39 inch Pompeii in Lincolnshire England

[andis]

Re: 39 inch Pompeii in Lincolnshire England

I know that it's about strength, but i've seen plenty of ovens that haven't fallen over because the odd joint has got near another. I would like it to be functional AND look semi decent - but I don't want to get a structural engineer in and still be cutting bricks come Christmas. There's a balance to be had and i want to be holding a pizza paddle rather than a trowel before the summers finished.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

I need help with the cuts to the arch bricks please.

If you look at the picture below it shows how I have cut them on two sides to form the arch.

I can then see how I can use my IT to cut the rear sides to match in to the shape of the inside of the dome.

What I cannot see is how to then work out the final cut to the top rear of the bricks. This is the cut that the chain bricks are stuck to. I can see the cuts on most people's build thread but I cannot find anything to show how the placing of this cut is done. How do I know where to mark and cut?

[Bookemdanno]

Re: 39 inch Pompeii in Lincolnshire England

...and the longer you look at it, the more confusing it gets?...

I don't know how these really spot on tight joint guys have done it, but i've seen many (and my own) just has the uppermost (as viewed in position in the arch) top corner nipped off. I did mine in-situ with a 4" grinder, just chewing bits off. My bricks aren't hard firebricks though. There's some pretty wicked compound angles, bevels and curves to consider, if you really want to get into it.

And guess what....

I can't see any of it anymore!

Looking at your picture, and the bricks for your arch (nice work so far, by the way) try to envisage an angled cut to each brick from around the mid point of the long side (outer edge) of the arch bricks to the mid point of the face inside the oven. Creating a chamfer all around the top internal edge of the arch. The amount cut off can increase as you get higher up the arch. Then any wedge offcuts can be used to infill and prop the bricks that sit onto the arch. You also probably only need to think of cutting seven from nine (for all you trekkies out there...phwoar), leaving the bottom two uncut as they look like they'll fit in ok with a small cut brick in the gap.

Tricky to communicate, easier to be shown!

There's some great builds on here, check out UtahBeeHivers approach. He's got a pretty concise photo blog on his build thread.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

I think I understand what you mean after having a look at russell's build and the photos of his arch with the IT mounted pen.

I shall make a conservative brick saw cut to the bottom rear of the arch bricks leaving a bit extra to grind off later.

Then I will mark and cut the top rear of the arch key stone, which will be longest brick, and then use it as a template to transfer the same cut angle to rest of the arch bricks.

Does this make sense and should it work?

[Bookemdanno]

Re: 39 inch Pompeii in Lincolnshire England

I'm sure that you'll find the way that works Andis!!
Sounds like you're on the right track.

[UtahBeehiver]

Re: 39 inch Pompeii in Lincolnshire England

Andis,
As you figured out top arch brick will be the longest. The template approach gets you a rough idea but each of the brick angles change as you move down the arch. Use our IT to help you set the angles they move in all three axis. Spend some time here and it will pay off during tie-ins.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

No more arch cutting yet. Laid a few easy ones before being rained off yet again.

Forecast for the next few days is good so I will be doing nothing but cutting and laying bricks. This week should see some faster progress.

Tip - I took the metal sieve from the kitchen and ran the dry dust from the brick saw tray through it with a spoon. The result was a nicer homebrew with no annoying gritty lumps.

Second tip - ask before you take the sieve from the kitchen to use as a builders tool the day you have people coming over for dinner.

[Gulf]

Re: 39 inch Pompeii in Lincolnshire England

LMAOROFL !!

Tip - I took the metal sieve from the kitchen and ran the dry dust from the brick saw tray through it with a spoon. The result was a nicer homebrew with no annoying gritty lumps.

Second tip - ask before you take the sieve from the kitchen to use as a builders tool the day you have people coming over for dinner.

There are countless ways in which the building of these ovens tend to "annoy" the other half . Tip #2 would probably irritate the sht out of just about any of them .

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Third chain finished. That's all I had cut and i didn't want the neighbours listening to my brick saw all Sunday afternoon.

The arch tie in won't be as neat as some but it's solid, and it's no pig, so i'm happy.

I have a 450mm chimney pot that I am going to use. This will be above a ceramic flue liner, housed in brick, to get me from the vent to above the roof on the house. They are both 9 inch diameter.
I hope this will work ok. I was worried about the weight but I plan to buttress the arches by building either side inside the house walls.
If this sounds unreasonable then please tell me soon as I am on a roll.

[Bookemdanno]

Re: 39 inch Pompeii in Lincolnshire England

Sorry Andis, i had my head on upside down! Less off as you go up the arch!!

That's a pretty good start, and not such a great start with HWMBO!
Have you not had the "you spend more time with that oven" comments yet?

[andis]

Re: 39 inch Pompeii in Lincolnshire England

The ready made mortar I used at the start has dried solid - but my homebrew is drying powdery and turns to dust when handled.

I made it 1:1:1:3 as seems to be standard.

Is this powdery result normal?
Should I up the portland ratio?
Do i return to using premixed?

Also my Firebricks are growing a white fury jacket as they dry out.
Is this just salt drawing out?

Just cutting today until I get some advice on here about the mortar.

[Bookemdanno]

Re: 39 inch Pompeii in Lincolnshire England

Is this mortar in the brickwork or just bits lying around?
If its within your brickwork, then usually that is due to the mortar drying too quickly through the bricks sucking the moisture from the mortar before it gets to cure. There is a chemical reaction that needs to take place. If your adding dry brick dust to the mix too, its a good chance that dry bricks and this added pozzolan is just too aggressive a mix, and causing the mortar to dry too quickly. Its seems a rich mix too. I'm not au-fait with the homebrew exactly though. I'd say that you'd need to hydrate the brick dust before adding to the mix, by creating a sludge and then mixing into your mortar?
Are the bricks you've laid still in place? Give them a tap with the butt of your trowel.

Not firebrick experienced either, but the fur sounds like efflourescence.

[UtahBeehiver]

Re: 39 inch Pompeii in Lincolnshire England

Neat chimney pot ur using for a chimney.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Russell - I pinched the chimney pot from my dads garden.
He has a few and most are a lot older and ornate so he won't miss this plain one.... And it matches the others on my house.

Bookemdanno - your drying out too quickly idea seems to fit. The mortar on the dome bricks seems ok and these bricks had soaked overnight. The mortar on the left arch has gone powdery and the brick dropped off as I touched it. This brick was only sprayed with water just before being placed.

I will soak all bricks overnight from now on. I have been putting a damp sheet over the brickwork when I am finished for the day.

The premixed seems much stronger than the homebrew so I shall use it for my arches and chimney support.

The old blade on my saw was struggling today after cutting another 80 bricks so i am off to get a new one in the morning. Getting a 10 inch segmented blade here in the UK is very difficult. I will have to make do with a solid ceramic blade rather than wait a week for a segmented delivered. You guys in the US and OZ are spoilt when it comes to tools and blades for this job!

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Had a look about for a blade today.

10" 25.4mm bore segmented diamond wet blade ?144 ($218 US / $238 AUS)
10" 25.4mm bore non segmented diamond wet blade ?18

It might not be ideal for the job but at a saving of 87.5% I will give the cheap one a shot.