Dino's 42" Pizza Oven Starts

[gjbingham]

Re: Dino's 42" Pizza Oven Starts

The cardboard is an expansion joint to allow for themal expansion without detriment to the walls during heating, correct?

Just a thought on cladding. Considering the cost of refmix, you might consider using the homemade type of refractory mortar for any cladding you place. You might save the cost of a bag or two of refmix. Perhaps?

[bbell]

Re: Dino's 42" Pizza Oven Starts

Along those same lines...

I've read about the 1" of cladding many add to the exterior of the bricks. What is the purpose of the cladding? Is it to add thermal mass to store heat for longer baking times or as an insulation layer to prevent heat from escaping?

And how is this different from the vermiculite layer surrounding the dome?

[Dino_Pizza]

Re: Dino's 42" Pizza Oven Starts

Thanks Mitch, George is right, the cardboard is for the 1/8" or so gap for the floor to expand (that's what others have done and said, so i did it). And ya, it's great that it's going vertical. I've got friends that look at my Picassa pics and some mistakenly think the storage area in the base under the oven floor is where the fire is and somehow the pizza cooks above it. Getting the dome going vertical should dispel any confusion.
And that's a great idea George, I might use the homemade stuff for the cladding. I've never seen this in a post before but for a 42" WFO, and without trimming the soldier course, I went thru a bag and quarter of Refmix. I will definetly buy 1-2 more bags. Would it be better to have trimmed all the soldier blocks to make a smaller pie shapped gap? I don't know. That's alot of bricks to trim.
Bill, as for the cladding, as I finished my 1st day of mortaring, I stare at the soldier course with it's ugly outside of Refmix between the bricks, smeared and stainded and I can't help but think it's only natural to want to make it look "nicer". If you smear more on the outside (you will never see it because it gets the insulation blanket and/or vermic-conc mix on it) it seems logical that it adds some structural integrity but it probably is not needed in something this heavy and sound. It will add more to the "mass" that needs to heat up (or wisk heat away) and is ALSO probably not necessary. I'll wait until I'm done or hear from others to determin if it gets a good coat before the FB blanket goes on it.
PS: Can't wait to get some rings or courses going! I've got updated pics on the web album.
Thanks, Dino

[exceloven]

Re: Dino's 42" Pizza Oven Starts

Dino,
Looking great! I just put a thin skim coat on the dome to fill in the gaps and, yes, make it look better, even though it will eventually never be seen. I used the FB mix for my mortar so cost wasn't a issue in using it to cover the dome.
Keep up the good work, it looks like today might be the last day for a while to get something done for us. If the weather forecast is correct. I hope not!
Mark

[egalecki]

Re: Dino's 42" Pizza Oven Starts

Dino- I used a coating of homebrew on the outside of my dome. It isn't very thick- less than 1/2 inch for the most part. I wanted to do it because I'd left big gaps at the back of my bricks- I put the mortar mostly where I needed it to hold them in place, and went back with a mortar bag and filled in. It did make it look tidier, but I was worried about my thermal mass not being even the way I'd constructed, so I fixed it. It works fine and my heating time is about where I was expecting.

The pictures are somewhere in my thread- I think the bricks look blue in most of the relevant ones. Les called them smurf bricks, I think...

[Dino_Pizza]

Re: Dino's 42" Pizza Oven Starts

That's a good idea Elizabeth. I think I'll finish off the outside with 1/4" (1/2" tops) cladding. That part seems so far away still.

It was fun going over your builds pictures again. I look at everything so much differently after finally mortaring some bricks. I've come to appreciate everyone's work so much more.

I measured my soldier course this morn and it gets higher for the last 5 bricks against the inside arch. Oh, well, since my 1st ring of dome-bricks are the half blocks sitting on my angled soldiers, I can just shave off 1/4-1/2" before placing them on those soldiers. This time, I'll keep a level handy and some sort of form with a maximum height on it to bring my 1st row to absolute level. It's gradual and in the domes blind spot so it would be hard to notice when it's done.

Like Mark mentioned, lot's of rain coming but I wont complain in So Cal. I've put up the "big-top" (mine's white, no smurf-blue bricks Elizabeth) but I bet I can find time in between the showers.

Thanks, Dino

[Dino_Pizza]

Re: Dino's 42" Pizza Oven Starts

I've had a bad mortar day with my 1st ring after the soldier course. I did my soldier course with the Refmix rather "dry". It was hard work packing it into each vertical, pie shaped space between the soldiers and if I wasn't careful, it would widen my gap between soldiers and you couldn't just try to mush or squeeze the bricks. The Refmix certainly did not "ooze" out the other end. But I'm happy with the soldier course.

TODAY, I still tried to stick with peanut butter consistency but again, the Refmix stays where you put it and nothing ever oozes out the edges so my clean, tiny gaps become 1/4" monsters and it's way to stiff to try to squeeze the bricks together. I am quitting for today after ripping out my 1st 3 blocks in the 1st ring. I don't know what I'm doing wrong. I just received another shipment of Refmix. I hope I can figure out how to use it. Any suggestions are greatly welcomed. Oh, and I did soak the bricks at least 5 min, usually 10.

Thanks, Dino

[Les]

Re: Dino's 42" Pizza Oven Starts

Dino,

I used very little Refmix on my Flue (I borrowed about 2 cups from Acoma) - I found that it fired FAST! Very little time to work it, but it dries hard as steel. Maybe you should go on the wet side - just a thought.

Les...

[mfiore]

Re: Dino's 42" Pizza Oven Starts

I soaked my bricks much longer than most. I don't know if you can over-soak. If you can, I certainly did. I had my kids little plastic swimming pool next to the work site, and I stored the bricks in the water. Usually they were in overnight. It left for a very damp oven that took longer to cure than I would have liked. But the mortar cured very well (I used Heat-stop) with no cracks inside (some hairline ones outside the dome).

[gjbingham]

Re: Dino's 42" Pizza Oven Starts

Dino,
How are you applying the mortar? Sounds like you might be using a grout bag or some other device to try to inject the mortar into the spaces. If that is truely the case, I'd recommend that you try buttering the bricks with mortar, and then use a rubber mallet to set them. The hammer will help move the bricks easier and improve the the mortar flow. If you're doing a precision cut "Les Special" oven, then you better talk to the master.

I agree with Les though. If the stuff is so thick that it doesn't flow at all, you need to mix it thinner. Try very small batches until you find the correct look and feel. Try to mix only what you can use in an hour. That will cut down on waste.
G.

[Dino_Pizza]

Re: Dino's 42" Pizza Oven Starts

Thanks for the advice guys. I was buttering the bricks with a spatula and will try again today with a wetter Refmix. I've got Mike helping me out today so maybe with me on the oven and him outside, I can apply the stuff the right thickness, kinda wet, and be ready to clean up the the drips.
I'll soak the bricks longer this time too. I also am mixing very small amounts and using it up within 10 minutes.

My 1st row of bricks are compound and they sit on my angled soldier course so there is VERY little space for the morter on this 1st row. I'll try to post pics later today of hopefull success.
Thanks again, Dino

[gjbingham]

Re: Dino's 42" Pizza Oven Starts

Small mortar joints are really tough. There's no two ways about it. Good luck!

[jrparks]

Re: Dino's 42" Pizza Oven Starts

I use a 4" spade trowel to lay my mortar down. I spread the mortar thin skim coat over the entire surfaces that I'm trying to adjoin. I then butter up a ridge of mortar down the center of the brick going from as small amount to more as I move towards what will be the outside of the dome. As I set the brick, I’m able to wiggle into place. The ridge fills in the pie shaped joint and excess mortar will ooze out. I have found that mixing enough mortar to set 10-15 brick will give me comfortable working time with the mortar before it starts to set-up. I also give the bricks a good soak prior to setting. I think I would soak more if the weather was warmer.
This is what has worked so far for me but I’m only three courses up the dome. My inside joints have been zero to 1/8” max. Laying bricks is not and easy task but the more you work with them the more comfortable you become. Hope this help,
Cheers,

[Dino_Pizza]

Re: Dino's 42" Pizza Oven Starts

Thanks JR. I'll use your method on my next ring. I had a successful 1st ring mortared yesterday. It was a lot easier with my partner Mike working outside the dome while I was inside the dome. I felt like a kid in his playhouse.

I used a very wet mix (runny toothpaste consistency) and it worked great for the no-mortar and thin joints. I waited until it hardened or sometimes made a peanut butter thick paste for the wider joints in the rear. I think I've finally tamed the Remix. I only made enough for 3-4 blocks. After 5 minutes it begins to thicken so I made very small batches. Here are picks of my 1 st row. The joints WHERE less than an 1/8" but it looks thicker when applied. There are some inverted V's, normal V's and just plain tilting vertical lines, but I'm already way over my pay scale so I'm happy with how it looks.


Thanks for the support, Dino

[egalecki]

Re: Dino's 42" Pizza Oven Starts

Glad you're getting used to the mortar. It does take a while. I only mixed up enough for 4-5 bricks too. Any more than that and it got harder to work with.

You might want to consider putting cardboard or something down on your oven floor- it will save you cleaning the mortar off the bricks, and having mortar work its way between the floor brick. I used a spare piece of tyvek for mine, but cardboard works fine too.

When I used the mortar, I only mortared the brick I was putting in- I wet the top of the ring I was putting the new brick on (used an old paintbrush), and buttered the inside flat of the new brick plus the side of that brick next to the previous brick. So, I had good contact between bricks in each ring AND with the previous ring. I also let the mortar function as the wedge to get my angle too. (I did have to support that some from the back, but not as much as you might think) Doing it this way seemed to help a lot with the mortar flopping off the brick when I turned it over to place it. I also got very little in the way of mortar lines on the inside of the dome.

This is why I had to go back and fill in between the bricks later, by the way. I used a lot less of the expensive stuff this way, and used homebrew to back fill. It's working fine....

I've drawn a picture using the ever-popular auto-pad to make some sense out of my unintelligible prose.