Post by rural on Nov 26, 2011 9:17:37 GMT -8
"Formable" because the mixtures I've used for wouldn't really pour into a mold, but could definitely be worked around a form.
Anyways I was able to gather up some raw materials (natural clay soil, a 50-pound bag of fire clay, Zonolite masonry insulation, and wood ashes) and have begun to make up test balls of various mixtures. The trouble is that I have very little experience with masonry, concrete, and mortars. I have no experience whatsoever with natural clay as a building resource. So I really have no idea where to start and need to tap into the knowledge around here.
My understanding is that, to get a strong product, I'm going to want mixtures that are just wet enough to work. Correct? To get more Zonolite or ash into the mixture, I've noticed that some extra water can help a great deal. Is that counter-productive?
The intention of these experiments is for me to be able to make an informed choice for the materials used in the 'J' of a rocket mass heater, the part that is is commonly made out of brick. At this point, I'm thinking of a monolithic structure, not bricks. I'm imagining a fairly thin layer of a strong and smooth product worked over a cardboard form. This would stand up to abrasion from fuel and tools to remove ash. Around that, a thicker layer of a more insulative material. Perhaps I would have to transition between the materials to avoid differential expansion problems (ie. cracks). I'm not sure. But I'm looking forward to finding out.
Just from mixing up some samples, I have to say that Zonolite is on the fine side of what I was hoping for, but it is fairly easy to mix up with clay slip. Ash clay makes a product that can be worked to a quite smooth finish. I sure hope it stands up to abrasion. Bagged fire-clay is pretty convenient both to obtain and mix, but it is expensive from the sources I've found here in Canada ($20 a 50-pound bag).
Anyways I was able to gather up some raw materials (natural clay soil, a 50-pound bag of fire clay, Zonolite masonry insulation, and wood ashes) and have begun to make up test balls of various mixtures. The trouble is that I have very little experience with masonry, concrete, and mortars. I have no experience whatsoever with natural clay as a building resource. So I really have no idea where to start and need to tap into the knowledge around here.
My understanding is that, to get a strong product, I'm going to want mixtures that are just wet enough to work. Correct? To get more Zonolite or ash into the mixture, I've noticed that some extra water can help a great deal. Is that counter-productive?
The intention of these experiments is for me to be able to make an informed choice for the materials used in the 'J' of a rocket mass heater, the part that is is commonly made out of brick. At this point, I'm thinking of a monolithic structure, not bricks. I'm imagining a fairly thin layer of a strong and smooth product worked over a cardboard form. This would stand up to abrasion from fuel and tools to remove ash. Around that, a thicker layer of a more insulative material. Perhaps I would have to transition between the materials to avoid differential expansion problems (ie. cracks). I'm not sure. But I'm looking forward to finding out.
Just from mixing up some samples, I have to say that Zonolite is on the fine side of what I was hoping for, but it is fairly easy to mix up with clay slip. Ash clay makes a product that can be worked to a quite smooth finish. I sure hope it stands up to abrasion. Bagged fire-clay is pretty convenient both to obtain and mix, but it is expensive from the sources I've found here in Canada ($20 a 50-pound bag).
