36" Pompeii Build in the desert

[UtahBeehiver]

Any refractory supplier will have ceramic rope. You might even find it at fireplace/stove stores. Kaowool moldable caulk is a high temp caulk in 10 ounce tubes but you won't find it at Ace, again refractory supplier. BTW, nice job finishing the dome.

[JRPizza]

Jim, for caulk I used 3M fire-block sealant FB 136. It was available at the local hardware store and was relatively cheap. I don't know how flexible is was supposed to be, but it is used for sealing around chimneys so I thought it would suffice. With the design I used gravity is holding in my rope and the sealant is mainly to keep it from migrating horizontally and falling into the vertical gap. I can't remember where I bought my rope - probably had my son "Amazon" it for me. In retrospect I probably would have bought Kevlar rope as I needed some to gasket my door and didn't think at the time how undesirable using glass rope for that application would be.

[jim lofaro]

Thanks all. Found the 3M caulk at Lowes (some 30 miles away). Got 3 tubes. Also found a source for ceramic in Tucson (Mineral Seal Corporation 1832 S Research Loop Tucson AZ 85710). Ordered the 3/8 inch rope yesterday and it arrived today.

So if I am reading JR posts correctly there are 3 different brick cuts I will need to make for the vent arch:

• The notched cuts adjacent to the inner arch
• The serpentine structure itself.
• The outer decorative arch

I posted a picture of the what I think would work for the serpentine bit; 2 tapered bricks with the small end facing inward and then 5 tapered bricks with the small end facing outward. The structure starts out at 24 inches wide at the bottom and closes to 6 inches at the top. Will this work? Do I need to cut deeper angles on the tapered brick? Not sure what is important here.

[JRPizza]

Wow, that really looks good! Smoke should not have any problem getting out of the oven and up your chimney . I am not sure how much additional side loads you might have from the steeper angles - I have seen lots of lower arch builds where buttresses were added to help stabilize the arches. Don't know how critical that is but I'm sure someone here does. I can't remember if you have the anchor plate for your chimney (or if you are using one) but now is where you want to make sure you have enough room to fit it on, and that your opening at the top gives you the square inches you need to feed the pipe.

[jim lofaro]

Allrightythen, let me order the anchor plate. i was thinking the Double Wall 8 inch DuraTech Anchor Plate, Sound about right?

[UtahBeehiver]

There will be a conflict if you have a 8" anchor plate with a 6" width at the top. What will you depth be at the anchor plate mounting area. I believe FB recommends 32-36" oven size uses a 6" ID chimney.

[jim lofaro]

Ouch, ordered the 8 inch yesterday. Anyway, attached is a photo of the ‘aerial’ view of the S-curve and a drawing of what I think it should look like aerially speaking. The depth I believe you speak of is 9 inches. Let me know if I have it all wrong.

[JRPizza]

Since a 8" pipe has 50 square inches of area, your 6X9 opening will be enough to feed it @ 54in^2, but you will need to build a transition to get to 8X8 to seat your adapter plate. I had no problem getting enough width but I needed more depth, which is the opposite of your build. I had to open up my front and rear bricks where I tied in my adapter, where you will probably need to open your side bricks to get 8" if your plate is like mine and has a projection down. You can see what I did in the attached pic. I didn't just want to make the opening 8X8 square as that would have pushed the bricks I modified out of position for what I was trying to build, so I cut the curves. Using my saw from both sides of the brick plus a little hit from the angle grinder with a masonry stone made quick work of the shape I needed.

[jim lofaro]

Thanks all. Let me digest this a bit and reread your vent build.

[JRPizza]

Let me know if/where you need help. I have some pics that didn't make it into my build that might help, plus I have a pretty good cad model of what I did that I can pull screen shots out of.

[jim lofaro]

Thanks again. The problem is I do not know what I do not know at this point. Hopefully with plate in hand all will be revealed.

[JRPizza]

Well, you do know what size your opening will be if you proceed with the serpentine and the sketch above, and you know you need to get to a square that will fit your adapter and provide the proper amount of area to feed the pipe. Now you just need to play with some designs that will get you from points A to B, and decide how you want to terminate the top of your brick chimney. Lots of us put a little "crown" on top to give a finished look. I'll admit the chimney was one of the parts that really had my head hurting, but once you can get a design in your head and figure how to build it you will be a happy man!

[jim lofaro]

I guess i do know some things.

Poured a 1 ½ inch layer of perlcrete to finish off the vent arch area and ordered another 2 inch insulating board. Cut brick for the inner part of the vent arch that is adjacent to the inner arch (not sure what to call this arch). Dry stacked um. Anything u’all can see that I am doing wrong?

[JRPizza]

When I did my cad drawings I called my vent arches fore and aft, mostly cause I was labeling them and needed to call them something. In your middle pic, is the lower left 45 angle there to get good smoke flow, and the upper right "extension" to go back over your dome arch? Just asking to understand what I am seeing in pic #3. Also in #3 it looks like you have some temporary bricks sitting on top of the aft vent arch - is that correct?

[jim lofaro]

U got it in one; the lower left cut is a copy of the DavidApp photo in your post #149. I assumed it was to aid in smoke flow. The upper right is the 2 inch extension that goes over the inner arch and there are temporary bricks setting on top to keep the aft arch in place.

A question. The aft arch sits on 2 runs of ceramic rope. Do u backfill that area with pcrete? Stuff more rope in the gap? All the above? What do you do about the contact between the back of the aft arch and the front of the inner arch? My tendency is to run a bit of ceramic rope along the contact.