So what is this white or grey slurry called CONCRETE that we use to make these wonderful decorative garden planters or beautiful garden art statues and plaques?
CONCRETE is made by mixing:
Coarse and Fine Aggregates
Cement powder, when mixed with water, forms a paste. The most common type is portland cement (type I or GP) which is all you need for any small to medium statue or planter. The other types are more expensive and can dry quicker or harder with less heat or no shrinkage. Premixed or Ready mix concrete is more expensive. Simply keep it cheap. Freshness of cement is key though as the minute you open the sealed bag it begins to absorb moisture from the air which will make the lumpy and useless when mixed and poured. Before buying check the bag and make sure it is soft and pliable with no damage to the bag. When not using the cement keep in a dry, well aired place.
Water is mixed with the cement powder to form a paste which holds the aggregates together like glue. Water should be cool, clean, and free from any dirt, unwanted chemicals or rubbish that may affect concrete. Too much or too little water with not allow the concrete to set properly so add slowly to get the mixture to get like a thick stew but soft and creamy.
Aggregates are of two basic types:
COARSE: crushed rock, gravel or screenings.
FINE: fine and coarse sands and crusher fines.Sand should be concreting sand and not brickies sand or plasterers sand.
Aggregates should be:
STRONG and HARD A stronger, harder aggregate will give a stronger final
concrete. Never use a crumble or flakey rock like sandstone.
DURABLE to stand up to wear and tear and weathering.
CHEMICALLY INACTIVE so the aggregates don’t react with the cement.
CLEAN Dirt or clay sticking to the aggregates will weaken the bond between paste and aggregates.
GRADED Aggregates should range in size so that they fit together well. Rounded aggregates give a more workable mix. Angular aggregates make concrete harder to place, work and compact, but can make concrete stronger.
Look for the next post on Admixtures and what they do……
I found an article recently on what makes a good birdbath so I thought I could use some of the information to pass on to you. We sell so many birdbath molds as they are by far the most popular cement garden art items people purchase.
A bird bath is one of the simplest ways to bring wild birds up near where everybody can get a good view of them. You can attract more species of birds with water than with a feeder as water is often more hard for birds to find than food. A bird bath is a simple idea, it is an artificial puddle on a pedestal made from a shallow, water filled basin for bathing and drinking. A birdbath is a strong attractor for wild birds, particularly so during hot summer months or droughts. A very shallow, gradually deepening birdbath located safe from predators, kept clean and freshened often with clean water to avoid contamination and mosquitoes may attract several various species of birds. Two inches of water in the middle is all that is needed for most backyard birds since they do not submerse their bodies, only dunking their wings to splash water on their backs.
What kind of birdbath is best?
The depth of a bird bath is important. It should be no deeper than two to three inches at the center. It ought be even shallower at the edge so that a bird can ease its way in to the water, as they will not simply leap into deep water. If you already own a deep birdbath, it can be made shallow by adding rocks to the bottom.
Birds don’t like slippery surfaces where they can lose their footing and they will pause before wading into a bath with a glazed, smooth or slippery bottom. If you already own a slick bottomed bird bath, you can add the non skid stickers or rocks.
A firm and stable platform for the birds works best. Also you should take into account the weather as the wind will blow over the resin ones and sun will bake the toxic chemicals right out of the plastic as well the winter will freeze and break almost anything. So a solid concrete birdbath will last you many years.
The splash of moving water is an absolute attraction to birds. Bird ponds and waterfalls, along with water misters and drippers are made just for garden songbirds and there are many decorative alternatives for drippers, misters, fountains or water wigglers. Adding water movement or sound can dramatically increase the amount and variety of species that frequent an area.
Where should a birdbath be located?
For bird bath placement, make sure that it is set in a space that is not where cats can hide. Cats like to lie in wait under shrubbery or lie in wait, hiding behind an object such as a garden ornament or statue, then jump on the birds once they’re wet and can’t fly easily. Locate a birdbath at least five to ten feet from hiding places.
At the same time, a bird bath should be located with a perching area nearby. After getting wet and cleaning themselves, songbirds will want to find a spot to perch, preen and fluff their feathers. A nearby tree or shrub is perfect for this, so long as the bottom limbs of the tree or shrub do not touch the ground allowing for predator hiding places,
Within reach of a hose
Make your birdbath in an area which is accessible to you when it is time to clean and refill. But place your bird bath at a distance from feeding stations, since seeds and droppings would soil the water rapidly and birds prefer to bathe away from activity. Change the water every few days, or even every day in hot weather. Pour it out or squirt it out with the hose. Brush out any algae that begins to form with a scrub brush.
Remember concrete is best !
The stats helper monkeys at WordPress.com mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health:
The Blog-Health-o-Meter™ reads Wow.
The average container ship can carry about 4,500 containers. This blog was viewed about 16,000 times in 2010. If each view were a shipping container, your blog would have filled about 4 fully loaded ships.
In 2010, there were 6 new posts, growing the total archive of this blog to 18 posts. There were 7 pictures uploaded, taking up a total of 2mb.
The busiest day of the year was February 9th with 378 views. The most popular post that day was How Hard is it to Pour a Concrete Mold…...
Where did they come from?
The top referring sites in 2010 were mail.yahoo.com, mail.live.com, cementmoulds.com, cementmolds.com, and en.wordpress.com.
Some visitors came searching, mostly for concrete molds, cement planter molds, concrete planter molds, concrete mold, and cement molds.
Attractions in 2010
These are the posts and pages that got the most views in 2010.
How Hard is it to Pour a Concrete Mold….. February 2010
Help I am stuck !! Decorative Concrete Mold Release Agents July 2009
Those nasty air bubbles !! February 2009
Coloring Decorative Concrete May 2009
Well it has been a few months and time for a new article on my blog about using concrete molds to make decorative garden features with cement. In today’s article I thought I would review the different types of molds available today in the marketplace.
- Steel or aluminum
These molds date back 60+ years and would be the original method for backing all those wonderful birdbaths we may still see today. The advantage to these molds as they may still be in existence today, so durability. The disadvantages are the high cost for the molds, the pure weight of just the mold itself, and the inability to get the finer detail you can get with rubber. If you are lucky enough to have any of these today hang onto them as the are a collectors item!
- Vacuum formed plastic
Now we have gone to the complete opposite extreme with these cheap molds. They are the hard brittle plastic molds you can buy cheaply on ebay or other online stores. For the complete amateur they may seem to be the exact ticket to get going but you will soon find out that you can make 1 to 5 items before they break. The other big disadvantage is that they can only make something 180 degrees or half designs. The way they are made is that they need to have a large flat surface to form the plastic too and suck out the air. If you wish to make a circle or anything that is not flat you will have to make two halves and glue them together. Only ok for someone who wants to make a couple of items for around their own house and then toss the mold in the garbage bin. You get what you pay for !
I guess I consider these the hard rubber molds that are firm enough to stand up on their own. They work like ice cube trays, in that you bend back the rubber and pop the item out. The designs for these molds are very limited and really only work for pavers or stepping stones. Again can’t make any full 360 degree statues or planters as you can’t demould them from the stiff rubber.
- Silicon or Latex rubber
This by far is the largest category of molds and can range from a thin rubber as flimsy as a condom to a thicker 1/2″ rubber. The rubber is used to allow designers to make very detailed sculptures as well as the flexibility to pull the rubber off and around complex designs. The rubber does need a support mold around it to allow the rubber to stand up while the liquid concrete is drying. Again you get what you pay for with these molds. The cheap ones you see on ebay are usually rubber only and they tell you to set the rubber in sand or sawdust to support the mold and concrete, good luck getting it just right. On the other end is the molds that come with fibreglass casings, such as our molds on www.backyardkitz.net and www.cementmolds.com (thought I would plug myself here). These molds stand upright with not other help and allow you to fill the concrete in, vibrate the concrete, and allow to dry all in the mold. The rubber gives you the finer details and th fibreglass give you the ease of use as well as the quality you need to make very fine finished sculptures. The rubber does have a lifespan depending on the type of rubber and the care you give it.
There are other types of molds people use out there but these are the major ones available. To sum this up spend the money on quality molds to get quality finished sculptures. It will save you time and frustration trying to make some money. If you have further questions please email me or check out the websites.
When I am talking to many of my cement mold customers, both new and existing, I am often asked how to mix the concrete for pouring into our decorative molds. Below is a simple concrete mixing guide:
How to mix concrete
Safety Tip: Prolonged contact with fresh concrete will burn your skin. You should wear safety goggles, gloves, rubber boots and long sleeves when working with concrete.
Small amounts of concrete can be easily mixed in a wheelbarrow with a shovel but if you are making concrete on a regular basis you may want to invest in a concrete mixer to save time and weiriness on your back. A low end electrical mixer will work on regular household power and may only cost $300 to $600. I have also seen mixing done on a flat plastic sheet such as the Crete-Sheet which sells for about $20 in the USA.
Firstly decide how much you are going to mix up. I know how much my mixer holds and then use a bucket for measuring our equal portions of the cement, sand, and stone. For general purpose concrete, the mix can be 1 part cement, 2 parts sand and 1 part gravel.
In the wheelbarrow or mixer, add gravel and sand first to give it a stir to combine. The add the cement and combine again. Finally make a hole in the middle of the dry mix add the water in small amounts since it is hard to remove the water once it is in the mix. You can go from a too dry mix to a too wet mix very e with just a little water. The water can also very depending on the moisture content of the sand prior adding your water.
You can use either just a bagged portland cement to which you add your own stone and sand which is much cheaper or you can use the pre-mixed bagged mix such as QuickCrete. Check out my blog on Cement!
How to mix concrete in a wheelbarrow
Small amounts of concrete can be easily mixed in a wheelbarrow with a spade or small shovel.
Add the recipe as described above and mix it all together before adding water. Next add water: approximately half a standard household bucket more or less. Add a little of the water at a time. Mix with the spade from underneath and fold over. Keep doing this and adding the water until the mix is a uniform consistency making sure you scrape the sides to get all the cement stirred in.
Tip: when mixing, a smaller spade is easier to work with than a larger one.
Too much, too little water-
One problem that you will soon figure out is that the more water is added to the mix, the easier the mix is to work, and also the easier it is to place the mix into the molds. The wet mix will help get a smooth finish to your molds and should also help keep down those nasty air bubbles! Try pulling the concrete up in a series of ridges with a hoe. If the ridges slump back down and can’t be seen easily, there is too much water. If you cannot create distinct ridges, there is too little.
Make sure you have mixed all the ingredients properly and thoroughly, scraping them from the sides and bottom of the mixing box. The concrete mix should be an even color. Light or dark streaks indicate poor mixing.
Remedying a poor mix-
If the mix is too wet, it doesn’t have enough sand and aggregate for the amount of cement paste. Add 5 to 10 percent more sand and aggregate, mix it well, and test. Repeat this until the mix is correct. Keep careful notes of the added amounts; when you make the new batch, you will follow the revised figures for sand and coarse aggregate. If the mix is too stiff, it has too much aggregate. Don’t try to remedy the problem by adding water alone. Instead, add a cement-water solution that has proportions of 2 to 1. Unfortunately, in most cases even this will not work and you will have to start from scratch with decreased amounts of sand and coarse aggregate. Experiment, keeping track, of the decreased proportions, until you have a satisfactory nix. You may have to try several small batches before you produce the right mixture.
I hope you find this information helpful in producing beautiful decorative concrete garden art !!
It is comon thing to happen and is very easy to do and in most cases the glue will be stronger then the concrete around it. In all the cases below you will have to repaint the entire piece to cover up the seam or glue so it does not show.
Piece broken off – I have found Liquid nails works great to glue a small piece of concrete back onto concrete. Make sure that you clean any loose sand on both surfaces and ooze glue on both sides and then push togther. Then wipe any excess off the seam area with a wet cloth. Let dry per the instructions and try and put pressure on it if you can.
Piece broken off and missing - If I have gap that needs filling you can use som Bondo Body Filler whcih is a car body repair kit. Mix together the two ingredients and shape to fit into the space. You will have limited time to do this and best to use tools you can through away afterward as celanup is difficult.
Small holes or cracks - If you have small bug holse I have found taking a little Quickrete Concrete Patch works well. You mix a small amount of the powder with water and stuff it into the hole with your fingers and then smooth over with a damp cloth to make smooth and match the surronding area.
Ok so you have just pulled your finished gnome, angel, deer, or birdbath out of its mold and want to give it some color. Finishing the sculpture will add value when trying to sell it as well it can be fun. Anyone can produce a plain grey concrete birdbath but not everyone will paint it to look beautiful and you don’t need a lot of talent to do it.
- First thing to do is let it throughly dry, maybe up to 1 to 3 weeks depending on the weather conditions and size of your item. It should not feel cold and clamy when you grab it.
- Next clean it up. Whether old or new remove all the loose sand with a light wire brush or broom. As well, file off any rough edges or seams.
- Repair any holes, cracks or chips. (see my blog next week on how to repair items)
- Personally I like to give the whole item a coat of the thinned out white or black paint over the whole piece. You can also use an acrylic concrete primer paint. This will give the item a good smooth seal prior to applying the color. Reminder to always leave the bottom unpainted so the concrete sculpture can still breathe so your paint won’t bubble
- Finally you can give it a lacquer spray or a concrete sealer such as Thompson’s can be brushed on to help protect the paint when you are satisfied with your piece.
SO now what kind of paint can you use? You can use a good quality exterior paint. It can be an acrylic or latex paint. For small items like gnomes, you can even use a craft paint which will give you lots of colors to choose from. I even have used a paint that contains iron chips and you get it to rust so it looks like an old iron rusted piece, as well a copper and other techniques.
Reminder: If the item is a birdbath or fountain and you want it to hold water then you need to use a pond sealer so the water does not just permeate through the concrete.
Please email and I can send you out a free copy of our PDF on finishing concrete! email@example.com
SO how many of you have tried something other than plain old concrete mix in your decorative concrete molds? I am seeing and talking to more and more people creating a market niche for themselves by going green and using recycled materials in their concrete molds. They are saving themselves money on materials as well as marketing themselves as a Green Manufacturer. Customers are attracted to them and to their products.
SO what can I do to grow my business?
Papercrete: The recipe has been around almost 100 years. It is a light weight mix using 70% paper(almost any kind) with sand and cement. The paper is soaked in water and as it softens then ground or mashed up. Best to us a paint mixer attached to a drill in a 5 gallon bucket. The mix ratio is:
Recycled Concrete Aggregate: You know all those roads and buildings they tear down and haul away the concrete. How about reusing the aggregate in your concrete wet mix and put it back into a concrete bench or Buddha statue. You can even purchase pre-mixed Green cement mixes so if they are doing it why not you? You can even go as far as using rain water in your mix.
Send me other ideas that you or others are doing out there!!
Declare yourself GREEN and increase your decorative concrete sales!
- Concrete Mix
Use a Sacrete or Quickcrete Concrete Mix ( with small stone).
- Mixing Bucket, wheel barrow, or mixer
- Shovel to Mix with
- Lubricant -
You will need to use a mold release. Castor oil or vegetable oil
8 parts Denatured Alcohol & 2 parts Castor Oil
1. Prepare Mold :
Apply mold release with a fine spray on the mold and wipe
it slightly with a cotton rag.
2. Mix Cement:
Follow directions on the back of the bag. Your mix should be wet enough to a consistency of a stew. After a few pours you will find ” A Recipe” that works for you, then stay with it.
Mix very well. Mixture needs to be smooth, neither runny nor dry or lumpy but don’t MAKE IT SOUPY.
Be careful withe the last little bit of water as it can go from perfect to wet very quickly with a little water.
3. Pour cement into Mold:
Pour half of the mold first. Now shake and tap bottom & sides of the mold to eliminate all bubbles.
Fill the rest of the mold up with your cement mixture.
Shake and tap again until the top surface is flat and even.
Keep mold in a dry area for 24 hours on a level surface.
YOU CAN USE A RUBBER MALLET TO TAP THESE MOLDS
Now comes the best part as you get to see you end product. Turn the mold upside down onto a flat surface, and open up the fibreglass casing and remove the rubber. Be gentle with the concrete item as it will still be “green” and fragile. The concrete will take an additional 2 to 5 days to finish drying all the way through the item.
Keep your molds clean. Wash with warm soapy water, rinse well.
I have been in the concrete business for quite a few years and I have made latex molds and pour concrete ornaments using latex molds. Latex does not like petroleum based products as well as sunlight. Your best bet is a castor oil mixed with methyl hydrate or isopropyl alcohol (1 part castor oil and 8 parts methyl hydrate). Add the mix to a spray bottle and shake it well before each use. Just a light spray with the mixture, remember that too much is bad as it will stop the concrete from setting.
A secondary option that I hear quite often is Pam or vegetable oil. These are ok and will w0rk, but not as good. These will also get sticky and hard on your rubber unless you wash it off after each use.
A third option is a pre-packaged aerosol spray can such as Crete-Lease or Synlube 531 as examples. These work extremely well, but can be expensive in comparison.
As a warning for latex rubber molds any kind of petroleum based oil, such as (motor or mineral) is bad as it will turn your latex into soft liquid mush!
I did come across this nice headless man giving a good demo on mixing and applying the castor oil mixture: Youtube video on applying release agents. He must not like the camera much…
As for fibreglass molds, you can use almost any kind of oil as long as it does not stain your concrete. If the concrete absorbs it, there could be a layer on the outside of your finished concrete which won’t let you apply any finish to the sculpture. I find it just easier to apply the same castor oil mixture.