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Slush Pour your Concrete Mold

Move over ‘Chia Pets’! Everyone is allowed to be silly sometimes, so it’s my turn. Yes, a ‘head planter’ is a bit odd but it’s purpose was to test a new casting system. Make your concrete pouring simpler and see how to slush pour your concrete mold. I love this method! Besides, I could not resist that baby pout!

To start this mold making I used this cute little fellow…

And I popped his head off. (Don’t worry, he is back together now)

My inspiration is this favourite planter of mine. She has aged well and her veil keeps growing gloriously…

Find yourself some type of head or perhaps even a mask.

Before casting I needed to fill the hole on the bottom of the neck. A quick patch of  — ya, duct tape!

 

Tools and materials needed to make the form:

Materials to Cast and finish Concrete:

 

Making the Mold:

The method to make this mold is the same as my first mold making tutorial. Lightly apply some vaseline on the master shape (the head). Mix the cornstarch and silicone carefully in the bowl without getting it all stuck to your fingers. Add cornstarch (just as you would add flour when working with dough) until it becomes workable without sticking.

It should be pliable to spread it around the ‘head’ and keep pushing it till it covers up to the rim of the head and fills the bottom. Spread it until it is an even thickness of at least 1/8″ thick.

It will set in about 30 minutes. Once it is completely ‘rubbery’, you can cut up the back, or at each ear side. Remove the ‘head’, adjusting by cutting as needed. I am alway amazed at the strength of this recipe! Mold is done!

Slush Pour your Concrete Mold:

To ready the mold, use elastic bands to keep the seams closed. Since it is a round shape this works well. To ‘line-up’ any seams you can also use my trick: securing with pins. This works well, as they make sure the edges stay together and later pull out without leaving a hole.

As with many of my projects this casting method works best with a strong, rapid setting concrete. This concrete is quite ‘plastic’ and will mix better if water is added first, and then slowly add premix until it has some flow. It has a working time of about 10 minutes. The flow should be ‘slow’ and somewhat thick.

Pour it into the form and start to turn it to coat all the inside. It may take a bit of trial and error until you have the right consistency. Turn slowly and watch for the flow to eventually stop. I discovered this slush-pour method when making the ‘balloon-cast’ monster eggs.

It may not be pretty, but it is easier than having a center form. Let it sit for an hour and then repeat and pour another layer. Depending on the thickness, you may need a third layer. This concrete is VERY strong and can hold well at only 1/8″ thick.

The top edge may be a bit uneven as well, but you can sand it as desired. As a planter it looks quite nice as a ‘broken’ edge style. Don’t worry about any texture that the mold has picked up, it IS concrete afterall.

To make it look aged, use some ‘washes’ as in my antiquing tutorial.

Instant Moss:

Do you want the ‘mossy’ look instantly? I came across some of my flocking material from my days as a ‘model builder’. It is also used in model train landscaping and can be found at hobby shops.

To adhere the flocking; use a bit of matte medium. Brush it in places that would naturally grow moss; areas that would tend to be in shadow.

Sprinkle the flocking into the wet medium. It’s the same method you would use for glitter. It’s your preference how much or little. To make it less likely to continue to lose bits, add another layer of matte medium. (If you can’t find flocking maybe you could put some moss in a sacrificed blender/coffee grinder)

I have tested some sealer methods (soon to be posted) before I planted up these fellows. Succulents are my favourite as they never seem to complain and they propagate like crazy!

Quite the hairdos! But this method is not limited to heads. (more projects in the works) It is somewhat reliant on a strong mix or perhaps a thick wall of multiple pours.

Happy casting and planting!

Can’t get enough concrete projects?! Check out my concrete obsession

 

barbmaker

I'm an artist & I make things... all kinds of things.

This Post Has 38 Comments
  1. Wonderful how to video. Have you ever made owl statues for your garden from concrete and if so would you share the how to? Hope to ake some of my own in various shapes and sizes.
    Thanks Selena

  2. what concrete mix did you use? I made a mold of hands, and am not finding a concrete mix that I’m happy with. You may text message me if you would like: my number is 641 860 1064. You are a woman after my own heart. I LOVE to make things, but I am forced to work full time- which severely limits my crafty time.
    I SO look forward to hearing from you soon!
    Much Gratitude,
    Pam
    pjslanding@yahoo.com
    641-860-1064

    1. Yes, sometimes work gets in the way of crafting! I have been using RapidSet Cementall, it is available at Home Depot here in Canada and also in the US. I have been using it indoors during the winter. (Just be careful with the dust) It is quite a strong concrete and is super fast setting.

      I hope it works out and would love to see it!

    1. I am not sure what that material is? I am familiar with drywall fibre-mesh that comes in rolls and have used that inside the stepping stones. The small fibres work well as they just mix in and flow with the concrete. I broke a tray and it held together without splitting because of the fibres. I think we could learn a lot from each other…

      Glad you stopped by…

  3. I’ve also been working/playing with the RapidSet Cementall and really like it’s strength and quick setting time. Love your work! I look forward to more posts.

    Your Faux Geode lamp instructable is wonderful. Thanks.

    1. Yes, I joke it’s better than making a cake; no baking!

      Yup, there are a few new ideas in the works. No shortage of ideas here, just time is another story. ‘Hope you are subscribed 😉

  4. Hi Barb,
    I love your concrete tutorial! You make it look so easy that I think a project of my own will be in order, as soon as I can find the time. Thanks so much for sharing your wisdom with the rest of us.
    -Carolyn

    1. Thanks! I believe everyone has more ability than they think they do. And the nice thing about concrete is that it fairly inexpensive, quite forgiving and can yield some cool results. There are more projects in the works…

  5. Hi…….love your blog and projects.

    esp this baby.

    could you estimate the size of the baby head. Maybe the circumference. Having a hard time finding a head. They all seem too small.

    thank you

    1. Thanks! This fellow has such a cute pout (being a long time doll collector) He is a ‘Berenguer’; they make great dolls. I’d say the diameter (distance across) is about 5.5″ at widest. Check the thrift stores. All the new dolls nowadays seem to have odd faces.

      Good luck!

  6. Hi Barb I would like to subscribe to your website but it will not allow me to start my email address with a lower case letter at the beginning Frances

  7. Hello Barb, so nice to virtually meet you!
    I came across your site by accident and I’m so very pleased I did! I’ve also been a Maker for as long as I can remember and I’m always up for getting my hands dirty with something new.
    You’ve given me the inspiration to try making a mold out of silicone + corn flour again (after several failed attempts) and the motivation to buy my first ever bag of cement. Thank you!!!
    I followed all your instructions on how to prepare the silicone mold and prepare the doll head. I kneaded the silicone with the corn flour for quite some time using a full caulking tube of silicone and a 300 gram box of corn flour. My mixture felt right to a point where I took my gloves off and kneaded some more. No matter how much more corn flour I added – the inside of my mix was still a little sticky, but the outer handling layer was fine. I got to a point where the mixture was getting quite heavy, so I decided to go ahead and cast the head.
    The next day, I released the mold by cutting down one side and I noticed a couple of things: 1 – my mold was bottom heavy around the neck of the head which made the top part weak. As much as I tried to make it even, my mixture was so heavy it kept on wanting to accumulate at the base (first lesson learnt – perhaps I should have put it to set upside down somehow and focused on an even layer). 2 – I had a large fold mark on the inside of my mold from pushing and patting the mixture around the head (perhaps this was due to the fact that it was already setting as I was pushing it around the head).
    I’m not happy with the result so I’m going to try for another as soon as I hear back from you.
    Here are my questions:
    Should the silicone mixture feel sticky inside or does it have to be non-sticky throughout?
    Is there a ratio of silicone/corn flour?
    Do you flatten the mixture so it can cover the whole surface of the object before putting it around the object, or do you stretch out the rest on the object like I did?
    Do I have to work the mixture faster?
    What’s the best way to flatten the mixture – by hand & pressing down, or with a silicone rolling pin?
    Sorry for the bombardment of questions, but I really want to give this another go soon. Meanwhile, I’ll continue reading through your fabulously creative ideas and getting lots of inspiration to make.
    Much love from your newest Australian fan xo

    1. Wow, I like your determination! Ideally the mix should be of a consistent denseness, not sticky on the inside. I liken it to bread dough, folding and kneading to incorporate the starch. I have run out of mix in the middle of a large mold and then added more (as in the large face)

      As for a ratio, It would be hard to figure out as humidity can play a factor as well. I have used a rolling pin when I made the artifacts to make sure it was really flat. But I am worried that in your case it would take up precious time. As I remember I flatten the mix with my hand so that it would be easier to push around the head. It was stiff enough that it did not ‘slump’ for the weight of the top.

      When I made the hands I realized that really thick walls of the mold made getting the concrete out quite difficult. I am quite amazed at how strong this is when cured so thinner is better than too thick. 1/4″ would be ideal I think for a doll size head. Larger things would be quite heavy in concrete so that would affect the stability of the mold.

      Perhaps it would be good to do a smaller mold to get the feel of working with this stuff. Then you will not incur so much expense. Any found plastic object could be your subject. The bird was my first thing that I casted.

      I’m glad you are giving it another go, as us DIY’ers keep trying. That is how we master and get even more unique! Good luck!

    2. Hi Barb, another fan from Oz. I’m having trouble with the mold-making too. My mix just didn’t bind together, despite adding more and more silicone to the cornflour. I wonder if there is a problem with the Australian ingredients? I shall give it another go, this time starting with the silicone and adding the cornflour. Lyn

      1. That’s odd. I have done this more times than I can count. Are you sure it is 100% silicone? I think working reverse will make a huge sticky mess. Maybe the corn flour is different? It’s very smooth & fine? Not cornmeal. If still experimenting, do super small tests. Other thought; maybe the climate? I’m in canada… Anyone else in in Oz have issues?

  8. Got your information about your site from your sister-in-law, Sonya. We have cottages just down the road from each other. She speaks very highly of you Barb and I can definitely see why. I always have 5 girls up for a craft week in late summer. Thinking of trying your Slush Pour molds. They are very interesting, and we can pick up some exciting pieces I’m sure when Thrift shopping. Will continue to follow your work. Good stuff, thanks for sharing.

  9. Can you patch/repair your mold with additional silicone caulk/corn starch after it’s dry? My mold was too thin in spots and tore through.

  10. Ok. I’ve tried 5 separate times and just can’t get it right. Are these one-time use molds? The first three completely shredded as I was taking the original out of the molds…too thin at about 1/8″ thick? So the next two I made at about 1/4″ thick. These completely stuck to the CementAll and had to throw them away. One part even looked like the silicone didn’t harden. At this point I’m invested (money and time) and am determined to get at least one usable piece. Thanks for any insight. P.S. I’ve worked with different clays in the past: ceramic, polymer, etc. and have never had this much trouble manipulating a medium.

  11. Hi barb, I love your website! I’m making the doll heads, and was wondering if you add sand to your slurry? I’m having trouble with the consistency. I’m using quickcrete, which is a quick drying cement. I haven’t been adding anything, and I’m wondering if this is my problem. My heads are not coming out of the molds smooth. I find myself doing a lot of sanding. How do you get your doll faces looking so perfect? Thank you.
    Your fan,
    Carrie

    1. I’m glad you did not say they were breaking, that’s a good thing. Honestly, the RapidSet Cementall is such a dense mix that it almost doesn’t look like usual concrete. I’d rather have more texture but it is super strong at a thin wall. I don’t add sand, and the ‘sand’ that is in the mix is super fine, unlike other concrete. Maybe a thinner pour to be smoother to fill the mold followed by a thicker will make it fill in the shape better, and do tap/vibrate to get the little bubbles out. I have even tried a thin pour of portland cement to coat the mold walls and then the regular concrete after. Lots of options in the concrete world 😉

      Quikrete makes many mixes, not sure which you are using.

      1. Thank you for responding so fast. I’m using hydraulic water stop quickrete. Ill try a thinner pour again. I absolutely love your ideas…so inspiring!
        Thanks again,
        Carrie

  12. You are simply Amazing! I have been making Hypertufa planters. Off and on for 18 yrs. I ran across your site and saw the doll head pour. I’m in love with these. My problem is that I can’t purchase Rapidset creteall. Not within a 100 mile radius. And I SO want to try the doll head planters. Is there anything that is equivalent to it in the Quikcrete brand. Thank you so much! Your such an inspiration.

    1. Haha! I have been testing the Quikrete brand lately (wish they were would be more supportive, hint hint) I have used the FastSet Allcrete and it sets fast and strong too. It ends up darker colour though. So far I’m happy with it!

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