First, let me amend what I said in my last, pre-coffee post.
I've never heard of anyone having cement that didn't firm up after 24 hours,
except where either
way too much water was used, or the salt was either the wrong type or the salt was over-mixed. And I know that cement that freezes before initial set can have a lot of problems too.
Anyway, I wanted to post my latest 'Cube Backwall. A guy over on Nano-Reefs commissioned it from me. His system is already setup, and I couldn't talk him into moving stuff for a couple of days while silicone cured, so we went with the magnet route. Mostly the magnets will keep the pieces from falling forward off the wall. I sort of designed this with a keystone of sorts; the top left piece fits over everything else and sort of locks it in place.
He has the same tank I do, but wanted a solid, single piece. We compromised with overlaps so the breaks aren't as noticeable. I cast the thing, and have a hardish time seeing the breaks...
This is the piece in the form I made.
This is "true color", so folks don't think I made yellow rock
Again, but without flash - shows better detail, I think.
And finally, a "blown out" photo - so you can actually see where it breaks, if you had any problems. The camera can see the breaks better than the naked eye can.
I cast this on Saturday night. I cast on a piece of glass that I had drawn the foot-print of the wall on in Sharpie (on back-side). Used Styrofoam and hot glue to make a form so I couldn't "color outside of the lines".
I used a bit of "gutter-guard" to reinforce the opening around the return head - square piece, with a hole, so this part should be really sturdy.
To get the overlaps, I used waxed paper, in thin strips. I laid a line of cement along the break-lines, and then "ramped" it, pressed down on one side of the line until the whole line formed a slope. I laid the waxed paper down over those ramps, and then cast the rest of the rock, being careful to make sure the waxed paper didn't get completely covered. It worked amazing well.
I let it sit, tied up in a bag, for 18 hours, then steamed it in the MRS. Total time of steam was 8 hours, plus I let it stay in the MRS for cool down over night. I'll let it dry out now, and tomorrow or the day after, I will start the kure. I was hoping to kure these in the toilet, but I think the ledges under the overflow and the return might make that hard to do...
