Longmont, CO new WFO build - casted over sand

[rajhlinux]

Enclosure is only lacking some support for cement board around chimney, which I will weld today. Then the enclosure needs to be put in it's final resting spot on the stand, and fastened down well.

OMG... are you building a military tank for the US forces which is powered by wood? lol

[ThePizzaGuy]

What a great thread with boatloads of helpful info.

[cnegrelli]

I've been working on my "santa maria grill" which is built the same as this one shown here (see link at bottom to Damer419's build.

There is wood storage under mine and thus I build the stand much like the WFO's stand with CMU and a 4" slab with rebar on top. The firebox is built from CMU and will be lined with Fire Brick. The question I have is what kind of Firebrick? Unlike the WFO, there is no real objective to "hold heat". But the fire needs to burn on the Fire Brick floor. My options seem to be:

1. 1" foamglas under FB (or just not bother with the Foamglas?
2. Insulating Fire Brick (lighter, less dense, not for use in pizza ovens) - but how about this application?

[UtahBeehiver]

Congrats on the nice oven you build, you can now say "I built it myself" with envy from friends and family.

[cnegrelli]

The keystone was casted with left over refractory. The apron countertop was cast in pace, with just normal concrete and polished. It was darkened to match (roughly) the keystone.

[cnegrelli]

Well, I am done with the oven! I will be working on adding some additional counterspace/storage and a patio around it come spring. Many thanks to some key contributors here, who I leaned on heavily and have cited as I went along. But special thanks to Russell UtahBeehiver who I tended to follow especially close due to his obvious engineering brain, and near identical climate conditions, to deejayoh, Gulf and others for Counters and masonry guidance. And to david s (who Russell pointed me to for all things castable, and also some good advice on stucco). I simply did not have the time to attempt a brick build and I'm very happy with the performance and how the oven came together. I started the build Memorial Day weekend (May), and had pizza by early July (could have been much sooner but went very slow in curing), finished by Thanksgiving.

[david s]

Outer decorative arches usually employ standard mortars. I sometimes do some tiling on the front of mine and find a quality outdoor tile adhesive works ok. But every oven design varies and basically it depends on what you can get away with. I have a 10 mm expansion joint between the outer decorative arch and the flue gallery so mine may be a little cooler there than yours.

[cnegrelli]

I'm going to be attaching some Thin Brick veneer around the opening to my oven. It does get pretty hot at the top of the opening (where the keystone will be). Should I consider a high-temp mortar? Can I make this with the left over castable refractory mix I have?

[cnegrelli]

It's difficult to tell what you did from the pic, but I get the gist.
I sort of did mine in a different order in that I stucco'd the oven and then poured the counter top up to the igloo and stucco.
I've now polished to 400 grit and I think the grinding pads have cut into the stucco a bit. I shouldn't really need anything there like a bead of caulk I guess.

I would llike to touch up a few spots on the stucco, mainly because I got some of the chimney caulk on it in a few places.

Is there a good method to dab some synthetic stucco on the existing in spots? Almost like a small paint brush or sponge I would think?

[david s]

I'm at that point in a build now. If you are trying to bond onto a polished and sealed counter top then you may have a problem with bonding. I like to clean the area with the angle grinder and diamond blade, then get it damp so the stucco will bond. You may have to look hard at the pic to see what I've done.

[cnegrelli]

What have people found that works best for sealing between the stucco and concrete countertops?

[cnegrelli]

Have you read anything on the product about it's compatibility with the acrylic? The acrylic fortifier makes the concrete less porous. I'm sure that may also depend on how much water was replaced with the acrylic. The quote calls it Penetrating Lithium Sealer. I'm just wondering how well it will penetrate this type of concrete. I am very interested in how well it turns out. I have some kitchen counters to do and my oven landing could also use a little more polishing while I have everything set up for it..

They do recommend a polyurethane sealer, but I couldn't get anything definitive from them. Since I used 100% acrylic fortifier, my expectation is that little of the sealer penetrated and thus it may be of limited use.

Which begs the question, do I need a sealer? Should I wax it? Should I go with a polyurethane sealer that is more of a covering membrane, than a penetrator? All discussion on this welcome! Winter is closing!

The Colors Direct sight support folks state it depends on the look I'm after. I'm after protection from freeze/thaw!

[Gulf]

Have you read anything on the product about it's compatibility with the acrylic? The acrylic fortifier makes the concrete less porous. I'm sure that may also depend on how much water was replaced with the acrylic. The quote calls it Penetrating Lithium Sealer. I'm just wondering how well it will penetrate this type of concrete. I am very interested in how well it turns out. I have some kitchen counters to do and my oven landing could also use a little more polishing while I have everything set up for it..

[cnegrelli]

To fill the bug/air holes I just used a slurry of cement,dye and acrylic fortifier. The following is from Cheng's Concrete counter web site:

Slurry is a mixture of cement paste, pigment, and water. It is used to fill in the small air bubbles in the surface of the concrete. This is especially important in something like a concrete countertop, because bacteria can get into those holes and grow. Otherwise it’s an aesthetic preference, some people don’t mind the natural look while others are looking for a more refined surface.

Thanks Russell. That was helpful and it went pretty easy, followed what you did and it seems to have gone pretty well.

I was re-reading the directions this morning of the Colors Direct Lithium sealer I bought, and the directions on the bottle don't really specify when you apply it, but then I did find the app note on the right side of their web page entitled "How-to-Apply-DCI-Penetrating-Lithium-Based-Sealer1" and sure enough, it states:

"Polished Countertop Application (once the countertop has cured): • Polish to 200-grit. Acid Stain if desired and clean before sealing. • Apply the Penetrating Lithium Sealer with a pump up fence and deck sprayer. Spray enough to create/maintain a uniformly damp surface for 20 minutes. Apply more sealer only to areas that appear more dry or absorptive than others. No membrane should be forming on the surface. • Squeegee away any excess sealer remaining on surface. Do not allow sealer to pool anywhere on the concrete. • Allow to dry for 24 hours and begin polishing from 400-grit up to 3000-grit."

So that alters my plan today! I will polish off the slurry, and apply the sealer late today. Then I'm off to SLC for business for a few days and the rest of the polishing will have to wait (but you can certainly cash in that beer I owe you Monday night)! I think having the sealer on there for a good 24 hours before the snow hits us again on Tuesday should help a lot. Would you both to cover the counters given this scenario?

[UtahBeehiver]

To fill the bug/air holes I just used a slurry of cement,dye and acrylic fortifier. The following is from Cheng's Concrete counter web site:

Slurry is a mixture of cement paste, pigment, and water. It is used to fill in the small air bubbles in the surface of the concrete. This is especially important in something like a concrete countertop, because bacteria can get into those holes and grow. Otherwise it’s an aesthetic preference, some people don’t mind the natural look while others are looking for a more refined surface.