Because your PG-based nicotine concentrate at 18mg is too low to get a 40PG juice at 6mg. You need a PG-based nicotine concentrate of 24mg strength minimum.
Switching to mixing by volume isn't likely going to change anything for you since you always have to calculate something, be it in your head or using a calculator. You have issues with calculations, and the that won't change regardless of what method of mixing you use.
As I stated previously to you in this or another thread, that doesn't matter. The fact that one calculator is programmed with a VG weight of 1.25g/ml while another is programmed with a VG weight of 1.29g/ml or 1.19g/ml makes no difference because the difference is so minuscule it actually won't be noticeable. This example is actually extreme. You're not likely to even see that much of a discrepancy from one calc to the next, but even if you did it doesn't matter. We're not making bombs or rockets here. Hell, people used to (and still might) mix by drops. Drops are very inexact measurements since how much a drop is depends on variables beyond your control.
Switching to mixing by volume isn't likely going to change anything for you since you always have to calculate something, be it in your head or using a calculator. You have issues with calculations, and the that won't change regardless of what method of mixing you use.
As I stated previously to you in this or another thread, that doesn't matter. The fact that one calculator is programmed with a VG weight of 1.25g/ml while another is programmed with a VG weight of 1.29g/ml or 1.19g/ml makes no difference because the difference is so minuscule it actually won't be noticeable. This example is actually extreme. You're not likely to even see that much of a discrepancy from one calc to the next, but even if you did it doesn't matter. We're not making bombs or rockets here. Hell, people used to (and still might) mix by drops. Drops are very inexact measurements since how much a drop is depends on variables beyond your control.
