Budget Build 36"

[cobblerdave]

Re: Budget Build 36"

Gudday Bevan
Looking great! I'm particular taken by the pics of the oven inside. Because of the thinness of the pavers hardly any great gapes. Not like you would expect with full thickness brick! I've seen a paver/bulster built oven and I know the gapes at the top would have larger ones but its not important. If you had to tap your last keystone's in with a mallet they should be tight enough.
Sorry to hear that the blow up ball was a pain to use , I'm now of the opinion that it would only be of use in say the last 2? Rows. What do you recon?
Good idea to use those bricks to force the sides up by the way.
I noticed 2 bricks hanging around in a few pics is it those, or are you planing to use your antique bricks as a feature on the entrance?
Regards dave

[brickie in oz]

Re: Budget Build 36"

Can I build the vent and outer arch while I am waiting?

You sure can.
Exceedingly quick build..

[Laspaz]

Re: Budget Build 36"

Hey Gang,

I decided to remove the form quickly and get the exercise ball in place, and the n put the form back in place. The arch held, fingers crossed that I haven't made it weaker by messing with it.



I had quite a bit of trouble with the ball and wouldn't use it next time. The ball needed to be at low pressure to have the shape I wanted. This made it really difficult to keep the bricks at a nice even level (and prevented me from being able to see)

I tried to use full bricks to weigh down the center of the ball making the pressure around the edge where the bricks were being placed higher.



The result was the top inside of the dome being quite uneven and quite disappointing. I guess that is another benefit of a cut brick vs. a uneven bolster cut one, you can know the inside profile based on the outside somewhat. I don't think this should limit the operation of the oven.

Either way, 266 half pavers later the dome is closed. I ended up with a 17" internal height and I am quite happy about that. I tried to make sure the dome had a more flat final few courses.







I did have to hammer in the keystone (stones) pretty firmly so I felt reasonably calm about removing the exercise ball right away. Hopefully she holds

Now I supposed to leave it to dry out for a week before starting curing fires right? Can I build the vent and outer arch while I am waiting?

Cheers,

Bevan

[stonecutter]

Re: Budget Build 36"

With the small arches that these ovens have, pulling the form early isn't going to effect it much. When you get into larger spans and more mass then the centering needs to stay in place longer.

As a point of interest, Roman arch building was very rarely built dry. Even if there was no visible mortar, the voussoirs had joggles filled with lead or cementitous material.

[boerwarrior]

Re: Budget Build 36"

I removed my arch form a few hours after mortaring - so that I could clean up the underside of the arch before the mortar went completely hard. I had no issues.

My theory is that the mortar is under compressive load and if the arch is properly built then the mortar is really simply taking the compressive load and not really holding the arch together. The compressive strength of mortar is pretty high within a few hours (of course it gets much higher over the following days and weeks.) The Romans built plenty of arches with no mortar at all and a lot of them are still standing!

[stonecutter]

Re: Budget Build 36"

Ha! I guess that would work... everyone says the air is doing the insulation. I wonder what sort of strength would remain after the peanuts melt.

I though the pumice was a lot like a rice crispy treat (rice bubble bar)...

Bevan

My guess is that the resulting layer would be very weak unless the foam peanuts were broken down into tiny pieces. But smaller voids and more cement would reduce the insulation properties. Large voids and a network of Portland would quickly degrade from the heat if it was used as a direct contact insulator.

[brickie in oz]

Re: Budget Build 36"

You can remove the arch for the next day if you want too.....

[Laspaz]

Re: Budget Build 36"

Gudday Bevan
It's looking pretty good from the photos. Leave the arch form for a week if possible . You ripping ahead compared to most builds so a little wait is alright.
One thing you might try on the oven entrance is to clear the mortar off with a bucket of water and sponge. You'll find it impossible to remove when dry.
Again great progress
Regards dave

Thanks Dave,

I whipped back outside and gave the arch a wipe down and now it looks much better.

That's is a shame about the arch form needing to hang around so long, as I wanted to position the valve of the exercise ball in the entry for easy inflation and deflation when the dome is complete.

Oh and should of I mortared the arch to the floor? Because I didn't. Hopefully it will stay put because it is tied into the dome?

Thanks

Bevan

[Laspaz]

Re: Budget Build 36"

You may like to try this approach some cheap cramps and wood/leftover brick cramp the wood to the brick you are trying to lay

That is pretty cool! I don't have any cramps on hand unfortunately. Amazing solution, I never could have thought of that

Bevan

[Toomulla]

Re: Budget Build 36"

You may like to try this approach some cheap cramps and wood/leftover brick cramp the wood to the brick you are trying to lay

[cobblerdave]

Re: Budget Build 36"

Gudday Bevan
It's looking pretty good from the photos. Leave the arch form for a week if possible . You ripping ahead compared to most builds so a little wait is alright.
One thing you might try on the oven entrance is to clear the mortar off with a bucket of water and sponge. You'll find it impossible to remove when dry.
Again great progress
Regards dave

[Laspaz]

Re: Budget Build 36"

I am scared to post photos of my recent progress. I'm just after an oven to cook some pizza's well, so it's not pretty!







Gravity is starting to be a real PITA with keeping the bricks in place, so I think it is time to retire the IT and seek out a swiss exercise ball to finish the dome off.

When am I able to remove the arch form? Should be fine tomorrow right?

Cheers,

Bevan

[Laspaz]

Re: Budget Build 36"

Are your pavers concrete? If so I see a problem.

Nope, clay pavers fired to 1200c. They should be fine. There was a run down on them and the other options a few pages back.

Bevan

[mrchipster]

Re: Budget Build 36"

Are your pavers concrete? If so I see a problem.

Sorry, did not see conversation on clay in prior posts....

[Laspaz]

Re: Budget Build 36"

This is where my build takes a different path from most of you guys.

I have begun building the dome, but not using any cuts. And because I am using pavers with a rounded top edge the mortar joints look bigger than I hoped.

I also decided to make some changes based on info I have found on the fourm, such as more sand in my poor man's mortar and not wetting the bricks.

I would like to shorten my IT at some point soon to start bringing the dome closer in. This is because the pivot point of the tool is higher and if I don't bring it in I will end up with a 19" high dome. Better to do it a couple of times to make the transition smoother and earlier right?

If these are mistakes please let me know!




Cheers,

Bevan