robmhill: That is so cool, if they added some veg. oil to it they would have a crude epoxy like substance.

The cooked rice, probably with some vinegar, becomes a gel, the large starch polymers broken down to a useful size, which keep the long egg protein chains from clumping, by forming hydrogen bonds along them. Just like when you cook a sauce, the starch in the rue thickens and keeps the protein from curdeling. When they dry it is like a bunch of molecular spaghetti. Lime is added to reduce solubility and it may encourage some repolymerising by picking up the extra H from OHs in the middle of the amylose, turning it into amylopectin, which can branch millions of times. The lime also helps to turn the protein into a glue, which is still used in the production of magnetic tape, which is why vegans do not use cassette tapes.

I will have to try this at some point, and see if adding oil helps or ruins it. They could also paint some oil after it sets, like re-pointing, to seal it.

Cynthia did you see any of these walls, and was the layer thin? About how many mm? I read that it was used with very uniform bricks in the forbidden city but they did not say how thickly it was used, I would guess 1-5mm at most.

comment left Jun 27