You might consider making a POP mold and casting first. You can then fill and/or sand the cast copy as needed...then make your final mold from the new cleaned up master. We have to do that all the time with old and damaged pieces people want more copies of.

Best of Luck.

That sounds like the way to go....but what mold release should I use on the master before applying the POP?

Thanks!

A

We use a wide variety of commercial releases but for old concrete you can try this homebrew combination. First, seal the surface if possible. It will keep anything from penetrating and forming a bond. The best choice depends on the nature of the piece and whether or not it must remain "as is". If yes, then seal with something that will be removeable and will not permenently affect the surface. Painting on liquid soap or a light wax for example. These can always be removed later with water or alcohol. If not, then a more aggresive release like oil, Pam, Shellac, etc. (these penetrate concrete and will be there for a long time as well as altering the appearance of the original). Once you have applied a sealant, one of the best releases for POP is a very fine coating of a dry powder...baby powder works great. Dust it all over while the sealant is damp or tacky and it will form a lightly bonded layer that very little will ever stick to. It also leaves the POP mold clean on the inside, where oil alone can impart and leave a layer inside the mold that never quite sets properly and may lose a lot of detail by coming off when the original is removed.
Take a look at the Reynold Advanced Materials page on the link below. They have a lot of different releases for different situations and are great people to go to for advice. They are really knowledgable and helpful. Even put
on hands on" seminars at their locations.

Hope this helps, best of luck and let us know how it turns out.

Here is a link that might be useful: Molding & Casting Supplies & Info...

Hey Tango!

Wow, thanks for all the information!! How odd, I had never heard of Reynold Advanced Materials and via your post and someone I was speaking with regarding molds, I heard about them twice in one day! Thanks for the lead!! They are a few hours north of me in Orlando and think I may head up there this fall.

Really appreciate your input! I'm off to put your advice to good use.

Amanda