How many bags of vermiculite

[Art nj]

Re: How many bags of vermiculite

So I've been working outside on the ground surrounding the oven , we cut down a big maple 7 yrs ago and the stump was ground down below grade so I thought it would be rotten by now.... Nothin doin on that one , it was hard as stone. The roots thankfully were rotted and broke with an ax.
Anyway , I was able to dig around and get the foundation and side countertop formed and the small one poured before the rain yesterday.. I secured 1000 red bricks also , so the materials are really coming together. I'm trying to figure out how to post multiple Picts from my iPhone, but if not ill just do one at a time.
Art

[Art nj]

Re: How many bags of vermiculite

If you put stainless and aluminum in contact, that can cause galvanic corrosion.

Thanks stonecutter , I thought I was going to use stainless but it's actually aluminum. I own a boat that is used in saltwater so I know all about it .

Art

[stonecutter]

Re: How many bags of vermiculite

Thanks for the responses, I was looking at the aluminum today and think I'm going to flip the u channel over and have the flat side sitting on the concrete and have the "feet" of the Uchannel facing up, then I'm going to put a sheet of perforated stainless steel sheet on top of that, then the ceramic fiber board, and finally the firebrick floor, installed on edge. I think it would work better that way.
I can't wait to be up to that point.. But at least by then hopefully the weather is a little better. I plan on pouring the foundation on Sunday and I'll work on the block base next week after work.

Art

If you put stainless and aluminum in contact, that can cause galvanic corrosion.

[Art nj]

Re: How many bags of vermiculite

Looking at it now , I may fill the voids with loose vermiculite.

Art

[Art nj]

Re: How many bags of vermiculite

Here is another picture, I'm trying to get more than one in each post..

[Art nj]

Re: How many bags of vermiculite

So I was able to take a picture of what I was thinking with the u channel turned upside down with perforated metal.
I'm still trying to get the giant maple tree stump and roots out of the ground so we can start putting the foundation together.

[Art nj]

Re: How many bags of vermiculite

David, good point with leaving a gab between them. I'll add .090 spacers between them then weld everything together. I definetly plan on leaving the ends open.

Art

[Art nj]

Re: How many bags of vermiculite

Thanks for the responses, I was looking at the aluminum today and think I'm going to flip the u channel over and have the flat side sitting on the concrete and have the "feet" of the Uchannel facing up, then I'm going to put a sheet of perforated stainless steel sheet on top of that, then the ceramic fiber board, and finally the firebrick floor, installed on edge. I think it would work better that way.
I can't wait to be up to that point.. But at least by then hopefully the weather is a little better. I plan on pouring the foundation on Sunday and I'll work on the block base next week after work.

Art

[david s]

Re: How many bags of vermiculite

Your channel will stop any moisture wicking from the base to the insulation. If the hollows in the channel are left open and you left some gaps between each channel it would also help the insulation dry out should it get wet.

[GianniFocaccia]

Re: How many bags of vermiculite

Since aluminum is such a good conductor, isn't the aluminum going to act like a heat-sink and simply transfer the heat from the ceramic fiber board to the concrete anyway?

I'm no engineer, although a few years ago I had many WFO oven discussions with my late father-in-law who was an MIT grad who specialized in heat transfer. If he was still with us, he would surely point out the following data:

The Thermal Conductivity of the following materials is:

Fibre Insulating board - .048
Rockwool - .045
Firebrick (500C) - 1.4
IFB - .15
Aluminum - 205

(I include the rockwool and IFB only for comparative interest since these are commonly used in insulating ovens)

My $.02 worth is that the calsil board is going to do its job regardless of the material it sits on. If it's concrete, the contact area is 100%. Like Les pointed out in a different post, firebrick doesn't transfer heat all that fast anyway. The 'leg' area of the aluminum greatly reduces (90%?) the total contact area between the board and concrete, providing an additional layer and reduction of the heat transfer rate.

I'm not sure how much heat is going to get through 4" of firebrick

All of it, eventually.

[Art nj]

Re: How many bags of vermiculite

Not sure I guess we'll find out. I'm not sure how much heat is going to get through 4" of firebrick plus 2in of fiber board anyway. But being that there's "air gaps " I don't think the heat will migrate to the concrete slab but I could be wrong. I have perforated stainless steel panels I could put down instead of sinking it into the Crete. I think the idea is at least worth a shot, since a lot of builders concentrate on keeping heat in and making their ovens as efficient as possible. I was going to figure out a way to measure the temperature inside the air gap to see if the heat was making it through too.
I'm digging my foundation and ran into a stump and roots from a 30" maple we cut down 6 years ago... Nightmare.
The whole thing needs to be ripped out because I'm doing all paver work around the oven at the same time.
Art

[jeeppiper]

Re: How many bags of vermiculite

Since aluminum is such a good conductor, isn't the aluminum going to act like a heat-sink and simply transfer the heat from the ceramic fiber board to the concrete anyway?

[Art nj]

Re: How many bags of vermiculite

Ok .. So I came up with the u channel base at my shop, this is what it's gonna look like. The foam represents the ceramic fiber board. I'm probably going to sink the channels into the concrete about 1/2 in. We'll see how it go's..

[Art nj]

Re: How many bags of vermiculite

Thanks , I'm going with the 2 inch ceramic fiber board under the firebrick floor. And I'm going to try the Uchannel air gap under the c.f. board. Then I'll probably try that fire resistant insulation from HD.

Art

[stonecutter]

Re: How many bags of vermiculite

To your thread question, I once used. 9-11( it was 9 years ago, don't remember exactly ) bags to fill an enclosure around a 36" oven with one layer of ceramic wool insulation, and 4.5" of space between it and the masonry surround.