40” Pompeii in Rhode Island

[UtahBeehiver]

1/8" joints are a great target but you have some wiggle room to work with too. There is a tool called the Angleizer by General Tool that will help you set up the Ax arch and it use to have a program with it that spit our top and bottom dimesions of the wedge shape of the brick. I still have the files, not sure they still work but if you PM your email I will send them too you. The tapered arch whether Ax arch or full arch use the same concept as shown in the first pic. You start with the Top Dead Center brick (you need to use full size bricks in order to cut the taper) then work down each side "ONE" at a time, using the last brick to mark side near the previous brick then the IT to set the opposite side of the brick. You cannot cut all at once, since the angles change as you move down either side of the TDC.

[NewEnglandNewb]

I am planning a tapered inner arch. It will look more like the second picture than the third as I’m not planning on it being circular. Having the vertical sides seems like it will give a little more room for pulling pots in and out of the oven and that style of arch will match the arches in the stand.

I grabbed some 1/8” plastic shims to help space the bricks out to simulate the mortar joints. Are 1/8” joints a reasonable target for home brew mortar?

[UtahBeehiver]

Are you going to do a tapered inner arch? It is well worth the effort and makes the dome/arch interface easier. It is one of the more difficult concepts to visualize but worth considering.

[NewEnglandNewb]

I set the pump for the wet saw up in a separate bucket like Russell suggested. This setup worked great! I got the floor cutout, then wrapped the edge with corrugated cardboard to keep a gap between the floor and the dome to allow them to expand/contract independently when heat cycling. I’m hoping to get the inner arch and a few dome courses laid out and cut tomorrow. One of the local building supply places has everything I need to make home brew, I will pick up those supplies this week.

[NewEnglandNewb]

Thanks Russell, I will grab a longer hose for the pump and give that a try over the weekend.

i made my IT and started playing with it to lay out the oven floor. It is screwed to a piece of melamine covered MDF that is cut to be the same shape as a brick. It was the perfect thickness for the pivot to be level with the floor. The IT length is adjustable from a little over 20” to a little under 18”. I do plan on reducing the radius of the dome a little as I go up, with the goal of having an 18” ceiling height. I also cut a grove into the block the inner face of the brick rests against to hold a pencil even with that face. That made it easy to draw the circle on the floor and should come in handy laying out the inside face of the inner arch.

[UtahBeehiver]

Good score, set your pump up by extending the water supply lines so the pump sits in a Homer bucket that you fill with clean water periodically, it will save the life of the pump. Both Gulf and I used this method and we never had to buy a new pump.

[NewEnglandNewb]

I was able to score an MK1080 wet saw on marketplace for $150. It needed some serious cleaning up, a new pump and a new blade but seems to be good to go now.

I also found a refractory supply store in a Boston suburb (Woburn) that has medium duty firebricks, calcium silicate board, and ceramic fiber blanket. I took a trip there last week and am now good to go with supplies. The calcium silicate is Skamol brand. I wasn’t expecting it to be as dense as it is, but I’m definitely not worried about it holding up to the weight of the bricks. Here is a shot of it cut to fit on top of the P/V Crete.

[mongota]

Coming along nicely!

Corsairmo, Were there reasonably uniform/consistent in shape?

The only time consistent brick size was something I was concerned with was for the floor. I did a herringbone pattern for the oven floor and transitioned to a running bond pattern for the landing tunnel.

I did an initial sorting by taking several bricks and standing them on edge like a deck of cards. With a quick flip/flop of the stack it was easy to eyeball if one was a 16th" longer or wider than the others. Once I had a decent stack, I laid them out in my proposed pattern on a sheet of plywood. The eye can pick out disrepancies. I'd swap one brick for another so the joints in the pattern were consistent and to minimize lippage between adjacent bricks. It was a fairly quick process.

Once everything was set, I cut and installed them on the floor insulation.

For the dome, any slight sizing issues will be resolved by the mortar joints.

Best, Mongo

[david s]

The clay body used contains a proportion of of both alumina and silica, the source of which varies from deposit to deposit. Silica and alumina are bound up chemically in the clay body rather than as separate ingredients. The main problem with high silica content bodies is its propensity to turn to glass at high temperatures. This can be discounted when our service temperatures are so low. Generally medium duty firebricks are the most suitable for pizza oven buildin because the provide adequate durability, but don’t kill diamond blades as fast as high duty ones. As the floor takes more of a beating than the dome, a higher refractory material is required there.

[MikeD55]

I’m not a fan or Whitaker Greer. Ive spoken to a few professional masons who’ve used them. They chip easily. They are best suited for fireplaces. Alsey is the best I’ve seen. If you want extra abrasion resistance go with their Pilot DP which is 41.3% alumina. The thermal conductivity 1.20 fairs favorably with their Jet DP 1.23 (37.6%) and Smithfield 1.23 (30.8%). I like the Jet DP for the dome and Pilot for the floor. That difference in thermal conductivity between all three is negligible at best.
Regading Mt Savage what I was told there’s more to a firebrick then alumina content. Theres also silica content, the clay used, the way it was manufactured, etc.

[NewEnglandNewb]

Thanks Mike, I appreciate that feedback. If they are that hard on blades I’m guessing they would also have good abrasion resistance, which would address Corsairmo’s feedback on using low duty bricks. Maybe a good compromise would be to use Mt. Savage bricks for the floor of the oven and the Whitacre Greer low duty for the dome?

[MikeD55]

The oven I’m building now (my second) is a combination of Alsey Jet DP (37.6%) and left over Mt Savage medium duty that a bought off a retired oven builder. I hate the mt savage. Despite the lower alumina they are a b****h to cut and I went through and extra blade because of them. $300! Give me the Alsey any day.

[NewEnglandNewb]

Corsairmo, I appreciate that feedback! I did find a place about 2 hours away that carries medium duty firebrick and Skamol brand calcium silicate board. I’m thinking I will just take a trip up there.

The place that carries medium duty firebrick that I tracked down carries Mt. Savage brand, they are 32.9% alumina. They are $3.55 a brick, so not a lot more than the $3 for the Whitacre Greer light duty ones that are 27% alumina that I can get locally. From the posts I have read on the forum Alsey brand medium duty are really good quality, the Whitacre Greer light duty ones are also good quality, but I have seen very little on Mt. Savage. Does anyone have any first hand experience with that brand bricks? Were there reasonably uniform/consistent in shape? Attached is the spec sheet the distributor I found sent me. I did reach out to Alsey, they don’t have any local distributors and it would be about $7 per brick to buy them straight from them and have them shipped to my house (shipping/pallet charge is more than the price of the brick).

[Corsairmo]

Fwiw, earlier you asked about light duty bricks. I built my first oven out of light duty bricks because I couldn't source anything living out in the sticks like I did, and the wear factor around the landing and the arch where my door slid into place was extremely disappointing after all the hard work to build the oven. Dome construction with light duty bricks is fine, but as was said, using medium duty bricks for the wear areas is a very smart choice for the long run.

[UtahBeehiver]

Looking good, nice work.