Post #70585 by tikitony on Sat, Jan 17, 2004 5:30 PM

Try adding pirlite, or pertite, I can't quite remember, but its the white small foam balls you can buy at Home Depot for lightening soil. Also, you're suppose to add wire mesh shreads for added strength, I can't remember where to get those. I got the formula from a Martha Stewart article for making peat moss large concrete planters.. it may be on her website..? Another idea for taking a casting, Art supply places sell plaster-guaze for casting body parts. You just layer strips of moisened plaster guaze over your oiled up original. Do one side at a time, then you can make it hollow by placing a fat PVC pipe in the mold while you fill it with with the light weight cement.
If you do the sand thang, the cement dries first on the edges that touch the sand, so you can scoop out the middle when the cement is strong enough on the edges yet wet enough to still scoop out.
Also, you could put in coat hanger wire sticking out the back of the concrete, so that when you are filling the back side of the tiki, you lay the first half on top of the wet cement which injects the hangar wire in the wet cement of the second cast.
Sorry, I just took my medi.. steroids for poison oak, I'm a bit rambly. email me if you have questions, I could send you a drawing of what I mean. I'm betta with pictures than words.