cheap excellent material for oven walls

[gbtweedy]

How about heating up the oven then spraying hi temp powder on the inside of the oven instead of painting it?


The Hardi Backer is a concrete based product and the seams can be sealed using a mortar.

Well it looks like I am going to have a giant oven in the basement.

[smittie]

Originally Posted by dpmphoto

it seems to work fine in my oven however i'm not sure if any hazardous fumes are emitted(make sure you vent properly)

maybe you could go ahead and lay ceramic tile over that

[upncoming]

thanks for the pic

[Banditperformance]

I am sealing the gaps in mine with fire proof caulking. Thought about the powder for the walls, not sure yet.

[iwannapowdercoat2]

i saw your pic of your oven ..do you have pics of it finished and how well does its work ...it looks good so far ...i would love to have a walk in oven ...some day lol....thanks

[Scratch]

So now that it's been a little while since people on here started using the hardi-backer for oven interiors and exteriors... What's your thoughts on using it.

Have you baked with it yet?

Any regrets?



I'm planning on a 3X3X6 oven with this stuff inside and out.

[Banditperformance]

I've been up to 250 so far. Havn't got the doors sealed and need 2 more elements to get to cure temp. It seems to take a while to get up to temp. Cause you are basically heating up rock. But, it also keeps heat nice. OPen doors, long enough to simulate loading pieces, doesn't drop as much as my small oven

[67shelby]

Originally Posted by Scratch

So now that it's been a little while since people on here started using the hardi-backer for oven interiors and exteriors... What's your thoughts on using it.

Have you baked with it yet?

Any regrets?



I'm planning on a 3X3X6 oven with this stuff inside and out.

I'll post results of some tests I'm doing this week. Right now, with about 5200 watts, it takes me about an hour to reach 400 degrees in an oven that is about 6 ft x 3ft x 3ft (actually about 4 inches short on all dimensions).

It is MY opinion, that the backer board is acting as a heat sink and because it doesn't have the reflective properties of a piece of sheet metal, it is keeping the heat and releasing upwards. I am in the process of covering the top of my oven (inside) with sheet metal, after having run some expirements with different configurations. By the end of the week, I should have a semi-scientific opinion on the use of backer board vs. sheet metal on the inside top of the oven.

I am also using the backer board on the doors, and I have sheet metal ordered to replace it as well. I will replace them and then do another set of tests to determine how much they sink as well.

I have already put sheet metal (offset 2 1/2 inches) on the bottom between the backer board and the elements (based on my first attempt to do this, I put the elements on the top thinking it wouldn't make that much difference). When I put the elements next to the backer board, mounted just like they would be on an oven using the same hardware, it baked the backerboard and charred the insulation. Then put a piece of porcelin covered metal from the oven between the elements and the backer board thinking that it reflect the heat back down, but that really didn't work either, I baked the backer board even more. When I say I baked it, I baked it. It was dry and crumbly. I do not think that having them on the top vs. the bottom would make much difference in that aspect. If you read the original post, the manufacturer said if it was exposed to a 500 F temp, it would be ok, but when you have elements, they much hotter than 500 degrees. The lesson here being I would not have the elements close to the backer board, even separated by a piece of porcelin covered metal was not enough.

So, in my opinion, the backer board has become my enemy and for the most part, I'm covering it all in sheet metal and thus, it has made my project more costly. Others can chime in, but when I posted my question, only one person answered who was using backer board in a finished oven and he was using kerosene heat, which is not as hot as using elements. NOTE that this is a novice opinion as this is the first oven I've ever built.

[Scratch]

Good to know...

[Waorani]

A few months ago I picked up a stainless steel food warmer with internal dimensions of roughly 4'w x 2'd x 5'h. On its own it would heat to 200F. Concerned about whether the foam insulation in the 2" walls would handle PC temps I plucked a chunk out, stuck it in an oven, and progressively heated. At 400+ it charred so I began trying to find something cheap to buffer the heat flow into the insulation a bit.

Before finding this forum I bought some 1/2" hardibacker to line the cabinet so I was glad to find this thread. Then with other info I found here I calculated that the 2 2600W elements I had should be ample to bring up to temp. What I'm finding though is that the hardibacker is releasing a lot of moisture as steam and I can't get temp much above 200F.

This stuff apparently holds a lot of moisture. At our local Lowes its stored outside and gets rained on frequently. Hopefully it will eventually dry out. Anyway, if you're looking at using it for an interior lining though - you might want to store in dry place for a while before mounting and firing up.