I built a base using elmers glue and water in a 50/50 mixture and mixed it with potting soil. When the mixture was wet it looked great but after drying for a couple days it developed cracks some up to 1/2 inch wide. What can I do to fix this problem? Was it the mixture or materials that caused the problem?
Put a layer of full stength elmers gule down first. Then put your potting soil down. On top of it.Then mix more elmers gule and water thin enough to spray out of an atomizer bottle.And spray it down then let it dry over night. I think you probably mixed your soil with the elmers gule mix and when it dried it cracked this shold fix your problem.
If you do as Rob has suggested you will have a "dry" looking dirt base;
but the way I read this you are wanting a mud or "wet" base?
If that is the case, then you did it properly; if you mix elmers and dirt and just a little water you should get a wet look.
To repair what you have just mix up some more and fill the cracks; to prevent cracks in the next one apply to your base in thinner layers!
In a sense it is just like skins- the thicker it is the more it
will shrink when it dries. Sometimes it works better to put on two thin layers.Another hint- Paint your base dark brown before applyinf dirt mix, the minor cracks will be less obvious.
I prefer use a resin to make that wet mud look. Just mix the dirt with the resin and pour it over your painted base.