82cm Corner Underway in Bulgaria

[mrchipster]

Re: 82cm Corner Underway in Bulgaria

The second photo tries to show the interior and top cut vectors for the arch bricks, the line that goes up to the right is the vector tobe followed for the inner side of the arch bricks, the line that points up to the left is the vector from the center of the floor to the outside of the oven.

[mrchipster]

Re: 82cm Corner Underway in Bulgaria

Take a look at the edited photos.

First photo has 2 curved lines, they represent the cuts for the top of the bricks on the arch.

The bricks you have mortared in for the arch appear to be correct. The uncut bricks need the surface to be a vector from the center of the oven floor out to the outside of the dome.

Your IT will show this vector or a simple string will also show it.

Because I am doing this on an ipad I can only do one photo per post so the second photo will be described on the next post.

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

Ok, back from wet and cold UK and back to the oven.

Have done the 3rd row today, but ran into a couple of problems, I took several bricks off the course to make it easier to work but found I was then putting too much mortar on the side of brick and by the time I realised you can see in the pictures the inverted Vs also I have 2 joints in line, hope it doesn't effect the structure too much. (Photo 3)

I am still struggling with the arch angles for the transition, sorry guys, I know you have given me pointers and I have read and read about the string or IT to measure but its still not clicking.
as you can see I have cut the bricks in readiness for closing the arch but still unsure how to work out the angle to receive the following rows.(photos 1&2)

I cut another arch brick for the next row using the string method and quadruple checked it again and again but it is still short of the IT and I can't figure out why. (Photo 4)

I am thinking of putting in the fourth row and see if it clicks or I shall wing it when it comes to closing the arch, however if the It does not meet my arch top that would possibly mean that the transition bricks will overhang slightly over the inside of the arch bricks.
Would this be a great problem to the stability/building of the oven.

Once again my apologies to those who have tried to show me the way.....

Paul

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

Between replies I was finishing off the course and trying to figure how to make the semi template thingy.

Many thanks Faith for your lovely pictures I see how you've fitted the courses on to the arch, your oven looks huge in the pictures is this the new one.?

Russell, You are of course right about finishing the arch maybe when I have all the arch bricks all cut I will see the angle I need to make without use of this half template.

As you see from the 2nd picture I tried to make the template but its higher than my arch as I did not take into account the board and height of IT castor and couldn't work out how to correct it.

However your great outline on picture 1 gives me a better idea.
Looking at this picture my IT doesn't quite reach the arch SO, would I be right in thinking that the angle you drew would be slightly further out from the arch to meet the IT?

With regards to joint lines, whilst it is recommended to avoid them, Looking at picture 3 it seems that the arch so far has a continuous line. Looking at other pictures it seems the case, that mine is no different to others. Maybe the line will start to move now the arch is getting higher?

I can see by picture 4 that the courses attaching to the arch would be cut at a slight angle inwards for a better close fit. Am I on the right track here?

I am now at a standstill with the oven as I am awaiting new diamond discs and next week we are back in the Uk for a couple of weeks.
Perhaps my sore back will get chance to mend

[Faith In Virginia]

Re: 82cm Corner Underway in Bulgaria

Lets try this again perhaps this time it will make more sense. This is how I did my arch/ dome intersection.

Note that the inside of the upper arch follows the contour of the inner oven.

Also note the flat spot on the inside of the oven arch at the floor. As my next redo I would cut that corner off because it catches ash and takes some attention to clean out for bread

[UtahBeehiver]

Re: 82cm Corner Underway in Bulgaria

Yorkie,

You are on the right track. Here are some pics to help you. You should do the top dead center brick of the arch then work you way down. Proabably should cut and fit complete arch before going to much farther with your dome courses.

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

Tex, The picture in thread 38 & 41 you reffered to. Does that currve go all the way to the top inside of your dome.

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

I think I've made a little progress in the understanding of building my arch and many thanks for your help guys. Please take a look and let me know if I'm proceeding OK.
Looking at my arch ends (on photo) they are slightly of different dimensions somehow, will this prove a problem as I go round?

I have had a go at tapering a few bricks with the angle grinder for the arch its hard work but I'm managing although they don't look pretty Im pretty happy with my efforts, but my back is aching from all the bending over of doing my first 2 courses and cutting.

Picture 1 shows my new arch template and my first tapered arch bricks.
The mortar joints are about 20mm at the back of some of the row bricks 15mm on others. I am using only the heat resistant glue (cement based) which has a 1000 deg C tolerance, so my thinking is that the temps we will use will not be a big detriment to my larger joints as it stipulates 8mm max joints.

Picture 2 shows the pencil marks ready for cutting.

Picture 3 Is the IT telling me the line to cut.

Picture 4 Shows where my IT reaches the bottom of the arch. Is this right?

I now need to understand about the board some of you have placed flush with the arch to the centre of your domes.

I understand I need to cut / taper my arch bricks using this guide board but not yet cut the angle. Which angle?. sorry for being such a thicky but I keep reading and looking at pictures but the pennys not dropped on this part yet.

[mrchipster]

Re: 82cm Corner Underway in Bulgaria

!st Row completed.
I noticed when I put the arch template back it doesn't quite match with the edge of bricks can this be rectified on the next course?

To make my hemispherical arch do I start turning the bricks in at this point, I have noticed others turn after the 2nd course?

Cobbler Dave, thanks for the tip will look at this method if its not a detriment to doing what Dennis, chip and Octo etc have done. Your idea was done on the outside arch but maybe it will work on the inside too.

Thanks Dennis, I see that you went through a similar problem although you had the right tools for the job to cut angle your bricks for the arch.

Wrap the top of the arch template in a thin sheet of tin, the inside edge of the template is of no concern, get some shims under the template before continuing your arch also. The shims can be removed easily and the template will come out without any major issues once dropped.

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

Hi Tex, I will put the board back in tomorrow with the IT and start looking at the arch formation its a little clearer now but I must overcome the problem of large gaps/ cutting my bricks to shape or I may use wedges between each course as I go round.
Undecided yet but may have time to have a good scratch of my head in the morning.

Yes I intend to rest the flue on the inner arch and outer arch(hopefully) going by what Ive seen, when the arch is done there will be 9inches of front brick which you can see in the photos plus whatever room is left on the arch bricks. If you get my drift.
Will look at those threads you mentioned Tex.

Cheers Paul

[texman]

Re: 82cm Corner Underway in Bulgaria

Paul

If you will get your IT set, it will greatly aid in your setup and alignment of your arch template. You will want to put a brick in the IT and test the top of the arch template. See Russell's #38 and my #41 on your thread. Those should be looking familiar to you now.

Also, you need to decide how you will build your vent and flue. Will the chimney rest on your inner arch or be separate?

Texman

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

!st Row completed.
I noticed when I put the arch template back it doesn't quite match with the edge of bricks can this be rectified on the next course?

To make my hemispherical arch do I start turning the bricks in at this point, I have noticed others turn after the 2nd course?

Cobbler Dave, thanks for the tip will look at this method if its not a detriment to doing what Dennis, chip and Octo etc have done. Your idea was done on the outside arch but maybe it will work on the inside too.

Thanks Dennis, I see that you went through a similar problem although you had the right tools for the job to cut angle your bricks for the arch.

[deejayoh]

Re: 82cm Corner Underway in Bulgaria

Today I have enquired about shaped fire bricks for the arch, unfortunately the suppliers have said there are none, I must cut them.

I wished to make my arch like that of Octoforno and Chips etc so to incorporate the transition, this means I would have to cut my bricks on there edge lengthways, difficult with only a angle grinder, so I have an idea that if I make a small cut around the line I wish to cut and then finish off with a hammer & chisel would this work? ( I shall practice on an old brick first to see how It turns out)

Secondly does anyone have a spreadsheet/calculator for the angles I would need to cut.
My opening is 410mm x 26mm (16" x 10") the bricks are 65mm deep x 250mm L x125 W and I wish for gaps to be max 8mm.

Paul

You don't need a spreadsheet for those cuts. Use your IT to figure out the angle for the top bricks and carry that around

[cobblerdave]

Re: 82cm Corner Underway in Bulgaria

Gudday Paul
If you have 5 full bricks spanning a section of an arch you have 4 large gapes inbetween on the outer edge. If you split those bricks lengthways you now have 10 1/2 bricks occupying the same space and 9 spaces inbetween . The 9 gapes inbetween occupy the same space that the four did but are smaller.

The arch on my oven is made up of 2 in pavers instead of 3 1/2 in brick and as you can see makes the arch look smoother because of the larger amount of smaller gapes.
If you were to cut full size bricks to suit the arch you would have to produce them with a cut on either side. A fairly accurate cut as well , I built with an angle grinder and I recon it would be hard to keep your accuracy. Perhaps you might consider a single straight cut lengthways though each bricks and build the arch with more pieces and more smaller gapes on the outside.
Of course I didn't think of this by myself another forum member beat me too it!
Hope this helps in some way
Regards dave

[yorkshireknight]

Re: 82cm Corner Underway in Bulgaria

Today I have enquired about shaped fire bricks for the arch, unfortunately the suppliers have said there are none, I must cut them.

I wished to make my arch like that of Octoforno and Chips etc so to incorporate the transition, this means I would have to cut my bricks on there edge lengthways, difficult with only a angle grinder, so I have an idea that if I make a small cut around the line I wish to cut and then finish off with a hammer & chisel would this work? ( I shall practice on an old brick first to see how It turns out)

Secondly does anyone have a spreadsheet/calculator for the angles I would need to cut.
My opening is 410mm x 26mm (16" x 10") the bricks are 65mm deep x 250mm L x125 W and I wish for gaps to be max 8mm.

Paul