I ordered some extra pyrex tubes while testing the Pyrex SS Hybrid Wick detailed by Scubabatdan. This can get a bit technical but I wanted to see if I could get a 95% VG ejuice to wick using only pyrex tubing and no SS mesh. The short answer is no, it is not practical; it will not be a pure substitute for other wick materials such as SS mesh etc.
I tested the capillary rise of a multiple thin walled pyrex tubing construct to determine the potential for use as a substitute/complimentary wick mechanism. My interest was to see if adequate ejuice delivery to a coil at typical genny dimension could be achieved. Typically, coil height from the bottom of a tank to the coil is around 4cm. I used a multi tube capillary tube construct placing pyrex tubes within each other to minimize the distance between the surface walls of three pyrex tubes. There is a formula for capillary rise of liquids based upon their properties, and the closer the walls of the tube are the higher a liquid should rise, but Ill just stick with the test results here for now.
Pyrex Tubes Wilmad Labs
1.0mm OD/.8mm ID
1.7mm OD/1.3mm ID (avg. gap between walls -~.15mm)
2.5mm OD/2.2mm ID (avg. gap between walls ~.25mm)
I test the construct first with tap water to see if the calculated dimension adhered to the formula for capillary rise.
Water Rise:
Water Rise Micro View:
Interesting that the smaller diameter inner most tube provided the greatest height. (Contrary to formula, but the shapes are different for the outer tubes.)
Using 95% VG the results overall did not reflect the formula and were lower than anticipated.
95% VG Rise
95% VG Rise Micro View
For VG, The capillary rise was less in the inner most tube and not visible in the picture. (Consistent with formula)
On a side note, based upon the properties of PG, theoretically, the rise would be greater than VG, but in no case will it be higher than water.
So if water provides the best case scenario, capillary rise at best will be 32mm and in this case would not be good enough to use a pyrex only wick. 95%VG provided only ~15mm at best.
The rate of capillary rise for VG was also significantly slower than water, but was expected due to much high thickness of VG. Interesting, the total liquid contained within the tubes for VG was approx. 6 drops and would most likely be sufficient for gennys.
I tested the capillary rise of a multiple thin walled pyrex tubing construct to determine the potential for use as a substitute/complimentary wick mechanism. My interest was to see if adequate ejuice delivery to a coil at typical genny dimension could be achieved. Typically, coil height from the bottom of a tank to the coil is around 4cm. I used a multi tube capillary tube construct placing pyrex tubes within each other to minimize the distance between the surface walls of three pyrex tubes. There is a formula for capillary rise of liquids based upon their properties, and the closer the walls of the tube are the higher a liquid should rise, but Ill just stick with the test results here for now.
Pyrex Tubes Wilmad Labs
1.0mm OD/.8mm ID
1.7mm OD/1.3mm ID (avg. gap between walls -~.15mm)
2.5mm OD/2.2mm ID (avg. gap between walls ~.25mm)
I test the construct first with tap water to see if the calculated dimension adhered to the formula for capillary rise.
Water Rise:
Water Rise Micro View:
Interesting that the smaller diameter inner most tube provided the greatest height. (Contrary to formula, but the shapes are different for the outer tubes.)
Using 95% VG the results overall did not reflect the formula and were lower than anticipated.
95% VG Rise
95% VG Rise Micro View
For VG, The capillary rise was less in the inner most tube and not visible in the picture. (Consistent with formula)
On a side note, based upon the properties of PG, theoretically, the rise would be greater than VG, but in no case will it be higher than water.
So if water provides the best case scenario, capillary rise at best will be 32mm and in this case would not be good enough to use a pyrex only wick. 95%VG provided only ~15mm at best.
The rate of capillary rise for VG was also significantly slower than water, but was expected due to much high thickness of VG. Interesting, the total liquid contained within the tubes for VG was approx. 6 drops and would most likely be sufficient for gennys.
