36" in Seattle

[kebwi]

Re: 36" in Seattle

Parged one side of my hearth, a highly nonvisible side, experimentally, at 3:1 sand/portland. I'll let it set good and solid, assess it, then decide what to do about the more visible sides of the hearth and the foundation.

Finished mortaring the first course (at floor level in my design) to the entryway arch-support bricks. This required the brick in the first photo, amongst my fancier cuts so far. The floor had some fancy cuts in it too (see earlier photos).

Built a form for the inner arch: two layers of masonite with 2x4 chunks in between and a thin strip wrapped over the edge (strip not shown in the first picture, but visible in that later picture).

You will notice in the third picture that I have cut a 45-degree edge off the inside edge of my inner-most arch (a cinch with the 45-degree guide that comes with the HF saw). This should serve two purposes: one, to facilitate better airflow and let smoke escape more easily, and two, to provide a slightly wider angle of access to the oven.

Mortared up most of the inner-inner arch (my inner arch consists of two arches, I really need to post some updated CAD designs). The last brick was going to be really tight, probably pushing the other bricks out of the way, so I decided to just rest it in its place to hold the arch together. I'll shave it and mortar it in place in a day or two, no need to rush it.

I used 3:2:1:1. I arrived at this not as a variant of 3:1:1:1, but rather by starting with Lars' 3:2:1:1/2 and then deciding that a little more lime might make it creamier...which I guess maybe it does, I don't really know, but that's what I decided. So, any feedback or thoughts on that are welcome. Basically, what I've got is a mortar that has more fireclay than the Pompeii/FB mortar. If anyone can speculate what effect more fireclay would have, I'd love to hear it.

A point of concern: If a mortar joint breaks due to a bump after it has become mildly solid (is this what "setting" refers to?) after a few minutes (or after a few hours in some cases), I have little choice but to push the bricks back together and hope for the best. However, the mortar is often dry enough at this point (even after a few minutes) that the crack remains quite obvious, which suggests to me that the bond has not been reestablished. When this occurs (minutes, hours?) is the joint basically ruined forever. Is that particular brick-brick bond pretty much a lost cause from then on? It kind of seems that way upon visible inspection. Of course, I'm not going to purposefully test it later to see how well it holds, so I will never really know whether such bonds are considerably weaker than bonds that don't break. Thoughts?

[ThisOldGarageNJ]

Re: 36" in Seattle

nice,, keep going

[kebwi]

Re: 36" in Seattle

Finished the floor, mortared the first course (except where the course meets the entryway on one side), finished the second course (except the eventual arch merges), started the third course. I soaked each brick that was about to be added and thoroughly sponge-brushed the adjoining faces of the already-placed brick that was about to be bonded to. Seemed to work for the most part.

If you look closely, you will notice that my first three courses (all vertical side walls with no dome-curve) consist of right-trapezoids instead of isosceles trapezoids (credit to Lars for the seemingly obvious idea which I admit never occurred to me). I can produce two oven bricks from as single fire brick with a single cut this way. Isosceles trapezoids would require three cuts.

Other than chronic curiosity about variations of the mortar recipe and apprehension about the mortar to water mixture/consistency, I feel that everything went pretty well.

I used 6:4:2:1 (Lars') for absolutely no particular reason. I haven't tried anything else (including the Pompeii 3:1:1:1) because I wouldn't have the first clue what to look for when weighing variations against one another. I would love to commit to a recipe so I can mix up large infrequent dry batches instead of small frequent batches.

I used 4 1/2 parts water. 4 seemed too dry and 5 seemed too runny, but maybe I'm wrong. Maybe 4 looked just right or maybe 5 looked just right and I simply didn't realize it. I just really don't know.

Anyway, I feel really good about getting some bricks in place and starting the vertical assent. I will have to make the inner arch next of course. Vertical work is done (except for completing the third course shown in the picture) until I get the inner arch in place.

[ThisOldGarageNJ]

Re: 36" in Seattle

home depot or lowes should have a similar one in the drywall department near the bags of mud... (joint compound) they use them for mixing the mud...

Your definitely welcome
Mark

[kebwi]

Re: 36" in Seattle

Yep, I wanted that along time ago for concrete but my local HF didn't have it (or I didn't find it). HD and Lowes sell the same thing (for $13 instead of for $4) I'll have to consider another trip, although they're far enough away that is isn't worth it unless I get a few things per shot. I'll have to consider my shopping list first.

Thanks BTW.

[Les]

Re: 36" in Seattle

keb...- Harbor Freight Tools - Quality Tools at the Lowest Prices when i was mixing my mortar i used this on my dewalt 18v drill,, for small batched it works fine

Mark

Ditto - simplifies the task a LOT!

[ThisOldGarageNJ]

Re: 36" in Seattle

keb...- Harbor Freight Tools - Quality Tools at the Lowest Prices when i was mixing my mortar i used this on my dewalt 18v drill,, for small batched it works fine

Mark

[jmhepworth]

Re: 36" in Seattle

I tried mixing mortar in a bucket. Without a power tool, it's just too hard. I bought a mortar mixing tray from HD and mix it with either a hoe or for smaller amounts with the trowel. I was much happier after I stopped trying to mix mortar in a bucket.

[kebwi]

Re: 36" in Seattle

Yeah, I've seen those online, and I admit that mixing it up was disappointingly difficult with a stick. I'll look into it.

Thanks for the tip.

[ThisOldGarageNJ]

Re: 36" in Seattle

peanut butter smooth no chunks

Are you mixing by hand, Try a 5 gal bucket with a drill and a paddle mixer

cheers
Mark

[kebwi]

Re: 36" in Seattle

Maybe I mixed it too dry. I'm not sure it was peanut butter. I'm familiar with that trick, but I don't know. What is it with me and mixing cement too dry? I screwed up my concrete three times this way. I did make the mortar pretty pasty. At first I put too much water in, so I added more "stuff" and then was paranoid about adding water again, but maybe I should have.

On the plus side, I just looked at them (now a few hours after the job) and the seams haven't dried up, spread apart, cracked, or otherwise failed. So maybe tomorrow they'll turn out to be okay.

Next time I'll actually measure the water so I can figure out how much water to apply to a given mixture.

Peanut butter. Okay. I'll avoid a pedantic line of questions about brands, smooth vs. crunchy, and shelf vs. refrigerators.

[ThisOldGarageNJ]

Re: 36" in Seattle

mixed consistency

hey keb,, I didnt use the home brew, I used heat stop, But as far as the consistency,,, Go with peanut butter.... Worked for me.. Glad to see the weather hasnt stopped you

Good luck
Mark

[kebwi]

Re: 36" in Seattle

Progress has been a little slow, owing to noncooperative weather. A surprisingly vociferous thunderstorm reduced my awning to a modern art piece made of poles, fabric and cord, the general disarray of which quietly invited the observer to reflect on the chaotic paradoxical inner conflict inherent between the ego and the id within each of us. In a panic about the InsBlock that was arranged on the hearth -- protected by not a small number of bricks thankfully -- I piled multiple layers of tarps and plastic over the hearth, weighted it down and hunkered down for the storm to pass...

...which dumped a genuine hailstorm before it was done.

Anyway, built a new awning, cut more bricks, and tried my first mortaring. You can see the guide I made to help cut tons of identical bricks for the first three courses (three vertical stretcher courses that replace soldiers, but serve a similar function of providing a vertical side wall before the dome starts curving in.

I didn't mortar anything "on site", but I mortared pairs of bricks together in prep for the first three courses. This should, theoretically, halve the required work at the hearth...

...assuming these pairs stick together. I'm not at all confident about my mortar. One thing that disturbed me was that after mortaring all these bricks together from a single batch, I didn't feel like the mortar in the pail was behaving any differently. It didn't feel like it was setting at all. I'll find out in the morning. My mix was the 6:4:2:1 ratio advocated by Lars.

One problem is that while there is much discussion of ingredient ratios, I haven't really found much guidance on water and mixed consistency. I'm not sure what to shoot for.

The final picture is 2.5 quarts of firebrick residue (probably a brick's worth at least!)...and I've got a long way to go.

[kebwi]

Re: 36" in Seattle

Okay, that makes sense. I guess other people just shaved their bricks more precisely than I did on my first pass. I think I'll have to do that anyway, regardless of aesthetic concerns. They currently protrude past my interior perimeter a smidge which I suspect will push everything steadily out of whack. I'm going to have to trim 'em down before proceeding anyway, which should make them rounder in the process.

[papavino]

Re: 36" in Seattle

Ditto to what Joe said. I just made multiple passes with the wet saw to make my floor bricks curved. You don't want to make a truly curved cut with the wet saw. Only straight cuts.