36" Pompeii Build in the desert

[shanxk8]

Thanks for clarifying. I think you may have told me about this before, but my search skills couldn't find the old posts and my memory served me up the wrong name (PRV instead of breather vent). Would either of these work? (hope the links work)

https://www.acklandsgrainger.com/en/product/BREATHER-CAP-3-8IN-NPT/p/BUYHBF6

https://www.acklandsgrainger.com/en/product/STRAINER-FILLER-CAP-W-PLASTIC-BSKT/p/BUYTFAN3

[agrasyuk]

Why bother with these? All you really need is literally a piece of some sort of pipe, copper, elec conduit, anything. Put something over it to prevent the few sniper drops of rain from getting in

[UtahBeehiver]

That will work as well but a breather cap you install and forget. The main issue is the ability for the dome to vent water vapor. I recall that David S mentioned the liquid to gas volume of water is over 1000 fold. One of the major issues with ovens after construction is wet insulation whether absorbing from high humidity, leaks in the dome structure or from the water entering the front or hearth floor. It is an issue we see time and time again on the forum so any process to minimize this problem is good.

[agrasyuk]

No argument there. I firstahnd seen a measurable impact of moisture on performance. My only point is that a complete solution to this issue (venting) does not take more then 0$ to implement. Cheers

[jim lofaro]

Great discussion/insight into dome venting all. Damn Gulf, 60 inches of rain. I am originally from the low country in South Carolina. Not sure what the rainfall was there but it happened so often you did not notice it.

Anyway the final 2 inch insulating layer is in the process of being put on FrankEnDome.

[shanxk8]

That is looking great Jim! Do you have any more photos of it in progress and/or completed? What I'm trying to do with my outer arch looks similar and I'm looking for inspiration

Did you use a form for the inverse to make the funnel for the chimney?

[jim lofaro]

Thanks David for the encouraging words.

For the serpentine arch I followed Russell’s advice and JR’s model. I did not use a form for the serpentine arch. I did lose control of the mortar thickness and ended up cutting a notch out of the top bricks. My only advice would be to figure out a method to control mortar thickness and do a vertical dry stack like JR. Not sure if these photos help.

Serfs rule.

[Gulf]

They're as pretty and curvey as Petticoat Junction. But, I have yet to see an ogee that I was 100% comfortable with. Just say'n.

[jim lofaro]

Wow, i had to climb into my Wayback Machine to come come up with that reference. Anything i should be concerned about having built the S-curve Joe?

[Gulf]

Not to my knowledge. It's been working fine for others. Now that the front and sides are in the same plane, I would interlock the corners on at least a couple of courses before attaching a flue plate.

[jim lofaro]

About to finish up with the outer pcrete layer. My plan is to let that dry for a few days and then start the drying fires (paper, cardboard, twigs, and progress up to mesquite branches/logs. During that time I could work on finishing the hearth. Then stucco the dome. Sound about right?

I was thinking of just buying a stucco mix and adding an oxide to it. Any advice?

[UtahBeehiver]

You really need to be patient (a few days in not enough) with the drying out of the pcrete, it holds a lot of water which will make the blanket wet. When water turns to steam the volume becomes over 1000 fold and if you stucco the dome before the water is gone you risk cracking the new stucco. You can start with charcoal briquettes, fairly low temps and with minimal temperature spikes. Work on something else while the pcrete drys, in you area it dry out faster than usual....patience

[jim lofaro]

Thanks Russell. Patience it is. Poor timing on my part as we have just started our rainy season.

[jim lofaro]

More or less finished the outer p-crete layer and poured an extension to the hearth. Added some landscape glass to part of the hearth pour to see if I could figure out how to work it (aka Russell colored glass counter top). Waiting on things to cure.

[jim lofaro]

Just about to finish up the forms for the next hearth pour. For this pour the back of the form will be 4 ½ inches higher than the front. My plan is to pour a 2½ inch front concrete counter top in place making the difference between the back and front ~ 2 inches. No real reason just a different look.

The outer p-crete insulating layer has been curing for approximately 2 weeks. My questions are:

When should I start the break-in fires (after pouring the hearth, before the hearth pour …)?

Any advice on a concrete counter top pour? I have read mixtures from a pure sand mix to adding extra aggregate to a strong concrete mix.