Chch NZ build

[John French]

Re: Chch NZ build

Hi
Good luck with your project you will enjoy. I found that NZ is a more expensive place to build compared to US and Aus and these escalated as i worked through each stage. Hopefully the final working oven will prove worth this but i am not there yet! Certainly the time aspect is huge.
To answer your question i have used the 'homebrew' mixture throughout as outlined by previous posters - sand / portland cement / fireclay / hydrated lime in 3:1:1:1 ratio. It was easy to use especially once i got used to its consistency and application. I have not yet cured the oven by firing so i cant comment on it performance yet.

[John French]

Re: Chch NZ build

Cut the bricks for the flue shoe and mortared them in place. Doing this in a howling Norwester ( a hot wind that blows of the southern alps across the Canterbury plain ) made it a bit tricky in terms of my balance and the homebrew drying out too quickly.
I allowed for a good expansion gap which i will fill with insulation / vermicrete when the flue is inserted. For once the tile saws circular blade was useful in helping to shape the necessary internal arcs.

[John French]

Re: Chch NZ build

Cleaned up the inside of the oven. Good to see the herringbone floor again although with the protective layer removed it was apparent that some mortar had slipped down behind the wooden framing securing the I tool. The mortar was really firm and took a fair bit of persuasion to remove.
Decided to start the heat curing process - used a gas burner to help control the temperatures. Took it up to 120 C max ( at the top of the dome ) and then let it cool down. The vent seemed to perform well with hot air being released from the chimney and not the front opening. Cooled down at about 1 deg C per minute.
Hopefully the new year will see an opportunity to use the oven in ernest!

[John French]

Re: Chch NZ build

Tried to start a small wood fire but it was difficult to start and when it did catch is was very smokey. So much so the neighbours were out looking for the fire! So abandoned that venture. Used some charcoal brickets ( coconut shells source ) and a hot air gun to get a more acceptable heat source. Got upto to 80 C inside and after 6 hours the external dome temperature reached 38 C. A nice slow heat release which should be compatible with the curing process.
My really big concern is the smoke - there is no way i can produce anything like this mornings pollution in our urban situation. I really hope i have not constructed something i can never use!
Brickie in Oz i note you have suggested charcoal as an alternative - how much is needed to get up to pizza temperatures?

Also had some major aftershocks today including a 4.9 - really scary!!

[brickie in oz]

Re: Chch NZ build

Brickie in Oz i note you have suggested charcoal as an alternative - how much is needed to get up to pizza temperatures?

I use the heat gun on timber too and it reduces the smoke to almost zero.

As for charcoal a couple of 5 kg bags gets the oven hot enough, at $15 per bag it can get expensive.

Try the heat gun on the timber first, set it to high and have the door slightly ajar, aim it at the base of the fire, the heat gun will melt over time.

Also had some major aftershocks today including a 4.9 - really scary!!

It must have been some fire ...

[Lburou]

Re: Chch NZ build

Cut the bricks for the flue shoe and mortared them in place. Doing this in a howling Norwester ( a hot wind that blows of the southern alps across the Canterbury plain ) made it a bit tricky in terms of my balance and the homebrew drying out too quickly.
I allowed for a good expansion gap which i will fill with insulation / vermicrete when the flue is inserted. For once the tile saws circular blade was useful in helping to shape the necessary internal arcs.

The news reported an earthquake in Cristchurch, yesterday I think....Was it near you? I hope you are OK and that there is minimal negative affect on you and your neighbors

[wemme]

Re: Chch NZ build

Hey john its looking good. Could you use a LPG burner instead? may make drying easier. BBQ factory near bunnings tower junction had some a year or two ago. Anyway nice work and well done. Any damage in the quake?

-Edit- Never mind i see your using a burner must have missed that post

[John French]

Re: Chch NZ build

The news reported an earthquake in Cristchurch, yesterday I think....Was it near you? I hope you are OK and that there is minimal negative affect on you and your neighbors

Yes the quakes were close. the two biggest 4.9 and 4.2 within 5 miles and pretty shallow. Pretty scaring but no major damage to house or oven. In town some of the older and already weaken buildings suffered. A few streets and shops closed off but relatively minor problems - most damge is to the psyche of people.

[Neil2]

Re: Chch NZ build

"Tried to start a small wood fire but it was difficult to start and when it did catch is was very smokey."

I think in the long run you will be happier if you can make your oven work using firewood alone.

Well seasoned wood will reduce (but not eliminate) the large amount of smoke you get when you first light the fire. I suggest you talk with your neighbors, and have them over occasionally for pizza. The smoke will be produced in large volumes only for the first 1/2 hour or so. Most reasonable people won't object to this if it is explained to them.

[Lburou]

Re: Chch NZ build

Yes the quakes were close. the two biggest 4.9 and 4.2 within 5 miles and pretty shallow. Pretty scaring but no major damage to house or oven. In town some of the older and already weaken buildings suffered. A few streets and shops closed off but relatively minor problems - most damge is to the psyche of people.

I'm thankful for your news. We live on a geologically active planet.

I was surprised to learn that I lived 100 yards from a fairly inactive fault line at the foot of the Rocky Mountains in Colorado, USA. It is unsettling to say the least.

[John French]

Re: Chch NZ build

Took the advice offered and tried a small wood fire. Bought some dried kindling. Two twisted pieces of paper and 8 kindling. Pre heated the kindling with the hot air gun, lit and away it went. Kept the gun on the fire to maintain the high heat. The smoke was much lower. Still a few wisps but i felt a bit more comfortable especially as the neighbours are away. Temperatures went up to 200 C - so i need to up the ante shortly once my confidence increases.

[brickie in oz]

Re: Chch NZ build

Thats the way, I almost invariably use the heat gun if the timber is wettish.

I sometimes have it going for 30 minutes or more thats why its all melted and twisted, but for $20 it dont really matter....

[C5dad]

Re: Chch NZ build

What model of heat gun are you using?

[John French]

Re: Chch NZ build

What model of heat gun are you using?

I had an old paint stripper. Electric made by Black and Decker. May well be better devices available now but like i say i happened to have this to hand.

[brickie in oz]

Re: Chch NZ build

I think it used to be a Ryobi, you can get cheap ones from Bunnies for about $20 now.