How do you measure?

[zoiDman]

The big advantage to using accurate measuring tools is, someone on the other side of the world can duplicate your recipe exactly, regardless of the particular bottles his flavorings come from.

This is true. If you are planning on sharing recipes, working with standardized volumes or percentages is best. That is about the only time I will break out a graduated cylinder and translate it into ml or %. I have done that all of 3 times in the last 2 years.

Here is One of the Three recipes I did that with...

I"ll give up my recipes when they pry them from my cold, dead hands. j/k

ROTFLMAO

 

[studio52]

2o drops is about a ml, varies on droppers they say, but still if 20 drops is a ml its easy to add flaors by the ml by counting drops.

 

[MaxUT]

Using a graduated medicine dropper, I get 30-31 drops per mL with my FA flavorings, or about 0.03mL per drop.

There are a number of tools here: Liquid Medication Tools

I often use these:

1 Ml Calibrated Droppers- Item 69347-plastic, 69349-glass

I have both the glass and the plastic versions. I use the plastic ones most frequently since they're marked in 0.1mL graduations; the glass ones are marked in 0.02mL grads.

Since these droppers are intended to be reusable, the markings are durable and have held up for nearly a year of regular use.

 

[zoiDman]

Those are nice.

If your into measuring then you might consider using a Graduated Cylinder. Some people find it easier to make a "Ladder" mix and then you only have one piece of lab glass to wash.

 

[Old Chemist]

Right, zoiDman, but one should be aware that measuring the volume using graduated cylinders is less accurate than when you use pipettes or syringes.
Usually I am using plastic Pasteur pippettes. Quite cheap, unbreakable and easy to use. And quite accurate, too.

 

[zoiDman]

Right, zoiDman, but one should be aware that measuring the volume using graduated cylinders is less accurate than when you use pipettes or syringes.
Usually I am using plastic Pasteur pippettes. Quite cheap, unbreakable and easy to use. And quite accurate, too.

I agree... But then again what level of accuracy is needed? Perhaps mixing on the Mole level is overkill but where do we draw the line?

Can a person Really tell the difference between 18.1mg juice and 18.275mg juice? Or even 18mg to 19mg? And if their VGG Ratio is off by +/- .5ml, are they going to see a Significant difference in their vaping experience?

Sometimes being able to measure and finer and finer levels of accuracy is a nice academic exercise. But there will become a point when the Limit of human Perception is reached. Past that point, increasing accuracy starts to lose it's meaning.

When I first started out I was very gun-hoe about DIY. I had a desk full of stuff like this...

Micro Glassware Set Micro Glassware Set : United Nuclear , Scientific Equipment & Supplies

(BTW - A nice price for the Mad Scientist in your house.)


... and I spent a Huge amount of time measuring and mixing. But as time past, I found that it wasn't all that necessary and that there were ways to streamline the mixing process without lose of flavor repeatability.

I'm not saying that measuring everything to the +/1 .1 ml level is bad thing. And if a person enjoys doing it and has the time, then by all means do it.

 

[BiffRocko]

I haven't mixed in a while, but when I did I'd make 30ml batches. For that I found 10ml and 25ml graduated cylinders to be most convenient. I bought mine from US Plastic.

http://www.usplastic.com/catalog/item.aspx?itemid=35632&catid=529&clickid=searchresults

 

[Old Chemist]

I agree... But then again what level of accuracy is needed? Perhaps mixing on the Mole level is overkill but where do we draw the line?

Yes, you're right. In fact the accuracy of 5% would be good enough. That was just a chemist's academic remark.
Quite often I just use drop count to get eg 2 ml of new mixture. Fast and efficient.

 

[zoiDman]

Yes, you're right. In fact the accuracy of 5% would be good enough. That was just a chemist's academic remark.
Quite often I just use drop count to get eg 2 ml of new mixture. Fast and efficient.

And as long as the drops come out of the same dropper, your recipe is repeatable. And your recipe can be scaled up from 2ml to 30ml or whatever very easily.

Like I said, If you have all the lab ware, which I knew you do, and enjoy doing it, I see nothing wrong with doing precise measurement. Nothing what so ever. I just don't like to wash all that lab ware every time.

Maybe I'm just lazy or can't taste the difference when I mix using Kimax glassware or use drops. But when I use drops there's nothing to wash.

And so life is good.

 

[Old Chemist]

I just don't like to wash all that lab ware every time.

Me neither! That's why I use Pasteur pipettes as they're disposable. But I'm looking around... maybe I will wind someone bearing a sign "will wash your lab stuff for e-liquid".

 

[Kurt]

Well it looks like I will be the first to chime in and state I use a pipette pump. Depending on recipe I will use a 2ml, 5ml or 10ml pipette with graduations at .1ml or finer.

Oh, I so want a pipette pump!! That would be easy, accurate, and fast. Right now I use syringes exclusively, 3 mL or 12 mL. I think it is an 18 gauge blunt needle. My high-nic unflavored is in glass bottle with eurodropper inserts, which make them non-spill, and provides a nice port for the syringe needle, so I never come in contact with my 100 mg VG. In fact, most of the liquids I am mixing are in these bottles for syringe dispensing. Capellas bottles can be syringe dispensed from by just sticking the needle firmly into the dropper tip of the bottle, inverting it, and drawing flavor into the syringe.

BTW, drop size is more a function of liquid viscosity and polarity than dropper type. Not worth taking a chance on inaccurate measuring of 100 mg liquid. The variance can make for VERY different juice strengths compared to what you think they should be.

And yes, good light is often needed to see those graduations with dark liquids.

 

[Old Chemist]

BTW, drop size is more a function of liquid viscosity and polarity than dropper type.

Polarity? How come? Dropper type is not important, but its opening is.

Not worth taking a chance on inaccurate measuring of 100 mg liquid. The variance can make for VERY different juice strengths compared to what you think they should be.

Absolutely right, Kurt. This might be dangerous. In fact, I wouldn't play with such concentrated solution if I weren't a professional. In my opinion such solutions shouldn't be sold freely, 'cos they might be really dangerous. Here in Poland we have an upper limit of 38 mg/ml. It was our joint decision - suppliers and vapers.

 

[zoiDman]

...
BTW, drop size is more a function of liquid viscosity and polarity than dropper type. Not worth taking a chance on inaccurate measuring of 100 mg liquid. The variance can make for VERY different juice strengths compared to what you think they should be.
...

I will go with the Viscosity and as Old Chemist mentioned, the cross-sectional area of the dropper opening, as well as temperature, but what does Polarity have to do with it?

My personal opinion is that 100mg juice or higher should NOT be sold to the general public. I don't know if you saw it or not but there was a post about 2 weeks ago from a member who found his toddler laying on the ground with a bottle of juice in his hands.

Thank God that the child was ok but it shows just what kind of Tragic things could happen when a Irresponsible person is allowed to handle potentially hazardous chemicals. (Not sure why the member felt there was time to post a thread on the ECF and wait for replies instead of getting his child to a hospital or at least contacting a Poison Control Center!)

I know of a few vendors who will not sell High mg nicotine just for that reason.

 

[Critter Man]

what does Polarity have to do with it?

You may recall, from many years ago for most of us, that back in elementary school we learned about polarity and how it affects liquids. The way that eLiquid wicks to the atty in our PVs is due to polarity. Capillary action is a result of polatity, as is the meniscus you see when measuring liquid in a graduated cylinder. The same property affects how big a drop gets before gravity overcomes polarity and the drop falls away from the dropper. There are other factors that affect drop size, but polarity is counterintuitively important.

 

[Old Chemist]

Hmmm... in fact, I wouldn't agree with you Critter Man. It's rather a matter of density, surface tension, adhesion etc.
As for polarity - consider two liquids: ethyl ether and car oil. Both are non-polar. Do you think they would form similar drops? On the other hand - both water and propylene glycol are polar. Compare the drops formed by these two liquids in the same dropper.
Hope this explains.

 

[Critter Man]

Hmmm... in fact, I wouldn't agree with you Critter Man. It's rather a matter of density, surface tension, adhesion etc.
As for polarity - consider two liquids: ethyl ether and car oil. Both are non-polar. Do you think they would form similar drops? On the other hand - both water and propylene glycol are polar. Compare the drops formed by these two liquids in the same dropper.
Hope this explains.

I was including those other factors in the "other factors" I mentioned. At second glance, it did look like I was crediting most of the drop size solely to polarity. It's a force that holds the liquid to the material of the dropper, but by no means the only force that significantly affects drop size. I'll defer to your obviously superior knowledge on the topic, Old Chemist.

The main point is that the same liquid from the same dropper will give a consistent drop size, but a new bottle of the same liquid will give a slightly different drop size. The bigger the batch you are making, the less repeatable the recipe. When it comes to flavoring a 15 mL bottle, the difference is probably unnoticeable. When getting the right nicotine level in a 100 mL bottle, the differences can be significant, but may not be noticed by the vaper. As is said many times in these forums, your mileage may vary.