How to make a mold of our sons hand prints which we placed in our driveway?
when my son was a baby we put his hand prints in our driveway by pouring concrete. Now we are moving and my son wants to make a mold of the hand prints to take to our new home. I have cast plaster, but not sure how I can make the mold. Should I spray the concrete with oil before pouring the plaster? We don't want the plaster to set into the concrete because we will need to use it as a cast/mold. How will remove the plaster from the concrete once it dries?
Mike2012-08-24T12:13:12Z
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You could put wire into the mold (sticking out higher of course) and then pour in the plaster that way you can just pull it out when it dries.
Not sure if any release, and which release, might be needed for making a plaster cast in a cement "mold", but these links might help: https://www.google.com/search?q=plaster+release+cement+mold
Especially since his hand prints are likely to be small though, you could just use a polymer clay to make the 2 casts in your cement molds. Plain white bulk "Sculpey" (or "Polyform" if you buy it in an art supply store) will be the cheapest, and flesh-colored SuperSculpey will be next-cheapest. Those are also the most brittle when thin after baking of all the brands and lines of polymer clay (with SS a bit stronger), but if you mount the finished casts on a plaque or something (glue down with Liquid Nails or Gorilla Glue--have to weight that one while curing--etc) it will be plenty strong enough.
Polymer clay is what's often used in those "make handprints of your kid in a frame" kits too, so you might want to check out my previous answers about using those and the Sculpeys, etc: http://answers.yahoo.com/question/index?qid=20101211033832AAdQzSz http://ca.answers.yahoo.com/question/index?qid=20090512071301AA9bnlg And this lesson might be fairly similar since many headstones are cement or rock: http://www.art-shrines.com/instructions/rubbings-casting.htm
Polymer clay must be baked to harden and is oil-based so it's not like air-dry clays though (those would shrink some while drying so if you want to keep the exact size, air-dry clays wouldn't be best). Generally polymer clay won't need a release but with a very soft one like original Sculpey or even SuperSculpey you might want to wet the cement as a release or dust it with cornstarch. You can lift the casts out more easily when they're cool since the clay will be firmer (so dont' do on a hot day), or you might want to embed a couple of bent-open paperclips, etc, to help with removal --then pull out before turning over and baking.** You can also paint polymer clay (generally with acrylics) or just use a clear finish*** like water-based polyurethane or others if you want.
(If you can find SuperSculpey-Firm, it's stronger than the other Sculpeys ...bulk, in a package, and not as cheap.)
** http://answers.yahoo.com/question/index?qid=20111224000037AAQSEfC http://answers.yahoo.com/question/index;_ylt=Ahyzrx_gxg2vveKgcS7NeWXty6IX;_ylv=3?qid=20120530001320AA8DXaJ To make those 2 Sculpeys stronger, you can bake them much longer--say up to 90 minutes or so though this will definitely affect their color--if painting on top, that wouldn't matter though. Try to keep the polymer clay to less than about 1 1/4" in thickness so it will bake well.