Ever since I can remember I have been fascinated with casting things in molds. ('moulds' or 'molds', seems they are interchangeable words) Currently, I am a bit of a concrete-o-holic! I look at all kinds of things to see if they could somehow be a mold. This project is a super easy way to cast coasters using just old CD cases, concrete and the gifts from nature; Leaves!
Everyone has a bunch of CD cases somewhere! Each coaster becomes unique and has such amazing texture. I marvel at how some trash, and things laying on the ground can make something so beautiful! Mother Nature is so generous... and never seems to give us a bill.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Gather Your Stuff:
To Cast the Coasters:
- CD cases (as many as coasters to be made)
- Large Leaves (Look for any that have a nice vein pattern and are not to fuzzy) I used grape, maple leaves
- RapidSet Cementall concrete
- Mixing container, water, stir spoon (see here for my tips on working with concrete)
- Dust mask and ‘rubber’ gloves
- flat surface/table (cover or protect for working with the concrete)
Get your leaves ready
Go for a walk and look at the leaves. Be conscious of where you get them please. I look around the sides of the road etc. Look for leaves that have a size large enough to cover a circle of at least 3.5 inches (8cm) and a pronounced vein pattern on the back. Cut off the stems close to the leaf. The old grape vines seemed rampant and maple leaves also work well. I am sure you have many old CD cases somewhere, so take them apart for the flat top and bottom pieces; as you want the smoothest surface
Step 2: Mix the Concrete
Where the casting magic happens:
Suit up with mask and gloves… I have used this RapidSet Cement all for many projects and I am quite happy with how strong the finished product is. It sets really fast as well so make sure you are prepared. It is an all-in-one mix that only needs water added. This product has quite the plasticity and will seem a bit odd when mixing. It is recommended to add the water first, however I am a bit of a rule breaker! Be careful not to add too much water as it uses less than most mixes, work slowly and add a tiny bit at a time.
You want a mix that will somewhat hold it's shape, not run. Waiting about 30 seconds also lets it just thicken a bit. You will see that it ‘flows’ at an even thicker consistency. I use about 1.5 -2 tablespoons of mix for each coaster/leaf and I make a few at a time. Be sure to put the leaf with the back/vein side up on a very flat surface. No mold release agent needed here!
Once you have plopped a bit on each leaf, take an old CD case lid and centre over top, and slowly squish it down. Wriggle it a bit and it will make quite a consistent round shape. Do not flatten too much, aim for about 3mm or so. Yes, I know that is thin, but this mix will be able to handle it. To rid of air bubbles I smack/slap it lightly a couple times too. If you are unsure, just try one to start with. Leave the CD case in place until it is set.
Yup, that’s it! No mold needed! Just make sure your table surface is nice and flat. You see; those childhood playtimes in the sand box come back to haunt you…
Step 3: The Big Reveal
Voila! After about one hour go ahead and peel off the leaf. If you are careful you may even be able to reuse it! I marvel at how this concrete mix picks up each detail of the texture!
The edges are quite clean already however you can sand them a bit if you like.
HINT: to make sanding easy and cheap, I make little ‘sanding discs’ when I have leftover mix. I just plop it onto a flat surface and let it set. Once cured it can be used like a sanding block, as it does have sand in it and does not rip like paper.
This mix creates a very fine concrete, much different than most standard mixes.
Step 4: Adding the Finishes
You will need:
- Black Acrylic Paint, copper, silver, gold, (or acrylic inks)
- tacky glue
- Clear acrylic Matt medium optional
- brushes, water, paper towel/rags
To make the texture just ‘pop’ I use the typical method of antiquing. I have been using this method since the my days of glazing beer steins 30 years ago. (ya, I’m kinda old)
Mix a bit of a black acrylic paint with some water to make it quite runny and thin. Use a big brush to sop the entire coaster. You want it to get into all the grooves, and can be messy.
Before it dries, grab a rag and wipe off the surface paint. It will have absorbed a bit of colour to be darker but will now accent the veins quite nicely.
You could be done at this point or go on...
Step 5: Adding the Metallic Finish
To make these even more amazing, a quick and easy dry-brushing will make the texture 'pop' even more!
Apply a TINY bit of metallic paint of your choice on a wide DRY brush. Rub most of the paint off on a paper towel and then very quickly brush over the surface textures. It should be little paint that is needed to accent the details, not clog them.
Step 6: Covering the Bottoms
To make these not scratch the tables you need to add some felt or foam to the bottom.
- Trace out the shape on some accent colour felt or thin foam sheets and then cut and test.
- Apply some tacky glue to coaster and apply the felt/foam
See how amazingly thin these are. They are much like ceramic.
Step 7: Enjoy!
Yup, you will keep picking them up! As you will be amazed at the detail.
They make a great hostess gift to go along with a bottle of wine too! Such great conversation pieces!
If you want more unique (not the typical internet rehash) go to my site: https://www.madebybarb.com/
Or visit the concrete projects page.
Participated in the
Trash to Treasure
shylock made it!