Thickness Testing

To see the importance of Thickness Testing, either watch the video below or read the full article.

Nothing like a thick coat of paint right!

Well, that actually isn’t the case. Sometimes yes, but sometimes, applying a thick coat of paint is the worse thing that you can do.

This all depends of course on the manufacturer’s requirements for the paint that you or your guys will be using.

Or in the case of your contractors, what paint they are using on your building.

Applying the paint either too thick or too thin can have very adverse effects on the coating like cracking paint, flaking paint and even the paint surface peeling off. And even a milky appearance can occur.

So how do you know if the paint you are brushing onto the wall or window or whatever surface you are painting is the correct thickness?

Well, this is all determined by what is called the Wet Film Thickness. And this is always specified by the manufacturer.


They are always different.

So how can you check?

The worse way to check is with an Electronic Thickness Meter. That is if you had no way of checking the thickness when you were painting it on yeh!

And what if the thickness is all wrong?

What do you do then? Sand it all back and start again?

No! What you want to do is ensure that you have the correct thickness when you are brushing or rolling or even spraying the coating on.

And how do you do this?

Easy! With this little tool called a Thickness Tester.

And what we are testing for is what is call the Wet Film Thickness. Or WFT.

Yep, that is the thickness of the paint when you have just applied it to the surface and it is still wet.

All you do is take random thickness tests of the coating to ensure that you have the thickness correct.

And then adjust as needed to apply more or less, depending on the manufacturer’s instruction.

Here is a quick demo:

Easy right!

That’s right.

So just use the gauge at regular intervals to keep a check on yourself and then when the paint dries, you will find that the thickness is just fine.

And that is then what we call the Dry Film Thickness. or DFT.

Have a look at the Data Sheet now and you will see more easily what the information means.

Hope that this helps.

See you Next Time. On The Ropes!

mike king on the ropes

Mike King
Lead Technician

9560 3929 or