42” Pompeii in San Felipe, MX

[david s]

It is far easier to cast it in place because that will result in a perfect fit where it joins the dome. It is easier to brick up the sides so you only have to cast the top part. You can use something like polystyrene boxes that are easy to remove, than damp sand on top of them to form your mould to cast over. Attempting to create compound curves with brick units is complex whereas a cast is simple and fast.

[modified9v]

Thanks David S. I’m assuming that I should shoot for 2” thick using 3:1:1:1, no rebar? I don’t have access to styrofoam blocks. What about making the form out of thin plywood and an 8” tube? I was thinking that if I split the tube vertically in two places I could get it out easily... especially if there was some sort of anti-bonding agent I could put on the tube and plywood. Or, I could go on a scavenger hunt and find some foam.

Thoughts?
Mikie V.

[david s]

Just wrap a few layers of plastic around the pipe for easy removal. It is best to make it a slightly loose fit to accomodate an expanding flue pipe.3:!:1:1 home-brew should be ok as the flue gallery doesn't get that hot (the black soot won't burn off there. Get some castable refractory if you want it more durable. 1.5" should be plenty thick enough. Do not try to reinforce it with rebar. The steel will expand faster than the surrounding refractory and result in cracking.

[modified9v]

Thanks David s. I really appreciate your knowledge and helpfulness. Couple things, one is I’m wanting to mount an adapter plate so I’m gonna want either bolt holes or cast the plate directly into the casted vent. Also, my vent area is not a straight up wall. It is a like my inner arch only bigger to allow for the door reveal. I really think I can make this happen going with the casting method. I’m gonna try anyway.

[david s]

The first pic shows how the anchor plate can be trimmed so it can be fitted in place during casting. The second pic shows the method I use which does not require an anchor plate. I do pack around the junction with 5:1 vermicrete, which is sufficiently strong enough to hold it in place, but still allows for easy removal should the pipe need relocation or replacement.

[Chach]

I cast my arch with the flue gallery then mortared it place. I built brick sides and mortared the flue/ arch right on top.

[modified9v]

Man, I should have been done with this project by now. But here we are. I spent 2 days building this arch form and I’m still not happy with it. I’m going with it at this point as my patience has run it’s course. I know it looks unconventional, but it is what it is. What a pain in the tail.

I had originally planed to make 5 identical plywood forms and link them together. I ran out of plywood and honestly, the plywood here just sucks. In the end I decided to go with 2 forms and span it with 2mm plywood I salvaged from the back of some kitchen cabinets I tore out of the kitchen. I had to trim the plywood arches to make room for the extra 2mm on each side... ughhhhh!!!! I missed it and had to run a borrowed belt sander on that thin plywood to make it fit. I just couldn’t make it work and ended up knocking a the bottom bricks off of the left side. The good news is those bricks were major league glued on. I guess this home brew does work.

I was trying to make the laying of the arch “idiot proof” with the horizontal lines. Easy-Peasy. NOT. Seems all that work with the aggressive belt sander changed the radius of the inner and outer plywood forms. The circumference differential is nearly 1/2”. Man, it really multiplied.

Bottom line is I am gonna wing it. It will be fine and no one but you and I will know it. I will just have to adjust as I go up. Still planning to pour the flue after I get up to L7 & R7.

Thanks for following along. I’m so ready to be done with this project. I can see the light at the end of the tunnel.
Mikie V.

[modified9v]

Question: Can I lay tile on the outside of outer arch for decoration? Worried that the heat might pop the tile off. Was hoping to use local tiles like the one pictured. Special thinset I suspect?

[Gulf]

Insulate and stucco over that to form a strong shell on which to apply the tiles.

[david s]

Question: Can I lay tile on the outside of outer arch for decoration? Worried that the heat might pop the tile off. Was hoping to use local tiles like the one pictured. Special thinset I suspect?

I was concerned about this problem the first time I attempted it too. Since then I’ve done lots with no problems, although in my design my outer decorative arch does not contact the flue gallery. It is separated by either 8 mm insulation at floor level, or by a similar sized air gap at the sides and top. This allows for free expansion of the inner parts of the oven and also reduces conduction to the outer decorative arch. Make sure you use a good quality outdoor adhesive (I use mono flex, but that brand may not be available in your part of the world). Also use glossy tiles which will clean off beautifully and a black grout.

[modified9v]

Well, looks like I may have painted myself into a corner. I kind of just kept going and forgot about going vertical for a chamber below the anchor plate. I can cast it up but there will be little space for volume of the smoke exiting the oven. Is this a problem? Should I pull a few rows and go for it again with the thought of building a larger smoke chamber?

Thanks, Mikie V.

[Chach]

Well you can just leave it and go with it and the oven would work smoke will come out the front especially in the beggining of starting your fire. What I ask myself and what I tell others in amything I do as a project is if I know its sorta not up to par or I know its wrong and ask if it will work I know I would not be happy with it and always would think to myself I should have just did this or this it may have set me back a day or so. When I think this I end up just doing what I have to do to make myself gappy with what I'm trying to accomplish at least this way I know I did everything I could to do the best I could.

My advice to you is your at a point where you realize what's wrong and you have the opportunity to fix it and make it the way you would like it to be. Once you start putting the finishes on you would have a harder time to change things. I have ripped pieces off of mine to correct things that didnt look right and I am extremely happy I did because I don't have the what if I did this or this instead of just leaving this. The last thing I did was filling perlite in the enclosure. I had the plywood roof on and tossed up the idea and was like nah Ill leave it empty and then I thought what am I nuts I spent all this time and money working on this what's another few hundred dollars and a day of time and a little inconvenience of cutting the roof open and adding this. So glad I did as the oven can be cooked in with retained heat for 4 days. Not sure what it would have been if I didn't but I always would have been wondering what if I put that in.

It's a long reply bu I Hope this helps keep up the good work!

Ricky

[modified9v]

Hey thanks Ricky. It’s what i needed to hear, not what I wanted to hear. LOL. Those bricks will be a real bummer to pull out of there. I will have to be super careful I don’t knock the whole thing down. I think I can get by with pulling 2 courses and taking a look.

One thing that I told myself when I started this build was I didn’t want smoke coming out the front on initial start up... kinda a peeve of sorts. I’m gonna pull those bricks today and post another picture.

One other note. I did mortar the bottom arch bricks to the floor and there is a slight crack at the join to the floor... I shocked that the thing stands like this without snapping off... true testament to the “Home Brew”.

I will report back after I clean up this mess.

Thanks, Mikie V.

[JRPizza]

What kind of transition were you planning on building? You need to pull bricks if you are going with a serpentine vent but there are other designs that you could probably make work by building upward and not constricting the opening any more.

[modified9v]

JR,

I went ahead and pulled 2 rows. Looks like I have room to work now. I really screwed up... I had no plan. Initially I had thought about copying your arch, JR, but I gotta say I am so burned out on the project I figured I’d just wing it. That didn’t work out so good. I need to suck it up like a big boy and get this thing done and done right. No half arse stuff. I’m going to spend some more time looking at other builder’s flue galleries. Yours included.

I think now I will do something like Brad’s in the UK. Kinda a hybrid between your’s and his.

I gotta say that getting the 2nd brick down was a real chore. Sucker was stuck and I had to cut it out with my angle grinder. What a mess. I was surprised to see that the mortar in the very counter was still damp while the rest had dried white. I set that brick almost 2 weeks ago. Amazing stuff this Homebrew.

Thanks for the help,
Mikie V.