Casting Concrete Ornament Using Latex Molds.




Introduction: Casting Concrete Ornament Using Latex Molds.

About: 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. I also work wood , old school and build furniture.

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.

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.

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.

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    Reply 6 years ago on Introduction

    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 .


    6 years ago on Introduction

    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.


    Reply 6 years ago on Introduction

    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 .