39 inch Pompeii in Lincolnshire England

[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.

[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

...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 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?

[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.

[david s]

Re: 39 inch Pompeii in Lincolnshire England

I have already got a joint line up on the second chain. Not going to worry if I get two together, just won't ever let 3 line up. It's good to make it look nice but at some point you have to remember that it's first purpose is to function as an oven, not win a beauty contest.

The purpose of staggering the joins is not for appearance, but strength.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

I have already got a joint line up on the second chain. Not going to worry if I get two together, just won't ever let 3 line up. It's good to make it look nice but at some point you have to remember that it's first purpose is to function as an oven, not win a beauty contest.

[UtahBeehiver]

Re: 39 inch Pompeii in Lincolnshire England

Andis,

Could be tear drop adjustments or could be to keep the joints from lining up vertically, or from mortar creep (what look good during dry fit do not work as well when mortared), Bookem is right, it is a aesthetic thing but way not hide the booboos where no one can seem em.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

I've been collecting my cutting dust to make homebrew for the larger joints higher up the dome.

From the 2nd row up I shall be using the offcuts I have as wedges and and laying with homebrew.

Its a nice sunny morning so I shall try to get at least another full row on today inbetween other jobs.

The oven keeps getting relegated by other jobs. Repointing and a new throne for her in doors being the latest time eaters

[Bookemdanno]

Re: 39 inch Pompeii in Lincolnshire England

Doing well, and a great start!!!

The fine nature of that ready made mortar is fine early on, and if your intending to cut trapezoid bricks and maintain fine joints. Otherwise, when the outer joints open up further up the dome, you may find it better to wedge the outer joint with tile, or timber and back fill with a coarser homebrew mix after the chain has set up and you can remove the wedges. The fine mortar will slump and crack.
And yes, you can end up with a teardrop type effect, like "the man" Russ mentioned.
Its only an aethestic problem, and you soon forget about most things that were "issues" during the build, like cracks that you can't get a finger into, non staggered joints, etc!

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Do you mean make the adjustments for any teardrop effect at the front above the arch so they are not visable when I am finished?

[UtahBeehiver]

Re: 39 inch Pompeii in Lincolnshire England

Nice work, somewhere along the way you may have to make adjustments to your brick adjust them in the front 1/3 of the dome where one never sees them after you are done and cooking up a storm.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Started with the muck. First chain almost done.

I am using the premixed stuff I have rather than homebrew and it is nice to work with. Smooth like wet peanut butter and sticky when on wet bricks.
The bricks get a wheelbarrow bath overnight to get as wet as possible before laying.

Pleased with the floor being pretty level. I could have messed about to get every brick perfect but it looks like it should work ok.

Concentrating on getting the inner face of the dome neat and clean. Not bothering too much with the tops and backs as they will never be seen.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Floor going down on a fine mix of 50:50 fireclay and sand.

Rain stops play yet again. That's English summer for you.

[andis]

Re: 39 inch Pompeii in Lincolnshire England

Calcium silicate board in place and painted with a watered down homebrew to try and stop it soaking up too much English rain during the dome build.

Glad I have no more of that board to cut - boy is it brittle!
Used the finest jigsaw blade and took it nice and slow.

An inch of board on 3 inches of vermiculite concrete mixed 5:1 should be just adequate. Don't want my oven floor any higher than it is, so that will have to do.