Block Stand Question - Pompeii 42"

[the Beagle]

if you're building in the twin city area and familiar with Smith Sharpe buy calcium aluminate cement from them instead of portland. Your hi-heat mortar wll be more heat resistant. Portland breaks down at temps above 450F. Calcium aluminate cement is good at much higher temps and is used in castable refractories.Smith Sharpe has the stuff in 47# bags for about $20-25

[UtahBeehiver]

Nice taper joint cuts. It may be an optical illusion but check and see if the centerline of the rod on your IT is at the centerline of you brick face. If offset, this introduces a angle error that is cumulative as you move up in courses along the dome. Now would be a good time to confirm and correct if necessary. Leave the cardboard spacer in on the floor, it will keep errant mortar from falling in the gap that could cause expansion gap problems later on.

[Yeager]

Made some progress yesterday - hopefully more today!

[gastagg]

Menards has a great product for sand. It is $5/bag and is used for mortar mixes. Super consistent, almost white, great to work with. They'll have the lime and portland too. I just looked at my recipe on the previous post and I listed lime twice. It's 3 sand, 1 lime, 1 portland, and 1 fire clay. Get from Smith Sharpe or Continental Clay a block away from Smith Sharpe if they don't have it.

[RandyJ]

Hi Yeager I got mine from menards along with the Portland cement. The sand I got from home depot and fire clay from Smith-Sharpe. You picked the right option.

Randy

[Yeager]

Thanks everyone. I'll go with the homebrew. Any suggestions on where to buy the hydrated lime(I think that's what i need?) in Minneapolis area? (I live in Burnsville\

Yeager

[RandyJ]

You are welcome. I would recommend that you not use the refactory mortar. If you do not keep your joints to under 1\8" and I do mean under. It will crack. The home brew is used on the vast majority of the oven builds on this site. Make sure to use the finest sand you can find. The stuff I had was like sugar. It was quick Crete commercial ultra fine sand. It was like the stuff they use to put in ash trays at the mall.

Randy

[gastagg]

Ok, I'm jealous...I never got any scientific analysis at Smith Sharpe! Thanks for posting that! However, they were very helpful for the many times I went in there. Looks like I went with Scenario 2/11 with 160 degrees. Your worksite and patio look great. Keep the pics coming!

I used a 3:1:1:1 (sand: lime: portland: fire clay) homebrew. Some say a 5:1:1:1 mix for mortar is better. Homebrew is less expensive. Throw it in a bucket with a lid and roll it around your yard a bit to mix. I don't know anything about the refractory mortar.

[Yeager]

Thanks Randy! Now I have to make a decision on whether to use the refractory mortar (see link below) or homebrew mortar. I have 2 bags of the refractory mortar, but am now paranoid about some people indicating that product could crack if thicker than 1/8".

[RandyJ]

Hi Yeager how is it going. I didn't use any of the dome spreadsheets. I looked at them but did not understand what they were saying. So I just winged it. For the angle on the solider course I pulled a string from the center of the dome to the outside of the brick crossing in the middle of the brick so both halves were the same. My angle was wrong but not to much. If you clamped a brick to your IT tool that would give you the proper angle. But the more I think about it it is now really necessary. A flat top should be just fine. As for the tapered bricks unless they are about the same price I would not bother with it. I just used flat bricks and filled the gaps in with mortar. I used a lot of mortar. Don't be afraid of it as it is your friend.

Randy

[Yeager]

Thanks Randy! I would go with the half soldier, but in the spreadsheet from the other spreadsheet it says the angles wont be right unless the soliders are above the IT pivot. I have 3/4" plywood and the IT Pivot is about 1 1/2" above the plywood - so 2.25" above the floor which would be 1/4" inch higher than the solider.

Did you shave the sides off the soliders or buy the tapered ones? I noticed Smith Sharpe sells the 2 1/2 -> 1 3/4" firebrick that would work slick.

Also, to come up with the appropriate angle atop of the soldiers to I just hold up my IT to it and scribe the angle - and then cut?


thanks!

[RandyJ]

That is cool that they could help you out like that. I was very impressed with everyone at Smith sharpie. Even though my project was tiny they still treated me like I was a contractor. If I ever have to build another one I will seal their advice.

You can do the full length solider it won't really hurt anything. I opted to do a half height one on mine. I also cut the angle in to the brick to make it easier. You won't need the extra height at the side in the 42" that the full height solider gives you. It also weakens the dome just a little. But yes just mortar through bricks togather and not to the floor. The dome just sits on the insulation.

Keep up the good work.

Randy

[Yeager]

Got back at my pizza dome this weekend! The weather was fairly cooperative. I was looking at canopies to help provide shade/protection from rain and they all were about $140-$350 and didn't look like they would last through any storm. So I just built one that was solid for about 65! (plus a heavy duty tarp). The 12x12 structure can be moved to follow me as I finish my outdoorkitchen project!

The HF Saw worked great!

I think I am going to use a full length solider since I am not having it rest on the floor. Should I put mortar underneath the soliders or juston the sides?

Lastly, I did something a little different (I'll post some pictures later. I used 2.5" Insulating Brick on my first layer, then 2" of Insulation Board. That way if there is any moisture that would seep in on the concrete stand it wouldn't get to the insulation board. The guy at Smith Sharpe ran a simulation with a 800 degree oven with medium duty firebrick and various configurations to show what the estimated temperature would be touching the concrete stand. I was really impressed that they went the extra mile to help put some science behind selecting material. I went with #7 below!

Scenario 1:
2.5" Medium Duty Brick
3.0" Insulation Board
142 Degrees

Scenario 2:
2.5" Medium Duty Brick
2.0" Insulation Board
160 Degrees

Scenario 3:
2.5" Medium Duty Brick
5.0" Insulated Brick
177 Degrees


Scenario 4:
2.5" Medium Duty Brick
4.5" Insulated Brick
183 Degrees


Scenario 5:
2.5" Medium Duty Brick
.25 Insulated Paper
2.5" Insulated Brick
201 Degrees


Scenario 7:
2.5" Medium Duty Brick
2.5" Insulated Brick
2.0" Insulation Board
147 Degrees


Scenario 8:
2.5" Medium Duty Brick
2.5" Insulated Brick
223 Degrees

Scenario 9:
2.5" Medium Duty Brick
3.0" Insulated Brick
210 Degrees

Scenario 10:
2.5" Medium Duty Brick
3.0" Insulation Board
142 Degrees

Scenario 11:
2.5" Medium Duty Brick
2.0" Insulation Board
160 Degrees

[thomasmn]

This is a link to a company in Farmington, MN that sells refractory products. I bought my blanket insulation there and they told me they could get any product needed for a wood oven.

Ohhh, I'm going to have to call them. I'm about ready to start my build and was sweating fire blanket/board/bricks. That would be right down the street from me.

[gastagg]

This is a link to a company in Farmington, MN that sells refractory products. I bought my blanket insulation there and they told me they could get any product needed for a wood oven.