DIY Techniques and Tips Part 3: Drops and What You Can and Probably Can't Do With Them
What is a drop? It is an indeterminate volume of liquid in another medium, in this case typically air. Note the indeterminate!
Those calculators that you see that give these nice figures to 3 decimal places? Total horse....! A drop is highly variable. It depends upon the viscosity and density of the material, the orifice from which it is formed, and a number of other factors. 20 drops to a mL? 30 drops to a mL? None of them are correct without qualification! I suggest you forget about calculators. If you really need them to get your nic level right, fine. But realize that it is an approximation only. So do not record some kind of bogus percentage from a calculator, record drops instead.
The good news about drops is even though they are indeterminate, they are acceptably reproducible given careful technique. And because most flavors come in dropper bottles, you are usually working with the same set of parameters so a drop can be delivered in a reproducible way over and over.
To properly add drops
1) NEVER EVER touch the tip of the dropper bottle against anything. Hold it above your mixing vial, and allow the drops to fall freely through air into the bottle.
2) Don't squeeze more than you have to. A little pressure to get some liquid down the tip. Then you can rotate the flavor bottle gently and a drop will usually form and fall off. If you need a little pressure use just enough to barely detach a drop. Don't squirt it.
If you add drops as described, even though the amount is indeterminate, you will be able to add them repeatedly in a reproducible manner.
One thing about drops, since they are indeterminate, and I don't suggest using graduated cylinders, your final volumes will not be say exactly 3 mL. I suggest you adopt a standard, say 20 drops to a mL even though that is not accurate. Then you can make minor adjustments in your PG/VG base to get approximately 3 mL and some approximate nic level. The differences will be fairly minor using this assumption and remember, the accuracy is limited and not even that important. What is important is reproducibility.
So if you know you added 1.5 mL PG/VG base, 0.5 mL Nic base, and X number of drops of various flavors, you may end up with 2.95 mL, you may end up with 3.05 mL, but what really matters is that you know you carefully added 1.5 mL PG/VG base, 0.5 mL Nic base, X number drops of flavors, and you can do that over and over and over again and get the same result!
Now I know some people may disagree. Realistically, if the difference between 15 mg/mL and 16.6 mg/mL nic even matters in the first place, you don't likely have the tools, and probably not the training to make these kind of adjustments, and almost certainly do not the analytical equipment to even know what the accurate nic content of the base you bought is in the first place.
So the technique I describe allows some variances, albeit minor, but I doubt you can do better, and if you follow the techniques I describe, you CAN do it over which is what is ultimately important.
Similarly, I do not try and do not advise you try to control your PG/VG ratios to some set number. Again you really probably just don't have the facilities. If you like 50-50, buy 50-50, if you like 70-30 buy 70-30. Make your base and your nic, and add the flavors. Sure, many if not most are in PG, and this will change your ratios somewhat. But it is probably not within your scope of resources to control that in any meaningful way. I just let it float. Without the proper tools and training, attempting to control these variables is most likley to be an additional complication that lowers your ability to REPRODUCE a previous attempt.
The bottom line is this. I've worked as an expert analytical chemist. I can calibrate a low resolution mass spectrometer at nanogram range detection limits, a high resolution mass spectrometer to picogram detection limits. You probably don't know those words, but that is billionth of a gram and trillionth of a gram respectively. That takes a certain training, technique, and tools.
Making e-juice? I am doing exactly what you are doing, sitting at the kitchen table with plastic syringes and dropper bottles. What I can do with this is also what you can do with this and what anyone can do with this. And you can figure it out yourself. Observe closely, a drop of 10% EM solution, a drop of some typical flavor, and a drop of tobacco Absolute in ethanol. You can easily and plainly see you have three drops and they are not even close to being the same. HOWEVER, a drop of 10% EM is a drop of 10% EM. A drop of a flavor is a drop of a flavor. A drop of tobacco Absolute is a drop of Tobacco Absolute. AND THAT IS WHAT MATTERS!!!
And I can tell you in no uncertain terms, anyone with the same training I have had would be doing exactly what I have described. They would look at these calculators and some kind of 0.349% and just shake their head. What they can do - calibrate a mass spectrometer at billionth of a gram precision - is what I can do. What they can do with this - use a syringe properly, allocate free falling drops consistently - is all I can do with this and all you can do wit this and all anyone really needs to do with this. You or I or most anyone does not even know what most of this .... really is to begin with. We are sitting at the table mixing up some kind of old lady's douche water and hitting it to see if we like how it tastes.
Learn to use a syringe properly, just round the amounts off to even increments like 1.4, 0.6 etc, learn to carefully add free falling drops whatever the volume happens to be, keep a careful record of what you do, and that will get you further than sweating out details like some exact PG/VG ratio or nicotine level or some bogus percentage from a calculator that you realistically will not be able to accomplish anyway.
Isn't that cool? The most scientifically sound approach to all this also happens to be doing what is easiest. ;-) Trying to do anything more complicated is just going to cause you trouble, and will not be as reproducible. 1 drop versus 2 drops of 10% Ethyl Vanillin is important. 68.4/31.6 PG/VG as opposed to 70/30 PG/VG? That is just a dingleberry on the ... of an endeavor which is largely subjective in terms of finding what you like, but also largely dependent on your ability to do things over and over in a consistent fashion.
And on a final note, what you are syringing and dropping into:
Bottles:
I recommend using basic 5 mL PET bottles with the dropper tops for mixing. You simply mix directly into the bottle. Some people prefer glass vials. One word about glass vials the tops are rarely suitable for storing flavored mixes. If you want to use glass vials, get some heavy plumbers tape. Stretch the tape over the vial before you cap it. This will prevent the flavors from leaching into the top material (and vice versa).
Finally now that we have covered the details I'm gonna backtrack and talk about some basic practices which will make more sense once you have gone through the details.
What is a drop? It is an indeterminate volume of liquid in another medium, in this case typically air. Note the indeterminate!
Those calculators that you see that give these nice figures to 3 decimal places? Total horse....! A drop is highly variable. It depends upon the viscosity and density of the material, the orifice from which it is formed, and a number of other factors. 20 drops to a mL? 30 drops to a mL? None of them are correct without qualification! I suggest you forget about calculators. If you really need them to get your nic level right, fine. But realize that it is an approximation only. So do not record some kind of bogus percentage from a calculator, record drops instead.
The good news about drops is even though they are indeterminate, they are acceptably reproducible given careful technique. And because most flavors come in dropper bottles, you are usually working with the same set of parameters so a drop can be delivered in a reproducible way over and over.
To properly add drops
1) NEVER EVER touch the tip of the dropper bottle against anything. Hold it above your mixing vial, and allow the drops to fall freely through air into the bottle.
2) Don't squeeze more than you have to. A little pressure to get some liquid down the tip. Then you can rotate the flavor bottle gently and a drop will usually form and fall off. If you need a little pressure use just enough to barely detach a drop. Don't squirt it.
If you add drops as described, even though the amount is indeterminate, you will be able to add them repeatedly in a reproducible manner.
One thing about drops, since they are indeterminate, and I don't suggest using graduated cylinders, your final volumes will not be say exactly 3 mL. I suggest you adopt a standard, say 20 drops to a mL even though that is not accurate. Then you can make minor adjustments in your PG/VG base to get approximately 3 mL and some approximate nic level. The differences will be fairly minor using this assumption and remember, the accuracy is limited and not even that important. What is important is reproducibility.
So if you know you added 1.5 mL PG/VG base, 0.5 mL Nic base, and X number of drops of various flavors, you may end up with 2.95 mL, you may end up with 3.05 mL, but what really matters is that you know you carefully added 1.5 mL PG/VG base, 0.5 mL Nic base, X number drops of flavors, and you can do that over and over and over again and get the same result!
Now I know some people may disagree. Realistically, if the difference between 15 mg/mL and 16.6 mg/mL nic even matters in the first place, you don't likely have the tools, and probably not the training to make these kind of adjustments, and almost certainly do not the analytical equipment to even know what the accurate nic content of the base you bought is in the first place.
So the technique I describe allows some variances, albeit minor, but I doubt you can do better, and if you follow the techniques I describe, you CAN do it over which is what is ultimately important.
Similarly, I do not try and do not advise you try to control your PG/VG ratios to some set number. Again you really probably just don't have the facilities. If you like 50-50, buy 50-50, if you like 70-30 buy 70-30. Make your base and your nic, and add the flavors. Sure, many if not most are in PG, and this will change your ratios somewhat. But it is probably not within your scope of resources to control that in any meaningful way. I just let it float. Without the proper tools and training, attempting to control these variables is most likley to be an additional complication that lowers your ability to REPRODUCE a previous attempt.
The bottom line is this. I've worked as an expert analytical chemist. I can calibrate a low resolution mass spectrometer at nanogram range detection limits, a high resolution mass spectrometer to picogram detection limits. You probably don't know those words, but that is billionth of a gram and trillionth of a gram respectively. That takes a certain training, technique, and tools.
Making e-juice? I am doing exactly what you are doing, sitting at the kitchen table with plastic syringes and dropper bottles. What I can do with this is also what you can do with this and what anyone can do with this. And you can figure it out yourself. Observe closely, a drop of 10% EM solution, a drop of some typical flavor, and a drop of tobacco Absolute in ethanol. You can easily and plainly see you have three drops and they are not even close to being the same. HOWEVER, a drop of 10% EM is a drop of 10% EM. A drop of a flavor is a drop of a flavor. A drop of tobacco Absolute is a drop of Tobacco Absolute. AND THAT IS WHAT MATTERS!!!
And I can tell you in no uncertain terms, anyone with the same training I have had would be doing exactly what I have described. They would look at these calculators and some kind of 0.349% and just shake their head. What they can do - calibrate a mass spectrometer at billionth of a gram precision - is what I can do. What they can do with this - use a syringe properly, allocate free falling drops consistently - is all I can do with this and all you can do wit this and all anyone really needs to do with this. You or I or most anyone does not even know what most of this .... really is to begin with. We are sitting at the table mixing up some kind of old lady's douche water and hitting it to see if we like how it tastes.
Learn to use a syringe properly, just round the amounts off to even increments like 1.4, 0.6 etc, learn to carefully add free falling drops whatever the volume happens to be, keep a careful record of what you do, and that will get you further than sweating out details like some exact PG/VG ratio or nicotine level or some bogus percentage from a calculator that you realistically will not be able to accomplish anyway.
Isn't that cool? The most scientifically sound approach to all this also happens to be doing what is easiest. ;-) Trying to do anything more complicated is just going to cause you trouble, and will not be as reproducible. 1 drop versus 2 drops of 10% Ethyl Vanillin is important. 68.4/31.6 PG/VG as opposed to 70/30 PG/VG? That is just a dingleberry on the ... of an endeavor which is largely subjective in terms of finding what you like, but also largely dependent on your ability to do things over and over in a consistent fashion.
And on a final note, what you are syringing and dropping into:
Bottles:
I recommend using basic 5 mL PET bottles with the dropper tops for mixing. You simply mix directly into the bottle. Some people prefer glass vials. One word about glass vials the tops are rarely suitable for storing flavored mixes. If you want to use glass vials, get some heavy plumbers tape. Stretch the tape over the vial before you cap it. This will prevent the flavors from leaching into the top material (and vice versa).
Finally now that we have covered the details I'm gonna backtrack and talk about some basic practices which will make more sense once you have gone through the details.
