Notes for Casting Cement

Plaster will not hold up outdoors.

Portland cement and the fine white quartz sand used for sand blasting, 1 part portland to 2 or 3 parts of sand.

If you add more sand there may not be enough of the glue, which is the Portland cement, to hold the mix together.

Overly wet mix should not be too bad, unless you will be exposing it to freezing weather. The mix will be too porous and thus crack in winter. With a wet mix the heavier cement will sink, and you will have water on top. The cement should still set. You will most likely have a layer of plain Portland and sand on the top since the heavier stuff will have sunk in the fluid.

Cement needs to cure for a long time to attain its max strength, so you should make your best effort to keep it moist as long as is possible. Even the fast set cements will gain additional strength if they are not allowed to dry.

Lumpy? ohhh... there's only two ways I know of that can happen;

1) You MUST use fresh dry sand and fresh dry lump free cement!

2) you MUST mix the DRY sand and the DRY powdered cement completely and thoroughly.

Since you dont have a plasticizer or vibrator, I would don rubber gloves and pack the concrete in the forms carefully and work it into the forms to get the air bubbles out of the face.