Home - Made pour-in insulation

[offroadaudio]

I'm thinking about collecting ash from my wood stove and storing it in a large trash can. After I have a lot, I want to mix it with concrete at maybe a 70%ash to 30% concrete ratio and pour it in between a SS liner and clay tiles in another chimney that I have. Obviously I'll test different ratios on a small mock up on the ground first.
Ash is supposed to be an excellent insulator, and the combination would be strong and lightweight.
Might save some money - might ruin my chimney - what do you think?

 

[bluefrier]

I don't like the poured in insulation concept. What would you do if you have to replace the ss liner?

 

[pgmr]

I agree about not using a total fill of concrete type mix. Loose fill like vermiculite or perlite, while messy, could be vacuumed out the top or released from the bottom to facilitate replacement of the liner. I poured in about 10 gallons of homemade lightweight concrete to seal the area where the liner penetrates the bottom block off plate, then poured loose perlite to fill the rest of the way. Still get small amounts of perlite working through the gap, but nothing significant.

 

[NHFarmer]

I ran out of the pour-in so I made some from portland cement and vermiculite.It seemed to work for me.

 

[savageactor7]

Hell NO...that's not a good idea. If you want to experiment and build a back yard barbecue grill you can observe over a couple years go ahead. I know the volcanic ash was used in cement applications in the past but don't go experimenting on your chimney...and I certainly don't mean to disrespect this idea you have. Just my 2 cents is all.

 

[Heem]

I would think that would make it really heavy, unless I'm misunderstanding the application here

 

[NHFarmer]

I used a ratio of 1 part Portland to 6 parts vermiculite.You mix it really dry.It should be the consistency of potting soil,not too wet.It will harden like a porous cement

 

[drizler]

It seems like a lot of work to experiment with something that you can just go buy for a few bucks and have the real item. I do know they use incinerator ash as some sort of additive in industrial concrete but what is the sense of going to all that headache for a chimney. Besides, at the end of the day it's just another excuse for some slick insurance adjuster to deny a claim.

 

[Adios Pantalones]

Vermiculite stays in pieces, so it's an insulator suspended in another material (cement). Ash mixes with water or dry material, and will alter the cement- I don't think it'll be just stiffer ash. I dunno what it would be like, but it won't be insulating like ash might be.

I have made insulating refractory with a little cement, fire clay, sand, and lots of sawdust- but that relies on burning out the sawdust at really high temps (that you won't get in a chimney, or maybe even a woodstove).