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

[Sugar_and_Spice]

I think(?) I have to disagree (at least as I am reading it , sorry if I am misunderstanding), that those are for display purposes only. The values for:
View attachment 798077
are all used to define the specifics of the base you are using, and that in turn, alters the specific gravity values of your recipe.

Here are a couple of pictures to illustrate what I am trying to say:
Example #1
View attachment 798079
Example #1 result:
View attachment 798083
Now, in the second example I will change only the PG/VG ratio, by reversing them.
Example #2:
View attachment 798085
Example #2 Result:
View attachment 798087
Notice, that not only does the nic base description change, but so does the grams amount. All other values remain unchanged.


Precisely. The final nicotine amount changes dramatically.
However, the specific gravity does not change, because pure nic (1,000mg/mL) has a specific gravity of 1.01 (nearly a perfect neutral 1.00). That is not enough of a difference to alter the calculation. Change the PG/VG ratio though; and the "Grams" amount changes easily.

Does that help at all? Are we at least talking about the same thing? I am really sorry if I am being clueless.
I am trying to help... honest!

You are only repeating what I said except your being able to show examples in pic is a better way to show it to all reading it.
You stopped reading my post at that point. I had edited it to show further use for this info in the next line. ...long before you came back to read it.

 

[IDJoel]

@Sugar_and_Spice,

Today, after working the math out with paper and pencil, I now see that I was wrong, and you are correct. I thought I was correct. And, in that mind; my replies were sincere, and meant to be helpful... not argumentative. But that, in no way, changes the fact that I was wrong. Good intentions do not replace facts. I humbly stand corrected.

@Sugar_and_Spice, I am sorry, and I apologize. I should have checked the math for my self, before I responded. I hope you can find it in yourself to forgive me.

For those of you who dread my long posts( ), you can stop reading here. This is my main intent for this post.



For anyone wanting to know how I figured out I was wrong (and that the ELR calculator does, as Sugar pointed out, have at least one flaw); the rest of this post details my thought process, and I would welcome any feedback if you see any further flaws.

Besides speaking about something I had failed to first verify; my error was to assume that the volume of the mix, was just too small to reflect any significant/measurable difference. This was wrong. When I increased the batch size to 1 full liter (1,000mL); there was still no change.

I then tried multiple times, and in every way I could think of (changing data in the same screen, starting with a fresh screen, even opening multiple screens/tabs at the same time), to get different "grams" to add. It did not make any difference, whether I used a 100mg/mL 40P/60V base, or a 6mg/mL 40P/60V base. The weight of base to add remained at the 100mg/mL value (1112.45 grams).

I still thought it might be just an issue of the differences being too small to show (choices of where, when, and how to round off excessively long decimal places)(I was wrong about this too). This is when I decided to work it out for myself on paper.

Disclaimer: I am in NO WAY condoning the use of pure nicotine. I only use it below, to demonstrate its influence on total weight. I am aware of ECF's rule regarding direct conversations of nicotine concentrations exceeding 200mg/mL. This is for mathematical purposes ONLY.

I use botboy's weights, that @DaveP shared the link for, in post #2 of this thread:
1.010g/mL for Pure Nic (1,000mg/mL)
1.038g/mL for PG
1.260g/mL for VG

From there, I worked everything out long-hand, from scratch. I am 38 years removed from any formal math education. So, if anyone sees errors in my calculations, PLEASE point them out.

I calculated the weight of 100mg/mL nicotine in a 40PG/60VG base, 100mL batch size:
milliliters required to formulate 100mg/mL nicotine in a 40PG/60VG base:
10mL of 1,000mg/mL pure nicotine (PN) to arrive at a final dilution of 100mg/mL, or 10%.
36mL of PG
54mL of VG
10mL + 36mL + 54mL = 100mL Total volume

10ml x 1.010g = 10.1000g/mL nic
38mL x 1.038g = 37.0368g/mL PG (40% of 90mL)
54mL x 1.260g = 68.0400g/mL VG (60% of 90mL)
10.1 + 37.0368 + 68.04 = 115.508g/100mL
115.508g ÷ 100mL = 1.15508mg/mL ≈ 1.155 rounded off to the third decimal place

1.155g/mL is the weight I used for 100mg/mL nicotine in a 40PG/60VG base.

I calculated the weight of 6mg/mL nicotine in a 40PG/60VG base, 100mL batch size:
milliliters required to formulate 6mg/mL nicotine in a 40PG/60VG base:
0.6mL of 1,000mg/mL pure nicotine (PN) to arrive at a final dilution of 6mg/mL, or 0.6%.
39.76mL of PG (40% of 99.4mL)
59.64mL of VG (60% of 99.4mL)
0.6mL + 39.76mL + 59.64mL = 100mL Total volume

00.60ml x 1.010g = 00.606g/mL nic
39.76mL x 1.038g = 41.271g/mL PG
59.64mL x 1.260g = 75.146g/mL VG
0.6 + 39.76 + 59.64 = 117.023g/100mL
117.023g ÷ 100mL = 1.17023mg/mL ≈ 1.170 rounded off to the third decimal place

1.17g/mL is the weight I used for 6mg/mL nicotine in a 40PG/60VG base.

My final step, was to use the results of these calculations, and calculate the same recipe using each nicotine base. The recipe is simply:
9.5mL of 40PG/60VG nicotine base (95%; either 6mg/mL, or 100mg/mL)
0.5mL of random PG flavor concentrate (5%)

First, I did the calculation using the 100mg/mL 40PG/60VG base:
9.5mL x 1.17g/mL = 11.115g
0.5mL x 1.00g/mL = 00.500g
11.115g + 0.5g = 11.615g/10ml Total Weight

JuiceCalculator confirms these numbers:

So does the ELR calculator (though cut off at 2 decimal places):

Next, I did the calculation using the 6mg/mL 40PG/60VG base:
9.5mL x 1.155g/mL = 10.9725g
0.5mL x 1.00g/mL = 00.500g
10.9725g + 0.5g = 11.4725g/10ml Total Weight

JuiceCalculator again confirms these numbers (rounded off to 3 decimal places):

But, this time ELR DOES NOT agree:

As you correctly pointed out earlier, @Sugar_and_Spice, the ELR calculator STILL reflects the weight for the 100mg/mL nic base ERRONEOUSLY (not just from a simple rounding-off choice; as I had assumed). I was 100% wrong in my assumptions, and I should have checked the math, BEFORE I responded. I was wrong; and again I apologize, and ask for your forgiveness.

 

[zoiDman]

@Sugar_and_Spice,

Today, after working the math out with paper and pencil, I now see that I was wrong, and you are correct. I thought I was correct. And, in that mind; my replies were sincere, and meant to be helpful... not argumentative. But that, in no way, changes the fact that I was wrong. Good intentions do not replace facts. I humbly stand corrected.

@Sugar_and_Spice, I am sorry, and I apologize. I should have checked the math for my self, before I responded. I hope you can find it in yourself to forgive me.

For those of you who dread my long posts( ), you can stop reading here. This is my main intent for this post.



For anyone wanting to know how I figured out I was wrong (and that the ELR calculator does, as Sugar pointed out, have at least one flaw); the rest of this post details my thought process, and I would welcome any feedback if you see any further flaws.

Besides speaking about something I had failed to first verify; my error was to assume that the volume of the mix, was just too small to reflect any significant/measurable difference. This was wrong. When I increased the batch size to 1 full liter (1,000mL); there was still no change.

I then tried multiple times, and in every way I could think of (changing data in the same screen, starting with a fresh screen, even opening multiple screens/tabs at the same time), to get different "grams" to add. It did not make any difference, whether I used a 100mg/mL 40P/60V base, or a 6mg/mL 40P/60V base. The weight of base to add remained at the 100mg/mL value (1112.45 grams).

I still thought it might be just an issue of the differences being too small to show (choices of where, when, and how to round off excessively long decimal places)(I was wrong about this too). This is when I decided to work it out for myself on paper.

Disclaimer: I am in NO WAY condoning the use of pure nicotine. I only use it below, to demonstrate its influence on total weight. I am aware of ECF's rule regarding direct conversations of nicotine concentrations exceeding 200mg/mL. This is for mathematical purposes ONLY.

I use botboy's weights, that @DaveP shared the link for, in post #2 of this thread:
1.010g/mL for Pure Nic (1,000mg/mL)
1.038g/mL for PG
1.260g/mL for VG

From there, I worked everything out long-hand, from scratch. I am 38 years removed from any formal math education. So, if anyone sees errors in my calculations, PLEASE point them out.

I calculated the weight of 100mg/mL nicotine in a 40PG/60VG base, 100mL batch size:
milliliters required to formulate 100mg/mL nicotine in a 40PG/60VG base:
10mL of 1,000mg/mL pure nicotine (PN) to arrive at a final dilution of 100mg/mL, or 10%.
36mL of PG
54mL of VG
10mL + 36mL + 54mL = 100mL Total volume

10ml x 1.010g = 10.1000g/mL nic
38mL x 1.038g = 37.0368g/mL PG (40% of 90mL)
54mL x 1.260g = 68.0400g/mL VG (60% of 90mL)
10.1 + 37.0368 + 68.04 = 115.508g/100mL
115.508g ÷ 100mL = 1.15508mg/mL ≈ 1.155 rounded off to the third decimal place

1.155g/mL is the weight I used for 100mg/mL nicotine in a 40PG/60VG base.

I calculated the weight of 6mg/mL nicotine in a 40PG/60VG base, 100mL batch size:
milliliters required to formulate 6mg/mL nicotine in a 40PG/60VG base:
0.6mL of 1,000mg/mL pure nicotine (PN) to arrive at a final dilution of 6mg/mL, or 0.6%.
39.76mL of PG (40% of 99.4mL)
59.64mL of VG (60% of 99.4mL)
0.6mL + 39.76mL + 59.64mL = 100mL Total volume

00.60ml x 1.010g = 00.606g/mL nic
39.76mL x 1.038g = 41.271g/mL PG
59.64mL x 1.260g = 75.146g/mL VG
0.6 + 39.76 + 59.64 = 117.023g/100mL
117.023g ÷ 100mL = 1.17023mg/mL ≈ 1.170 rounded off to the third decimal place

1.17g/mL is the weight I used for 6mg/mL nicotine in a 40PG/60VG base.

My final step, was to use the results of these calculations, and calculate the same recipe using each nicotine base. The recipe is simply:
9.5mL of 40PG/60VG nicotine base (95%; either 6mg/mL, or 100mg/mL)
0.5mL of random PG flavor concentrate (5%)

First, I did the calculation using the 100mg/mL 40PG/60VG base:
9.5mL x 1.17g/mL = 11.115g
0.5mL x 1.00g/mL = 00.500g
11.115g + 0.5g = 11.615g/10ml Total Weight

JuiceCalculator confirms these numbers:
View attachment 798291

So does the ELR calculator (though cut off at 2 decimal places):
View attachment 798293
Next, I did the calculation using the 6mg/mL 40PG/60VG base:
9.5mL x 1.155g/mL = 10.9725g
0.5mL x 1.00g/mL = 00.500g
10.9725g + 0.5g = 11.4725g/10ml Total Weight

JuiceCalculator again confirms these numbers (rounded off to 3 decimal places):
View attachment 798297

But, this time ELR DOES NOT agree:
View attachment 798299
As you correctly pointed out earlier, @Sugar_and_Spice, the ELR calculator STILL reflects the weight for the 100mg/mL nic base ERRONEOUSLY (not just from a simple rounding-off choice; as I had assumed). I was 100% wrong in my assumptions, and I should have checked the math, BEFORE I responded. I was wrong; and again I apologize, and ask for your forgiveness.

Nice Retraction IDJoel.

It would have been Easy to just let this thread die. And not have said anything.

 

[IDJoel]

Nice Retraction IDJoel.

It would have been Easy to just let this thread die. And not have said anything.

Kind of you to say. But, when I am wrong, I am wrong. I was raised to own up to it. Not doing so, only makes me look even more ignorant, than I already made myself appear.

My apologies to everyone; for making a mess of the thread.

 

[Sugar_and_Spice]

@IDJoel

No apologies are necessary for there isn't a need for one. Mistakes happen(we are all guilty at some point for making them) , viewpoints differ as well as miscommunications. And this thread is not a mess, it is a learning session for all of us. On my part I was not trying to say one or the other of us was right or wrong, I was just trying to get you to see my viewpoint. Had I been the one who was in error, I, like you, would have owned it.

Ignorance is probably the last word(if at all) I would use to describe you. Don't be so hard on yourself, I doubt any of the members reading the thread thinks it's true either.

I do want to thank you and @zoiDman (and all who took an interest in this thread) for taking the time and having the patience to help me to understand why my results were so different between the different mixing methods and why a piece of that was my own error. Trying to sort all the pieces out by myself just kept me going in circles.

 

[IDJoel]

Very generous of you, @Sugar_and_Spice. Thank you! Though, the label does fit. Ignorant is defined as lacking in knowledge, and until I worked out the arithmetic for myself, I was certainly that. Lesson learned. Okay; `nough said, I'll stop groveling now.

What I found interesting, after doing the math is (if my math is correct) this doesn't look like it is the culprit of your under-sized batches.

We are in agreement that the calculator is using a fixed nicotine weight for 100mg/ml nic. It should(?) be causing the batch size to be over the expected volume (vs. your experience of under-sized batches). I arrived at that conclusion the following way.

Using the calculation results (shown in post #42); the Total Weight (base+flavoring) of each 10mL recipe is:
-- 11.6150 g/10mL (100mg/ml nic 40PG/60VG base used)(incorrect weight; too much)
-- 11.4725 g/10mL (6mg/ml nic 40PG/60VG base used)(correct weight)
11.6150g - 11.4725g = 0.1425g (greater than the correct target)(or a 1.2421% overage).

(Disclaimer: variance may differ slightly, based on actual PG/VG ratio, and nicotine content.)

To find the the excess volume:
I divided the difference (0.1425g/10mL) by the correct Total Weight (1.14725g/mL) per mL:

0.1425 ÷ 1.14725 = 0.12421mL (for a 10mL batch size)

This appears(?) to check out correctly; because 1.2421% of 10mL is 0.12421mL.
10mL x 0.012421 = 0.12421mL

It is not a whopping big difference. But, it is not insignificant either. At any rate, it doesn't look like it shouldn't be causing the under-sized batches you have experienced (if my calculation are correct). I don't know what is causing your shortages, Sugar.

I am not at all confident that I am looking at the math correctly. I welcome anyone thoughts.

 

[Sugar_and_Spice]

Very generous of you, @Sugar_and_Spice. Thank you! Though, the label does fit. Ignorant is defined as lacking in knowledge, and until I worked out the arithmetic for myself, I was certainly that. Lesson learned. Okay; `nough said, I'll stop groveling now.

What I found interesting, after doing the math is (if my math is correct) this doesn't look like it is the culprit of your under-sized batches.

We are in agreement that the calculator is using a fixed nicotine weight for 100mg/ml nic. It should(?) be causing the batch size to be over the expected volume (vs. your experience of under-sized batches). I arrived at that conclusion the following way.

Using the calculation results (shown in post #42); the Total Weight (base+flavoring) of each 10mL recipe is:
-- 11.6150 g/10mL (100mg/ml nic 40PG/60VG base used)(incorrect weight; too much)
-- 11.4725 g/10mL (6mg/ml nic 40PG/60VG base used)(correct weight)
11.6150g - 11.4725g = 0.1425g (greater than the correct target)(or a 1.2421% overage).

(Disclaimer: variance may differ slightly, based on actual PG/VG ratio, and nicotine content.)

To find the the excess volume:
I divided the difference (0.1425g/10mL) by the correct Total Weight (1.14725g/mL) per mL:

0.1425 ÷ 1.14725 = 0.12421mL (for a 10mL batch size)

This appears(?) to check out correctly; because 1.2421% of 10mL is 0.12421mL.
10mL x 0.012421 = 0.12421mL

It is not a whopping big difference. But, it is not insignificant either. At any rate, it doesn't look like it shouldn't be causing the under-sized batches you have experienced (if my calculation are correct). I don't know what is causing your shortages, Sugar.

I am not at all confident that I am looking at the math correctly. I welcome anyone thoughts.

Thank you Joel.

I believe the culprit was with an old calculator eliquid program that was probably developed very early on in the DIY world and never had corrections made to it as the industry developed.

Because I have no access to its actual formulas'(in order to correct anything) they are still present in it. I went 1 by 1 through a recipe using the volume method and also what that program was telling me to use for gram weigh. Then compared results of those findings to elr and the old program was off either way by quite a bit.
So, having said that, I believe that is what was causing both problems I was having, Wrong total results in weights and in taste. And another reason I was mostly doing my recipes in volume mixing and by hand and good old fashioned math.

Thanks again for all of your help. I do plan to abandon that old calculator and begin using the elr faithfully. But I will no doubt double check the math at least at first before totally trusting results.

 

[bombastinator]

I would say gravity is very important for DIY. Otherwise it’s all kinds of mess.