Wood Ashes Make Cement?!

This kinda blew my mind when I first saw it. I have other uses for it, like making pottery glaze, but this is super cool.

That was wood ash plus what? It would have been nice if he would have talked a bit through the video.

Wood ash plus water, heated in a fire then disolved in water and allowed to absorb it then mixed with fired clay (terracotta)

Uploader suspects sand will also work in lieu of the terracotta but has not tested it.

Thank you for responding. Sand and ashes seems like a more do-able mixture than broken terra cotta pots. But I'm not sure what need it would fulfill as it would be rather labor intensive. At least the way he did it.

You could easily scale up to whatever size heating fluid vessel you have to work with

Gotta say, that's some cool beans. I wonder if it would be more practical used as mortar vs fabricating whole objects with just that? One could also use it to make small objects like beads, if it sounds fun but seems too labor intensive for big projects to some folks.

Just typed this thread

You should really check it out if you're interested in repeating what Prim did.

Love his channel, but there's a lot missing from this video - and it kinda sucks in that regard.

In a nutshell: The Wood Ash has to be calcined AND rapidly cooled - or it is unreactive and basically just a super-fine filler (which is good for mechanical reasons, but doesn't goo anything together).

And, BTW, NO! Sand does not work in place of his crushed pottery. Sand is super unreactive (unless you've got a very high pH) and is nothing but a filler. Crushed pottery is not only a filler - it's a Pozzolan. Pozzolans are half-reactive.

A Pozzolan!

Do dooo doo doodoo...

A Pozzolan?

Do doo doo doo...

Calco-Aluminosilicates are the bedrock of buildings (quite literally actually....) You got your Alites, and your Belites, your Feldspars, and your Limes....

Again - love Prim, but I've watched the results of his accidental success lead to some sad stuff :(