Pdx 42" update

[Frenchie]

Great progress, you can almost hear the first curing fire cracking away. Have you decided what wine you’ll drink to warm by the curing fire to celebrate?

Very nice inner arch, I have oven envy.

Not far to go now, keep it up

[Macrinehart]

I'm moving along now! The 8th course is finished and I've set a couple of bricks for the 9th course. The slope is now steep enough that wet mortar will not hold the bricks in place.

I found that each of my courses is using less bricks than projected in the excel template. I got through the 8th course with 20 bricks, about four less than planned. Four less than planned seems to be the case since the 7th course. Fortunately I haven't been cutting all the bricks called for the the plan in advance, so no material lost. However, I still think I could be short on my brick supply. I may need to do a 3rd run to the landscape supply yard to finish the dome.

[Macrinehart]

Things were a luttle slow at work so I decided to take a couple days off to work on the oven. So far I've completed half a course and having used up the mortal I mixed for the morning I decided to let things dry for a bit while I prep for the 9th course.

It's nice to have the appearance of accelerated progress! While I'm pribably not working much faster on an absolute basis, each layer now is noticably less work.

[Frenchie]

Your work is looking fantastic! Your dome and arch proportions are very aesthetically pleasing and the bricks are very neat. Look forward to seeing your completed project, good luck with progress and finding the time in the coming months!

My project also continually goes on the backburner and is going into its 4th year this year, still haven’t closed the dome. Juggling life’s priorities is a challenge, now we have our first child on the way there is some motivation to get it done asap!

[Macrinehart]

Hi all - It's been a while, but I'm back working on the pizza oven again. Last time I was half way through the 7th course. Things got busy and the pizza oven got put on the back burner. Then winter threatened snow so I packed up my project and I'm just getting back to it now.

Yesterday I finished the 7th course and now I'm about to set the first bricks for the 8th. Here are the latest pictures.

[Macrinehart]

Once I finish marking all the guide lines on a course of bricks, it's time to start cutting. Using the HF wet saw with tilt blade makes this task a lot easier. I start by setting the blade tilt using a magnetic angle finder. The angle should match the side tile angle. Perfection is not required. I'm content to get within a 1/10th of a degree.

Once I have the angle set, three cuts yields 2 bricks. I line up the line with blade and cut. Do the two outside cuts first, then the middle cut. The only additional consideration is that I clean the cutting bed after each cut because the debris can destablize the bricks.



And for those wierd angles, I just prop the brick I'm cutting with wedges from remains of other cuts found in my boneyard discards, as shown below.

[Macrinehart]

There is room to get 2 dome bricks for each firebrick. To finish marking the second domebrick flip the firebrick and rotate 180 degrees so that that the inside top edge is facing you. Then use the calapers to mark the outside bottom corner on the swcond fire brick.
I label the top and bottom for reference. Notice that the top of the first dome brick is on the same face as the bottom of the second brick.

Next we mark lines 9 - 12. Keep in mind the rule of no parallel lines, lines 9 - 12 will converge and then diverg from the center line. When your finished the origin of line 9 connects to the end of line 12.

[Macrinehart]

The rest of the lines for the first brick are drawn relative to the end point of lines 1 & 2. On the top of the brick, use the side angle T-Bevel to mark lines 3 and 4 as shown. These converge to the top inside edge, the narrowest width.



Rotate to the inside face and use the side tilt T-Bevel to mark lines 5 and 6, which diverge.



Finally rotate again and mark lines 7 and 8. These also diverge and should connect to the starting points on lines 1 and 2.

[MarkJerling]

See, that's why your oven is so much tidier than mine! I just 'eyed' it all and marked my cut lines with school board chalk. But, mortar hides a multitude of sins, so all good! LOL

[Macrinehart]

The marking of the lines will come in a couple posts since the upload limit is 6 files.

First I pick a starting point, which will be the bottom outside edge, and mark my side tilt link for the back of the brick (line 1). Then I measure the width of the bottom back with the calapers, after which I I mark the other side tilt (Line 2). There are no parallel lines in the process. The first two lines should be approaching each other up the back face of the brick. If you have parallel lines at any point, then the T-bevel angle needs to be flipped.


Measuring the width of the bottom outside edge.


First to lines illustrated with the T-Bevel set for side tilt.

[Macrinehart]

First, I mark each brick with the lines I want to cut. For this job I have two adjustable T-Bevels, a woodworking protractor and digital calapers, all borrowed tools. I also printed the dome calculator spreadsheet, found elsewhere on this site, which has all of the required angles and brick dimensions for each course.
Following the guidance on that worksheet, I set one T-Bevel for side angle and the other for side tilt. The digital calapers are set to the brick width at the bottom back side, the longest dimension.



The dome caluculator file is very helpful but I recall someone saying it's not perfect, without going into the details. What I found is that my mortar joints are a little thicker than planned, which has a nominal impact on the number of bricks for each course. Furthermore, it seems like the calculator over estimated the # bof bricks required starting around course 4 or 5. Since then I've been estimating the number of bricks with each course, which is the handwritten notation on the worksheet.

The other observation, marking bricks is not like fine woodworking, the dome calculator reports angles in 1/10 of a degree, but I just get as close as I can with the protractor. There is mortar that covers any error in precision.

[Macrinehart]

I got back to work this weekend after taking a break to visit family and also to get some fall chores done. It was a beautiful day yesterday but by the time I finished my chores most of the day was gone so I spent the evening washing mortar stains off my bricks with undiluted distilled vinager. Today I put in a few more bricks between the dome and opening arch. I also cut bricks for the next course.

It's been over 1.5 years since I started my build, and one thing I learned along the way is that cutting bricks is actually a lot easier than I originally expected. When I started I spent a lot of time planning each cut and designing and building jigs to help with alignment. But after wasting a lot of time with this side projects, and a fair amount of money, I landed on my techique which is simple and low cost. I'm sure it's not original, but it can be hard to find things on this site so I thought I'd share my process in the hopes that it demystifies things for other aspiring builders. This is my technique for cutting dome bricks. Due to the limit of # of photos per post I'll spread this over several posts.

[Macrinehart]

Today I rebuilt the opening arch. While I usually with I would have followed UtahBeehiver's advice, today I decided not to adjust the height of the arch form as that task seemed like a fairly unsafe use of the tablesaw, and I figured safety first. I also measured the height of my lath strips and they are 3/8" total with 2 strips. Hopefully it is enough.

I built the entire arch in one go with slightly higher hydration on the mortar to make minor adjustments easier. The entire process was smooth, but I'm leaving the arch support in place to allow the mortar to setup some more. I used a level to check things throughout and the front face is now smooth and perpendicular. (The picture is crooked, not the arch. )

I did have to pull it forward a little, and there is now about 5/8" gap to the inside radius of the dome. I imagine that means I'll have a little offset between the back face of the arch and dome bricks. I'm not too concerned about it.

[UtahBeehiver]

Before you start the rebuild, check how much release you have under the form, one of the pic show small wood shims (1/4"??) this "may" not enough release to drop the form after the arch is completed. In my build I started like this but soon found out 1/4" was not enough and redid form and had a release of about a 1/2".

[Macrinehart]

Today was a day of prep work for rebuilding the opening arch. I started with cleaning mortar off the arch bricks, using a hammer and cold chisel. I found the process worked best if bricks are soaked thoroughly before cleanup. It keeps the dust down and I think the mortar comes off more easily.

After that I started improvements on the arch support. My brother brought over a custom tool for bending wood, and we cut some thin mahogany plywood down to size and bent it befor attaching to the arch support. I also used some scrap wood to add a faceplate to the front of the arch support, ensuring all bricks are plumb. Borrowed this idea from one od the pros on the forum, can't remember who but I'm sure you'll recognize it - thank you!

The inside arch now ihas an extra 1/8" radius, so after dryfitting and checking measurements I went to work on the dome removing mortar and a few filler bricks to expand my opening a bit. The arch will be a little forward of it's planned position, but much better than the out of true build I had on the first pass.

As dinnertime approached, I decided rather than starting to build the arch I'd do some cleanup instead. Got out the shop vac, removed Ll the spilled mortar and dust from inside the oven, and then took out my floor protector and cleaned up around the edges. Things are looking pretty tidy and I'm ready to rebuild the arch tomorrow.