Aloha!

[Sananguero]

Aloha everyone here at the Forno Bravo forum! My name is Karl and I live on the big island of Hawaii in rainy Hilo. Ive been reading several books on ovens including The Book of Masonry Stoves and Bread Builders among others while considering the many different design options out there. I recently acquired 115 firebricks from an old sugar cane mill that will need some work cleaning off, but excited that I may be able to begin this project soon. They are an assortment of JayBee, Aztec, Morex, and Carnegie bricks, some with chipped edges, but they were the best that I could find. Firebrick for pizza ovens is tough to come buy here so I jumped at the chance to purchase these bricks, as Home Depot wants about $6-7 per brick plus tax to ship them in from the mainland!! ouch I am definitely on a budget and plan to build the oven on an off grid piece of land as part of a small stone cottage built up around a steel frame and metal roof. This idea is inspired by the book Living Homes and the many rocks laying about the property. One thing I have a lot of is Volcanic rock, and I was hoping to finish the outside of the oven with this rock too, I have already been collecting brick shaped pieces and setting them aside for the arch and frontispiece. I am also considering using regular clay brick for the dome, as I dont know if I will be able to find the additional firebricks at a reasonable price. I have never built an oven before, but I think that the tuscan style ovens mentioned on this site sound like they are for me. I joined this forum to learn more about ovens and to hopefully find a design that will work for me and I look forward to the learning process. Much aloha and thanks for those willing to share!

Karl

[Sananguero]

Re: Aloha!

One more thing while I am still considering options... Does anybody have any info on what type of stone would work for the hearth? Ive come across a few pictures now of some really old ovens that seem to be made primarily of stone. The one type of rock that Ive heard may be suitable for this is the adze from an andesitic lava flow... It is the hardest rock on the islands... thanks

[GianniFocaccia]

Re: Aloha!

Karl,

Welcome! I just joined and am ready to pour my oven foundation slab after pouiring an outdoor kitchen counter and island foundation. Your rock-covered oven design sounds awesome. I've read on this site that while common red clay bricks are not ideal to use for an oven, an oven built with these will work and it sure beats no oven. Hopefully some more firebricks will come your way.

Most of my family lives in Kaneohe and St Louis Heights on Oahu but I've lived here on the mainland all my life. I'll bet not too many ovens in HI.

Good luck,

John

[Sananguero]

Re: Aloha!

I know its been a while but thought I would add an update to my oven progress. Ive had some challenges that come with working off grid with no electricity or water. After reading Lars posts on handcutting brick I thought I would give it a try. The only electricity I used was a skill saw to cut the forms. I still have to finish the dome, but paused when I realized I was going to need a form and that cutting 1/4 bricks by hand is going to be a pain in the a$$. I used the Pompeii plans in the pdf but somehow I did not follow exactly where the chains join the arch. I ended up w a gap between my form (circular) and the front bricks over the arch since the oven is slightly longer at the front (a few inches). Also at about the 8th chain the bricks were no longer level and the last brick ended up 2 1/2 in above the first brick. Rather than knock a couple chains off, Im thinking that problem will be solved by wrapping the final layers like a turbin, since my chains did not completely meet up. As long as the bricks are held in by the keystone, Does anyone see any problems with this? I will include some new pics as I recently got a digital camera. I hand mixed the ref mortar using the formula 3 parts mortars sand, 1 part lime, 1 part fireclay, and 1 part cement thus far. I recently bought a dry mix of Russel ref mortar for peace of mind that the dome will hold. Im hoping the rest will hold during the firing process. So far it has sat covered w a tarp for nearly a year as circumstances have left me on another island. I hope to complete the dome at the end of the week so that the next visit I can add the insulation and finish w all of these brickshaped rocks I have been collecting for the last couple years. Also I still plan to enclose this in a rock cottage, 1 story. I am thinking of first starting w a frame and corrugated roof and then cement around and incorporate into the walls as I progress. Anyone happen to know where to find a good prefab kit on something like this? Thanks for the input heres a couple pics I was able to dig up, more to be on the way shortly....

Karl

[Lburou]

Re: Aloha!

Search online for a yurt kit. It may or may not meet your needs.

I like the solution you proposed to lay bricks like a turbin. Eventually, you'll need an oddly shaped plug for the last bit

Good Luck

[Sananguero]

Re: Aloha!

Ok well finished the dome except for the keystone. I had some issues the closer I got to the top keeping the sandform at the hgt I wanted. I found myself adding more sand as I neared the top. I also felt the bricks at the end may be slightly lower than level, so I hope there is not a collapse when curing it. I left the keystone unfilled, I will make a form and cast a brick with the leftover Rutland refractory cement that I ended up adding to the refractory mortar mixture that I had. That said I really wasnt impressed with it all that much, it did appear to set nice and firm and claims to be cured when set but at $76/bucket I couldnt justify after seeing how few bricks I could lay. after seeing the lime/clay ref mortar that I mixed I was really impressed w how the lime has seemed to slowly increase in strength over time (it has been sitting almost finished for a year). Now it will probably sit till spring break when I would have a week to cure it, then insulate and throw up a lava rock exterior. Would you guys recommend to do a stucco coat in between... I was planning to do 2 in of Inslufrax and a couple of inches of vermicrete, but some of these lava rocks are heavy... was thinking a stucco coat might add to the overall strength of the dome and help to support the lava rocks. Anyone know where to get the ceramic fabric from?

here are a couple pics of the current progress

[brickie in oz]

Re: Aloha!

was thinking a stucco coat might add to the overall strength of the dome and help to support the lava rocks.

The stucco wont add much in the way of added strength, the dome should be be strong and self supporting.
Not sure how strong it will be though if you start adding huge rocks to it.

[dmun]

Re: Aloha!

insulate and throw up a lava rock exterior.

Lava rock sounds porous. How are you planning on keeping your oven/insulation dry? Even stucco isn't particularly water resistant.

[tusr18a]

Re: Aloha!

With respect to the ceramic insulation, look for a commercial insulation supplier. I am sure that there is this type of vendor on one of the islands. My guess is Oahu. The commercial suppliers carry the ceramic blankets usually to wrap around steam pipes. Just call any insulation vendor. If they do not have the ceramic blanket, then they should know who to call to get it. Be prepared to pay a lot of money. Regardless of where you buy it, the ceramic blankets are pricey.

[WoodchuckDad]

Re: Aloha!

With regard to ceramic blanket. When I bought mine at the end of the summer I got a really good deal.( I already had 40 feet of 2ftx1 ceramic blanket from a woodstove instalation I had done myself. But I wasn't sure taht would be enough. so I wanted another roll. I found plumbing supply dealer here who could get it for me for less than $50 because the specs on the material had just changed and this was old stock. I'm not sure if that could be available to you but I would ask. My guess is the the new spec is pricey and they might be able to get the older stuff for a discount.

[C5dad]

Re: Aloha!

If you know anyone at the local power plant/sugar mill, you can have them check with their maintenance department on where they get the insulation. You may be just so lucky to score some "off spec" stuff because it got wet - you'd be surprised what maintenance departments/purchasing tosses!

Chris

[Sananguero]

Re: Aloha!

Thanks for the info guys, I started checking around and finally found someone that could order the stuff, but there on vacation for a week... typical hawaii... hehe.... ok well considering it is extremely wet on the BIsland maybe I should pick something else to cover with. What would be the best material to make a waterproof coat with?

[Sananguero]

Re: Aloha!

Aloha everyone,
Getting nearer to finishing off the dome. Will post some more recent pics soon. I have decided to insulate the dome with vermicrete due to the fact that its easier for me to get and will be cheaper. I still would like to finish the outside with lava rock, but realize I need something that is waterproof to seal the vermicrete layer. What is the recommendation that you folks would have? We get a lot of rain in Hilo/Puna, wettest city in America! thanks in advance

Karl

[dmun]

Re: Aloha!

In wet climates, I think you should take your cue from the local structures. My guess is that there aren't many lava-rock roofs there.

[Sananguero]

Re: Aloha!

Aloha! Finally got a chance to visit the land after graduation and finished the oven to where I can bake in it regularly with good efficiency. Here is the first step, including build a makeshift roof out of local strawberry guava, eucalyptus, and ohia poles, and a good test for the Hilti cordless set. I decided to finish the dome with 6 inches of vermicrete, and added a TelTru SS industrial thermometer that can read over 1000F. I removed the SS pipe fitting covering the inside tip which is only 1/8" dia (as opposed to the 1 inch fitting end. As I was laying the soldier course I left a space near the hearth off to the side of the oven (after firing the second time I actually saw what I thought was the end protruding into the oven) on top of the hearth.