Ask the Expert Question-and-Answer Archive

by Ron Joseph

September, 2003

Measuring Viscosity with Ford #4 Cup (Viscometer)

Q. Actually the cup is Ford # 4, in india as per Indian Standard the cup is called the B4 cup. I can't find the procedures for checking the viscosity in the byk-gardner site. Kindly help me in this regards as early as possible.

A. Place the Ford #4 viscometer on its stand. Allow the paint to stabilize at room temperature, or at whatever temperature you intend to measure the viscosity. Measure the temperature. Plasce a small container under the Ford cup. Fill the cup all the way to the top until a small of overflows into the outer ring, but place your finger under the orifice to prevent the pant from running out of the cup. Start a stop watch and immediately remove your finger. Allow the paint to efflux (run out) into the container below. As soon as the paint stream stops flowing stop the stop watch. Record the time it took for the paint to efflux from the cup.

You can also get a very detailed description of the method from ASTM D1200-94. You can download this method from the ASTM website, but you will need to pay a small fee for the document.