36" in Seattle

[david s]

Re: 36" in Seattle

Keith,
Be careful about adding too much water, it is a major cause of excessive shrinkage and results in a weaker product that is more prone to cracking. It seems like a good idea to add more water to make the stuff flow and easier to get air bubbles out. To reduce the water content, but retain fluidity use some plasticiser or add some detergent. Only add sufficient water so the mix becomes easier to turn over.
Dave

[kebwi]

Re: 36" in Seattle

Did you float all your concrete with a piece of wood ?? or are you just screeding off the excess in the pic ??
Mark

That pic isn't me "floating". I have a real float. Here's a photo of me pretending to use it on my ridiculously dry hearth:
http://keithwiley.com/pictures/brick...5-floating.jpg.

I was using that 2x6 to pack the concrete down a little and sort of screed the concrete. I say "sort of" because without opposing form walls I can't properly screed. One side of the counter runs up against the side of the oven if you see what I mean.

[fxpose]

Re: 36" in Seattle

Looking really good. I've always admired the shape of that front arch. I like the shape of that counter too. Very practical design.

[ThisOldGarageNJ]

Re: 36" in Seattle

Hey Keb,,

Did you float all your concrete with a piece of wood ?? or are you just screeding off the excess in the pic ??
Mark

[kebwi]

Re: 36" in Seattle

Poured the counter, 8x80lbs Sakrete, about 4" deep (the oven floor is 5.5" above the hearth). The plan is to finish the counter with 1/2" granite tiles.

For those following my thread from the beginning, I mixed the concrete *MUCH* wetter than ever before (actually, I did the same thing last week when I filled the cores of the side wall). It still didn't finish with the float to a "glass-like sheen", but it is very wet, soupy, and dense (and had significant pools of water sweating up and wiping off). I'm satisfied with it (speaking only hours after the job, we'll see what I think later this week when the forms come off).

The astute observer will notice a small lip along the front edge relative to the front face of the hearth and stand, the width of a 2x4, so about 3.5".

Cheers!

[jerrycook]

Re: 36" in Seattle

Might be your oven hasn't fully cured yet. Every time I fire my oven, The floor temp comes up 10 - 15 degrees. I've been making dough with bread flour and it cooks better than the Caputo at the beginning of a firing. I also make a batch of Caputo dough that I use last. My last firing, I had pizza cook really fast. I wasn't quite ready for it. Good though.

[Tscarborough]

Re: 36" in Seattle

It is. Ferrous=of or relating to Iron for general usage.

[kebwi]

Re: 36" in Seattle

Actually, the stuff I bought is described as iron oxide, not ferrous oxide:

CONCRETE COUNTERTOP COLOR PIGMENT CEMENT IRON OXIDE - eBay (item 120469550837 end time Apr-11-10 23:31:34 PDT)

However, while ferrous has a specific chemical definition that distinguishes it from "ferric", it is also a catch-all term for "iron", so I think this is the same stuff you were talking about.

[Tscarborough]

Re: 36" in Seattle

"Ferrous". One or 2 coats of SBC and a finish coat of Thoroseal and it will be bulletproof.

[kebwi]

Re: 36" in Seattle

Hmmm, so I should decide on my final approach before proceeding then, since presumably I would add the (feris?) oxide powder to that instead of the SBC and leave the SBC uncolored?

[Tscarborough]

Re: 36" in Seattle

Final coat, it looks like stucco. Thoroseal is basically portland, marble dust, acrylic modifiers and graded sand, plus proprietary ingredients, probably stearic acids and water reducers.

[kebwi]

Re: 36" in Seattle

Would I apply Thoroseal as an undercoat or over the SBC? If the latter, how would it affect the appearance. Would the oven "look" painted instead of stuccoed?

[Tscarborough]

Re: 36" in Seattle

Thoroseal is an excellent product, and it can be tinted like the SBC. It is not troweled on, it is applied with a stiff brush (although you could trowel it if you wanted to).

[kebwi]

Re: 36" in Seattle

With regard to waterproofing, as stated, my basic stucco will be multiple layers of Quikrete Surface Bonding Cement with Quikrete Acrylic Fortifier, but since I am exposing this oven to some serious water (planter beds, although they will be lined with plastic), I am looking for additional options.

Ideally, I would like an undercoat, not an overcoat, for the SBC, so that the external appearance isn't affected by any additional waterproofing. So I would need something that can first be applied to basic portland parge and hardibacker and second to which SBC can then be successfully applied, if that makes sense.

Recommendations welcome.

[kebwi]

Re: 36" in Seattle

Hey Keb,,
The quikrete color faded a bunch after a few months,,, and after the winter the color faded tremendously... What kind of colorant are you using ??

I'm using the stuff you found for me on ebay; it's an iron oxide powder, which I believe is what Tscar recommended.

Will you be adding the acrylic fortifier.. ??

Yep. I'm still worried about waterproofing though. I'm shopping around for ideas for additional methods, additives, under/over coats, whatever. Quikrete makes something called Masonry Waterproofer, but no one here has ever mentioned it (I started a thread just about that particular substance alone and got no replies). I've also heard someone here mentioned Thoroseal, so that's another possibility. I'm not sure which coatings would affect the appearance of the SBC either in terms of texture or color. There seem to be so many waterproofing methods that I can't makes sense of them all.

If it makes you feel better, mix up a small batch of the sbc and practice on that inside wall in the first picture..

Hmmm, I handn't really intended to SBC the lower walls at all, just the oven. Not sure what I'll do on the lower walls, I would like to ledgestone them at some point. I really don't think SBC is necessary, may a simply parge, but nothing as expensive as official SBC, unless people think that's an important step to take in prepping the lower walls for ledgestone. What do you think?

Aside from that, I intend to begin by applying it to the base of the planter beds, for multiple reasons: No one will ever see it there because it will be buried under dirt, I won't color it there, at least the first coat, so I can practice in a section where I'm not wasting the colorant, and finally, if I do want multiple coats and the last coat is partial due to running out, then the bases of the planter beds should be most heavily coated areas. So, I think that'll work out fine. I'm still worried about it bonding to the hardibacker which seems like a pretty smooth substance, but oh well, everyone says it's not a problem.

Cheers!