In the continuing series of posts in the category of How To, may we present the instructions, with accompanying photos, of the way we, here at the Fairegarden, go about making leaf castings? Let us proceed with the gathering of materials needed. I suggest you read all of the instructions before you begin, to familiarize yourself with the process. It is quite simple, but time matters once the cement mixture is wet. Shown above is our very first leaf casting attempt from a few years ago, a Colocasia esculenta ‘Black Magic’ leaf.
It is easier on an aging, or even young for that matter, back to be able to stand comfortably while doing any project,it has been found. An old table with a metal top is the workspace. Outdoors under the deck is the studio. This space has a gravel floor and cement projects can be messy, so find an appropriate area to work and dress accordingly. You will need a bucket of water to moisten the dry ingredients. Sometimes I use the cement bonding liquid along with water, but it is not necessary. It does make for a stronger casting, however. You will need a large tub in which to mix, and a long handled tool to stir. The mixture is one part Portland Cement to three parts coarse builder’s sand. Mix the dry ingredients well with the long handled tool. DO NOT WET IT YET. You may also use premixed mortar, but I much prefer using the Portland Cement and this is the same cement used to make hypertufa, with peat moss and perlite, so there are a lot of projects in one bag. It comes in large bags for a cheap price and needs to be stored in the dry, moisture is the enemy until you are ready to begin. Depending on the size of the project, various measuring devices can be used. Old pans, plastic containers, whatever is used should not be used for food preparation after being used for cement measuring. Also, wear rubber gloves, as the cement is very, very hard on human skin. Again, the mix is three parts sand to one part cement.
You will need a mound of moistened sand on the base, larger than your chosen leaf. This will form the curve of the finished project, but you can also make the casting flat, if desired. For the base of flat or curved leaves, I use pieces of packing styrofoam saved from the purchase of electronics, or a board also works well. It is good to be able to move the curing project out of the way to clear your workspace for the next project, so either foam or a board or something strong enough to hold the sand and finished project is best. You will need plastic wrap on top of the moist sand to neaten the edges, as the mixture can sometimes run and/or drip. In choosing your leaf, look for a nice size with prominent veining on the underside. This is what the top of your casting will reveal, so the more prominent the veins, the more interesting your cement leaf will be. Use a freshly picked leaf for the best results. I have used many different types of leaves and really like the look of the cucurbit family, squash, zucchini, pumpkin, etc., but today, I have none of those so will use the nicely veined large hosta leaf. (Brush the sand off of the leaf before adding the leaf casting mix. I wondered why the surface was all pebbly on the finished project and can now see why after viewing these photos.)
I wanted this finished product to be something of a bowl shape, so mounded the moist sand on the base before placing the leaf, UPSIDE DOWN, upon it. The veins should be facing up. For more or less of a bowl shape, adjust the moist sand to your liking. Place the plastic wrap on top of the sand with the edges sticking out well past the leaf, if it is too large a leaf to do it all with one piece of wrap, use several sheets. You will be glad to be able to lift the plastic to neaten the edges once you have spread the wet mix on the leaf. Smooth the leaf as neatly as you can on top of the sand and plastic wrap. Cut the stem off if it is in the way and fold or snip the leaf to make it lay flat at the stem end.
Now you are ready to wet your mixture. Getting just the right consistancy can be tricky, so add the water or bonding agent a little at a time, mixing well as you go. There will be a small window of wetness to be able to work with the mix before it begins to harden, that is the reason for waiting until everything is ready before proceeding. There is no formula for how much water to add, but I like the mixture to be fairly dry. If it is too runny, it will slide off the leaf into a puddle and you will have a casting that looks like a blob of melted ice cream. You should be able to squeeze it in your hand and have it hold the shape, but still be wet enough to spread easily.
Apply the mix onto the leaf using your gloved hand, placing a couple of handfuls in the center. I like for the casting to be about one half of an inch thick in the middle, tapering to one third to one quarter of an inch at the edges. You can make it thicker than that, but no thinner. If you are going to be using the leaf as part of a fountain, make it thicker. (If you want to make a very large leaf, it will need reinforcing with wire hardware cloth. I have not tackled that as yet, so you will have to look elsewhere for instructions.)
Begin patting the cement mix gently towards the edges of the leaf with your fingertips. This is a two handed job, but I was taking photos during the process is why there is only one hand showing. I pat with one hand and hold the other hand along the edge of the leaf. Try to be especially neat along the edges, following the shape of the leaf as best you can. The hosta leaf is simple, but the squash leaves will take more time to keep those edges crisp. For your first attempt, simple is best.
Once the leaf is covered completely, I like to build up the surface on the bottom, which is the top while you are working on it, so the leaf will stand without tipping. Build up feet or one larger foot with mix, a little bit at a time until you can level it somewhat. I used a board to make the three knobs more level, pressing it very lightly onto the project. You can see the bits of wet mix on the board. If you don’t care about tipping, follow the curve of the leaf.
When you are satisfied with your work, lift the edges of the plastic wrap to clean up any drippings and pat outside the plastic with your fingers. Look for the green edge of the leaf to follow the shape. Hopefully you have not made the mix too wet, but if you did, don’t fret, just keep neatening the edges as the cement dries out some more, you can fix the edges later on, after pulling the leaf off.
After you are done, cover the entire project loosely with plastic of some kind, to allow it to harden slowly. The longer it takes to dry, the stronger it will be. Use props to lift the plastic cover off of the wet casting. Keep it out of the sun and allow it to set up overnight.
The next day, lift the veil of plastic to check for hardness. Depending on the air temperature outside, it should be set enough to move to the next step. Cold will lengthen the hardening time. The casting should not show an impression when you press your finger on it, and seem hard when gently tapped. If still soft, allow another day of hardening. When you feel it has set up properly, you will now turn it over, oh so carefully, for it can be easily be broken at this stage. Wearing gloves, slip one hand under the plastic of the entire leaf, the sand will allow you to get well under it. Place your other hand centered on top and carefully flip it over from hand to hand. Don’t blame the gnomes for these broken pieces, this was a casting from a large banana leaf and should have been reinforced with hardware cloth. Heartbreaking still, so do be careful!
Gently pull off the leaf. If bits of leaf are stuck, you can use a sharp knife to carefully lift what you can. All leaf bits will dissolve over time, it is best not to muck about with it too much at this stage, the leaf casting is quite fragile right now. (You can see what the sand left on the leaf did to the surface, shame on me!) If there are any globs along the edge that you don’t like, rub them off with your gloved fingers, or use a sharp knife to carefully cut them off. This is why the leaf is unmolded while it is not fully set, to fix any imperfections. If you need to make the veining more distinct, use a large nail, again, very carefully. When you are happy with it, cover again with the plastic and allow it to cure for a few days.
After the curing, which makes it much stronger, you can finish as you would like, or let it be as is. I like to paint the leaves and top with several coats of water-based polyurethane. For the paint, I use the small plastic bottles of craft paint, mixing colors and adding many layers for an aged look. Let the paint run into the veins for contrast, if you wish. Painting then wiping off some of the paint with a cloth or paper towel will give a nice effect. You are on your own with the painting, but using the protective poly coat will help the colors last, even when outside and exposed directly to the elements. Here are some projects that have been made over the years with the leaf casting mixture and posts about some of them:
Cement Reflections, click to see the post
A Little Whimsy In The Garden Click to see the post
May your creative juices be flowing like rivers as you get out there and cast your own leaves with the cement/sand mix.
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