36" in DFW Area - IT, jigs and forms

[Texas]

Here are the links to the different portions of our build:

In Getting Started section, I included the Design, Specs and Supplies & Equipment:
36" in DFW Area - picture of finished product - post #1 http://www.fornobravo.com/forum/f6/3...rea-21562.html (36" in DFW Area)

36" in DFW Area - Design Phase - post #5 http://www.fornobravo.com/forum/f6/3...tml#post184271 (36" in DFW Area)

36" in DFW Area - Specs - post #14 http://www.fornobravo.com/forum/6/36...tml#post184280 (36" in DFW Area)

36" in DFW Area - Supplies & Equipment - post #15 http://www.fornobravo.com/forum/6/36...tml#post184281 (36" in DFW Area)

In the IT, Jigs, & Forms section, I included our IT, Jigs and Forms used:
36" in DFW Area - IT, jigs and forms - http://www.fornobravo.com/forum/f28/...tml#post184284 (36" in DFW Area - IT, jigs and forms)

In the Pompeii Oven Construction section - I included the building of our oven:
36" in DFW Area - Building the Oven - http://www.fornobravo.com/forum/f8/3...tml#post184381 (36" in DFW Area - Building the Oven!)

We had the base for the oven made by a contractor, then we built the oven, and they came back and did the oven enclosure and finishing work. The concrete on top of the oven base was covered with a leveling concrete to make it smoother and more level.

It, Jigs & Forms:

•Circle cutting jig (picture #1) - we used this for any circle we needed to cut (floor insulation guide, floor brick guide, arch templates, etc). Take a scrap piece of wood that is a little longer than the radius of the circle you need to cut. Draw a line in the center along the entire length of the board (half way mark). Cut small strips of wood to form a frame around the base of your jig saw. We used the jig saw to cut a slot and then formed the frame on the left, right and front of the jig saw base. We screwed the frame into the board (drilled pilot holes and used small diameter screws). Pick out a nail that will go thru the thickness of this jig board and any of the boards you will be cutting into your circle (or half circle). Drill a hole in the jig board the distance of the desired radius. Measure from the slot where you jig saw blade will be cutting. When you use this, drill a hole in the center of what you want cut, put the nail thru the hole in the board to be cut from the bottom, put your cutting jig board hole over the nail and push it down. Try to start your cut at the edge of the board to be cut, or drill a hole for your jig saw to start. Cuts amazing circles easily. Drill new holes at different distances. We used the same jig for all of our circles, but just moving the pivot hole!

•Arch forms were made by the following method.
1.cut boards to similar lengths (for the inner arch, we used 2 boards, vent arch used 3 boards).
2.clamp boards together with the bottom edges exactly even.
3.using a straight edge and a circular saw, cut through all boards, perpendicular to the bottom, at the desired final width (for our inner arch it was 19"). Leaving the boards clamped together, draw a line 1" from the bottom, parallel to the bottom. This marks where the center point of the arch circle is (we used a 2x4, which is about 1.5" thick, the first whole brick is 2.5", so the difference is 1").
4.Mark the center line by drawing a line perpendicular to the bottom at the half way point (for inner arch 9.5" from each side).
5.Drill a hole where these two lines intersect (center line and the 1" up line) to put your nail for your circle cutting jig.
6.Unclamp the boards and draw the 1" line and the center line on each piece. The pivot holes should be at the intersection of these lines.
7.Drill a hole in your circle cutting jig at the desired distance (in this inner arch example, 9.5").
8.Start your jig saw at the 1" mark (the circle is tangent to this point) and saw the circle. It should be complete at the 1" mark on the other side.
9.Repeat for the number of arches you need cut.

We found this method to be very accurate. Our jig saw would not cut cleanly through two boards for the entire arch. It would start off OK, but the blade would bend as it went around the circle. For the vent arch "wings", we used the pieces of board that were cut off and screwed them onto the arch form tangent to where we needed them for the height and spread (distance apart). There are pictures later of the inner arch form and the vent arch forms. I do not have any pictures of us cutting the arch forms because it took both of us to hold and cut, so no one to hold the camera!

[Texas]

36" in DFW Area - IT, jigs and forms

?Inner arch - 19" width, 12" total inside height, 9.5" radius, arch sits on a 2.5"x4.5x9" brick (so arch height = 9.5" + 2.5" = total inside height of 12". Putting the arch on top of a base brick allows us to get the height we want and still have a hemispherical arch. Each arch brick (19 total), was cut to 2 3/16" on the wide side (outside) and 1 7/16" narrow side (inside). 1/8" mortar joint. Form was cut 1 1/2" shorter so it could sit on 2 pieces of 2"x4" blocks and be at the correct height. Used 1/8" balsa wood pieces to dry stack. Used 1/8" balsa wood strips as a guide for how much HeatStop 50 to apply before placing. After dry stacking, we marked the top and bottom corner of each brick on the arch form to help keep us in line as we mortared. The bricks were numbered on the back and I recorded what order they were put on. Used a 2x4 under the wooden arch form to raise it up. Nailed a scrap piece of laminate on the wooden arch form to keep bricks from sticking since it would be in place for awhile. The inner arch bricks were cut to 6" long before we cut the wedge shape.

picture #2 - Inner arch form with laminate covering

picture #3 - Inner arch bricks dry stacked with balsa wood or popsicle sticks to allow spacing for mortar. Once in place, the position of the corners of the bricks were marked on the form. The string helped us position the bricks at the correct angle.

[Texas]

36" in DFW Area - IT, jigs and forms

?IT information - here are the parts we used. A hole was drilled in the wood covering the floor for the weld nut. The threaded rod was cut so that the total distance was 18". The rod and clevis rod end were attached. The threaded rod was put in the clevis rod end and two nuts were added to keep the rod length steady. A coupling was welded on each bracket such that the center of the coupling was at 1 1/4" from the inside lip (half a brick, so that the rod was at the center of the brick.). The extra part of the bracket was cut off at 1 7/8" like post #40 of jcg31 "My indispensible tool (a variation on a FB theme)" http://www.fornobravo.com/forum/28/m...me-2985-4.html

At layer #9 (2.5" bricks - we did layer #8 with 3", then went smaller), we switched ends and used the narrower holder. When we put in the plug, we used another weld nut on the end to mark our 18".

In addition to the parts with part numbers shown in picture #2, we also used a threaded steel rod, 2 couplings, 2 nuts, and clamp.

[Texas]

36" in DFW Area - IT, jigs and forms

•I made templates with the measurements in the table and wrapped the template around the brick to mark the target. We had a digital angle measurement device (from Harbor Freight), but found it was not very consistent and had quite a lengthy response time to changes. We would use it to get our jig close, then put a marked brick on the jig and use a metal square against the blade on our wet saw to line up the parallel cut to the blade. We used a combination square with the ruler moved even with end, to rest one edge on the saw table and the other edge to help line up the perpendicular cut with the mark on the brick. We would cut 3-4 blocks and then test fit before cutting the rest for that row.

We ended up just using the bricks marked using a template to set up the saw because the digital angle finder was not giving us as good of results. By using a template designed for each level, transferring the markings to about 3 bricks, we could set up the jig and cut the blocks for an entire layer, rather than constantly going back and forth to the saw. We would leave a couple of blocks with just the one side cut, so that if we needed a shorter block to stagger mortar joints, we could just cut the other side and it would work pretty good.

Attached is the file containing the templates for our 36" oven layers 1-10 (not floor layer, sailor layer, or plug) Publisher 2002 version

[Texas]

36" in DFW Area - IT, jigs and forms

•When cutting using our jig, we would mark a B and a T on the left and right of one side of the brick and then turn it over and mark a T and a B. The first cut would be on the right side as shown in the picture. The second cut, to form a complete block, would be made using the same jig, and flipping the brick on the long axis and sliding it to the right. The markings will now say T on the left and B on the right. The part of the brick that hangs off the right side of the jig, would be the finished piece. We normally put a small scrap brick or wood piece to help prop it up so that the cut part wouldn't fall off during the cut. The last cut was made with a jig that mounted to the right side of the saw and was set up just like the first. Flip the brick again (B up), and make the last cut. Two blocks from one brick, three cuts! When the angle gets steeper, we started with the brick on the jig on the right part of the saw, and moved it to the left as we cut, then made the last cut on the jig put on the left. There was more clearance on our saw on the right side of the blade. This is the same method as described in post #2 here: http://www.fornobravo.com/forum/f28/...ble-16780.html . The only difference is that our first jig was used for cut #1 & cut #2, then we moved to the other side of the saw and jig #2 to make cut #3. For the lower courses, we started cutting with the left jig and finished the last cut on the right jig, but as the cuts got steeper, we started on the right and moved to the left.

We used a block of wood or something, to make a stop for the end of the brick, so they would all be the same length. We would place the stop and make all the cuts with that stop first. Then re-position the stop, and make the next set of cuts.

At layers #8, 9 and 10, we could get 3 bricks from one full starter brick. Follow the same process, but do one more flip!

Picture #1 only shows one of the jigs. There is a second jig, that is a mirror image of this one.

By wrapping the templates around the brick and holding and flipping it, it becomes much easier to see how this one cut, flip, cut, flip concept actually works. The templates are here http://www.fornobravo.com/forum/f28/...tml#post184287

[Texas]

36" in DFW Area - IT, jigs and forms

•Vent arch form - we made a form using 3 arch boards 3" spacing between the board furthest from the oven and the middle one and 6" between the middle and the board closest to the oven. We used 2x4's cut to length and screwed the arch boards to the ends of the 2x4 pieces. We made "wings" from the part of the board that was cut off to support the vent portion of the arch. The wings were installed such that the screws holding the wings onto the middle board could be removed when the brick arch was installed. With the screws removed, the front set of wings would fall down. The back set of wings on the last arch board, were cut off/then broken off, through the vent opening using a roto-zip tool.


•Vent arch - ours has a 1.5" reveal. Vent arch dimensions are width = 22", radius = 11", total height = 13.5". Arch sits on a 2.5"x4.5"x 9" base brick to get total height (arch height = 11" +2.5" = 13.5"). Putting the arch on top of a base brick allows us to get the height we want and still have a hemispherical arch.

[sharptailhunter]

Re: 36" in DFW Area - IT, jigs and forms

Thank you for posting this! As a newbie in the planning stage of my build, this info helps tremendously. Your attention to detail in your build shows not just in the brickwork but also in your jigs/tools. Thanks again :-)

[Texas]

36" in DFW Area - Techniques

?Picture #1 - shows our set up for the saw (http://www.fornobravo.com/forum/28/d...r-18131-5.html - shows the tilt and side angle figure - these terms used in the picture) The metal stand was our old chimney cap. We did soak the bricks, just a few minutes, prior to cutting. In post #4 - http://www.fornobravo.com/forum/f28/...rms-21566.html, I described using the two different squares to help line up the jig to cut the bricks where we wanted.
?Picture #2 - After cutting the bricks, we washed them with a wet brush before mortaring in the dome. The brick saw table had to be periodically cleaned off.... we normally used a putty knife to scrap off the extra "brick saw dust".... that is what I called it!
?Picture #3 shows the next layer cut and stacked ready to install.

[Texas]

36" in DFW Area - Techniques

?This picture shows our technique for controlling the amount of HeatStop50 used in our arches to keep the mortar joints consistent with our dry fit measurements. We laid the popsicle sticks or balsa wood on the surface to be mortared, them left them in place while "buttering" the mortar on and scraping it to the thickness of the sticks. The sticks were them removed and the mortar smoothed out, with maybe a tad more added to fill in where the sticks were.

If the bricks were recently cut (for the arch or any layer in the build), they were probably still damp enough that we did not use the spray bottle. Otherwise, we sprayed the bricks before putting the HeatStop50 on them, so the moisture from the mortar would not immediately be sucked away.

[Texas]

36" in DFW Area - Techniques

?Technique for measuring and mixing HeatStop 50: Used measuring scoops that came with Tide detergent. One scoop holds about 3/4 cup. I used plastic trays with lids to store pre-measure the HeatStop50 and carry to the work site. Measured 1,2, or 3 scoops per container. When ready to mix, we dumped the pre-measured amount into an empty 3 lb butter container, then added about half the water we thought would use, mixed, added more water, etc. Used about a 3-1 ratio of HS50 to water. So the containers that had 3 scoops of HS50, used about 1 scoop water. I marked on the scoop the levels for water for 1 scoop or 2 scoop batch. The actual amount of water varied based on the weather, how tightly the scoop was packed, etc, but was a good guideline for us. Pre-measuring helped us not to mix too much at a time. Once we started mixing and using, we could get a pretty good feel for how much we should mix at a time. We never mixed a batch larger than 3 scoops, cause that amount was the max we could put in our butter container and use in the 15 minute timeframe that I read that HeatStop50 should be used. I used popsicle sticks laid on the lids to help keep track of how many scoops were in that container. In the first picture, the container on the bottom right, has 1 scoop, the one more toward the middle of the picture has two scoops in it. I would scoop out several containers (I think at one point I had 5 or 6) with one, two or sometimes, three scoops. There were only a couple of layers that we used the three amount, but by having multiple one or two scoops measured, I could quickly make a variety of size batches (like dump a two and a one into the mixing container, for a three batch), then I could adjust what I measured when the containers were refilled, based on what we thought we would use.

I bought a metal serving spoon at a thrift store that we used to mix with. After mixing was complete, the spoon was washed off between each batch, so we didn't get dried parts mixed in the next batch. The butter container was washed periodically between batches, but not between each batch.

[DavidApp]

Re: 36" in DFW Area - IT, jigs and forms

Hello Texas

Thank you.

You have posted a wealth of information for others to learn from. That is what makes this Forum so valuable.

I used pieces of cutoff brick to keep my vent brick spacing. I like the popsicle stick idea.

David