Acoma 42" Tuscan

[jcg31]

Re: Acoma 42" Tuscan

Robert, I would be honored, I have attached the template for the curved brick if that will be helpful, and a picture of the supports used in the making. I am also looking for the photos I took while the dome was still partial of the inside of the arch where it conforms to the inside dome shape, a bit hard to get the same angles at this point. There are on a CF somewhere.

Next is to cut half bricks for the solder course. Jim(JC), you have me so tempted to utilize your arch design if that is ok? Like we say, there are so many great experiments and improved designs that it appears best to use what one favors at the time of need.

[Acoma]

Re: Acoma 42" Tuscan

For insulation to hearth I used masonry mortar, type s. For the rest of the dome work where heat is much more a concern, I will be applying Refmix for bricks and cladding.

[RCLake]

Re: Acoma 42" Tuscan

When you mortared the insulation blocks in did you use the refractory mortar or a general masonry mortar?

[Acoma]

Re: Acoma 42" Tuscan

I finally placed the insulation on the hearth. I am heating the hearth from below still. I will be getting my tent Friday, and from that point, I will be heating from above. I am using tarps for now to keep the top warm. I had to shave a little bit of the insulation board to get it perfectly level.

Next is to cut half bricks for the solder course. Jim(JC), you have me so tempted to utilize your arch design if that is ok? Like we say, there are so many great experiments and improved designs that it appears best to use what one favors at the time of need.

Once my tent is up, I will transition the floor bricks to the outdoors to place them in their permanent location. I am still waiting for my thermocouples, but they should arrive by Friday too. If alll goes well, I would like to recommend the source, and I will place the persons information and a photo of the thermocouples on the tools thread. Great person, and great price.

Well, here is the photo of my latest accomplishment.

[Acoma]

Re: Acoma 42" Tuscan

I will do the tapered arch with minimal mortar. The photo was of the draft version, with editing by peers such as yourself. I have the angle of the arch I like, now being to taper bricks. Thanks Wade.
Today I mortared the insulation in place. Tomorrow, confirm or shave minimally to level. I had to work so fast, it was 25 degrees and no heat to help. I have a tent to help me along, but will not show up until next week. As for heating, I picked up a 24 hour electric heater, tower series. I have it heating up the underside of the hearth for today. Tomorrow, after I have the insulation confirmed, I will build a temporary tent for the obove area, then I will get the outside area prepped for a perminant work site. Wednesday, I plan to put the floor bricks down if the heating works with the temporary tent experiment. One step at a time....

[wlively]

Re: Acoma 42" Tuscan

I think the 1/4 inch gap you mention is plenty. When I was asking about what could be Ken's cause of cracking I was not thinking about the floor pushing out, but the dome itself. That may or may not be correct, just an idea thrown out there based on where the cracks seemed to have occurred. Based on watching the further firings, Ken should have a good idea.

I might suggest an alteration to the arch design. The arch will be stronger if the bricks are cut to taper and the mortar joints kept to a minimum. The idea being that it will be freestanding on it own, even if the mortar fails. I tested mine, by pulling the form immediately after putting it together, while the mortar was still wet.

[Les]

Re: Acoma 42" Tuscan

Robert,

Cold is right - 16 deg this AM with a high of 36 today. The white stuff doesn't want to leave I guess it could be worse. The good news is that in 10 days the sun starts heading back our way.

Les...

[Acoma]

Re: Acoma 42" Tuscan

Well, I have now cut the insulation board. The layout of the arch is nearly done as well. Fine tuning the cuts, similar to Les's for the internal look of the arch will be done shortly. I would like to have the insulation board and floor bricks in place this weekend. Here are a few photos of progress. I have included a photo of the recent snowfall. Two days after our recent storm and we still have snow on roofs, cold!

[Acoma]

Re: Acoma 42" Tuscan

Wade, if expansion of brick is .21, then having a floor gap to dome should be 1/4? Keeping the floor from putting added outward pressure to the dome? I am then curious about how to apply this to the transition to the arch to prevent the potential for crack like Ken or others may have. I will likely go 1/4 gap between floor bricks and dome. As for the arch to dome, I am curious about the best way for this transition due to outward force, not downward by chimney, flue.
Ken, do you think that by your side supports to the arch, the arch was kind of kept from its expansion needed for the bricks, causing pressure to release where it did? Maybe cladding the dome and arch would be best remedy.

[wlively]

Re: Acoma 42" Tuscan

I am satisfied with the Insblok. When I say crumbly it is more of a shear crumbly. It will not hold anything from moving, but of course it is only there for insulation, like vermiculite concrete. It works fine in compression and it was simple to work with. I only used 1" and think you are better off with your 3".

As for floor, can't say how well mortaring the floor helps with evening temp as have no comparison. It probably doesn't matter either way, but if you are going to put your dome outside the floor, than you would probably be better off not mortaring. Leaving them a liitle loose will help take up any expansion. I did the math a while back and over 42" the thermal expansion of refractory brick is only about 0.21 inches.
http://www.fornobravo.com/forum/f8/t...arth-2618.html

[Acoma]

Re: Acoma 42" Tuscan

Wade, still satisfied with your Insblock then? Got some myself at 3". This is a tough call for me with which way to go, being that you went with mortar, ken without, both with success, both with Insblock. It seems Ken has only the entry as the issue. And if it crumbles easily, what of the opinions of its use? Seems to work well still with great heat retention, holding up the dome, etc. Just don't get it wet. I will be doing my solder outside the floor bricks, same with the entry.

[wlively]

Re: Acoma 42" Tuscan

1. Yes, though bedding would be a better term as the Insblock would not hold anything as it crumbles very easily.

2. Yes, bedding again. My thought was to get better temp uniformity of the floor as well as level. Again the Insblock will not hold anything, which would allow the floor to float on top if it wants to move.

3. Yes, a very thin mortar joint. Followed original plans, so the dome sits on top of the floor.

4. Yes, no gap. Since the dome sits on top of the floor, there is no way to have a gap.

I continually inspect both cold and hot and cannot find a crack anywhere yet (from inside of course). With my ugly looking dome and arch, I really expected at least a couple to show up by now. Will keep looking and post any that I find.

Wade, looking at your oven building thread, it appears that you did the following:

1.Mortared the insblock to the hearth
2.Mortared the floor bricks to insblock (not to each other)
3.Mortared the solder course to floor bricks and insblock
4.Left no gap of floor bricks to solder

If this is true, have you had any expansion issues with the dome and arch regarding cracks? Most recent builds have floor bricks and solders with no mortaring, and yet varying crack issues. Also, some are doing a paste of brick dust, sand, water combo for insblock and floor bricks, solder course.
You have used your oven long enough to get good judgement of its success, so please share if you don't mind.

[Acoma]

Re: Acoma 42" Tuscan

I am confused at the outward push being mentioned about your dome to arch, yet the crack is so clean along the brick edge, it looks like it didn't bond to the brick, too much maybe?

[Ken524]

Re: Acoma 42" Tuscan

Ken, how are you with the cracks? Just the arch area still?

Just the arch... I'm tickled at how well the dome is holding up. Frustrated as heck about my arch

[Acoma]

Re: Acoma 42" Tuscan

Ken, how are you with the cracks? Just the arch area still?