Raffy's WFO Build

[Raffy]

Re: Raffy's WFO Build

Nice work, now the fun part begins.

Thanks and I heartily agree. I've been looking forward to "handling" the brick and constructing the dome. There is something strangely cathartic about using something rectangular to create something circular and sloping. Shaping, grinding and fitting... there should be a limit of how much fun a person can have.

Before I get too philosophical, thanks to everyone for your encouragement and help. I wouldn't have even attempted this if it weren't for the knowledge unselfishly shared by J-A-M-E-S and the rest of the members here. So, to James and the rest my deepest and utmost gratitude.

[Raffy]

Re: Raffy's WFO Build

I've laid the brick for the cooking floor and I will be cutting them soon. I'm occupied with the arch templates for now. The soldier course will be around the perimeter of the cooking floor and not on top of it. I plan to mortar the soldier course into place. We live in an earthquake zone so I want these babies to stay where they are. The cooking floor wont have any mortar just in case I need to replace any brick that has suffered considerable wear and tear.

[Raffy]

Re: Raffy's WFO Build

By the way, I'm a bit of a perfectionist (most Virgos are) and I just hate the spaces in between some brick for the cooking floor. Not all the bricks are uniform. Try as I might to find a piece that fits snugly it really wont close the gap. Is it ok to use the mortar as sort of a grout?

[eprante]

Re: Raffy's WFO Build

Raffy,
I am a little ahead of you and had the same thought about the floor bricks. Once you start lighting fires and cooking, ash should fill in the voids that are there. Adding anything else will probably make the changing out of floor bricks more difficult. Good luck, this part is much more satisfying than building the stand.
Eric

[Raffy]

Re: Raffy's WFO Build

Hi Eric,

You do have a point there, Eric. I guess I was over thinking this. It is too much to expect firebrick to fit like a glove UNLESS I decide to take a grinder to it. Hahaha! I'm really peeved about the gaps much like Jack Nicholson's obsession about cracks in the pavement in "As Good As It Gets." BUT, you ARE correct and let the ash fill in the gaps. Besides, like you said, why make swapping out damaged cooking floor bricks harder?

I have to agree working with the brick is very satisfying. Even though making a pre-cast dome would have been easier it would not have been as satisfying I think.

Regards,
Raffy

[Raffy]

Re: Raffy's WFO Build

I mocked up the inner arch today and seeing it up there made me smile. I was going to start applying some mortar to the base and start on the soldier course as well but I had some trouble with the mortar. I am perplexed with the mortar that was given to me by the brick supplier. Terminologies used here in the forum and the supplier has got me confused. Originally, I asked for fireclay and firebrick and they said they'd have it ready for me. Once I arrived to pick it up, I saw in the sales invoice fireclay mortar SK32, so, I asked what was the difference (between fireclay and fireclay mortar) and they said that the only fireclay they know was that aforementioned mortar. I explained that I was going to mix it with cement lime and sand for the home brew high heat mortar. They said that this was all I needed and nothing else should be added but water until it became a thick paste.

I followed their recommendation and this stuff is completely foreign to me. It's a clay like paste with sand in the mixture and doesn't act like cement at all. It doesnt harden like cement but provides some adhesion to the bricks through (I'm guessing) surface tension because of its viscosity. I mortared two bricks together and after 4 hours I checked on it and it's still soft, not as pliable as before but definitely still soft. I'll check the bond strength tomorrow once its dried out. It's got me worried.

Is fireclay mortar and fireclay the same thing? If so, should I just follow their instructions and simply add water or should I still use the home brew recipe for high heat mortar (sand, fireclay, lime and cement 3:1:1:1)

This is really one of those "Duh" moments when I haven't got a clue which is which. I was already set on mixing the homebrew til the supplier threw me for a loop.

[Raffy]

Re: Raffy's WFO Build

I'm still bothered by my mortar problem but I decided to use the SK32 Mortar they gave me for the homebrew and surprisingly it worked well. It set hard and seems to be strong. I'm beginning to think it is just plain ordinary fireclay and not the mortar they suggested it was. I'm shopping around for refractory cement to ease my mind. I would rather get from forno bravo but shipping will be prohibitively expensive for my budget.

I have cut the cooking surface bricks and arch bricks and mocked up the soldier course and arch. It's ready for mortar but I'm still waiting for the strength results with the homebrew mortar utilizing the "SK32 mortar." If all seems well then I'll mortar the soldier course into place.

[Raffy]

Re: Raffy's WFO Build

I have mortared the soldier course into place and after a couple of tries the arch has gone up as well. The brick is so porous and dried out the mortar in a flash. I suppose I didn't dunk the bricks long enough. The lime hardens the mortar quite quickly and small portions are mixed so that none is wasted while laying the brick. On Monday, the second course will be laid and the arch will be finished.

I am psyched! The frigging thing is starting to look like a freaking bomb shelter. I don't think a bunker buster could dent the darn thing. If ever there was a fallout or major typhoon, I'll know where to hole up hahaha. It cozily fits me and my dog. We tried it on for size by sitting in it together hahaha.

[Tscarborough]

Re: Raffy's WFO Build

Looks good! You did right by using the fireclay in your homebrew, I bet it feels a lot better on the trowel now.

[eprante]

Re: Raffy's WFO Build

Nice work Raffy! One thing I have learned is to soak the bricks before laying them up. Otherwise the mortar changes consistency so fast that unless you are a pro, you are fighting it the whole time. Soaking the bricks gives you some time to wiggle the bricks so the mortar moves into all the spaces you need it to. Great work so far- good luck

Eric

[Tscarborough]

Re: Raffy's WFO Build

I would caution you that while having the bricks damp is good, having them soaked is not. The primary bond strength of the mortar is developed by the brick sucking moisture from the mortar.

[Raffy]

Re: Raffy's WFO Build

I would caution you that while having the bricks damp is good, having them soaked is not. The primary bond strength of the mortar is developed by the brick sucking moisture from the mortar.

Point taken. I dunk them now just before laying and I avoid soaking them too much. But its difficult to get that balance cause weather here is HOT. You'd be surprised how quickly water evaporates from everything. I'm again burnt to a crisp. I keep forgetting to put sunblock being so engrossed in building.

[Raffy]

Re: Raffy's WFO Build

Nice work Raffy! One thing I have learned is to soak the bricks before laying them up. Otherwise the mortar changes consistency so fast that unless you are a pro, you are fighting it the whole time. Soaking the bricks gives you some time to wiggle the bricks so the mortar moves into all the spaces you need it to. Great work so far- good luck

Eric

Hi Eric,

Thanks for the compliment! About the mortar, yeah I agree, that's why it took me a couple of tries to get the arches to adhere to the floor cause you only have one chance to position it. The arch base lost its adhesion to the floor while I was fiddling with it to get it positioned correctly.

Raffy

[Raffy]

Re: Raffy's WFO Build

Oh, for future builders, one of the troubles I had with the arch was with the smooth side of the firebrick. I scored the smooth surface with a grinder for the mortar to "hang" onto. After scoring the brick, the mortar would not slide off the smooth surfaces anymore.

[Raffy]

Re: Raffy's WFO Build

Well, today was an eventful day. The angle grinder got away from me when it bit into something hard in the brick. My hands were all dusty by then so it slipped and got me on the foot. But no worries... a little peroxide and betadine and alls good. Let this be a cautious reminder of the potential dangers of power tools. Hehehehe

Finished the arch and was able to remove the form underneath. I couldn't resist removing it when the mortar hardened. It is very sturdy and I fought the urge to stand on it.

Second and third course went on without any event and my crude indispensible tool lived up to its name by ensuring a uniform curve to the dome. You'll have to forgive my mortar work. In terms of neatness, it leaves a lot to be desired but it's as sturdy as hell. Its a b**** hydrating the sucker in this summer heat but I'm very happy with todays progress.