Mark's 42" in MN

[AtTheLake]

Well it's almost warm enough to finally start.
Building a 42" Pompeii into my outdoor kitchen I started last year at our cabin on a lake "Up North".
Been planning this for over a year now and after the last couple of weeks staying up late reading this forum I now think I have another expense to add to this project "The Internet" for the cabin. Only problem is no cable or DSL available only dial up or HughesNet.
The more I read, the less I knew! (thought I had this thing figured out)

Anyhow, tomorrow I am off to buy supplies.
Minus the Sairset I think?

[AtTheLake]

Re: Mark's 42" in MN

OK spent an hour at the local refractory store today
I have my supplies. Most of them anyhow.
200 medium duty firebricks. $475
24 sqft 2" insulating board $364
50sqft 8# insulfrax blanket $375
50lbs 30mesh fireclay $16
100lbs 20mesh fireclay $42
90lbs Portland cement $9
200lbs sand assorted sizes $14

Starting on my oven this weekend "Priceless"


I know I still need lime. Home Depot didn't have any. I will find some before Friday.
Any reason a person can't use mortar mix? Holcium N
It is a mixture of portland, lime and plasticizers

[Tapir Force]

Re: Mark's 42" in MN

Mark,

Well, at least you have come to the right place. The people here are friendly and knowledgeable. The trick is that you have to share as much information as is humanly possible. The literally thousands of reads that you can have on your progress becomes a safety net. I have been saved on numerous occasions now by members who have had similar experiences. The members read what you have to say, examine your pictures and give constructive (no pun intended) criticism.

I am a DIY type guy who has been on dozens of forums. This one has to rank right up at the top two or three that I have ever seen. Not a finer bunch of people to be found anywhere, and they come from all over the world. If the nations of the world would put aside their differences, build a bunch of Pompeii ovens and bake some warm bread to share, we would all be better for it.

Enjoy the experience, work hard and do not be afraid to make some mistakes. A couple of years from now as you are sharing experiences over a meal at your cabin, you will wax nostalgic over your great accomplishment and all of your new virtual friends. Can't wait to see your pictures.

Robert

[AtTheLake]

Re: Mark's 42" in MN

Robert
I have to agree, I have been reading this forum since I started this project over a year ago. I just hope that meal two years from now that you're referring to isn't the first pizza I get out of the oven. The cabin is 200 miles north and with fuel at $4.20 a gallon I have to optimize my trips.

Here are a couple of Sketchup drawings of what I have planned.
The oven will sit in the back right corner.
The kitchen portion with the roof is almost complete. So its time for the oven.

[Tman1]

Re: Mark's 42" in MN

Looks like a pretty good start!

You'll want to get your stuff from Smith Sharpe. They'll be able to answer any questions you have too regarding refractory concrete.

[AtTheLake]

Re: Mark's 42" in MN

Thanks, That's where I went.
Seem like knowlegable people.
But they think I am way over doing it with the insulation.
Also, they recommended Sairset for the mortar.
I told them that it had mixed reviews from forum users, mainly based on joint size and they agreed. So I opted (for now anyway) to go the "home brew" mortar route, because I don't think I am going to be precisely fitting my bricks.

They then recommended using Grog in my mortar if the gaps were too big 1/4"+.
I told them I would be drinking plenty of Grog each night.
Then they informed me that Grog was crushed firebrick so there is no shrinkage. Has anyone ever tried this?

[splatgirl]

Re: Mark's 42" in MN

I haven't heard it referred to as grog, but the suggestion of using scrap wedges of brick in the bigger joints is out there. I did it--more as a means of propping up and maintaining the angle on the steeper courses while my mortar set--but either way, it is a valid method for reducing the amount of mortar/joint size.

[splatgirl]

Re: Mark's 42" in MN

p.s. that is a lot of insulation board...are you putting two or three layers under the hearth, or what? If that's the case, consider adjusting the height of your block stand or your opening will end up pretty high.

[Tman1]

Re: Mark's 42" in MN

Italian Master builder Stefano Ferrara builds his ovens by filling in the cracks with some 'grog'. If you look into stuff on the web long enough you can find a bunch of info about it. I wouldn't think FB has a problem with me posting stuff about him, but just in case I'll let your fingers do the walking.

[dmun]

Re: Mark's 42" in MN

In my misspent youth as a potter, grog was crushed fired pottery, added to clay to reduce shrinkage for thick wall hand built (as opposed to wheel thrown) pottery. This said, we got it out of bags labeled "grog", not from smashing failed pots, so I don't really know what it was.

Wikipedia seems to think it's a refractory material.

[AtTheLake]

Re: Mark's 42" in MN

I decided to forgo the Grog for now. Like Splatgirl said I can always use scraps to fill in the voids.
My greatest concern/anxiety is the decision to use Homebrew mortar. I know there are many builders on this forum that use it. That is why I went away from the Sairset. But when I consider the total investment in this project, time/money I would hate to have something go wrong trying to save a few dollars.
So I am thinking about calling FB and ordering 4 bags of their mix. Call it a Piece of Mind thing. Besides I feel like I owe them something. I could call it my donation to a good cause.

Mark

Also, Splatgirl
1 layer 2" thick
I bought enough insulboard for 6x4.
I will be cutting a little of the length and adding it to the side to get to the 51" required width.

[stoveup]

Re: Mark's 42" in MN

If the nations of the world would put aside their differences, build a bunch of Pompeii ovens and bake some warm bread to share, we would all be better for it.

Well said, Tapir Force. Let's argue about recipes, not religion and politics.

[dmun]

Re: Mark's 42" in MN

Wet premix mortar has proved problematic again and again. You won't regret the decision to use the homebrew.

[splatgirl]

Re: Mark's 42" in MN

With all due respect to the dmun, every example here where wet premix mortar "has proven problematic again and again" is when people have allowed their ovens in progress to get wet or rained on. As far as I know, beyond that one known issue, we have no other long or short term info to judge it on.

I used Sairset, kept my oven dry during my build, and it was and continues to be perfectly fine. I found not needing to worry about the timing of cement based mortars a HUGE advantage as it allowed me to work in dribs and drabs without having to mix/slake/waste mortar just to get in a half hours' worth of work. It's a decision I would be fine with making the same way again.
Of course I have no idea how my oven will fare in the next 20 or 30 years vs. ovens mortared with homebrew or Heatstop, but I don't know how my person or anything else about my life will fare in that time period, either. I guess I have better things to worry about.

[dmun]

Re: Mark's 42" in MN

Splatgirl used sairset, and therefore is qualified to speak on the subject in a way that I'm not.

That said, the history of wet premix mortars goes back a long way on the board. I read every post for a year before I put shovel to dirt, and learned a lot from multiple builders before I begin. The original ovens were very simple affairs, with brickset halved bricks, and angle iron over the doors. An early and influential builder was Paulages. This was in the summer of 2005. He was an early brick arch adapter. His was the first corner-entry build. He was one of the first to scope out Harbison-Walker, and all they have to offer. He was the first to use tapered firebricks, medium duty firebricks, refractory tiles, castable refractory for the vent. He was the last to use the vermiculite layer under the support slab, and his build was one of the main reasons we don't do that anymore. One of the things he got from H-W was wet, premix mortar. He found it so unworkable that he re-did the courses he built with the stuff.

It's really interesting to go back and read Paulages' build, as i just did. He was in a real sense my teacher here, and you tend to stick to the things you learn early, unless there is a real reason to jettison them.

We've had lots of subsequent problems with the "wet stuff". This isn't exactly an irrational prejudice. What I would say to those contemplating using wet premix mortar is that they should plan on keeping their oven as dry as a cobb oven.