How to fix air bubbles?

How do you fix your cement mold finished mold that has a lot air bubbles holes

mikeasaurus8 months ago

An ounce of prevention is better than a pound of cure. So, spend the time to vibrate your molds after pouring to remove all the air bubbles.

Repairing bubbles after concrete is cured is tough. You can apply grouting and then try to blend the patch into the existing concrete, but it usually won't look that good. You'll probably have to paint the piece to really cover the patching.

You will have to rub it in. Mix a fine sand and cement (same color as in the cast) and water to get a thick soup. Wearing rubber gloves, wet the piece thoroughly. Scoop up some mix and push it into the bubbles on one side and rub it in forcefully. Go around to every side that needs it. Then use a brush to get off sand mix that is on the surface where you don't want it. Also use a small wooden tool. After an hour, mist the fixed sides.