Components and Mechanical / Chemical Bonds and Bonding

Just to make things more difficult I have been coming up with ways to finish the backside of my photo fresco prints with brick styled panels that fit into the back. There is no one reason why I have to do this as I could just pour my pieces thicker to begin with, but it has gotten me thinking in terms of component parts that are assembled versus the all in one casting. I think the component concept also comes from the fact that most of these pieces require additional anchoring and bonding methods to make them adhere to the frame anyway, so why spend all my time anchoring things to begin with when I can do the bonding later. There may also be some advantages for working on panels outside of the frame as they are more like blank pieces of canvas or wood that I can paint on, like flat work, before putting the item back in the frame. Lastly I have been able to test more concretes and mortars to find something that I can work with and that is strong enough to be managed in these multiple stages without cracking and breaking. I have come to the conclusion that the Fast Setting Concrete is my favorite material due to my impatience. I really liked the Top Surface Concrete that had fibers in it, but it dried with a glossy backside and didn't seem as strong as I thought it should be without extended drying times. My problem is that if things don't dry quick enough I end up breaking them when I try to get the pieces out of the mold. No patience. Some of the motars, even with extended drying times, cracked while drying, not to mention the pulling out of the mold cracking. Some of this cracking could be because the concrete was mixed too wet, or the concrete was setting in direct sunlight, which created to much heat. But if you were pouring this stuff outside in the sun it would react similarly, so the mortars are not working for me. I even tried a couple of Grouts in the mold, but those grouts had simlilar results to the mortars. Now that I have been making panels I am faced with mounting and adhering the panels to the backs of other panels or directly in the screens them selves. I tried construction adhesive and grouts to see which materials I liked best. The adhesive was great for getting into holes that I had drilled in the center of the pieces to create a bond into the frame, like anchoring a tooth is anchored into a jaw. The finish was smooth and the General Purpose adhesive seemed to bond well. I consider this a chemical bond since the adhesive is making the bond and if it releases from the material over time the bond is released also. My next step was to mount some plywood squares on the back of some pieces using thin set mortar and I also adhered a brick panel to a plaster frame with some thin set Mortar. The thin set mortar seems to hold well and although it requires setting overnight the bond looks pretty good. I am still mindful of creating a physical bond because impact may cause the mortar bonds to release over time and the adhesive caulk may break down over time. I like the idea of anchors mounted into the wood, but haven't decided on a good system for installing the physical anchors that won't be more work that what I already am doing.