Toby Newell
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Amazing dry stone. How thick are the walls?
- Thread starter joelpriley
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Thanks, they’re about 2 foot thick.
Toby Newell
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Amazing. I once did a Welsh stone cottage that was built over a brook, the walls were 3 feet thick, the floor lacquer took 24hrs to dry (normally 4hrs) Shame to cover them, but its the sensible thing to do.
Lacan07
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That's pretty good insulation qualities straight off the bat, your hemp & lime plaster will be the icing on the cake.
Wish my walls were that thick.
I’ve confirmed it this evening, my hot mixed hemp-cork-lime is producing so much heat when the water is introduced that it is literally COMBUSTING / BURNING some of the hemp while it’s UNDERWATER! Absolutely insane. This mix I did this evening has clumps of ash in it and I actually saw a piece of hemp float to the surface a minute or two after adding the water and it was GLOWING red and smoldering. Astonishing. From now on I’m just going to slake the lime and cork together and mix the hemp in afterwards, as the hemp forms too much of an immovable matt at the bottom of the barrel which then starts to burn cause it doesn’t get wet.
This pic shows two patches made from 2 different batches that were mixed in different order of ingredients. The color difference is obvious, the darker tan color is the first batch where I had hemp actually burning, and the resulting ash discolored the mixture. The lighter white stuff is from a batch where the hemp didn’t combust because I layered it ontop of the lime in the bucket instead of underneath the lime.
This pic shows two patches made from 2 different batches that were mixed in different order of ingredients. The color difference is obvious, the darker tan color is the first batch where I had hemp actually burning, and the resulting ash discolored the mixture. The lighter white stuff is from a batch where the hemp didn’t combust because I layered it ontop of the lime in the bucket instead of underneath the lime.
Toby Newell
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Interesting. It's quite an exothermic reaction.
Yeah even pre-mixing the dry cork and quicklime before adding the water hasn’t stopped it from combusting some of the bio-aggregates. I’m going to switch to fresh hydrated lime and stop attempting to hot-mix with quicklime. Too much hassle, too dangerous, too damaging on the bio-aggregates and I don’t fully believe the explanations for its supposed benefits over non-hydraulic hydrated or putty lime.
Toby Newell
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Could you not just add the bio aggregates after it has cooled?
Yeah but that’s where the supposed advantages of hot-mixed mortars seems to lie, so at that point I don’t see any reason not to switch to hydrated lime, as long as it’s fresh.
Annnnd, I melted my plastic mixing bucket…
I do almost all the slaking / hot mixing in a metal garbage bin but I ran out of space to complete the ratios on my latest slaking batch (as I tried to fit a double batch and it was ever so slightly too small), so I had to move some of it into this plastic tub while it was mid-slake. Next thing I know, molten plastic mixed with lime-juice is pouring out the bottom onto the gravel driveway.
I’m definitely going to switch to using fresh hydrated lime. This is too much work and I’m finding the full-on slaking reaction too difficult to control.
I do almost all the slaking / hot mixing in a metal garbage bin but I ran out of space to complete the ratios on my latest slaking batch (as I tried to fit a double batch and it was ever so slightly too small), so I had to move some of it into this plastic tub while it was mid-slake. Next thing I know, molten plastic mixed with lime-juice is pouring out the bottom onto the gravel driveway.
I’m definitely going to switch to using fresh hydrated lime. This is too much work and I’m finding the full-on slaking reaction too difficult to control.
Toby Newell
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Sorry, I don't know any advantage to hot mixing from a theoretical point of view. PH is 12.5 which is super high so it will start to dissolve any organic material anyway at any temperature, if that is important for bonding to the lime matrix. I just don't see what the scientific advantage is. Edit: I mean in the context of mixing with organic aggregate.
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Lacan07
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If you going to use hydrated lime from the builders yard I would put aside a 'briquette' when you make it into putty and wait for it to dry. If it sets hard the batch is good to go of course. Hydrated powdered lime is renowned for going off in storage.
Yes this has been my growing suspicion as well.
Ok that’s a good tip, thank you.
Toby Newell
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I think the advantage of mixing it yourself is that you know it's fresh, simply add the bio aggregates after it has cooled in an hour or two. I worked with pH14 Potassium hydroxide at around 70C which is very similar to slaked lime, for over 6 months in a research lab, so I am very familiar with it's effects on organic matter! I was interested in understanding what advantages there possibly were in effectively boiling organic stuff in a pH 12.5 solution, as in industry and research it is precisely how you go about dissolving organic matter. As a lay person in lime bio aggregates I was struggling to work out what the benefit of partially dissolving them was. I would of assumed a negative effect, that was seperate from the combustion! Seems like a totally nutty idea to me.
Well I slaked a full 25kg bag of quicklime totally by itself (in my metal bin) yesterday afternoon and then only mixed the dry ingredients into it late this afternoon ready for our evening plastering session.
That worked MUCH better. No burning aggregates, and I was able to use less water so the reaction seemed more controlled. It just happily and calmly boiled away for a couple hours. It also made a dryer, stiffer, more plasticy mix which was delightful to work with.
We did some detailing above and around the lintel and started the plastering within the window reveal itself.
That worked MUCH better. No burning aggregates, and I was able to use less water so the reaction seemed more controlled. It just happily and calmly boiled away for a couple hours. It also made a dryer, stiffer, more plasticy mix which was delightful to work with.
We did some detailing above and around the lintel and started the plastering within the window reveal itself.
Toby Newell
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Looks amazing, like porridge, I guess you found the goldilocks mix...
Thanks! Yeah possibly… now I just need to replicate it…
Lacan07
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Well done! Looks great