Well here goes nothing

[UtahBeehiver]

Re: Well here goes nothing

If you compare the specs Insoblok is actually better in two ways, thermal conductivity and compressive strength. But I will let you do the comparisons. You need to have the dome walls and the floor sitting on your insulation for complete isolation from your concrete hearth otherwise it is just a heat sink for your oven.

[hubert_s]

Re: Well here goes nothing

Insblock 19 is very easy to cut. I used a jig saw, but I am sure you could easily cut it by hand. Wear a mask and protect your skin, even if it is hot.

I have not fired my oven yet, so I cannot tell you how the stuff performs. I decided to use it based on a lot of posts here where people seemed to be happy with it.

[Bubb]

Re: Well here goes nothing

Okay seems there are diffrent things
With the same name on the market. Fire
Clay?? Is what I need the 50 lbs bag of
Fire clay you mix with portlland cement..? I'm reading
On here you guys are talking about fire clay you
Just mix with fine sand and water to make
A paste. This is all that is used for laying FB
And laying up the dome? Does someone have
A picture of a bag of this stuff??

[hubert_s]

Re: Well here goes nothing

I used fireclay and sand mixed 1:1 to level the insulation board because my slab was less than perfect.

For building the dome, I used a mix of 3:1:1:1 sand/fireclay/lime/portland mixed with water. This is commonly called home brew mortar. From what I read recently, some people use a higher percentage of sand in the mix. I don't know much about mortar, maybe the experts can chime in.

I bought one bag of fireclay for my 36" oven and I have slightly less than half left over after completing the dome.

[Bubb]

Re: Well here goes nothing

Hubert thanks for those ratios. Did you use a shovel full per part or did that make
To much to use before it got hard? Since I'm no mason I ll be slow laying things up.
So I plan on small batches to keep it fresh. Would be nice to hear from anybody who used
More sand?? See if it made a difference for them? Got a lead on the ins block 19 will be enough to do my 42" and another 36" so will be for sale at cost! Just gotta get the blanket insulation. Might check ebay out. Thought I saw some on there cheap!

[UtahBeehiver]

Re: Well here goes nothing

Bag on left if fire clay from a brick manufacturer (H. C. Muddox)

[hubert_s]

Re: Well here goes nothing

Bubb, I used a plastic Solo cup as my measurement device. I think it is 16 fl.oz filled to the top. 3 cups sand and 1 cup each of fireclay, lime and portland was just about the right amount for me to use up before it started getting too hard. On the lower levels, it was enough for about 2/3 of a course and more the higher I got up the dome.

I would recommend you start out with small batches to get a feel for how long the mortar lasts and how quickly you are using it. The mortar gets harder to use the older it gets. With home brew, I think it is ok to add some water to reconstitute it and keep it workable. The batch size also depends a lot on how many bricks you have pre-cut. On the first few courses, I pre-cut everything and it took maybe forty-five minutes to use up the mortar. On the higher courses, i spent more time cutting and was struggling to use up all the mortar. If you do not bevel and taper your bricks, you will probably need more mortar and larger batches will work. I'd say start with a small batch and work up from there.

[Gulf]

Re: Well here goes nothing

Hubert thanks for those ratios. Did you use a shovel full per part or did that make
To much to use before it got hard? Since I'm no mason I ll be slow laying things up.
So I plan on small batches to keep it fresh. Would be nice to hear from anybody who used
More sand?? See if it made a difference for them? Got a lead on the ins block 19 will be enough to do my 42" and another 36" so will be for sale at cost! Just gotta get the blanket insulation. Might check ebay out. Thought I saw some on there cheap!

Sorry to chime in , I know this was directed to Bubb.
But, you will need to make much smaller batches than using "shovel fulls" for parts. But, as for as the ratios go, it doesn't matter if you use red solo cups or shot glasses. As long as you use the same size container....

EDIT: Sorry ,
After posting a reply, I saw that Hubert had already answered the question. I tried to delete but, it did not work .

Any reference to "solo cup" is strictly circumstantial .

[Bubb]

Re: Well here goes nothing

Gulf I'm all ears! Thanks guys I'll be ordering my ins block 19 tomorrow. I can get fire clay local, and fire brick. I should get to craft store to get layout paper Tomorow also. As I can't find a tile saw to barrow big enough to use a jig for bevels. I guess I'll go the cut in half use shim method. I don't know there would be any difference once built. You only see those nice cuts while doing it.. I need to search forum on EBAY bought ceramic fire blanket. There is different weights and#? I just know I need 3"??? What's the deal with non ceramic safe blanket? Something new??

[hubert_s]

Re: Well here goes nothing

Bubb,

Not sure if you are aware of this, but Insblock 19 is available in different thicknesses. The price for 2" thick I was quoted was only slightly higher than the price for 1". I think it is also available in 3" thickness. Depending on what total thickness you want you might be able to save quite a bit with the thicker blocks versus stacking 1" sheets. The 2" sheets I got were 1" sheets lightly glued together and one or two separated during cutting. You'd think they would cost twice the price, but they were only about 35% more per sheet.

The Harbor Freight tile saw is currently on sale, I believe it is about $260. Not sure if that is an option for you or not.

[Bubb]

Re: Well here goes nothing

Hubert I getting the 2" ins block. Price is 132$ plus
Shipping. And it's quit a lot of it more than I'll need.
So I'll sell the rest. I've been all over the Habor website
Couldn't find a 10" tile saw??? Only little ones 7"? Might
Run out to store tonight. It's hit or miss with them on what
They got. It's to be a nice weekend so I'll be doing
Something on the dome, making my arch tool, forms, layout.

[hubert_s]

Re: Well here goes nothing

Bubb, you may find uses for the left over insulation. I have seen people use it for insulating the oven door. I plan to use the left over for insulating my stainless steel vent.

Go to the harbor freight website and look at their monthly add. The 2.5 HP tile saw is on the first page for $264.99. This link should take you to the saw directly.

[UtahBeehiver]

Re: Well here goes nothing

The same place you get the InsulBlok will have the CF blankets too.

[Bubb]

Re: Well here goes nothing

Ya I'm looking at that? It's weird heat ratings? I'm
Not sure how to measure? I need to know the
Outside sq area of the dome? If I get a roll 25" of
1" would I have enough to get 3 layers?

[Bubb]

Re: Well here goes nothing

Okay guys I'm ordering today getting is wool
Ceramic blanket 1" x25 ft total 50 sq ft. I'm just
Guessing but that should be enough for 3" on a
42" in side diameter dome??? Yes, no??