Insulation Efficiency

[Tscarborough]

Re: Insulation Efficiency

If it is from Boral out of Houston, it is probably Able fireplace mortar. It is good stuff, but you do not want to use it for a leveling bed. It does not have enough body and is a water soluble mortar. Let me make some calls and see if I can find someone that has fire clay over there, if nothing else, I can get it to you from here through Headwaters.

[gdest]

Re: Insulation Efficiency

Tscar

I tried to reply on the e-mail, so I don't know if you got my message. What I would like to know is what does adding fireclay to the sand do for you? Why can't I just use fine sand for leveling?

Gary

[Dino_Pizza]

Re: Insulation Efficiency

Gary, other here have used just sand, others even used the Refmix. The point is sand alone MAY work, but it might slip a bit and therefore need the fire-clay and water to "set-up" the sand slightly. (sand alone may shift) If you need something with some peanut butter consistency to hold the bricks in place at the level you need, then your next resort would be to add some of that premix you've just bought to give the sand some body.

What do you others think of that as a solution here? I've read of some on the forum using the Heatstop to mortar the floor in, which the pompeii pdf plans don't say to do,, but it did not do anything bad to the build (and actually worked quite successfully for all that I've read on this forum who did it).

Does anyone else agree? Gary, I've got almost a full bag I'd give if you were closer .

[Tscarborough]

Re: Insulation Efficiency

I used regular mortar on mine. It is not in direct contact with flame, and I doubt that the temp will ever get hot enough to bother it. Even if it does, it is restrained enough that nothing will happen to it.

I did not get an email, nor have I found fire clay in Houston.

[Spunkoid]

Re: Insulation Efficiency

Just for the record, the floor gets "red hot" underneath the fire. I verified that one winters night when I fired up the oven, built a good fire and let it burn down. When I banked the coals over to the side, the firebricks on the floor were glowing a very nice cherry red color. As such, there is a lot of heat there.

[dmun]

Re: Insulation Efficiency

What does adding fire clay to the sand do for you?

Makes the floor stay put. Ever heard of shifting sands? That's why brick walks are laid on stone dust instead of sand. It's also a refractory material, so it won't be damaged by overheating.

[Dino_Pizza]

Re: Insulation Efficiency

Great point dmun. The sand needs something or else it will move.

Gary, can you cut a bunch of bricks in half, let the wet brick dust dry in your wet saw (assuming your using one) and use the saved brick dust. You will have tons of it eventually. OR you could just waist 1-2 bricks and a bit of your diamond blade and make shaving cuts to create lots of brick dust.

I found that the brick dust was actually "stickier" than the bagged fire-clay I mixed with fine sand.

[Tscarborough]

Re: Insulation Efficiency

If your hearth brick were incandescent, they are not firebrick, or you are running a pure oxygen system into it.

[wlively]

Re: Insulation Efficiency

I've read of some on the forum using the Heatstop to mortar the floor in, which they weren't suppose to do, but it did no anything bad to the build (although it wasn't needed).

As one who HeatStop mortared my floor, I am afraid I don't understand the sentiment. There is no "set in stone" way to build an oven. The only drawback to this method is not being able to easily pull up a floor brick. But, that is not much of a concern as there should be no reason to ever have to do so.

I am sorry if I am being overly sensitive, but I very much enjoy my oven and am very happy with every single carefully considered change to the plans, as they were in 2005.

Gary:
I must agree with the previous advice, it is not recommended to use pre-mix wet refractory on our outdoor ovens. If you choose to use it the floor is probably the best place for it, but keep it covered. There have been oven floors layed with sand, fireclay, refractory, mix, and dry and all work, some better than others. Just think about the end result. Are you laying it on ceramic insulation board or vermcrete and what do you have to do to get a nice tight floor that is level and stable?

[Dino_Pizza]

Re: Insulation Efficiency

Wade,
that was my point exactly. It "did not do anything bad to the build" so it was a good thing, something that the instructions we all came across on this forum did not say to do but worked! I actually think what you did so successfully should be mentioned as an option. Sorry I said "weren't suppose to do" but I meant that as a good thing, (I should have italicized " suppose")as you said "there is no set in stone way to build an oven" and you proved how great it is to have a community work to make changes and updates that benefit all of us.

I've gotten so much go info from you and others on this forum however I wish I had paid even better attention to your build: it would have saved me a day of calling and driving around for a bag of fire clay when I could have been closer to playing with the oven floor and setting soldiers.

Thanks, Dino

[wlively]

Re: Insulation Efficiency

Dino

I am sorry I took your post the wrong way. Thanks for the kind words. You did a great job on your oven as well.

[gdest]

Re: Insulation Efficiency

Wade
OK now I am getting real confused!
Please explain why "it is not recommended to use pre-mix wet refractory on our outdoor ovens"
I completly understand about the floor, but the mortar that I was talking about is from the company WESCO and the product is called TexBond. It is good for up to 2300F.

And to answer your question I am laying the floor on perlite concrete, the last time I looked it was very stable with very little need for leveling due to local depressions or imperfections.

[Tscarborough]

Re: Insulation Efficiency

TexBond is an airset water-soluble. I wouldn't worry about it too much, I used it for mine on the dome.

[Jonsan]

Re: Insulation Efficiency

Add the insulation first, since that will cover the largest area. You can caulk around the windows to help seal them against drafts until you have the resources to replace them, if needed.

[laffingmonk]

Re: Insulation Efficiency

If I have a rectangular oven with an inside layer of firebrick and an outside layer of facing brick, and I add a layer of insulation between the firebrick and the facing brick, how do I get the insulation to adhere to the firebrick and the facing brick to adhere to the insulation? 2 different kinds of mortar? Just pour a layer of perlite and concrete between the bricks? How would I use insulfrax in that application?