Experimental Norse-Kiwi Hybrid Oven!

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

G'day Zoe
My intention is not to use Stablesprings oven as an example.
My oven has a huge chimney and has to have the chimney cleaned from time to time of soot and creosote.
My oven entrance is 18 ins wide and the chimney is 20 in X 4 ins, and has to be due to not having an arch entrance. Its plenty to draw the smoke in, no smoke stains on the front but it still needs cleaning.
Because it a square sided chimney the smoke basically goes up middle in a round path and the corners particularly are a dead spot where the smoke tends move slowly and drop its deposits.
Having say a 6 in square chimney means that the smoke really only passes up a 6 in circle in the middle so its only as efficient as a 6 in round chimney.
Making your smoke entrance above your entrance at least 3/4 of the width of your arched oven entry is most important to funnel the smoke.
Of course smoothing the brick is an improvement but width and depth of that smoke vent and the size of you chimney is more important
Regards dave

[SevenAcre]

Re: Experimental Norse-Kiwi Hybrid Oven!

I have attached a picture to hopefully clarify my concerns. I'm not trying to throw a wrench into your clockwork. I've enjoyed the build and believe you are doing a great job. It's probably nothing to even worry about, and when you get the oven way up to temp everything's going to burn off anyway.
-j

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hey Guys!
Thanks so much for your input. OK, I removed the form (and the arch stayed up!) and can definitely see areas where I can improve the smoothness of the transition, possibly with my trusty mate The Grinder. I guess any improvements I can make will be worth the effort.
I could also cut some wedge bricks and fix them to the inside of the arch to smooth out the transition, but this would have to be done a la dentist, with the mirror as my guide. Now would be the time to do it, since I can still get some access into the interior.
Dave, I plan to take the funnel up immediately from the first bricks on the side, so there should be a nice wide intake. The flu is 200mm width. I'm not sure if that's enough, but it has to be that if I am going to use the top of the Jotul stove, which I'm keen to do.
I'll go and ponder.

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

G'day wildflower
I'm sure that funnel is big enough, taking up most of the joul oven.
What size is the attached chimney by the way.
Regards dave

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hey Dave,
The attached chimney is going to be 200mm across.
Cheers,
Zoe.

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Annie!!!
You're back! So great to see you here...and as you can see things have been...developing?
Hope all well.
Zoe.

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hey Dave,
The attached chimney is going to be 200mm across.
Cheers,
Zoe.

G'day Zoe
8 ins that will do nicely, it will suck the Crome of of a "56" Chev.
Regards dave

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hehe, I know, power tools are so WILD!
Anyway, here I am after another tousle with the grinder. I've managed to cut four wedge shaped bricks that will create a vertical ride up from the opening to the flu outlet. Here's hoping I'll get the chance to mortar them in place tomorrow, then I can sigh a huge sigh of relief!
So, Annie, are you going to be building again?

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

OK, so I think I may be done with THE BEAST (the angle grinder, not the oven!).
I got in there and bevelled that pesky entrance arch brick so that - hopefully - the smoke/soot/creosote build-up is lessened. The other side I had already done, so just smoothed it off a bit.

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

The end is in sight! Yesterday I mortared in the other arch and vent wedgie bricks. Now I just have to build up the vent so it meets the top plate of the Jotul and the masonry is done.

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

G'day Zoe
That looking great! Well done.
Taking about looks. You were talking about insulating the jowl oven before.
I recon it looks great. Why don't you leave off insulation and rendering it over till after you have used the oven. Just see how it works first before you commit to covering it over.
Just a thought
Regards dave

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hey Dave,
Thanks!
I think that's good idea, to wait to see how it looks/works before covering and rendering the Jotul part of the oven. I guess I had hoped to use the entrance area as part of the baking zone when I had closed the door and turned the damper in the chimney, so wanted it to be able to retain heat. However, it is looking more and more like an entrance area, so yes, might just leave it uncovered.
I was wondering what I could use to clean up the white limey stuff left on the stove? I've washed it with water, and it looks like its gone, but then reappears when it dries. Is vinegar the thing to use?
Cheers,
Zoe.

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

G'day
It will work on a light haze of lime but if it doesn't don't use anything stronger the heat will remove it later.
Regards Dave

[Wildflower]

Re: Experimental Norse-Kiwi Hybrid Oven!

Hello after a break of a few weeks (family trip around the South Island!).
I came home and lit the oven....almost an emotional moment I did one very cautious fire followed by a second not-very cautious fire...and cracks appeared! Two 1mm wide cracks that run the length of the oven vault...not visible on the inside of the oven...or maybe they are, but it's so black in there I can't see them!
I think I might've gone a bit gung-ho, but I've read that lots of people have cracks no matter how carefully they've approached their curing fires. Anyway, I cranked the oven up today with it's new hat on...the chimney with damper insert is all go. The oven drew really well, and the smoke at the start gave way to nothing much when the fire was going well. I'm not sure where to go from here...should I really get it "like the fires of hell!" next, or should I do another medium fire?
I haven't got an infra-red thermometer so I have no idea how hot it's got. The outside of the oven was very warm to touch (on the roof) at the peak of today's firing.
Hope all going well with you, and of course any advice is welcome as usual!
Cheers,
Zoe.

[cobblerdave]

Re: Experimental Norse-Kiwi Hybrid Oven!

G'day Zoe
Oven looks great with the new chimney. Certainly suits it.
Keep the fires the same size you'll find that the temperature with jump as it dries. Even without a thermometer you'll know when you hit that sweet spot.
It seems that insulated ovens suffer less cracking than bare , but who knows perhaps they are just hidden
Regards dave I