Here's what I did:
Regular portland cement (dark stuff from Lowes), rock salt, and some leftover Southdown.
I put about 1:1 of sand and cement together, then mixed in the water to make a big thick mudball. Just mixed the water in very slowly and made sure it wasnt too much. If it was, I added more cement a little at a time to thicken it. I literally had to knead it to the point it was dry enough to be very sticky and muddy. I then added a LOT of rock salt (not sure how much exactly) so there was salt in every chunk that I pulled off. Knead and break the mass apart to make the random shapes and edges.
I then put the mudball on a bed of southdown and sprinkled southdown on top to coat it. Have to make sure that there is sand between the rock and the side of the container or it will end up becoming a smooth edge. I also picked up each rock and bent the bottom inward to create a cavity since it has a tendency to try to settle flat on the bottom.
Let it dry 24 hours and it's sitting in a bin of water soaking now and for the next four weeks.
Since then, I've gotten some other tips. Apparently I didnt need that much cement. I'm going to pickup some Riverside cement (supposed to be whiter) and more sand. I'll put 1 part cement with about 5 parts of sand, then water, then mix in the salt to see if that turns out better. Maybe I'll go the Garf way and use a sandbed to make shapes. Problem with their shapes is that they are smooth rather than "craggy".
Regular portland cement (dark stuff from Lowes), rock salt, and some leftover Southdown.
I put about 1:1 of sand and cement together, then mixed in the water to make a big thick mudball. Just mixed the water in very slowly and made sure it wasnt too much. If it was, I added more cement a little at a time to thicken it. I literally had to knead it to the point it was dry enough to be very sticky and muddy. I then added a LOT of rock salt (not sure how much exactly) so there was salt in every chunk that I pulled off. Knead and break the mass apart to make the random shapes and edges.
I then put the mudball on a bed of southdown and sprinkled southdown on top to coat it. Have to make sure that there is sand between the rock and the side of the container or it will end up becoming a smooth edge. I also picked up each rock and bent the bottom inward to create a cavity since it has a tendency to try to settle flat on the bottom.
Let it dry 24 hours and it's sitting in a bin of water soaking now and for the next four weeks.
Since then, I've gotten some other tips. Apparently I didnt need that much cement. I'm going to pickup some Riverside cement (supposed to be whiter) and more sand. I'll put 1 part cement with about 5 parts of sand, then water, then mix in the salt to see if that turns out better. Maybe I'll go the Garf way and use a sandbed to make shapes. Problem with their shapes is that they are smooth rather than "craggy".
