fitting off of the exhaust port and invert the pump over a funnel or collecting pan. Discard the oil in a proper manner (local service station, at the town dump, etc.) as you would automobile engine oil. If your oil is very contaminated we recommend that you refill the pump, run it for about 30 seconds, and then drain and refill again. Replacement Parts Pump oil: Vacuum pump oil can be obtained from local dealers who cater to the air conditioning trade (look in the yellow pages for HVAC). The most common brands are Robinair and J/B Industries. If you have trouble finding pump oil, please contact us. In a pinch you can use 30 wt auto engine oil. However this tends to be a bit smelly but it does work fine. Cap for pressure relief/vent: This is the little metal or plastic cap with o-ring. If you lose it, you may get a replacement for $6.00 ppd. in the USA. O-ring for debubbling chamber: We can supply these for $8.00 ppd. Further Assistance Any questions or feedback, please email: Steve for problems or questions with regard to the equipment shansen@tiac.net Deb for issues related to candlemaking with the BBB lovesalsa@cox.net Also be sure to visit Steve's vacuum web site, the Bell Jar, at http://www.belljar.net. If you are science minded you will also get a host of ideas for other applications that your vacuum pump can be used for. By March 2003 there will also be a message board at belljar.net which will include an area for vacuum applications in arts & crafts. Page 12
Examples of Debubbled Candles using the BBB Page 13