CWF Weight On Balsa?

This isn't very scientific, just an observation.
There have been forum posts about how heavy Carpenter's Wood Filler is. I was curious too.

Here's a forward fin for a Gyroc build.
This is smooth sanded 1/16" thick balsa with no filler applied.
The unfilled fin weighs in at 0.02 oz.

Later Elmer's Carpenter's Wood Filler (CWF) is applied and sanded almost to surface.
The fin now weighs 0.03 oz.

Not much of a difference. I don't fly in competition so this little amount doesn't matter.