Viscosity Experiment

Well, here is more useless trivia from Wheeler labs.  I’ve been playing around with thinning ratios and got to thinking about the viscosity of different thinners.  I could probably have found them on the web, but that’s no fun.  So I rigged up a crude gravity flow type capillary viscometer.  Here it is.

 

The way these work is to measure the time it takes a measured amount of liquid to flow through a small opening under the force of gravity.  The longer it takes the more viscose the liquid.  Mine consists of an eyedropper with a length of tiny Teflon tubing attached to the tip.  The inside diameter of the tubing is about .8mm, slightly larger than the diameter of the standard Badger Anthem tip.  The T assembly at the top connects on the right to a syringe with calibration marks, and on the left to a stopper made from the tip of an old brush handle.

To make a measurement, I dip the tubing in a liquid and pull back the syringe to the last mark.  This almost fills the eyedropper.  Then I simultaneously remove the plug on the left and start the stopwatch.  When the level of the liquid reaches the black mark on the eyedropper, I stop the watch.

Since my setup is not really calibrated to any standard, I can only do comparative measurements.  A liquid that takes twice as long is twice as viscose.  Here is what I have so far.  Each measurement is the average of several tries and is rounded off to the nearest second.

Acetone                                         4 seconds
Lacquer thinner                           5 seconds
Water                                             6 seconds
Mineral Spirits                              6 seconds
Testors Airbrush Thinner           6 seconds
Anhydrous Isopropyl Alcohol    10 seconds
Turpentine                                    10 seconds
70% Ethyl Alcohol                        12 seconds
2% Milk                                           14 seconds
Whole Milk                                     14 seconds
70% Isopropyl Alcohol                 20 seconds

So, it turns out that milk, the standard for airbrush paint thinning, is a bit over twice as viscose as water or mineral spirits.  Actually, the milk was cold, and it might be a little less viscous at room temperature.  The weird one was the 70% Isopropyl alcohol.  I did it over and over and it’s twice as viscose as the Anhydrous Isopropyl.

As I said, this is probably useless information.  But, I thought it was kind of interesting, and I wanted to share it.

Don