Cut a disc of polythene sheet and lay it in the bottom, and a strip around the edge, like you wood with greaseproof paper if you were making a cake.

(Or cling film?)

Del

Thanks, Mr. Bill! I gave you a good answer.

Del, I am a bit concerned the liner of film might shift and leave wrinkles. Maybe for the next project?

Guest, I am afraid the liquid detergent will react with the water in the concrete mix and affect the edge of the casting.

Bricktop, Castor oil was suggested on the link but I don't have that in the house right now. Close but no cigar!

you can apply some used petrol engine oil .

thanks

wasantha

The edges of the concrete will be under ground right ?

How about liquid detergent like used for dishes?

You may be able to get some idea's here:

http://www.sculpt.com/

I'd use Vaseline.

I do have clear mineral oil (sold as a laxative) or "ultra-pure" lamp oil that is clear also. I will probably use one of these to avoid discoloration.

Thanks everyone for the help and advice.

Ried

I'm concerned that those oils or greases will contaminate the concrete. Since the wife has already donated the mold, just cast it. Let it cure well before trying to separate the concrete from the mold. I'm betting that a slight tap or two with a rubber mallet will knock the mold off (every cake pan I've ever seen had a slight taper on the sides). If not, a bit of heat on the pan should help, or worst case - just cut it off.

Paint the cake tin, dry concrete will slip freely out each time.

Concrete will shrink when it drys and pull away naturally.

Is 12 in big enough ? Have tou tried writting the dog name within a 12 in area or circle ?

The plan is each family member gets a small oval stone to write on, place it into the fresh concrete to be part of the memorial. This will be placed in a small garden next to our patio. Stones are about 2" by 3-4", so we will double check the fit.

Thanks to all for resonding. Even though she is just a dog, she has been around our house for 13 years and will be missed.

..."she has been around our house for 13 years and will be missed."

Or, you could save some trouble and just toss 'er in a wood-chipper.

T H E N ... she would be mist.

I do not have a wood chipper, and the size I need would be expensive to rent. We're letting the vet deal with it.

Plus with the small backyard, I would not wank the kids to play downstream of the action!

This is off topic but was worth a small chuckle. Life and death should not be so grim that we cannot laugh at it sometimes. At least for those who know and try to rely on their creater to see them through. John 3:16

Ain't no such a thing as "just a dog", my friend. After 13 years of companionship, she was a de facto family member. Which shows in the creation of a family memorial. Are you inscribing into the stones' surface?

There are a lot of good answers here. I suggest the use of saran wrap but, as was mentioned, there may be wrinkles.

What about warming the pan in the oven to a little over 120°F and melting some parrafin in the pan? You can warm the pan once the concrete has set up to remove both the concrete and the parrafin.

Parrafin is food safe so any residual will bake away at the first cake.

"...curing or sealing the marker after casting..."

I'd let it cure out unadorned for 2 - 4 weeks (should reach 75% in 7 days) and coat with a clear polyurethane sealer. This will protect the concrete from surface deterioration for, well, longer than you will likely care about. Sorry to hear of your loss...

I had small dog Pomeranian (Snow White) very cute and sweet she was. We in India cremate the dogs so I could not have memorial.Here is her pic.

Why does cremation prevent a memorial?

It does not prevent memorial but here we don't have memorial ground for animals. There are cemeteries for human where they are buried with a memorial stone on top.

I have used many pots and pans for various molds. The thing that has worked the best is a white lithium grease. Just dab a little on a rag and rub it onto the surface that you are using for the mold. Most pots and pans today are coated with a non-stick anyway. If that is the case you won't need anything in the mold.

I carry the cheapest automatic transmission fluid on my service truck for many different uses. I have used it for a release on a wooden mold for the base for a decorative fountain in a garden. Even though it is very red in the bottle, no discoloration showed up on the concrete when we stripped the form. Sorry about your pet, he or she deserves the best! -- JHF

Ethylene glycol is a good release agent. However, you can get concrete release agents. Also, you can use spay PAM, this works for small castings, cheep.

There are quite a few probably good answers here. Since it is such a small project, why not try one? If it doesn't work, try another.

I like the parafin suggestion.

Well, the deed is done.

I did use some clear mineral oil, originally bought from a pharmacy as a food-grade sealer for a kitchen cutting board. It seemed to be adequate for the pupose.

One small error I made was getting a fast set concrete mix with 15 minutes working time! It did not leave much time to set the rocks we had written on into the surface but adhesion seems to be good enough. And if not that's what epoxy is for!

I will put on a couple of clear polyeurathane coats on the casting before putting it in our flower bed.

Gypsy was created and her ashes will be scatted on a pet cemetary/memorial park. I didn't want to into digging a hole in our small backyard, and that is customarily the way vets deal with the issue in our urban/suburban setting.

Thanks for all the advice, well wishes, and even the wacky sense of humor. Like the movie "Fargo" someday some of us might be "mist" also. (sorry, could not resist)