I'm getting somewhat close to the finish work on my thermal mass (posted a couple pictures of current state https://permies.com/p/950111) and I'm trying to figure out how to finish (as in "make durable and nice looking") it. So far plaster seems like the main contender (helpers around with lots of plaster experience). What I'm not sure about is what kind of plaster is right for the job. I've seen some posts in the forums discussing gypsum (not ideal for high temperatures, but the mass shouldn't be high temperature...) and some references to lime plaster. We've also been discussing hydraulic lime plaster as an option. I think the gypsum plaster around here has perlite in it, too.
So, considering the mass specifically is there a reason to prefer one kind of plaster over another? Again, this will likely be the final layer (except for any cushions or pillows or whatnot we end up with) so I want something that's going to stand up to some abuse.
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