Texman Build

[u863583]

Re: Texman Build

Great Build Texman,

I noticed in one of your pictures you are using Alsey Refactories bags. Is this mortar "Sarabond"? I ordered 3 bags from Larkin Refactory in Gorgia, and this is the material they sent. I am debating whether to use this material or use the home brew. I believe it will be good mortar. Did you just add small amount of water, or do you add some sand as well? Also, looks like your brick height is 3 inches, is this correct. I plan to do the same.

thanks

Manny

[texman]

Re: Texman Build

Manny

Thanks.

It is Alsey Flu set. I have attached the spec sheet. I ordered it from Larkin as well. Just a small amount of water is all you need, no sand. You will mix very small batches because the mixed mortar cannot be re-tempered with water to extend working time. The mix should be used within 15 minutes of adding water. So, you get really good at mixing.

The brick are alsey std. 9.5 x 4.5 x 2.5 straights.

No offense to the many superb builds that have used homebrew, but i wanted to use the refractory mortar. Since it has no portland it is easier on the hands and fingers too. HTH

Tracy

[Amac]

Re: Texman Build

well done Tracy - The inner side of the arch blends into the dome so nicely.

She may not be the prettiest gal at the dance, but i bet she will cook and keep me warm at night. I cleaned her teeth and did some minor dental work on the inside arch and i am pleased with the results

And in pic 2 I believe I see a "smiley" just above the arch - a bit more this than this - but she sure looks happy after all that cosmetic surgery.

[texman]

Re: Texman Build

Thanks Amac. Did you just "eyeball" the taper and angle cuts of the dome? Or did you have a method to make the cuts right the first time?
Tracy

[Amac]

Re: Texman Build

No - because I had a semicircle I could work it out. It is still not perfect but I was happy with the outcome.

If I remember rightly this is the method:

Get the length of the circumference of the outside of the arch (pi * D)/2. Then - allowing for your normal mortar joint - divide the thickness of a brick + mortar joint into the arch circumference. That will give you the number of bricks in the arch.

Then get the circumference of the inside of the arch. Divide that by the nr of bricks and it should give you the width that a brick + mortar joint needs to be at the inside. Subtract the mortar joint width and you have the inside brick width.
Subtract this from the normal brick width and either construct a template or carefully mark each brick using 1/2 that value on each side of the inner brick (see the pic).

I can't remember what type of cutter you have but I had an angle grinder and a lot of the cutting was more like shaving to get it more accurate. It is better to take off too little than too much.

Sorry that method sounds complicated but it isn't really. A close scrutiny will show you that not all the bricks are exactly the same, and I never succeeded in getting a single keystone.

[texman]

Re: Texman Build

That is exactly what i did as well on the arch. I guess i can use my inner arch jig and set shims on it to get the outer arch sized a 1/2" larger as the FB plans suggest to leave a reveal. some builders have angled the entry way to the inner arch, but i am thinking straight. Not sure.

On the cuts of the dome brick, i just haven't come up with a better way other than shaving to get as close a tolerance as desired. Sometime i get it the first try, but usually about two cuts (total of four) on each half brick to get it close enough to set. Hopefully, i can get courses 9 and 10 this weekend with a little work during the week. I cant tell how many courses to the plug yet, but i bet there are many that can on a 37" wfo. I will keep going til i get there.
Tracy

[Amac]

Re: Texman Build

Sorry Tracy - I misread "arch" for "dome".

For the smaller bricks (e.g 3 per brick) there was a bit of eyeballing OK. The inside to outsde of the bricks doesn't change (say 5?) but the angle from top to bottom was always changing so a bit of guesswork was called for. You can get three (at least) workable bricks from one using this method. Later I also cut the ends off but I can't find any photos. I used a plywood trapezium shaped template and used it to mark the bricks top and bottom and then joined them. Laku has a good sketchup pic of the principle involved.

BTW I did cut a completely new form for the entry arch and I made it at least an inch reveal. I could see any advantage just 1/2" gave.

[GianniFocaccia]

Re: Texman Build

A close scrutiny will show you that not all the bricks are exactly the same, and I never succeeded in getting a single keystone

OMG!!! Aidan, didn't we go over this a bunch! I never thought I'd hear you say this!

Honestly Tracy, you're doing a great job. Aidan nailed it when he described the process as shaving, rather than cutting. I too found this the only way to get the tolerances that I wanted. I think too many builders get hung up on '1/2 brick' and '1/3 brick' thing instead of just cutting the next brick to fit the bond. This might be the best approach for those who want to put their oven up asap, but for the rest, shaving is the way to go, especially for builders who take the time to bevel each brick.

I didn't worry and let the number of courses work its way out. When you get to the plug, you'll know what to do, just like correcting your slight droop.
John

[Amac]

Re: Texman Build

Hi John - actually I was talking about the outer arch tapers when I mentioned shaving (I hardly tapered the inner arch at all) - I think at the last few rows you can use the principle of cutting three shaped bricks from one brick. It saves the blade (and some brick). Shaving is hard on the blade.
The last row in the pic below I did using a small trapezium shaped piece of plywood for a template so it can be done OK. I found Lakus pic - it shows just two and two discards but for the top few rows, you can get three - a bit smaller - and discard both narrow ends.

[texman]

Re: Texman Build

course 9 and 10 are in. Seems like the closer i get to top, the farther it gets. I am guessing 12 courses and a plug, but we shall see.
I think my head is as thick as these firebrick. I finally realized (on course 10) that i could have been doing the simple calc (pi x dia/# of bricks) on each course to get really closer and easier cuts. I did that for the arch and then forgot it i guess. Too much brick dust and sweat and beer makes your head thick. Classic case of "damn the torpedos" and move on despite all the preparation and tools at your disposal. One unintended consequence i think of this though; even when i have a vertical joint that appears close to the one below on the inner oven, the actual vertical joint is some crazy angle that doesnt line up with the one above or below. Maybe it makes it stronger. I really think strength in a lot of ovens is overrated. I think you need enough mortar and strength to hold it together, and no more. Heat and gravity will take care of the rest over time. As i said before, i think Les's approach is the better technique as far as mortar application. It will be 100 degrees plus all week here in texas, so lots of water and learn to take my time.
Tracy

[Amac]

Re: Texman Build

I don't know how much closer you cn get those joints tracy - they look pretty much perfect to me - well done!

[texman]

Re: Texman Build

thanks amac. I have been using your three bricks from one method. It works good after I get past the learning curve. If go smaller on the next course i think i can get four.

For these last two courses, should i continue to get smaller with the brick or increase the size? I think smaller because it will have tighter mortar joints. Larger, less brick to cut but more mortar on the bottom of brick to compensate for curve. Any thoughts?
I am proud or the wfo. regrets on the bond in a few places, but i will take her as she is. On my last bag of mortar, so i should have enough for the outer arch and vent.
A few more pics too.

[texman]

Re: Texman Build

I am Finally learning to cut brick. On course # 11, maybe. Here are the steps that work for me:
1. Do the math. Picj
a. determine circumference of course for the bottom.
Measure the diameter of the opening (Pi x diameter at bottom of brick previous course=circumference of level you are cutting) 11.5" x 3.141592=34.56"
b. find # of bricks needed. (determines width of bottom of brick face)
Divide the circumference by # of bricks (# determined by size of the top of the brick of row just below)2? here. Thanks Deejahoy! 34.56/2"=18 bricks
c. Find the width of the bottom of brick at the outer edge.
Measure the diameter of the course at the outer top edge of the oven. That is 15? in this example. Put a scrap with a 2" bottom width in the IT and place it where it would set in the course and measure the gap that will be your outer mortar joint. That is 3/4" here. So 15? ? 1.5 (two mortar thickness)=13.5 diameter. 13.5 x3.141592=42.42. 42.42/18 bricks = 2.36 (.36 x16=5.76) or 2 3/8? for bottom width at outside. So you have the bottom of the trapezoid brick, 2? at inside and 2 3/8? at outside.
d. Find the width of the top of the brick face. Measure the distance from the top of the brick in the IT (from step c.) to the edge of course below. (face height plus mortar gap) 2.25? here. 11.5?- (2.25?x2)=7? diameter. 7 x 3.141592=22?/18 bricks=1.23 (I wrote 1.21in pic)
e. now you have the face dimensions and the bottom dimensions. Mark the face dimensions and use the angle tool to find degree from top to bottom and use that angle for back of brick and find the width of the top of the back of brick.
2. Cut your pattern brick and copy 17 times in this case.
a. turn your pattern brick upside down and set on brick you are cutting and mark top dimensions. Turn the pattern brick and mark back of brick cuts.
b. use the bevel tools (cut brick slivers) to get the vertical cuts to square. Check w/ square. Check angle cuts with square and align w/ blade. Repeat for both sides.
c. if you are at a level when the bricks get small, you can get three and even four from a brick. I am getting 4 on course #11.

I am thinking it is time to get rid of the IT clamp and use a round board or something. I hopefully can get Two set with the IT clamp on and then remove the clamp and use a board mounted to the IT.
See next post for more pics.

[texman]

Re: Texman Build

It is hard to put to words, but the results are great on the dry fits. It looks complicated, but really isn't. I did the calcs on my phone and wrote the numbers on the bricks. I will see if they still work with mortar. I have had to shave bricks on every course to get the joints i like, and even then, still not perfect at all. I am thinking of tapering the bottom of these last few courses to get really tight joints and make it pretty. not sure why, since that would result in all the calcs changing, but you have to leave room for mortar.
All this from the guy in pic C.
Would i Lie?
Tracy

[deejayoh]

Re: Texman Build

Good stuff Tracy. I figured the math out at about the same point in my dome...

I have been working on a spreadsheet that will give the calcs for a whole oven - number of courses, number of bricks per course, angle each course, angle of the side of each brick, width of the brick.

I just haven't found the time to finish it, but if I can I thought it might be something I can contribute back to the community. Just requires you to give the radius of the oven and the height of the soldiers, and figures everything else out.