It’s no mystery that I have quite the love for working in concrete. My fascination with casting things from molds started as a little kid and led me to this. Before I knew it I had used a bunch of different Concrete mixes, made my own and created quite the slue of original projects. I learned from ‘hands-on’ experimentation to create my own easy system that makes it all mess free and simple. For many the idea of making concrete brings visions of huge metal mixers, shovels and mess. Let me show you some of my Tips and Tricks for Concrete Crafting so you too can make it all the time, like baking a cake.
“What is concrete?”
The term ‘concrete’ is for a material that is created from a mix of aggregates with a cement that is activated with water. Once it goes through it’s reaction, which usually involves some heat production it ends up almost as hard as stone. Lime-based Portland cement is commonly used and mixed with gravel (crushed stone) to make the typical mix used for your sidewalks. But as a crafter I often use a finer mix but there are still a few to choose from.
Question: “What concrete mix should I use?”
Portland Cement can be purchased as is so that you can make your own mix by adding other aggregates. It is also used when making ‘HyperTufa’. Depending what you mix into the portland cement will determine the final characteristics. It can range from just sand to perlite, peat, vermiculite, paper, styrofoam and probably more I’ve yet to discover.
If you want total control, this would be your choice as you are starting from ‘scratch’. I use this when making the CONCRETE ORBS using some dipping of yarn, and also the STEP SPOOK. In those cases the fabric fibres are the ‘aggregate’. Paper can be used as an additive and works quite well as in my PAPERCRETE BIRD
Sand Topping Mix is also one of my favourites. It is a simple mix of portland cement and sand. This inexpensive mix is meant to be used at less than 2″ thickness so it was perfect for the STEPPING STONES which were my first concrete adventure many years ago. They still grace my garden and are aging nicely. It has a fair strength when used at thicknesses over 3/8″ and worked well for the making of BOWLS and LIVE EDGE BOWLS and casting LEAF PLANTER. If you are new to concrete this is a good way to experiment. It can not be used at a very thin thickness.
Setting time is not accelerated and will need a good 24 hours before unmolding.
Rapidset Cementall is a brand name for a quickset concrete. This mix acts quite differently as it sets really quickly (5 minutes) and can be unmolded in 1 hour. I love this mix since I am impatient, but also because it is super strong! I experimented and have used it at 1/8″ thick with good strength (obviously not walking on) as it my LEAF COASTERS. This mix can be used at different consistencies such as pourable or thicker malleable concrete. This pourability has allowed the ‘slush pouring’ of the CUTE HEADS and the TIN CANS, and even the EGGS. Thicker use has allowed the sculpting of the LEAF CIRCLES and the hilarious SMILING STONES and LARGE FACE SCULPTURE. Even the GEODES and GEODE LAMP used this mix!
There is something about this mix that does make the end product much finer though, as there are many additives to set it quick and add that strength. If you like the more rough industrial look this concrete has less of that since the aggregates are very very (powdered sugar-like) fine. Those are decisions you have to make. It is also more expensive due to those ingredients.
If you would like to see side-by-side comparison of a few mixes visit my post about fast-set and extra strength mixes.
Sakrete Top’N Bond is a form of a patching concrete which makes it adhere to existing concrete. It is sometimes called vinyl patch as there are added polymers. It has a good strength at minimal thickness and also some has malleability. The final product does have the coarser texture since there is sand in the mix. It has a medium setting time so it worked well for the GIANT ORBS since they are worked in stages.
“What do I need to Work with concrete?”
This is a what my collection of concrete ‘stuff’ looks like. It is really quite simple and I have quite the system now.
- Watering Can – is great as it just needs a bit of a tip to dispense, no fussing with a hose.
- Bucket of Concrete Mix and Scoop – keep this scoop dry and in the container to be able to add mix when needed.
- Plastic Mixing Containers – It is best if these are not too rigid (Yogurt containers work well). Wider containers are better for mixing than tall ones.
- Measuring Cup to dispense small amounts of water into the mixing container.
- Rubber or Nitrile Gloves – better quality makes them last longer.
- Dust Mask – rated for concrete silica dust I like my 3M8833 as it has an exhale valve.
- Spray Bottle with water – to mist when adding to existing dry concrete
- Mixing Spoons/Utensils – Plastic or wood
- Concrete Colour – if you would like a darker or tinted colour ( acrylic paints can work as well)
- Optional; Additives – if making a custom mix like Hypertufa or Papercrete; peat, sand, perlite, vermiculite, paper fibres, etc.
- Other Tools – like brushes, sticks, skewers, depending on project
“How To Work with Concrete and not make a big Mess?”
Use the scoop and place some ‘mix’ into the mixing vessel
Use the measuring cup to add water slowly, mixing after each addition. The consistency that is needed will depend on the particular project and type of mix. The Rapidset Cementall works better if the water is added first. (each project tutorial also has details) Then follow the instructions to make your ‘great concrete project’.
Do not wash anything, just let it set and dry. NEVER EVER wash it down the drain! It’s like NOT doing the dishes… We are not making a sidewalk here, usually just smaller objects.
Once it is hard, just flex the container and the concrete will chip off. Bang it a bit and it will be clean enough for the next use. I like to use recyclable yogurt containers. Plastic buckets work well if you are working a bit larger scale.
Flex the spoon as well and it will become clean too.
Keep a bucket for all the cast off concrete. It can be used as aggregate later on or other planting uses. No mess or fuss!
“How do I make the concrete stronger?”
There may be times where you need a bit of assurance that your project won’t just crumble into pieces. In the big professional world they use steel rebar rods inside the concrete. We can use other methods of adding some reinforcement.
Drywall mesh acts as a reinforcement that can be cut and covered with concrete. If it is visible after curing it can be burnt away with a little torch.
You can also buy reinforcing fibres that are added to the mix. These work great as I have seen pieces that crack but hold together since there is the cross lacing of the fibres.
Anything that does not stretch can act as a reinforcement. Chicken wire, other metal mesh, yarn, wire, even fabric will add strength.
“How do I finish the rough edges?”
I admit, I hate sanding! I do not want to make a cloud of dust! So I design ways to keep that part to the minimum. That is why I like the rustic edges. There are times where you may have mixed a bit too much concrete, don’t throw it away! Make a ‘patty’ on some smooth surface (plastic is best) and let set.
This is now a great ‘sanding disc’, instead of using sandpaper or emery cloth. Also if you work with the pieces wet, there will be no dust and it will work well enough to take off the sharp corners.
I like to come up with projects where the rough edges are part of the design as in the LIVE EDGE CONCRETE BOWLS. That’s an artist’s trick; make any ‘mistake’ look intentional…
So, there you have it! It isn’t as bad as you had imagined?! I hope I have taken away some of the fear of being covered in concrete. It is similar to working with plaster of paris but is much more durable. Go check out all the concrete projects I have and give it a shot! I know you can do it!
See this post before you go to the concrete store…