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