Hollow Concrete Garden Sphere

Super Tips & Advice To Cast ‘Em Big and Beautiful!

There are a few techniques you need to know before casting a hollow garden sphere made from concrete. These great tips will help insure that your creation comes out looking like you are a pro.

You won’t find these garden sphere tips and tricks mentioned on other “how-to” sites. I want to SHARE with you all that I’ve researched and collected over the years. These are techniques that have WORKED for me and other dedicated crafters.

Little & Lewis Concrete Garden Spheres

For inspiration, here are spheres created by the MASTER concrete artisans, Little and Lewis. I certainly say “wow” every time I view their work. If you’re not familiar with their incredible garden art sculptures, please take a moment to visit their site: Click Here

Easy Concrete Mixture for Casting Smooth Hollow Garden Spheres

What you’ll want to use to insure your sphere will survive many years in the outdoor elements is a fiber reinforced quick-set concrete. There’s really no need to mix a batch from scratch, because there are products on the market that are pre-mixed and ready to go. Make it easy on yourself!

A great product that’s readily available and that many crafters and artisans use to make “smooth as silk” concrete objects is QUIKRETE® Concrete Resurfacer. Just mix a batch per the manufacturer’s instructions. Here’s more about this product from the QUIKRETE® website:

” … a special blend of portland cement, sand, polymer modifiers and other additives, Concrete Resurfacer renews spalled, aged, dirty, stained and cracked concrete surfaces – indoors and outdoors. For a decorative finish, QUIKRETE® Concrete Resurfacer can be colored using QUIKRETE® Cement Color or Stucco and Mortar Color.
One 50-pound bag will cover approximately 25 square feet at a 1/4″ thickness and no special curing or sealer is required.”

Did you pick-up on the last part of the product blurb? The part that says: " … and no special curing or sealer is required.”

That is GREAT information to be aware of, because not having to deal with these two issues makes this product even more desirable to use, not only in my estimation but many other sphere-casters as well.

Casting & Finishing Techniques

More Expert Advice To Insure a Beautifully Smooth Sphere

How to Cast Your Concrete Garden Sphere

You will need an INFLATIBLE / DEFLATIBLE beach ball or exercise ball for this project. I’ve got everything you need to know about casting a sphere in the following article.

Please click here to read my step-by-step instructions: How to Make a Hollow Garden Sphere

How to Fill-in Pinholes Techniques to Achieve a Smooth Surface

Close-up of concrete surface pinholes

Unsightly pinholes (or air holes) seem to be an inevitable problem when casting in concrete.

Here are techniques to solve this problem:

  • A quick fix solution that works: Mix a couple of tablespoons of “slurry” (a runny mixture of concrete and water). With your fingers, rub the slurry back and forth over the casting to fill all the little holes. (Some people also wait about 20 minutes and then rub with a wet sponge to remove any excess slurry. This step may or may not be necessary for your project.)
  • Keep rubbing in the slurry and after a few minutes you won’t even know where those bothersome holes were. Voila! Like magic they’re gone. This finishing technique makes the difference between a professional looking casting and a homemade one.
  • Make sure to mix your ingredients slowly and gently. Do not whip or stir your ingredients vigorously or you’ll incorporate air into the mix. Try using a folding-over motion (just like folding egg-whites into ingredients in
    a baking recipe).
  • Use a multi-layer casting process (many people do): As you will find mentioned in the “How to Make a Hollow Garden Sphere” instructions, you’ll build up layers of your mixture to achieve the sphere’s desired thickness.
  • Tap or “plunk” the mixing container down on the ground (or hard surface) a few times to help bring any air bubbles up to the surface.
  • Gently “pat, pat, pat” your mixture onto the ball. This helps release the air bubbles, too.

**Remember: ALWAYS WEAR YOUR GLOVES when handling concrete mixtures! Read why!! Click this link: Concrete & Hypertufa Safety Concerns & Guidelines

Speak Your Mind


What is 26 + 19 ?
Please leave these two fields as-is:
IMPORTANT! To be able to proceed, you need to solve the following simple math (so we know that you are a human) :-)