OctoForno

[stonecutter]

Re: OctoForno

Dough makes lousy stucco.

[Tscarborough]

Re: OctoForno

Not as lousy as mortar makes for pizza crust.

[kbartman]

Re: OctoForno

Dough makes lousy stucco.

If it stick a well as it sticks to my pizza peel as my walls, I say it would make a excellent stucco.

Whenever you are mixing stucco or mortar, if doing it by hand, a minimum of 5 minutes is really a minimum. It goes through stages, depending upon how you add the water.

I add about half the water that I think will do to one side and then mix that into a slurry, then begin mixing in more dry material, still keeping the mix soupy. Once there is no more free water, begin adding small increments of water, mixing the whole mass together before adding more. When it is 100% mixed, no dry particles, evenly "wet", let it rest for a few minutes, then mix it for another minute or two and it is ready to go.

Hey! That is exactly the way to hand mix dough too, who would have thought....

I don't want to hi jack John's thread, so any response to this we can finish on my build thread. I mixed what I thought was a dry mix similar to what you explained in a electric mixer. I allowed it to continue to mix while tending to the stucco on the enclosure, only to return to a soupy mixture. The next batch started even dryer . Same thing ???? Again I think over mixing is my issue, the rest period I thought was sitting and my staging board. It ain't rocket science I keep telling myself, but the solution is eluding me.

I'm also looking forward to seeing the granite cladding. It should be awesome as the rest of the build, sound expensive though.

[stonecutter]

Re: OctoForno

Not as lousy as mortar makes for pizza crust.

True,true.

[stonecutter]

Re: OctoForno

...... sound expensive though.

Justified buy saving 80% through DIY.

[GianniFocaccia]

Re: OctoForno

Justified buy saving 80% through DIY.

So true. I rationalize almost all of my purchases/projects using this very sound logic! And, given the inordinate amount of time I invest to get them done, convince myself I can get a better result than paying someone who does it in a hurry.

[UtahBeehiver]

Re: OctoForno

Plus the bragging rights to say I did it myself.............

[Campmaki]

Re: OctoForno

Hello All,

Glad to be back after all these months considering my company closed its CA offices (laying everyone off) and then I hit a bit of a rough patch with my health which initially landed me in the ER. Feeling much better now, but getting old is really getting old and I'm still in my fifties!

Fortunately, I can report I'm on the homestretch on my oven (and now fully-cured dome ). I have completed the entryway save for the last two leveling courses. The welding of my custom-designed flue (by a family member) got derailed but is now at a commercial fabricator who promised it to me last week and now says hopefully day after tomorrow.

I really struggled with an approach to constructing my flared entry and integrating a 13.5"(h) x 22.5"(w) inner arch with a 12.5"(h) x 26"(w) outer arch. I finally got it figured out and kicked myself for not attacking it sooner because it really wasn't that difficult a job, just time-consuming. All in all, it was a fun part of the project.

Anyway, here's some pics and a profile of my vent. I really wanted the vent architecture to be totally seamless to give the oven exhaust every opportunity to go up rather than out the front of the oven. Hence the trapezoidal shape and an outer arch that is an inch lower than the inner arch. I think it came out okay.

I'll report back when I get my flue installed and hopefully a first fire (really?) video a week later.

John

John, I have been wondering about an issue I see with some of the builds on here. Being a mason by trade, what I see that concerns me is the construction of the entries on some builds. I believe the stronger entry is the type you built, where the arch starts right at the floor. I see some where a short height side wall is built then a shallow arch connects the two short height walls. My thinking is that this could over time collapse. These brick side walls are not tied back into the dome structure itself. Just thought I would pick your brain a little. Here is another issue , have not yet figured out how to make my messages get in the forum. Thanks again for any help

[Campmaki]

Re: OctoForno

John, I have been wondering about an issue I see with some of the builds on here. Being a mason by trade, what I see that concerns me is the construction of the entries on some builds. I believe the stronger entry is the type you built, where the arch starts right at the floor. I see some where a short height side wall is built then a shallow arch connects the two short height walls. My thinking is that this could over time collapse. These brick side walls are not tied back into the dome structure itself. Just thought I would pick your brain a little. Here is another issue , have not yet figured out how to make my messages get in the forum. Thanks again for any help

I guess I just figured that one out!!!!

[Campmaki]

Re: OctoForno

I guess I just figured that one out!!!!

Abutments
An arch abutment can be a column, wall or combination of wall and shelf angle. Failure of an abutment occurs
from excessive lateral movement of the abutment or exceeding the flexural, compressive or shear strength of the
abutment. Lateral movement of the abutment is due to the horizontal thrust of the arch. Thrust develops in all
arches and the thrust force is greater for flatter arches. The thrust should be resisted so that lateral movement of
the abutment does not cause failure in the arch. If the abutment is formed by a combination of brickwork and a
non-masonry structural member, rigidity of the non-masonry structural member and rigidity of the ties are very
important. Adjustable ties or single or double wire ties are recommended. Corrugated ties should not be used in
this application because they do not provide adequate axial stiffness. Consult Technical Notes 31A for further
discussion of abutment and tie stiffness requirements.

[Campmaki]

Re: OctoForno

[QUOTE=Campmaki;168640]Abutments
An arch abutment can be a column, wall or combination of wall and shelf angle. Failure of an abutment occurs
from excessive lateral movement of the abutment or exceeding the flexural, compressive or shear strength of the
abutment. Lateral movement of the abutment is due to the horizontal thrust of the arch. Thrust develops in all
arches and the thrust force is greater for flatter arches. The thrust should be resisted so that lateral movement of
the abutment does not cause failure in the arch. If the abutment is formed by a combination of brickwork and a
non-masonry structural member, rigidity of the non-masonry structural member and rigidity of the ties are very
important. Adjustable ties or single or double wire ties are recommended. Corrugated ties should not be used in
this application because they do not provide adequate axial stiffness. Consult Technical Notes 31A for further
discussion of abutment and tie stiffness requirements.[

[oasiscdm]

Re: OctoForno

there seems to be an echo

Like the information I too built the same type of arch as John. We discussed this a bit a hemispherical arch is much stronger for those reasons you have highlighted.

[stonecutter]

Re: OctoForno

there seems to be an echo

Like the information I too built the same type of arch as John. We discussed this a bit a hemispherical arch is much stronger for those reasons you have highlighted.

You mean a semicircular arch, Colin

The height of the pier which a segmental arch springs from is the real point of weakness. Most of the segmental arches built on here have sufficient thickness/ height ratio in the pier to worry about hinge failure, because the don't support that much load weight. A lot of builds here have buttressed the pier, creating and abutment, removing any possibility of overloading the arch.

[Campmaki]

Re: OctoForno

You mean a semicircular arch, Colin

The height of the pier which a segmental arch springs from is the real point of weakness. Most of the segmental arches built on here have sufficient thickness/ height ratio in the pier to worry about hinge failure, because the don't support that much load weight. A lot of builds here have buttressed the pier, creating and abutment, removing any possibility of overloading the arch.

I guess I was not giving my full thought on this issue. I think the shorter side walls need to backed up with at least a 4 inch block. there might not be an issue when using a metal chimney, but what about a clay flue liner. This adds some extra weight and downward pressure to the arch.

[stonecutter]

Re: OctoForno

I guess I was not giving my full thought on this issue. I think the shorter side walls need to backed up with at least a 4 inch block. there might not be an issue when using a metal chimney, but what about a clay flue liner. This adds some extra weight and downward pressure to the arch.

If the spans were greater than 24", had tall piers, and have 12" flues maybe, but the outer arch you are concerned about doesn't carry 100% of the load anyway. With the oven opening arch as part of the system, strength is further gained by the vent being constructed in a way so that it functions like a vault, even though it technically isn't one. It provides plenty of structural mass to support itself, and a few flues.

BTW, I was talking about loading the arch with several clay flues, not metal ones.

Just so I'm clear, I am not saying a segmental arch is as strong as a semicircular one. Only that building an abutment ( or buttressing as referred to on the forum) is not necessary in most cases and is over building. It's not a design flaw to omit it, but it is good insurance, and there is nothing wrong with that.