why do I get small bubbles when applying joint compound?

Answer 1

It may be that you are over-mixing the compound. Too much stiring will whip air into the compound, and then when you spread, bubbles form.

Answer 2

The only time I get those bubbles is when I apply the mud over an already painted surface doing fix-ups. I have been told that it's the air coming out as it can't go into the material behind it. There will be no bubbles on the new drywall, just where I have joined it to the old painted side. Sand them lightly and apply another coat and see what happens. Sometimes it tale 3 or 4 coats to rid the joint of the bubbles.

Answer 3

If you are using pre-mixed compound, add a little water. You don't want the mud to be real stiff, but not runny either. Maybe like soft peanut butter. If you are already adding water to the pre-mix you may be adding too much water.

Answer 4

With all due respect; too much added water will lessen the effectiveness of the MUD, plus during any agitation to STIR in the water; mixing to an even consistency, will add air bubbles to the MUD.

Obviously if you're mudding too heavily, as it dries it might also create pockets,,,and one answer states it well,,, you might just WORK it a bit more during your application.

Steven Wolf
Thousands of gallons of MUD later...

Answer 5

I get this all the time when using the premix. I usually find that if I work it in a litttle more the bubbles go away.

Answer 6

The pros that I have talked to say that when they place the compound into the plastic, handheld container, they work it (mixing motion) with the knife to remove the air.

Answer 7

You need to add more water to your compound and let it sit for a few minutes after you mix it.