Ruth, I have made latex molds, and also a few silicone molds from concrete leaf castings. I have NOT used the silicone in the tube, but a two part putty that is generally used for culinary work. For either the latex, or the silicone that I have done, I have not used a release agent of any kind. It will feel like the mold (latex or silicone) is sticking to the master (concrete leaf), but will release when pulled off of the master. For latex molds it is very important to sprinkle the back of the mold prior to peeling it off with talcum, baby powder, or cornstarch because in it's new state it will adhere to itself. Once the latex mold is removed sprinkle the veined side. Others here have used release agents for mold making and am hopeful they will respond. Happy casting, Dena

I don't have a picture, but it's just the barrel. I was wondering how to get the rounded side of the barrel? If I lay it in a box and pour rubber over it, the bottom will have some area that's not covered. Right? If I use brush on rubber, when I peel it off, how do I reinforce it so that when I pour concrete into it, it won't bend? Then I guess I would have to make a 2 piece box that I can press together? Or do I pour the concrete into 2 halves and then join them? If so, how do I join them? I would guess when the concrete is still kind of green? I have no Idea.

The reason that plaster moulds work for ceramics is because the clay gets pressed in while soft. The plaster then sucks moisture out of the clay, the clay shrinks slightly, and lifts out of the mould easily. So the mould can be used over and over again. If you cast concrete into a plaster mould it doesn't act in the same way. Even if you use a release agent (like vaseline, or clay slip) it will be difficult to release the concrete cast without smashing the mould. A way round it might be to cast a concrete tile from her mould, smash off the plaster, clean up the concrete tile well. Then roll out a thick slab of clay and use the concrete tile to make impressions all over the clay (use the concrete tile as a stamp). Then cast concrete into those impressions. Cover with plastic. When the concrete has cast, strip off the clay, clean the clay off and knead and roll it out into a slab to re-use it. PS, if you are going to use her plaster mould for concrete, make sure that the plaster can't suck the moisture out of the concrete you pour into the mould. Soak the plaster well beforehand, and coat the inside of the mould with vaseline.

Littlebug, I have to mention that what you just described has nothing to do with the word 'level,' which has a very specific meaning. It is not only straight and smooth, but also without ANY SLOPE AT ALL. So it would not work for following a slight uphill grade as the OP is doing here. What you are describing may be valid for his use, it is just not "level." Maybe it could be called a uniform slope. Lantern, where you're potentially going to get into trouble with this system is at the beginning of the walk and at the end of it .... exactly the places not included in your picture! Keep in mind that these are the two areas where the surface of your new walk must meet the surfaces of existing walks. Possibly, one end of the walk could be the landing for porch steps. (I don't know. I can't see it!) At any rate, you'll need to excavate to the thickness of the walk pavers at those locations in order that surfaces meet. Then, you'll want to gently blend the grade of the excavated area with the main portion of the walk such that there is no sudden rise, bend or dip that would be felt by a pedestrian's feet. If prior to placing any concrete, you prepare the base of the walk (what holds the pavers at their proper elevation) to be smooth, flat and uniform, and also account for and include the excavations at both ends, you'll be able to set the mold on top of this base and not need to worry about unevenness or trip hazards. A smooth base with a smooth layer on top of it equals a smooth finish surface. It looks like the existing walk is gravel, which is fine as a base for the new walk. If excavations at the end make what remains less than 2 1/2" thickness, technically, you should remove some soil below it and rebuild gravel to the 3" or greater compacted thickness. I realize that's probably something most people would ignore because of the work involved. If allowed, FYI, it could cause premature settling of those areas. As Gardengal mentioned, you'll need a subterranean restraint edging along the walk side edges in order that the individual pavers don't migrate outward, which is guaranteed to happen if you don't have it. Will you finish the walk with sand between the paver joints? It will need it. I'm not quite seeing how you're going to accommodate the curve of the walk if your paver molds are rectilinear. I think you'd be better off to find some kind of paver you could dry lay (on your nicely prepared base) and fit it around the curve. It would be easier and faster than working with the wet concrete, piece by piece. (Dry-laying pavers is best done on a smoothly screeded sand setting bed. I'm not going to describe it here, but it is not difficult. Then it is tamped to make a smooth, durable surface. A manual tamper would work for your small project. )