South Jersey Pompeii Oven - Am I Doing This Right?

[mintee]

Hi all,
years, and finall

Long time lurker, first(-ish)time poster. I've been getting the courage up to build this oven for about 5+y I'm cutting bricks!

Photo's can be viewed here. https://photos.app.goo.gl/oyuh2hy7Lc3z3vG1A

As much time as I've researched on this forum, read, watched videos and hand drew some horrible (and now lost plans) it's still SOOOO new to me. I had the hardest time determining where the "vent landing" was supposed to start, how long (deep) the opening should be, and how to figure out the difference in the two arches. Things aren't super clear until you get your hands dirty.

I decided on doing a 42" oven with interior floor, not connected to the walls of the oven, mostly due to the ability to replace floor bricks and I typically choose the hardest method of doing anything. I also set the first "soldiers" flat, cut at a 4.8-ish degree angle on both sides. (from a 4.5 x 4.5 split brick) I've laid out my second course as seen on the photo. Currently they are not angled or mortared, which leads me to my first question.

This first row of solders are directly on the FB board, no fireclay/sand. The second course is directly on top of the first course. Does the 2nd course need to be mortared to the first? After looking at Les' build and realizing that mortar lines are not necessary, I'm wondering if this is fine and I can just start cutting for the 3rd course, angled of course. (So far all my lines seem to be super tight, which I'm suprised about.)

[UtahBeehiver]

No mortar between dome and floor but side to side is mortared, it needs to be able to expand and contract independently. For sematic purposes, for other builders, the first course is not really a flat soldier but what is called a half header. This way we are all talking the same language. On your IT, as you move up, remember that the pivot point and along the bottom of the 2 x 4 needs to intersect the center of the dome brick not the bottom or the top edge. If this is not done the brick face is not perpendicular to the center of the oven and the error is cumulative and gets worse as you move up. Also about the 3rd or 4th course you will see what is called an inverted "V" unless you start to bevel the sides of the brick as well. Vent depth varies, but the key is the make sure you the chimney vent has similar square inches of opening as your chimney stack. Also, if you have not put weep holes in the hearth yet, now is the time to drill a couple in from the bottom side. Wet insulation is one of the most common problems with poor performance of these ovens.

[mintee]

Wow, thanks UtahBeehiver!

I wasn't planning on putting mortar between the floor and dome, but when you said "side to side", do you mean the sides of the bricks that line up the dome must be mortared? My main question is, do I need to mortar the first course of "half headers" to the second course, as they are laying flat currently? I'll start with the IT on the 3rd course and pivot the bricks accordingly.

This picture should help explain.

(Funny, I've been lurking on here for so long, your personal reply shocked me like I met a celebrity or something. Haha!)

[UtahBeehiver]

Left, right, top of #2 mortar, # 1 no mortar

[mintee]

Gotcha, this post also helped.

https://community.fornobravo.com/for...rtar-thickness

Also, thanks for the weeping hole suggestion. My FB board did get a little wet due to a hole in my tarp it was covered with. These 100 degree days should dry it out with weeping holes in no time. A dozen 1/4 holes should be sufficient, right?

[Karangi Dude]

Hi Mintee,

I am a little concerned about the distance that you have allowed from the front edge of the base to where your door will sit, in the pictures it looks a long way.
I know you will building a flue arch and decorative arch in front, but might be worthwhile checking before you go to much further, it would be easy to correct now but impossible later

Cheers Doug

[mintee]

Funny you mention that and thank you. Just this past Sunday I was concerned about it being to close to the front of the base, and I slid it back about 8 inches. I've had a hard time finding dimensions of how deep the front should be, say from the oven opening to the outside of the decorative arch. I'm thinking (4.5 - the difference of the pivot for the inner arch) + flue depth + (9 depth of the outer arch)

It shouldn't take more than 30-45 minutes to move it now, but yes, later wouldn't happen. I'll dig through some other posts and see if I can figure out a safe area.

Clearly I need to dry fit the arch and opening to get a better feel of the size and action of the peel.

[Karangi Dude]

Mintee, you would want to be able to reach in to the door arch comfortably to remove the door, the more shallow the landing the better, but not at the expense of having to small a flue gallery

Pending what sort of landing you plan on having you could say 4" with 1/2 brick 41/2 " for the decorative arch and 1 1/2 bricks 13 1/2" for the flue gallery thats about 22"
Check what others have done and go from there. I built a 48" oven and had a reasonable entrance but it was a long way to place wood on the fire

Cheers Doug

[mintee]

Thanks Karangi!

I got a decent amount accomplished this past weekend as seen in the photos. I moved the entire oven closer by 8 inches or so. I think/hope my placement is good now. I'm trying to wrap my head around the inner arch, but I think the closer I get to it, the more I'll understand. I need to snap a picture of the placement of the IT in terms of where the arch will be. I've noticed a lot of people have been doing L type cuts for the inner arch, and I can't figure out why. I assume it's to lay a pre-fabbed flue on top.

The arch bricks are just 1/2 bricks with a 2.5 angle sheered off each face. Seems like the best practice is to cut the back tapered angle as the dome gets higher for accuracy. I don't want to wing it, and the math is over my head to try and figure it out perfectly ahead of time.

I've used the scrap angles of fire brick as wedges to prop the bricks up to match the angle of the IT. I plan on grinding them off once it's completed.

Any and all feedback is welcome, as you know, there's no going back if I screw up.

Thanks again! Be sure to check out the other photos in my album in my signature.

[mintee]

Also, I mounted my IT directly into the middle firebrick. I figured it's easy to replace, as it's a floating brick and I didn't have to worry about the height of the pivot as much.

[mintee]

Lot's of progress yesterday. Row's 4 and 5 are up! Still struggling with the idea of the arch. As much photos and posts I look at, it's still not 100% clear to me if the location of my arch form is in the correct spot. As seen in the second picture showing the upright tapered arch brick, I'm not sure where to start my cut from the top down, and I don't understand clearly how to cut the bottom to angle up as to conform with the dome. UtahBeeHivers pictures and posts make the most sense, but I'm still a bit lost.

I'm planning on mortaring the arch in place as the courses start to intersect. Is this a practical way to go, or do I need to double up my thinking cap and mount the arch first?

[UtahBeehiver]

Fyi, it takes more than a half a brick to do a tapered inner arch. It appears that the arch bricks are half cut bricks. I'm out of town right now and can't send you any info. Maybe JR ot Gulf can help ya with this.

[JRPizza]

I didn't build a flat arch like you are doing, but UtahBeehiver often shares the pictures at the link below to show what the arch should look like. In the second picture he shows a full brick on the right side and a TDC brick that has had the inner radius cut on the lower rear and the slope for mating bricks on the top side. You need enough brick length to make these two cuts. Does this make sense the way I explained it?

https://community.fornobravo.com/for...627#post415627

[Gulf]

Mintee,

Like Russell pointed out, the half bricks will not extend far enough in to the oven to recieve the dome walls. The inner arch goes straight up in a vertical plane while the dome curves inward in a compound curve. I know that is clear as mud to you right now but, trust me, it will finally click. We all struggled with the concept at first. I see that you did a great job tapering those half bricks and numbering each one to fit the arch form. Do that again with full length brick. Once that is done, you can then use your IT tool to mark the inside diameter of the dome on each brick (both sides of each brick) as you dry stack and place them on the form with spacers. The inside diameter is the back side of the 90 degree angle that is formed by your IT. Make all those cuts first. We will get to the other steps once that is done. I don't want to muddy the water too much at once .

I just got a message that JRPizza has responded to your question while I was composing this response. In a few days, you will have this down pat and will be able to pass it forward. Take plenty of pics of each step. It will help someone else.

[mintee]

"I know that is clear as mud to you right now..."

Haha! Yeah Gulf, but it's getting clearer. My in-laws have been in town for the past week, so I haven't really had a chance to get to these posts until today. Tomorrow I'll be our there cutting and cussing again.

I cannot help but to be super embarrassed, as I've stared at the attached image more than a few dozen times, and it never clicked that it wasn't a 1/2 brick. Sometimes overthinking destroys the obvious. All 3 of you helped in equal ways, and I greatly appreciate it. If you ever find yourself around my neck of the woods, send me a PM and I'll be sure beers are on me!

Tomorrow I'll be tapering full length bricks, which isn't going to be easy on my make shift 10" wet miter saw. If I post back tomorrow missing some letters in words, be sure it's because of a missing finger or two.

Cheers!