I took a stab at making some DIY plugs
Filled a Plastic mixing container with sculpting sand. Came pre-moistened to perfect consistency.
They sell the plastic mixing containers with the concrete mix at Lowes and HomeDepot.
If your sand is dry, wet it so you can squeeze it and it keeps shape.
Next push your mold into the sand.
Now you are ready to make concrete.
2 or 3 parts reef grade sand
1 part Type I/II Portland Cement.
and a little water
The concrete will be a gray color when mixing but if you use white reef sand it will dry a little lighter. They do make white cement but it has to be special ordered. If color is important to you, check with me as I have some on order and it should be here this week.
I mixed it pretty watery so it takes to the mold better. Especially when making frag plugs with the bottom peg to fit egg crate.
Let it dry in the mold for about 24 hours and pull them out for a few days of air drying.
Dont forget to put them in water for 3-4 weeks to bring PH down before using them.
If you make some post up pics of your creations.