Les' Build

[RTflorida]

Re: Les' Build

I mixed it DRY first, then the water...in a wheel barrow, was either 5-1 or 6-1. I used chicken wire, and yes, it is a bitch to get it to stay in place. Be sure to start at the bottom, pack it in the full depth that you want and gradually work your way up. I found this process to be one of the most tedious of the entire build - even though it only took a couple of hours, seemed like days......you just have this thought in your head that you can slap in on and be done in no time.......NOT TRUE.

Hang in there...have a beer, pack it in, have another beer.........repeat till complete.

RT

[dvonk]

Re: Les' Build

Hi Les,
I was using perlite/cement (5:1) under the floor. I've used mixer - put the perlite, then cement, dry mix the ingredients, then add some water.

4 inch was very easy - I've bought 2 ply blanket, after unpacking it "inflates" to 4", didn't have any problems with fixing it and shaping on the dome.

[Les]

Re: Les' Build

Thanks guy's.

Dvonk - I just sold my mixer on Craig's list, thought I was done Still impressed that you could work the 4 inch product. Although, if you look at my pic's, the ugly stuff is just me stuffing in the scraps (why not, better than the trash) I just hated working with the stuff - you roll it out of the box and see this fine powder floating around - kinda scary.

RT - The beer thing is something I can relate to. If you have enough of it, you can just sit there and watch the grass grow Watching vermiculite harden should be a piece of cake.

Both, thanks again,

Les...

[dvonk]

Re: Les' Build

I didn't mention the floating powder, probably I was using another type of blankets, or maybe just was too concerned on the process, but it's not the most pleasant kind of job, for sure. Another point is perlite powder which is extremely fugitive too.

[Les]

Re: Les' Build

Al righty - clear another hurdle today. Finished the vermiculite / portland insulation. I had many attempts: first I tried the lath / mortar approach thinking I would just pour it in dry - failed big time. Then I tried to wrap it in foil so I could pour it in dry - wasn't to be. Finally I wrapped it in wire and sloped it on - that worked (thanks RT - great advice) I ended up using over 10 1/2 cubic feet of the stuff, thats on top of 2 rolls of 1 inch blanket. I would think that it will be plenty. Question to all, how much insulation did you use and how long will the oven keep the heat? I know there is a huge variable on the door - just looking for the average.

Les...

[RTflorida]

Re: Les' Build

Great work..we never doubted you for a moment.

I used the 2" blanket, 1 layer except directly on the top, where I put the leftover pieces. Covered with about 2 1/2" of perlcrete (maybe 3" at the base).
My door is my downfall...looks good and is indestructable (1/4" boiler plate steel - no insulation), but is not good at long term heat retention.
Pizza tonight at 6-7 pm and immediate placement of the door (coals left in oven)will net about 400 -425 degrees the next morning (9-10 am) over most of the dome and about 2/3 of the hearth. The area within 6-8" of the door will only be in the 350 - 375 range...still plenty of heat to slow cook or roast, but I would like to have the temps more even.
24 hrs after pizza, if I have not used the oven during the day (and have left the door in place), gets me around 300 -325 degrees in the dome and 200-250 in the hearth. Day 2 leaves me nothing more than a good warm oven to kick off another fire - not enough heat to even slow cook. The area nearest the door running 25-50 degrees cooler in all cases.
If you have not yet designed one I would seriously consider making an insulated door - I'm sure it will make a big difference. As soon as the weather cools down, that will be my next oven related project.
I would be curious to here from someone who has used both - an uninsulated and insulated doors

RT

[mfiore]

Re: Les' Build

RT, remind me, what did you use for insulation below the floor?

[Ken524]

Re: Les' Build

Question to all, how much insulation did you use and how long will the oven keep the heat? I know there is a huge variable on the door - just looking for the average.

Les,

My oven insulation is similar to yours (and nearly identical to RT's). Two rolls of 1" blanket (3-4 layers near the top, 2 layers at the base) and 2" - 4" of vermiculite mixed with portland.

With my insulated door, it retains usable cooking heat for 48+ hours easily (I could still throw in a pork shoulder after that if I wanted to!).

You are going to be in excellent shape!

[Les]

Re: Les' Build

RT and Ken - Thanks, I'm feeling good. 48 hours after the fire would be incredible.

Mike - FYI, my hearth is on 4 inches of the board.

Side note: When I opened the 4th bag of vermiculite, it had the texture of sawdust. Same bag, just a different seller. The first 3 had a texture of pellets - very strange. At this point, don't give a crap - tile, mortar, brick. done!!!!

Les...

[RTflorida]

Re: Les' Build

Mike - 4 inches of vermiculite concrete for the hearth insulation - 5:1 ratio. My next oven will incorporate insulation board.....just wasn't the "in thing" a year and a half ago when I began my build - and VERY expensive at the time.

Les - I think the 48 hrs later slow cook is possible.....with a good door.
I had the same issue with the vermiculite (part of the reason I switched to perlite for the dome); except my bags were each 1/2 "medium agriculture grade" vermiculite and 1/2 very fine sawdust like material (I attributed it to settling - much like a bag of potato chips). I stirred it all together in my wheelbarrow and everything seemed to work as it did for everyone else.....I just have to wonder how must that "sawdust" hurts or helps the insulation characteristics. In any case, if I insulate my door, I will be as happy as a fly on sh.....crap.

RT

[biondoli]

Re: Les' Build

Les, I have 2 blankets insulation 4" total plus 1 inch vermiculite/portland.
The drop down of the temperature is exponential, 1000K at night pizza time, 9am next day 400-500 bread time and then it stays around 200 for other 1-2 days. Ciao Carlo

[Les]

Re: Les' Build

OK - anybody have a brick stretcher? (the top left brick is short) If the brick gods made fire brick the same size as decorative brick, I wouldn't be in this dilemma. It looks like I need to rip all the brick on the left and right side of my entry. I also need to rip a row of brick to get them level with the entry way. (ignore the cores, I do have solids, they are just more cumbersome to play with). I have a question for you all, When I split the entry way row - what is more esthetically pleasing, put it in the middle, bottom or top? I have my own bias - just pinging the planet.

thanks,

Les...

[dmun]

Re: Les' Build

The brick gods make fire bricks bigger than common brick, because the former are laid up with minimal mortar joints, whereas the regular brick use 3/8" or bigger mortar joints. A mating wall of the two types should pretty much line up.

If I grabbed the right one, this photo should show the thin commons lining up with the fat firebricks because of the joint size difference.

[RTflorida]

Re: Les' Build

Les, PLEASE, no ripping out any of your fantastic work. I would agree that you have a dilemma based on your proposed facade, BUT I would use this as an opportunity to get creative around the entry. You can still use the red bricks so it matches the base....just try a few variations (cut bricks standing on end, or cut to length standing on the long edge.....etc). Have a little fun with it, all you need to do is have it appear that you are NOT trying to match the firebrick and whatever pattern you decide will look cool.....this could be your oportunity to show the world your creative side. We already know your a master builder/oven technician. Whatever you decide I am certain will be executed near perfection.....I'm just saying, look at all your options before you start dismantling anything. GOOD LUCK!

RT

[Les]

Re: Les' Build

Les, PLEASE, no ripping out any of your fantastic work.

RT

RT - LOL. By ripping, I meant slicing the brick to make it narrower. I'm anal - not stupid The width of the fire brick vs the commons caused the problem. It's not so obvious until I get to the arch.

David - I think you may have misunderstood me as well. I sliced (ripped) my brick to achieve the reveal I have on the arch. Thats when the train went off the tracks. I have to match a 4.5 inch brick in the vertical to a 3.5 inch in the horizontal

RT - I'll figure it out and make me proud (thats my opinion and I'm sticking to it)

Les...