Chip's 42 in Minnesota

[mrchipster]

Re: Chip's 42 in Minnesota

I have been working on curing my oven for the last two weeks.

The curing is going well I've had to repair some cracks and have used and oscillating multi tool to grind out the mortar with a diamond curved blade. This worked much better than the 4 inch angle grinder because I could grind in at a right angle easily with the flat edge.

The thing I am most happy is the heat retention I had a fire on Friday night where we cooked up some salmon filets. And the next morning the oven was still 580?. It is now Tuesday morning and the oven is 200? since then. I cooked a turkey bread and rolls and two other dinners since then. And I have not added any fire.

The insulation was 2 inches of ceramic blanket on the sides an three on top with some perlite on the sides, so not ideally insulated but good.

Last night I added another 20 cu ft of perlite and put on the roof sheathing.

With the exception of an insulated door I am now fully insulated.

I am still experiencing heat through the floor slab and am seeing the wood box ceiling reaching 120 degrees. I guess the vermicrete is still a little wet.

I have 2.5 inches of vermicrete 7:1 and 2 inches of FB board in the floor.

Chip

[mrchipster]

Re: Chip's 42 in Minnesota

Hi Chip, I've been looking for more brick oven owners in Minnesota. I live in Glenwood and just completed my first oven a month ago. Still working on the finishing touches, but I have been using it.

You are quite a ways out, I am in Crystal.

Made a dome clearing fire tonight. The one crack that I have on the outside (zig zags from chain 4 to chain 9) I now can see from the inside. I will let the oven cool down and go in and fix it in a couple of days.

Outside crack fixes seem to be holding, I used caulk tube refractory mortar.

Ground out the cracks with my 4 inch angle grinder and filled with mortar. seems to be working.

Chip

[GianniFocaccia]

Re: Chip's 42 in Minnesota

I did leave about 1/8 inch on the side for expansion. I did not know how the metal would react to the heat

Thanks for the tips. I'm clueless regarding metal expansion rates and will probably err on the side of caution. My thoughts right now are to leave the firebrick underneath the stainless for two reasons: 1) the stored heat will provide a better warming/staging area for food 2) the stored heat should aid the oven in staying hotter longer. My entryway bricks (like yours) will have to have at least minimal contact and since conductive heat transfer rate is based partly on the variance of the two sides swapping heat, a hotter entryway should wick less heat from the oven than a colder entryway would. At least that's the way I think it works.

MCSE?

John

[Grozio]

Re: Chip's 42 in Minnesota

Hi Chip, I've been looking for more brick oven owners in Minnesota. I live in Glenwood and just completed my first oven a month ago. Still working on the finishing touches, but I have been using it.

[mrchipster]

Re: Chip's 42 in Minnesota

Chip,
So how's the stainless entryway working out? I am planning on doing the same thing, and wondered what thickness you went with. Also, with insulation underneath the SS, does it not retain heat like the brick entryway? I was thinking of going with firebrick underneath, but that's a sure thing.

John

John,

Seems to be working fine, gets a little warm, not hot at all, near the oven and I may reduce the contact at the oven a little by removing even more of the flange. But it cleans up like a dream as expected. Because it is not hot nothing seems to stick.

It gets a little ash dust on it from wind blowing into the oven when the door is off so it does not look like a mirror all the time.

Had a little water come down the flue - horizontal rain storm. The water drops hit the stainless with black gunk in them and it cleaned right up. No problem with water on stainless

Gauge is 22 or .030 inch thick 304 SS

I do have fire brick at the decorative arch end, one row - 2 whole and one half brick. I did leave about 1/8 inch on the side for expansion. I did not know how the metal would react to the heat.

I think I would go a little thicker if you have the option because I think over time this thickness might dent but the price was right for this piece I traded it for an hour of consulting on a computer network issue.
Chip

[GianniFocaccia]

Re: Chip's 42 in Minnesota

Chip,
So how's the stainless entryway working out? I am planning on doing the same thing, and wondered what thickness you went with. Also, with insulation underneath the SS, does it not retain heat like the brick entryway? I was thinking of going with firebrick underneath, but that's a sure thing.

John

[mrchipster]

Re: Chip's 42 in Minnesota

Nice work chip! Is that with a door aswell?

Temp door on. Just a piece of 1/2 inch plywood with a stainless back to keep it from burning. Can be seen in prior posts.

Chip

[chidding]

Re: Chip's 42 in Minnesota

Nice work chip! Is that with a door aswell?

[mrchipster]

Re: Chip's 42 in Minnesota

Checked oven this morning and after 42 degrees F overnight with significant wind the internal oven temp was still 220. Minimal insulation, just 1 inch of FB blanket loosely covering the dome.

Used the Cuban Rolls for French toast this morning.

VERY HAPPY with the heat retention.

Chip

[mrchipster]

Re: Chip's 42 in Minnesota

Still curing oven but have started to experience some hairline cracks on the outside of the oven, I cannot see them on the inside. All are along joint lines so not sure if there is a serious problem here. I covered the oven in FB blanket to hold in some of the heat and only one location is displaying any smoke stain on the insulation. I will continue with the cure and see what happens I think I will need to do some minor grinding and filling at the leak areas.

Cooked up a beer can chicken, small red potatoes and some Cuban rolls for dinner all done in the oven. Chicken got real dark but was tasty and juicy inside. I had a smoldering Maple coal pile in the oven with the door on most of the time while the chicken was cooking and it got a real infusion of smoke. YUMM....

Raked out the coals and put in the rolls, still need more experience with bread as the bottoms were more done than the tops, but still turned out nice.

Chip

[mrchipster]

Re: Chip's 42 in Minnesota

Thought I would add a detail of my door and ring i am using for my curing fires.

Ring is the outer connector ring for my stainless flue sections it is about 7 inches tall and 12 inches in diameter, I did not put the bolts is so I could use a blow tube to reignite the coals should the flame go out.

The ring allows me to control the location of the fire I can drag the fire anywhere in the oven and move it regularly about every 15 seconds while the fire is blazing. Trying to distribute the heat around the dome.

The door is a piece of 1/2 inch plywood with a piece of bent stainless attached. There is a fiberglass stove sealing rope attached to the wood and a small wood handle. As you can clearly see my cure fires are using pine, Building up quite a layer of soot.

Chip

[mrchipster]

Re: Chip's 42 in Minnesota

Worked on cure fires today and Stainless entry floor and sealing door.

Stainless lays over vermicrete with 2 and a half bricks at the outside edge just in case it gets wet out there sometime. Stainless folds down 1/2 inch at the oven opening for minimal contact and I may reduce that to 1/4 inch, The sides fold down an inch and the outside edge folds down 2 inches.

This stainless entry floor is a trial balloon and if it works out great if not I will change it to traditional brick or soapstone.

Still going slow temp in dome reached 420 today. The dome is coming up in temp very quickly now and I decided to build a sealed door. No insulation but a glass rope seal and a stainless inside with a small handle. Not fancy but it puts the fire out real quick.

Final door will be insulated and much better built.

*** Help needed ***

Getting a few wiffs of smoke out the front when the wind blows but as you can see from the smoke pattern not much comes out the front. I have a 10 inch I.D. - 12 O.D. double wall Stainless Flue. and my thermal break between the inner arch and the flue arch smokes a little into the oven cavity. I think I will need to do some sort of sealing there.

Does anyone have any ideas as to what I can put there the gap was intended to be direct contact but at some points is less than 1/16 of an inch wide and a little irregular as there are spots where the mortar filled in the gap. It does not smoke when the flue is exhausting just when the door is closed forcing smoke directly into the gap area.

The temporary door is not build well and is leaking some air -- thus smoke.

BTW I love the 8 inch round tool for playing with the fire.

Chip

[mrchipster]

Re: Chip's 42 in Minnesota

Little more work done on the prep table wing. I am building a brick pillar to support the end of one wing of the roof; A single piece of re-bar down the center of the pillar. It started to rain so work is halted for the day.

Still doing curing fires. No cracks yet but there is still time.

Chip

[Aegis]

Re: Chip's 42 in Minnesota

I am not real worried about the floor as I have gone through a cure cycle of the floor already (second build of dome) and I believe it is quite dry. Did a couple of small fires today and the temp came up faster - it must be starting to dry out. moved the fire around in the stainless ring and kept checking temps, when the temp dome temp would get over 200 I would rake out the coals across the floor and let it sit. Outside of dome is getting to about 115 near the top so things are coming along.

Thanks for the complement, I just re-read your post and might consider putting more mass in my dome. You are getting great heat retention results.

Not sure if I want to stop curing and adding more water though. and restart the cure cycle. Winter is near even though it is 82 today.

Chip

I understand the winter thing coming sooner than we'd like. I am trying to close up the roof before snow flies! lol The extra mass is only worth it for baking bread and extending the cooking time a bit. Insulation, insulation, insulation cannot be stressed enough! Every penny I spent on insulation and or had been graciously given to me was well worth every cent!
Extra mass on top of the dome would not make you re-cure, but to cure longer. The bigger time set back is waiting for the mortar to harden. I waited 10 days before re-firing. I did it that soon, because the mortar/mass is not structual at all. So strength of mortar was not a big factor.
I am sure you were glad for the 80 degree day in Oct.
Good Luck!
John

[mrchipster]

Re: Chip's 42 in Minnesota

The hearth could probably stand a lot higher temps than the dome. No mortar in the hearth and nothing to crack in the hearth. The dome on the other hand still has lots of moisture unless you were working at my snails pace. lol I still got a monster crack, but I know it was from leaving, forgetting, and having pieces of firebrick in my expansion joint around the edges. You are wise to go slow and easy, it takes a lot less time to do a long cure once than to patch cracks and re-cure!
btw- great looking build!

I am not real worried about the floor as I have gone through a cure cycle of the floor already (second build of dome) and I believe it is quite dry. Did a couple of small fires today and the temp came up faster - it must be starting to dry out. moved the fire around in the stainless ring and kept checking temps, when the temp dome temp would get over 200 I would rake out the coals across the floor and let it sit. Outside of dome is getting to about 115 near the top so things are coming along.

Thanks for the complement, I just re-read your post and might consider putting more mass in my dome. You are getting great heat retention results.

Not sure if I want to stop curing and adding more water though. and restart the cure cycle. Winter is near even though it is 82 today.

Chip