Specific Gravity in DIY--How important is it? Does it really matter?

[Sugar_and_Spice]

HI all,

I am starting this thread in the hope that better understanding of the use of Specific Gravity OR the lack of it can determine the outcome of a recipe.

It does not matter if you mix by volume(ml) or by weight(grams) as it can make a difference if you are using a online calculator to break down the % of ingredients.

Specifically we are talking about nic, pg and vg. It is generally accepted that flavors use a 1 to 1 conversion so that is not in dispute.

Please stay on topic because this is not about whether one way to mix is better or worse than the other. It is about determining the weights and ml of any given recipe so that by mixing
EITHER WAY should both be equal in the amount of ingredients used in a recipe.


For disclosure purposes only--I mix by volume(ml). When trying out mixing by weight I found discrepancies in the volume of the final mixes. That is the reason for this thread. Why was the amount made with weight less than when I mixed by volume?

I suspect it is all in the way the online calculators do the math. Again, I am talking any online calculator as I have found the same results with more than 1.

Any and all replies welcome. Please keep replies civil and remember ECF rules. Attack the post --not the poster.

 

[DaveP]

Sugar and Spice, I use the EjuiceMeUp calculator. If the recipe is in volume form (ml) or weight (mg), the calculator shows me both ml, drops, and gram weights for each ingredient. If I'm mixing by weight, as I normally do, I use the grams column to measure out my ingredients as I mix up a batch. Easy, Peasy.

If your mixes are off using the scales, you might want to check out BotBoy's DIY mix page for mixing by weight calibrations for each ingredient. I use his ml/mg weight calculations for Nic, PG, and VG and I use 1 gram per ml for flavors and my DIY juices are flavored as expected and they are consistent between batches, IMO.

Botboy141 Guide to Mixing By Weight : DIY_eJuice

From BotBoy's weights for ingredients...

The basic values that you need to know for mixing by weight are below.

• Weight of PG: 1.038 grams per ml
  
  
• Weight of VG: 1.26 grams per ml
  
  
• Weight of Pure Nicotine: 1.01 grams per ml

When it comes to flavors, there are a couple of thoughts/theories surrounding mixing by weight when dealing with flavors. Many people enter the specific gravity as indicated on an MSDS for every flavor that they have. I feel this is a complete waste of time. After searching hundreds of MSDS sheets for flavors, all flavors fall into a range of .93g per ml to 1.07g per ml.

 

[Sugar_and_Spice]

I use the EjuiceMeUp calculator. If the recipe is in volume form (ml) or weight (mg), the calculator shows me both ml, drops, and mg/grams for each ingredient. If I'm mixing by weight, as I normally do, I use the mg column to measure out my ingredients as I mix up a batch. Easy, Peasy.

If your mixes are off using the scales, you might want to check out BotBoy's DIY mix page for mixing by weight calibrations for each ingredient. I use his ml/mg weight calculations for Nic, PG, and VG and I use 1 gram per ml for flavors and my DIY juices are flavored as expected and they are consistent between batches, IMO.

Botboy141 Guide to Mixing By Weight : DIY_eJuice

From BotBoy's weights for ingredients...

Thanks Dave for your reply but not really what i am aiming for. I was referring to the free calculators online and that you dont need to download to your own computer. I use chromebook and cannot use the ones that require a pc to run.

I was more hoping for a work around with getting the same results for all base ingredients in a recipe.
One big reason i never switched to mixing by weight is this inconsistency. I realize if a mixer is just starting out and never mixed before this problem does not exist for them. But someone who has mixed for years and looking for same results that they get when mixing with volume and not achieving them therefore puts all their long time proven recipes as not ringing true.

I was hoping to bring this matter to light for those mixers making or trying to make the switch from one method to the other and explore why that may be that inconsistency in their recipes.

 

[zoiDman]

...

I was more hoping for a work around with getting the same results for all base ingredients in a recipe.
One big reason i never switched to mixing by weight is this inconsistency. I realize if a mixer is just starting out and never mixed before this problem does not exist for them. But someone who has mixed for years and looking for same results that they get when mixing with volume and not achieving them therefore puts all their long time proven recipes as not ringing true.

...

There is a Say'n that "All Measurement is Relative".

Now that might be Relative to known Standard like a Gram or an Ounce. Or Relative to an Inconsistency of a Measuring device or Measuring Technique. Or maybe Relative to a Undefined Unit like a Drop.

If what you want to do is to take a Volumetric Recipe and then replicate it via Weight Measurements, the Easiest Way to do it is to Weigh your Components (PG, VG, Nic Base) after you Measure them using whatever method you use to measure Volumes.

Now you have a Weight Recipe that Isn't dependent on using Numerical Values for grams/ml that your scale May or May Not be giving you.

If you Make the Recipe again using the Weights alone, and it Tastes the Same as what the Volumetric Recipe tastes, then you know that your Scale is reputable.

So you could then take the Components for PG, VG and Nic Base and "Normalize" them to what 1ml weighs On Your Scale.

 

[Sugar_and_Spice]

There is a Say'n that "All Measurement is Relative".

Now that might be Relative to known Standard like a Gram or an Ounce. Or Relative to an Inconsistency of a Measuring Device or Measuring Technique. Or maybe Relative to a Undefined Unit like a Drop.

If what you want to do is to take a Volumetric Recipe and then replicate it via Weight Measurements, the Easiest Way to do it is to Weigh your Components (PG, VG, Nic Base) after you Measure them using whatever method you use to measure Volumes.

Now you have a Weight Recipe that Isn't dependent on using Numerical Values for grams/ml that your scale May or May Not be giving you.

If you Make the Recipe again using the Weights alone, and it Tastes the Same as what the Volumetric Recipe tastes, then you know that your Scale is reputable.

So you could then take the Components for PG, VG and Nic Base and "Normalize" them to what 1ml weighs On Your Scale.

That is a great answer Zoid, and was thinking of the actual scales and the weighing ourselves for our own personal results that could be addressed at a later time in this thread. But it is relevant to the topic and I thank you for bringing that possible problem/solution to light.

Unfortunately as I look at more of the free online calculators(and no this is not a plug to buy into a recipe calculator that costs money) I get much of the same results, with limited to no access to modify the variables beyond the % used.


Granted using only 1 flavoring and the size of a small bottle the results are not giving a huge difference between ml and gram totals(for the pg,vg, and nic). I mean who is going to notice a few hundreds of a gram missing, right? The problem rears its ugly head when mixing even a 1 oz bottle and grows with the higher volumes.

I did find I was able to modify 1 to my satisfaction of all things being equal in the calculations . I cannot link to show anyone as its one of those that ecf will not allow links to. Plus I only mention it because it's the one I use most often (and is very popular here at ecf) besides Dans excel sheets calculator(that is listed in this DIY thread here at ecf.)

Again this topic is probably relevant mostly to those making the switch from volume mixing to weighing grams, but may explain also why in the resulting ejuice some people may love a recipe and some may not find it as pleasing and why the final volume in the bottle is less and can taste different.

 

[Sugar_and_Spice]

There is a Say'n that "All Measurement is Relative".



If what you want to do is to take a Volumetric Recipe and then replicate it via Weight Measurements, the Easiest Way to do it is to Weigh your Components (PG, VG, Nic Base) after you Measure them using whatever method you use to measure Volumes.

Just to address this individually- no I am not looking to do this as I accept the standards that have been adopted among mixers and are listed numerous times through out the DIY thread. I am addressing the actual calculations that some online free recipe calculators use. I tried for a long time to understand how they arrived at their conclusions. I found only 1 that can give me what I seek in limited modifications to my own profile and want to help others realize and understand that there is a difference and how it can possibly be addressed. Which is why I still wonder just how relative the Specific gravities are to our finished ejuice.

 

[IDJoel]

When trying out mixing by weight I found discrepancies in the volume of the final mixes. That is the reason for this thread. Why was the amount made with weight less than when I mixed by volume?

Hi Sugar! Interesting take on an old topic.

I found myself in a similar situation. For me; I had been mixing by volume (using syringes), and had gone through 3 different downloaded (Windows) calculators. I was on to the third calculator (@HotRod19579's Juice Calculator) when I decided to try out mixing by weight.

I tried mixing up a few familiar recipes to try it out. Every one of them was off!

Looking a bit closer at the finished mixes; I realized that their finished volumes were all short of what they normally were, when I had previously made them using syringes.

After some kind hand-holding from the kind folks on HotRods thread, and reading the calculator's Help file; I discovered that the discrepancy came from my failing to input corrected specific gravities (turns out they all defaulted to a specific gravity value of 1.00), for my base ingredients (PG, VG, and 100mg/mL nic base in VG). I learned, that the higher (greater than 1.00g/mL) the specific gravity, the larger the shortage of the intended/expected volume I was dispensing.

So, while PG (with a specific gravity of 1.038) was only causing a shortage of roughly 4% to volume; my nicotine (SG of 1.235) was short ~23.5%, and my VG (SG of 1.26) was short by ~26%. Considering my recipes were made up of 6% nic concentrate, and 64% VG; it was no wonder that my initial mixing-by-weight efforts were coming up way short... and way off (over flavored), The PG and PG-based flavor concentrates were (mostly) the same; while the VG, and VG-based nic were significantly short, and therefore, not diluting the flavor concentrates enough.

Once I entered the (more) accurate specific gravity data; my recipes returned to their expected results.


So... does this mean I HAD to use appropriate values? No; I can't say that in all honesty. I could have gone back, and reformulated (by taste) all my recipes, until they tasted the same as they did when mixed by volume. But, that would have been extremely tedious, and my recipes would have zero usefulness to anyone else.

And, that brings up another reason to use appropriate (standardized) specific gravities, when mixing by weight: that being a "conventional" (agreed upon) understanding of values. In order to successfully share recipes; we (the people sharing) have to be speaking the same "language."

One could use anything to measure. I could use Grandma's sewing thimble as my basic unit of measurement. And, as long as I continued to use Grandma's thimble, I could get repeatable results. BUT, if no one else has any idea how big Grandma's thimble is, they can not replicate my results (except, by accident).

The use of "conventional" specific gravities, gives all who use them, that "common language."

 

[zoiDman]

... Which is why I still wonder just how relative the Specific gravities are to our finished ejuice.

All Specific Gravity is is a Ratio of One Density to Another Density. And that other Density is Almost Always Water (at 39F).

So if a Liquid like VG has a Specific Gravity of 1.26, then that tells you that 1 Unit of VG is 1.26 Times Heavier than Water. Notice that 1.26 is "Unit Less".

What we use in DIY (and when Most people use the phrase "Specific Gravity") is actually Apparent Specific Gravity.

Apparent Specific Gravity is when I compare the Weight on one Substance to the Weight of another Substance. And that other Substance is Almost Always Water (at 39F).

But to Define Weight, I must Define How Much of the Substance I am Weighing. That is where the Units come in.

By some Strange Cosmic Coincidence (or maybe they Set It Up this way) 1 ml of Water Weighs 1 Gram.

So if 1ml of Water weighs 1 Gram, and VG weighs 1.26 times what Water does, then I know that 1ml of VG should Weigh 1.26 Grams. e.g. 1.26g/ml

This is how I can bridge Volumetric Measurement to Weight Measurement. By Knowing what the Specific Density of a Substance is. And then just adding a unit of Apparent Specific gravity, g/ml, to a Specific Gravity that is known.

Does This Help?

 

[Sugar_and_Spice]

Hi Sugar! Interesting take on an old topic.

I found myself in a similar situation. For me; I had been mixing by volume (using syringes), and had gone through 3 different downloaded (Windows) calculators. I was on to the third calculator (@HotRod19579's Juice Calculator) when I decided to try out mixing by weight.

I tried mixing up a few familiar recipes to try it out. Every one of them was off!

Looking a bit closer at the finished mixes; I realized that their finished volumes were all short of what they normally were, when I had previously made them using syringes.

After some kind hand-holding from the kind folks on HotRods thread, and reading the calculator's Help file; I discovered that the discrepancy came from my failing to input corrected specific gravities (turns out they all defaulted to a specific gravity value of 1.00), for my base ingredients (PG, VG, and 100mg/mL nic base in VG). I learned, that the higher (greater than 1.00g/mL) the specific gravity, the larger the shortage of the intended/expected volume I was dispensing.

So, while PG (with a specific gravity of 1.038) was only causing a shortage of roughly 4% to volume; my nicotine (SG of 1.235) was short ~23.5%, and my VG (SG of 1.26) was short by ~26%. Considering my recipes were made up of 6% nic concentrate, and 64% VG; it was no wonder that my initial mixing-by-weight efforts were coming up way short... and way off (over flavored), The PG and PG-based flavor concentrates were (mostly) the same; while the VG, and VG-based nic were significantly short, and therefore, not diluting the flavor concentrates enough.

Once I entered the (more) accurate specific gravity data; my recipes returned to their expected results.


So... does this mean I HAD to use appropriate values? No; I can't say that in all honesty. I could have gone back, and reformulated (by taste) all my recipes, until they tasted the same as they did when mixed by volume. But, that would have been extremely tedious, and my recipes would have zero usefulness to anyone else.

And, that brings up another reason to use appropriate (standardized) specific gravities, when mixing by weight: that being a "conventional" (agreed upon) understanding of values. In order to successfully share recipes; we (the people sharing) have to be speaking the same "language."

One could use anything to measure. I could use Grandma's sewing thimble as my basic unit of measurement. And, as long as I continued to use Grandma's thimble, I could get repeatable results. BUT, if no one else has any idea how big Grandma's thimble is, they can not replicate my results (except, by accident).

The use of "conventional" specific gravities, gives all who use them, that "common language."

Thank you Joel for your response. You have just help explain my problem(in part) by your response. However, I am not in dispute with the weights of Specific Gravities of the nic, pg,vg per se. I am however totally unclear how some of the 'FREE' online calculators use this information to give results that often differ in their amounts. I know the old saying 'You get what you pay for' and this may or may not be true in the case of the Free online calculators(or even some of the paid ones).
Since volume mixing does not take the Specific Gravity of these ingredients for their use, I did realize it seems like more for grams by just looking at a number. But that number is somehow being skewed in FREE online calculators and so I get totally different results(for nic, pg and vg) and end up like you did in much less volume than expected and ejuice that did not resemble anything I had made before. I am glad that you spoke up and recognized that we are not alone in this problem. Lots of people use these calculators and the ones making the switch are going to be very disappointed and confused (as I am/was) in why their mixes are different.

 

[zoiDman]

...

One could use anything to measure. I could use Grandma's sewing thimble as my basic unit of measurement. And, as long as I continued to use Grandma's thimble, I could get repeatable results. BUT, if no one else has any idea how big Grandma's thimble is, they can not replicate my results (except, by accident).

...

Here's the Funny thing...

If you gave someone an Entire Recipe where the All the Units were Granny's Sewing Thimble, and the person dug out their Mom's Sewing Thimble, even if the Thimbles were Different Sizes, it would Taste Exactly the Same.

The Only Difference would be the Finished Size of the Mix would be Different.

This is part of what I meant Earlier about "All Measurement being Relative".

 

[Sugar_and_Spice]

All Specific Gravity is is a Ratio of One Density to Another Density. And that other Density is Almost Always Water (at 39F).

So if a Liquid like VG has a Specific Gravity of 1.26, then that tells you that 1 Unit of VG is 1.26 Times Heavier than Water. Notice that 1.26 is "Unit Less".

What we use in DIY (and when Most people use the phrase "Specific Gravity") is actually Apparent Specific Gravity.

Apparent Specific Gravity is when I compare the Weight on one Substance to the Weight of another Substance. And that other Substance is Almost Always Water (at 39F).

But to Define Weight, I must Define How Much of the Substance I am Weighing. That is where the Units come in.

By some Strange Cosmic Coincidence (or maybe they Set It Up this way) 1 ml of Water Weighs 1 Gram.

So if 1ml weighs 1 Gram, and VG weighs 1.26 times what Water does, then I know that 1ml of VG should Weigh 1.26 Grams. e.g. 1.26g/ml

This is how I can bridge Volumetric Measurement to Weight Measurement. By Knowing what the Specific Density of a Substance is. And then just adding a unit of Apparent Specific gravity, g/ml, to a Specific Gravity that is known.

Does This Help?

It is a great post full of information that is relative to weight in mixing liquids. And I do understand it and hopefully since it is so well written all will also understand it.
But I think at least for now we are not on the same page. I guess my questions should have been more clearly stated? My problem is more of the calculators(some online free ones) are not giving correct results. This ends up making 1 recipe use less nic,pg,vg that what is used in volume mixing and that is what is making the final ejuice result in less liquid in volume when compared to using syringes to measure each ingredient. And I am talking with the Specific Gravities in place in the calculator(whether input is done in by hand or by default).

 

[zoiDman]

... My problem is more of the calculators(some online free ones) are not giving correct results. ...

How Far Off are the Results that you are seeing with some of these Free Online Calculators?

 

[IDJoel]

I am however totally unclear how some of the 'FREE' online calculators use this information to give results that often differ in their amounts.
{Edit by IDJoel}
But that number is somehow being skewed in FREE online calculators and so I get totally different results(for nic, pg and vg) and end up like you did in much less volume than expected and ejuice that did not resemble anything I had made before.

Can you give us some examples of the discrepancies you are seeing? Either, screenshots of your results, as you are seeing them. Or, links/names of the online calculators, and the ingredient values (percentages, volumes) you are using, so we can recreate your tests.

I don't use any of the free online calculators; so I can't visualize the results you are seeing.

I am glad that you spoke up and recognized that we are not alone in this problem. Lots of people use these calculators and the ones making the switch are going to be very disappointed and confused (as I am/was) in why their mixes are different.

Just so I am being clear... it was my failure, by not providing the appropriate data, that caused the calculator I use, to calculate different results. This was entirely my own doing (or lack thereof), and not through any fault/shortcoming of the calculator. And... once I gave the calculator the correct data, I had/have no further problems.

I do recognize, this is using a downloaded Windows calculator (though still free of charge), and not one of the free online ones you are experimenting with, @Sugar_and_Spice. It may likely offer greater control/adjustment than the online versions.

 

[DaveP]

Sugar and Spice, you might want to compare (if you haven't already) the liquid ml conversion to gram weights using a Chrome based eliquid calculator and mix a juice using both methods (liquid and weight) and see how it comes out. The one below is from the Google Play Store. Notice that on flavor, 8ml = 8.32 grams in the conversion. That's also how it works out in my Windows 10 juice apps.

I suspect that you have already done this and still notice the difference in flavor and vape quality. Most of us haven't used both methods and are fat, dumb, and happy with our home made juices and consider them to be the Gold standard.

At any rate, weight to liquid measure equivalencies are a fact of life in DIY juice. I'd be interested in how you come out with your comparisons. I use BotBoy's equivalencies in my mixes for adjust for ml to weight equivalents in my recipes.



https://play.google.com/store/apps/details?id=com.vapefactory.liqcalc.liqcalc&hl=en_US

 

[IDJoel]

Here's the Funny thing...

If you gave someone an Entire Recipe where the All the Units were Granny's Sewing Thimble, and the person dug out their Mom's Sewing Thimble, even if the Thimbles were Different Sizes, it would Taste Exactly the Same.

The Only Difference would be the Finished Size of the Mix would be Different.

This is part of what I meant Earlier about "All Measurement being Relative".

That is a fair point. It is not all that common anymore, but I still occasionally see, recipes (for food or drinks) written out as: "1 part X, to 2 parts Y" (in ratio format). So, my example was a poor one.

Truthfully, as I was writing that paragraph; I was thinking of the substantial range/variation of droplet size (X drops/mL). But, I didn't want to introduce another debated DIY measuring method, to the thread's discussion.

 

[zoiDman]

That is a fair point. It is not all that common anymore, but I still occasionally see, recipes (for food or drinks) written out as: "1 part X, to 2 parts Y" (in ratio format). So, my example was a poor one.

...

We actually used to see Recipes a lot in this Format. And that was when people gave their Recipes in Percentages.

Because Percentages are another Unit Less Measurement. Just a Ratio of a Part divided by the Whole.

---

Yeah... Better we Don't mention Measuring by Drops. Because we All know what well happen if we do.

LOL

 

[Sugar_and_Spice]

Hi Sugar! Interesting take on an old topic.

I found myself in a similar situation. For me; I had been mixing by volume (using syringes), and had gone through 3 different downloaded (Windows) calculators. I was on to the third calculator (@HotRod19579's Juice Calculator) when I decided to try out mixing by weight.

I tried mixing up a few familiar recipes to try it out. Every one of them was off!

Looking a bit closer at the finished mixes; I realized that their finished volumes were all short of what they normally were, when I had previously made them using syringes.

After some kind hand-holding from the kind folks on HotRods thread, and reading the calculator's Help file; I discovered that the discrepancy came from my failing to input corrected specific gravities (turns out they all defaulted to a specific gravity value of 1.00), for my base ingredients (PG, VG, and 100mg/mL nic base in VG). I learned, that the higher (greater than 1.00g/mL) the specific gravity, the larger the shortage of the intended/expected volume I was dispensing.

So, while PG (with a specific gravity of 1.038) was only causing a shortage of roughly 4% to volume; my nicotine (SG of 1.235) was short ~23.5%, and my VG (SG of 1.26) was short by ~26%. Considering my recipes were made up of 6% nic concentrate, and 64% VG; it was no wonder that my initial mixing-by-weight efforts were coming up way short... and way off (over flavored), The PG and PG-based flavor concentrates were (mostly) the same; while the VG, and VG-based nic were significantly short, and therefore, not diluting the flavor concentrates enough.

Once I entered the (more) accurate specific gravity data; my recipes returned to their expected results.

The use of "conventional" specific gravities, gives all who use them, that "common language."

I think this may be the problem in the free online calculators. We cannot change the values. Not sure if this explains all of it though.

I do think that probably some of it is also my problem.

And I do owe an apology to @zoiDman as I have just realized part of this is my mistake. Looking only at the totals of ingredients used was a mistake as not all are equal. Of course there will be less used in pg/vg when using an already mixed base as the weight is different than when mixing all 3 individually. I compensated for this when I mix by volume by calculating my own values in ml. The calculator value for ml does not change in the online calculator however and that (to me) only adds to the confusion.

 

[zoiDman]

...

And I do owe an apology to @zoiDman as I have just realized part of this is my mistake. Looking only at the totals of ingredients used was a mistake as not all are equal. Of course there will be less used in pg/vg when using an already mixed base as the weight is different than when mixing all 3 individually. I compensated for this when I mix by volume by calculating my own values in ml. The calculator value for ml does not change in the online calculator however and that (to me) only adds to the confusion.

No Apology needed SxS. You know that.

 

[Sugar_and_Spice]

But I do have to wonder if others when mixing with volume and then making the switch don't think about that. I saw a comment the other day when a mixer asked the same questions I had/have. I am still not yet convinced thats is the entire problem tho. As that amount should not be as great as it turns out in the final mix. When it is visible to the naked eye in a 30 ml bottle it is more than just a few hundreds of a gram off. Can scales really be that far out, even when they are calibrated?

 

[Sugar_and_Spice]

@IDJoel
I was in the process of making screen shots when my wifi went out. Had to restart my computer and lost it.