Modified 3G Masterly Tail Build

[Mitchamus]

Re: Modified 3G Masterly Tail Build

I'm torn as to whether to add in the Ash drop or not.

I built one on the swishy, and I have used it about 3 times in 5 years.
I do think though it aids in drawing air directly into the oven, but as far as removing ash...
there is never really any ash to remove, and what there is... can be shoveled out with a peel.

The only times I think it's useful is to remove ash/charcoal when baking or roasting... but usually at these times you are removing a live fire... and are putting it directly into a metal wheel barrow or old paint tin.

[Mitchamus]

Re: Modified 3G Masterly Tail Build

Do you need to add re-enforcing in the insulating hearth layer?

to my mind, this would decrease the insulating capacity... but is it needed for strength?

[Mitchamus]

Re: Modified 3G Masterly Tail Build

ok so I got the hearth slab layed on the weekend

Nearly there:


All finished!


And I also got the insulation slab all poured too.
Formed up:


Done:


Next job this weekend is to pour a 2" mass layer under the floor, and then I can start the oven floor!!!

[brickie in oz]

Re: Modified 3G Masterly Tail Build

Next job this weekend is to pour the 2" cladding layer, and the I can start the oven floor!!!

Whats a cladding layer?

[Mitchamus]

Re: Modified 3G Masterly Tail Build

Sorry, I mean a thermal mass layer.
I have decided to add 2" of extra mass under the floor.

[david s]

Re: Modified 3G Masterly Tail Build

If this were my oven I'd be waiting at least a week, if the weather is fine and I was not in a huge rush. It looks like you have used around 260 litres of vermiculite so therefore have used around 85 litres of water. Only about a quarter of that water will be used up in the hydration process so the rest will have to be removed. If you cover it over now then that water cannot escape easily. It will take months to do this by fires alone, but if you let the weather do some of it for you then you can be further ahead.Take a look at the attached test I did which explains this better.

[Mitchamus]

Re: Modified 3G Masterly Tail Build

wow - thanks for that.
It's been sitting for a week tomorrow, uncovered, and we have not had any rain.

The oven is at around 3,600ft AMSL so the air is quite a lot drier than at sea level, so I am hoping that this will speed up the curing time a little bit.
- but on the other hand it has not been that hot either <25 degrees.

I'm going to put foil down - just as a barrier to stop the two layers mixing - not for any kind of insulating properties or anything like that.


thanks heaps for the info - very interesting.

[david s]

Re: Modified 3G Masterly Tail Build

If it were me I'd not use foil as it will create a vapor barrier and make the water removal even more difficult.

[Mitchamus]

Re: Modified 3G Masterly Tail Build

but the alternative is that the mass layer will mix (seep into) with the insulation, and I'll probably lose 1-2cm of insulation...

seems a high price to pay just so it will dry out quicker?

the drying issue temporary... but the loss of the insulation would be permanent...

[cobblerdave]

Re: Modified 3G Masterly Tail Build

Gudday
A layer of table margarine will do the job. It will biodegrade later
Regards dave

[Mitchamus]

Re: Modified 3G Masterly Tail Build

whoa! seriously?

[david s]

Re: Modified 3G Masterly Tail Build

but the alternative is that the mass layer will mix (seep into) with the insulation, and I'll probably lose 1-2cm of insulation...

seems a high price to pay just so it will dry out quicker?

the drying issue temporary... but the loss of the insulation would be permanent...

No it won't. Provided you use the correct water addition and don't make the mix too sloppy it will hardly effect the vermicrete at all. When screeding off you bring the moisture to the surface. I do multiple layers with different mixes like this all the time and it's never a problem, but do what you feel is best, you're the builder.

[Mitchamus]

Re: Modified 3G Masterly Tail Build

I guess I could just make sure the mix is on the dryer side.

or, leave a gap between the sheets of foil.

or both

[cobblerdave]

Re: Modified 3G Masterly Tail Build

whoa! seriously?

Yes seriously simple....if you want to complicate it use insalted butter.
Regards dave

[Gulf]

Re: Modified 3G Masterly Tail Build

I guess I could just make sure the mix is on the dryer side.

or, leave a gap between the sheets of foil.

or both

I agree with "mix is on the dry side". But, maybe also, a "little" cooking oil between the insulation and the "extra mass" and skip the foil.

I would have been more conserned with including a moisture barrier between the structural hearth slab and the insulation layer .