Concrete Leaf Castings
Article written by Dottie Baltz
Page 1 2
- Basic Materials Needed
- Choose Your Leaf
- Prepare Your Work Surface
- Mix the Concrete
- Place the Leaf
- Set the Concrete
- Optional Pedestal for a Birdbath
- Optional Hanger
- Initial Cure
- Smooth the Edges
- Optional Paint and Stains
- Seal the Casting
- Additional Tips and Troubleshooting
Step 6 - Optional pedestal for birdbath
At this point, you can build up the middle even further to create a pedestal so that the birdbath will sit up off the ground a bit. It is
notnecessary, just depends on where and how you want to place it in your garden. The pedestal should be at least half the size of
the leaf width and it can be any height. Mine are only about 2"-3" tall. Once you have the desired size, take a board and flatten
the top. You can use a level or just eye ball it to see if it appears level. Where you place it in the garden may not be level, so
don't go crazy trying to get this level unless you plan on putting it someplace where this will be important.
Step 7 - Optional Hanger
If you don't want a pedestal on the bottom, you can add a hanger at this point in case you'd rather hang your leaf casting on a
fence or garden shed. To do that, take a piece of heavy wire, form into a loop and bury the ends slightly in the mixture, leaving
the loop exposed. Wire coat hangers work well for this also. You may also not want to have the leaf cupped quite as much as
when you would be using it as a birdbath, so modify the mound of sand before beginning your casting.
Step 8 - Initial Cure
Place a plastic bag loosely on top of the leaf casting and do not move it for at least 48 hours. This is very important to avoid breakage. The air temperature should be on the cool side, but not below 40 degrees. If you are experiencing hot temperatures, make sure you prepared it in the shade and it can be misted a few times a day if you think it's curing too fast, but the bag alone should keep it from curing too fast.
Step 9 - Smooth the Edges
Once the casting has cured for 48 hours, you can remove the plastic sheeting and work your fingers under the leaf so that you can
flip the birdbath over to its rightful position. Peal the leaf off the concrete. It should come off pretty easily, but if it doesn't let it sit a day or two longer. If it still won't come off, you can use a wire brush to get it off after it has sat for 7 days, just be careful you don't rub off the pattern you have made on your concrete or chip the edges. The edges can be smoothed out by using a metal file or rock. Once it has sat for more than 72 hours, sanding the edges will become more difficult, so I like to perfect the shape
before it has completely cured.
Step 10 - Optional Paint or Stains
After 72 hours you can apply paints or stains to your project, as is the example on the right. Check the label instructions of your paint or stain to see if it requires the concrete to cure longer. I use
Patio Paints for most of my castings and usually wait a week to make sure it is fully hardened to help avoid breakage.
Step 11 - Seal the Casting
After 72 hours the birdbath can be sealed with a concrete sealer. These sealers are clear and shouldn't change the color of your
birdbath. Two coats should do it, but follow the directions on the sealer that you are using. Let dry for at least 24 hours. If you
are using an outdoor paint, sealing may not be necessary. Check the label on your paints for further instructions.
Additional Tips and Troubleshooting
If your birdbath won't hold water, check to see if it cracked during the curing process. Cracks can occur if the concrete cures too fast on a hot sunny day or it was moved too soon. If there are no visible cracks, the concrete is probably still absorbing too much water because there are too many air pockets. There are several ways this can be fixed.
Option 1 - Fixing a leaky birdbath
Mix a little Portland cement and water to create a slurry and coat the back of the birdbath. You may need to do two coats.
Option 2 - Fixing a leaky birdbath
Mix a little Portland cement and a white PVA glue (such as Weldbond or Elmer's) and coat the back of the birdbath. Make sure the glue dries clear.
Option 3 - Fixing a leaky birdbath
Use a concrete sealer designed for leaky basements on the back of your birdbath.
Option 4 - Fixing a leaky birdbath
If you plan on painting your birdbath, this will usually eliminate the problem as well. You'll want to protect your paint job with an
outdoor sealer or use Patio Paints instead of regular acrylics or latex paints.
Common Reasons for Breakage
- Drying too quickly in the sun
- Not curing long enough before moving it
- Mixture was too wet to begin with
- Project too large and needs reinforcing fibers or mesh to help reinforce the cement
- Leaf casting not thick enough
Your concrete birdbath will be able to remain outside all year round, however, if you have heavy snow falls or below freezing temperatures, you may want to turn your birdbath on it's side or upside down so it doesn't hold water.
I prefer to let my leaf castings sit for 30 days before use. This ensures that all the paints, sealers, and the Portland Cement have fully cured. Curing is essential for a long lasting project.
Page 1 2