It makes me crazy to unmold a sculpture and find that bubbles have made little pock marks. They always seem to happen in very visual areas around the sculptures lips or eyes or hands. I'm very careful to mix the concrete so it is smooth and I when putting it into a mold I use a long handled plastic spoon to gently move the mixture around in an attempt to break any air bubbles and get the mix into the detailed areas of the mold. I also do a little shaking of the mold to get the concrete settled. Are there any other tricks to keeping out the air pockets?

Here is a trick, fill a spray bottle with rubbing alcohol. Spray the surface of the concrete mix to pop the bubbles. Shake the concrete container and spray the surface again. Then spray the inside of the mold (but not overly saturated). This will break the surface tension of the bubbles as you pour. As additional steps you could bang the mold harder to force the bubbles to rise, and even put your hand inside the form and run your fingers along the inside surface of the mold to eliminate the bubbles. Some people use a soft brush to do this.

Thanks Leann. I have used the rubbing alcohol to eliminate bubbles when molding homemade soap, but I never thought to use it with the concrete mix, I look forward to giving it a try.

Mix some "Jet Dry" dishwasher rinse agent in a spray bottle with water and spray it in your mold before pouring. Also I found that by mixing the "Garden Cast" (that is what we used to pour, US Gypsum makes it) thinner than the manfacturer specs we eliminated the bubble holes in the final product. Hope this works for you.