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Create a white cement river planter and make the rivers gold!
Hey, I’m Ellen from Artsy Pretty Plants and I’m back today to share another cement project! In case you missed it, this is my last one. And if you want to know a little more about me, take a look here.
Oh, the things you go through sometimes trying to get a concrete project to cooperate. Sometimes the ones that turn out best are the ones that have the biggest hurdles in trying to figure out the perfect recipe so-to-speak. You can read about another set of follies with my Cement Balloon Planter, here.
11 attempts, yes, that’s right, 11 tries at making this white cement river planter until I had the right formula! No worries — I made it 3 more times to be sure it would be successful for you. We currently have 4 large Tupperware containers full of sour cream in our refrigerator (down from 6). And after much brainstorming, I actually think we came up with enough recipes containing sour cream to not have to waste a single one.
So, please read my important notes in the materials list, so you can make this super cool DIY cement planter — one and done!
Materials & Tools For White Cement River Planter
- Plastic drinking straw
- *Leaf Gold Metallic pen
- Tiny paintbrush
- Hot Glue gun and 1-2 extra sticks
- Needle nose pliers
- Rapidset Cement-All
- White Titanium Dioxide pigment
- Plastic grocery bag
- Tablespoon measurer
- Disposable mixing bowl
- Plastic cups (for scooping and for water)
- Sand or stones for weights
- Baby oil or other
- Permanent marker
- Safety Glasses– sealed is better
- X-acto knife
- **Outer container: Sour cream 1lb/16oz container- Daisy brand preferred
- **Inner container: Thin plastic top to the Play-doh container- will be your insert. It’s an acetate sheet type of wrapper. The actual Play-doh container is a little too wide and short for the sour cream container, so you will use the top. Also, many candles are packaged with this material and may be of similar size.
Potentially needed if you use containers other than what I have listed:
**I have suggested this type of paint pen because I love the color it gives. I test multiple other paints and didn’t love the colors, nor the way it covered. This paint pen was perfect for both. The downside is you will still need the small paintbrush to get into the tinier grooves, but I feel like it’s worth it.
**You have many options for the outer container, but all the instructions are based on the 1 lb sized Daisy container. It is the right thickness, shape, size and color for this project. You shouldn’t have any issues what-so-ever demolding if you are able to use these containers.
You are welcome to use a brand like Breakstone, which is mostly red, but a little bit of color may transfer to the white planter. If you use something else, just make sure your container has shiny plastic.
**For the inner container, it’s important to use a flat-bottomed container that also allows for the walls of the planter to be thicker than ¼”. It’s not typical to find a flat-bottomed plastic container. Be sure the plastic is shiny and smooth or demolding will become an issue.
I had good success at the Dollar Tree store and found a few things that could be used as the insert.
White Cement River Planter Tutorial Steps
Please note: The curing timing is especially important in this tutorial for the hot glue to release properly. More about this in Step 7.
Step 1 | Prep The Straw For The Drainage Holes:
First, heat up the glue gun at a low temperature.
The planter bottom should be about ½” thick. The length of the straw will depend upon what container you use for the plastic insert. If you use the Play-doh insert that I used, your bottom will be flat, so just cut the straw at ½” long.
If you are using a bottle with a slight indentation, then just add that indentation amount to the ½” length.
Once the glue has heated, glue one end of the straw, wait for it to cool so you don’t burn your hands, then glue the other end. When the glued ends are dry, glue the straw to the bottom center of the sour cream/outer container.
Be sure the straw is glued tightly- it shouldn’t have any wobble. Apply more glue if necessary.
Step 2 | Create The Inlay Grooves:
You’ll create the river effect by using the glue gun to make inlays. Squeeze the hot glue onto the sides of the sour cream container in any design you would like.
Remove those super thin stringy pieces- you know, the ones that look like cobwebs- just pull those out or they will look like hairline cracks in the cement. I found it easier get the strings out without messing up the rest of the glue if I did it one river at a time.
Step 3 | Lubricate The Glue Lines:
You need to lubricate the glue ‘rivers’ in order to be able to de-mold them from the cement. Take a q-tip and dab it in the oil, then apply it generously, only to the glue and straw, as well as the glue surrounding the straw.
The glue has a tendency to adhere to the cement and can be very difficult to remove, so don’t skip this step.
Also, don’t lubricate the whole container. Any lubricant can cause a yellowish tint.
Step 4 | Line Up The Molds:
Insert the inner container into the outer container and mark a line on the side of the bottle where it lines up with the top of the outer container.
If your inner mold is a flat-bottomed, smooth plastic container, then you won’t need to lubricate it.
Now add sand and some water to the container so that it will be weighted when inserted into the outer container.
Step 5 | Mix The Cement And White Pigment:
Don those safety glasses! Now pour about 2 cups of cement into the disposable mixing bowl. This is a little more than you will need, but it’s best to have more than less because if you need to make more, it will be difficult to get exactly the same shade of color.
Save the excess amount of cement mix to make your own sanding block in Step 6.
Now add about 5-6 rounded tablespoons of white pigment and mix it into the dry mix and stir so it is mostly mixed well. No need to add more pigment than this, it won’t make it any whiter.
Next, slowly add *cold water to the cement and stir again. Make sure all the white pigment is mixed in and there are no lumps. You want the water on the cool side because you need enough time to work out the air bubbles.
If you are working in temps over 80 degrees, I recommend adding an ice cube or two.
My cement mix in the above image was a little too thick and caused a couple of pits. Make sure it is pourable, like a thick milkshake.
You may need to adjust the mix with more water or cement until you have it the consistency and color you need. If you added more cement, make sure to compensate by adding more pigment.
Step 6 | Pour The Mold:
Pour the cement into the sour cream container so it’s just under ¾” full. Tap the container a few times on your work surface to get the cement settled.
Now tap the sides to help the air bubbles release- I did this for about a minute. Don’t do it too much longer or the cement will start to set before you are able to insert the inner container.
Once the bubbles stop rising to the surface, go ahead and insert the inner container into the outer container until you feel resistance where it meets the straw. Try to make sure the bottle is centered and be sure to gently push it down so it stops at the line you marked in step 3.
Wipe off the overflow on top and hold the inner container down with one hand, while shaking and tapping several more times with the other so that the top levels out and the air bubbles have risen.
*Important* Normally you would let this cure more than an hour, but you will need to remove the outer container early in order to be able to get the glue out of the cement inlays.
The right timing for this will probably be about 45 minutes to less than an hour in. The container should be on warm side, but not hot. Do not let it cool or you risk not to being able to remove the glue.
Step 8 | Make Your Own Sanding Block:
While the cement planter starts to cure, take the excess cement and make a mud pie shape with it. Flatten it on both sides so that you can use this as a sanding block. This is one of the easiest tricks to sanding cement with little effort. Let this cement sanding block cure so you can use it on the planter in the finishing step.
Step 9 | Demold The White Cement Planter:
When the container is still warm (not hot), go ahead and remove the outer container, leaving the inner bottle inside at this point. Be careful not to put any pressure on the inner container while removing the outer since the cement hasn’t fully cured yet.
To remove the container, make a small slit in the top edge with the scissors and then use the X-acto to carry the slit down the container. The container should pull right off.
If you weren’t able to use the same containers as I, then you may have de-molding issues. During my experimentation with this project, I found the following to be helpful.
Problem: The outer container is difficult to get opened enough to pull off.
Solution: use a heat gun to soften the plastic. Put the heat gun on a medium heat and run it straight up and down where you will be cutting. You should only need to go back and forth a few times for about 15 seconds total. Once heated, you should be able to tear the sides of the container.
Problem: The glue sticks inside the inlay grooves.
Solution: This one is more tricky and the solution isn’t perfect. You can try lightly using a heat gun on low to soften the glue, then use tweezers to remove it. You can also try very hot water to soften it. Sometimes I had success, other times it was just messy.
When you get to the bottom it will probably resist coming off, so snip it with scissors again and apply the heat gun to it, if necessary. You should be able to peel the rest of the container off at this point, and hopefully, most of the glue inlays come out with it.
Step 11 | Demold The Inner Container:
Wait another 5-10 minutes before removing the inner container. Put on your protective eye-wear first, then cut a long slit down the container in a few places to help release it. Then just pull it out with the pliers.
Problem: The inner mold sticks inside.
Solution: I was successful at getting the inner mold removed with most containers by pouring nearly boiling water inside it, leave it in there about 20 seconds, then dump out and use pliers to remove.
Be careful not to burn yourself. In most cases the plastic will soften enough to release. If that doesn’t work, the use the long lighter to burn the bottom of the bottle because that’s where it’s getting stuck. Only burn the bottom. You should see and hear it pull away from the bottom, then you should be able to remove easily with pliers.
Step 13 | Sand The Cement Planter:
After the cement planter is demolded, you should sand it. The sooner you sand, the easier it is. Take your homemade sanding block and sand the top edges of the planter the smooth side is your good side. To sand these, I just leave the block on the table and run the planter on top of it- gently. After it’s sanded, rinse the planter off and let it dry completely before painting.
Final Step | Paint The Gold River Inlays:
Take the gold leaf pen and color in the rivers. If some of your lines are too narrow for the pen, then use the paintbrush to help get into the smaller lines. In order to use the paintbrush, I just pressed the pen tip on a piece of plastic until some drops of paint came out, then I dipped the brush into that.
There you have it! For more Artsy Pretty Plants ideas, check out the blog here.