42” Pompeii in San Felipe, MX

[Gulf]

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

[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?

[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.

[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.

[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.

[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]

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’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.

[modified9v]

Question: I’m seriously considering going with a cast vent area. Would it be better to cast this thing on the bench and then mortar it to the arches or cast it in place?

Thanks, Mikie V.

[modified9v]

Yokosuka dweller, thank you for the kind words. I’ve been watching your build too and yes, we are right at the same points in our builds. I kind of lost interest in my oven build after I closed in the dome. Kinda got burnt out on the whole thing, but now we are (almost) cookin’.

Like you, I noticed every other build had a floating vent area so I was torn. I decided, in the end, to go the semi-floating strategy. My thinking is that if the vent structure is mortared to the floor it will give stability as I go up with the arch. If the mortar joint breaks at the vent floor during oven operation it won’t be a big deal and no one will see it. The goal was to keep the mortar joints in the arch itself intact. Also, I really don’t think the chimney will be that heavy.

Speaking of the chimney I am considering doing a casting up to the anchor plate. I know David S is big on that and I think it would be easier and actually less weight on the vent arch assembly. I have done very little research on the castable flue... looks like I have some searching to do.

Hopefully the rain will stop soon today so I can get back to it... Thanks!
Mikie V.

[Yokosuka dweller]

This is looking good - nice and clean work. I like the look of your heat break which acts as a transition into the dome chamber.

Incidentally I am at a similar stage as you, working on the flue area.

On mortaring bottom bricks of outer arch to floor vs. free-floating: I've seen people do it and others who didn't do it on this forum and I guess it's each-to-his own kinda choice at this stage. I am not decided yet whether I will mortar the outside arch arrangement to the floor or not. I will have a heat break in the floor and between inner arch/dome and second aft arch filled with gasket rope like yourself. If the arches outside are just floating will it be stable enough with all the top weight from upper flue and chimney - I guess that's my question..

[modified9v]

OK... I decided to let the outer arch float on the ceramic board but I mortared the vent area floor to the bottom arch bricks. I put down a layer of aluminum foil to protect the ceramic fiberboard. I really like the way it looks. One of the reasons I mortared the floor bricks together was to give the arch some stability and it should make it easier to remove hot ashes after a fire.

The second picture is of the heat break “L” brick. The ceramic rope is 1/2” square and will be squeezed into the 3/8” opening. I will put two layers of the rope in slot and seal with high temp sealant. The distance is about an 1/8’ between the inner and outer arches. This will also get an injection of high temp sealant.

The third picture is of the stainless steel break between the two floors. I really like how this looks and think it should be pretty functional.

I have cut 4 identical arches to build the template and have also cut plywood to protect the vent floor area. The build is covered with a tarp as we are suppose to get some much needed rain here in the Baja Desert. Maybe I can get the forms built tomorrow as the afternoon looks good weather wise.

Thanks for following along,
Mikie V.

[modified9v]

Sorry it’s taken me so long to get back to it. My flu turned into pneumonia and really put me down. Also had close friends here from Nicaragua for a month and of course they got the crud too. Everyone is better and our friends have left. Time to get back to it. I need to have this thing fully functional by mid March as we have a ton of company coming for the San Felipe 250 desert race at the end of March. We will have company from then all the way into May.

I do have a question that I may have asked before but haven’t gotten an answer to that I can find anyway. On the vent arch...

Should I mortar the base of the arch to the oven stand or should it “FLOAT” for expansion purposes? The reason I ask is that I was looking at my buddies arch, which is mortared directly to his stand, and several of his mortar joints are completely broken loose... it’s to the point that I would consider it hazardous. I was wondering if it was doing that because it wasn’t floating and the thermal expansion was just too much for the mortar.

Thanks for any help on this... Mikie V.

[modified9v]

Thanks David S... where I’m at I’d have to travel 6 hours round trip to get it and answer a bunch of questions when I brought it across the border. Luckily I found enough scraps of the fiber board to make it happen... migh come up short when I go to make my door but I’ll cross that bridge down the road.

Mikie V.

[david s]

Try agricultural suppliers, nursery suppliers or hydroponic suppliers.