Hi Carey, I wouldn't be to sure you would be able to remove anything wood .I'd recomend you use styrafoam to make your shape of a cross perhaps. I have used gallery glass liquid leading to make little sayings etc on a piece of plexi, then poured a concrete mix over top, and imbedded a hanger in the back for little garden signs.You have to do the writing in reverse of course, and I have heard of people using ge silicone 2 also, here is an example of a few I made with the liquid leading, and a colorant in my mix,
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You could do what ever you wish for your memorial, Cindy

How about a 12x18 box made of wood, screwed together so it comes apart easy. With or without a bottom. I use plastic lettering you press into the concrete and remove right away, like this:
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You could make a cross out of wood. plastic or anything hard and press it in and remove it.
The picture is of plant makers I made in a brick form.
Paws

Thanks for the advice. I was going to try doing the letters by carving in POP first and making a mold. (saw on a post here) I thought about using the styrafoam for the cross but wanted more detail.

If you wrapped the wood cross and the wood trim with plastic and sprayed it with a mold release, or silicone or even motor oil, I don't think that the concrete would stick. I use wood forms and metal molds lined with plastic (with no release agent) all the time and have no problem with the concrete adhering. The finish is smooth, but can be textured with a wire brush, etc.

Hope this helps.

Try modeling clay . What sticks can be washed out with water.

Paws, Is that what I think it is and you're a hostaholic? If so I just got Pandora's Box and Hope. Billie

Billie--Yes I am wanna make something of it.LOL Just started this year. Working on a Music Bed but alas Fall is here and Spring is so far away.
Paws