Introduction: Casting Concrete Ornament Using Latex Molds.

Picture of Casting Concrete Ornament Using Latex Molds.

There are different sorts of concrete mixes which will yield everything from rough as above in the feline , or a smooth finish like carved stone.

In this case we do a fast , straight forward mix and pour , the mold was agitated by hand only ( Shaken. )

Step 1: Latex Mold.

Picture of Latex Mold.

We used a latex mold , see my other videos here on instructables at oldschoolwood.

The mix was done with a home mix purchased at the hardware store. It is mixed in a bucket with a paddle and drill .

It is then poured into a mold treated with mold release ( castin' craft brand in this case , ) and then agitated by hand to bring up bubbles .

The mix was careless and allowed some grit ( small stones ) to build up here and there in crevices and hollows. This produces a relic like appearance to the finished ornament.

Step 2: Smooth Mix With Resin.

Picture of Smooth Mix With Resin.

A smoother mix using a resin based tile cement was used here. The pour was gentle and the mixing was done using my fingers to create as few bubbles as possible . Then it was hand shaken to release any bubbles.

Step 3: The Demolding of the Concrete After a Day of Setting.

These pieces are for my garden . Concrete lasts for decades when sealed or painted .

Coloring can be done in the mix stage itself.

Step 4: An Experiment With Countertop Mix .

I just tried to cast a Countertop mix ( commercial product.) I colored it with powdered pigment . At 24 hours the cast fell apart in my hands and had shrank about one percent or so . The detail might have been good but the thing fell apart.

I have one other cast which I shall let set for a week before pulling it .

This one came out like a green sand cast .

I shall try the non colored mix next , straight from the bag , as an experiment . The surface texture could be very nice.

Comments

bruceissmart (author)2015-08-25

Where did you get the molds?

I make the molds . First I sculpt in clay and then I make the mold . This sort of mold is latex ( see my other instructables . ) In this case(s) about thirty dollars worth , which is about three pounds wet weight for a sturdy mold.

I sell the molds but I cannot ship them with a mother mold . They are too heavy . So anyone purchasing the mold needs to come up with a way to make a mother mold .

The designs change annually .

NeilB13 (author)2015-09-03

next time remember to compact your concrete before you let it set. This can be done by poking the concrete in the mould with a stick. Compaction will result in a stronger concrete an less of the bubbles on the face too.

oldschoolwood (author)NeilB132015-09-03

Yes , I usually pat it with the flat of my hand for compression , poking sticks and latex molds don't go well together . In this case , for people doing it for the first time , I thought I would just let it go with the shake , with out the slap .

I usually have a few minutes to let it sit. Then I set in in a jig so that it is square when it sets. Then I start working it with a small trowel and wood block. Wit art work we have to be careful to prevent the latex from being damaged.

During the pour I take care to make sure that the detail sees some pressure by using fingers. Then I shake to make sure and then add the rest of the mix .

oldschoolwood (author)2015-08-26

Next update when I pull the countertop mix. ( Aug 26 today.)

About This Instructable

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Bio: I live in Milwaukee and sell plaster cast for hobby painters in finished and unfinished state. Molds for concrete decorative art and fine plaster decorations ... More »
More by oldschoolwood:Concrete casting :Part Two: Countertop Mix.Casting concrete ornament using Latex molds.
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