The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Semi Commercial WFO in Progress

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sgregory's picture
sgregory

Semi Commercial WFO in Progress

After over a year in the design and contemplation, I finally bit the bullet and started construction of my WFO.  Based on Davenport's designs from TurtleRockHeat, I scaled it to fit my operation.  William was busy at the time with larger projects, but gave some insight on my rendition of his work.  Working hearth is 46" x 60" with 19" vault.  Wall thickness is 9" minimum of Firebrick.  I started the project Aug4,2012 and hope to have it baking bread by Thanksgiving. 

The idea is that it is small enough not to be a huge cash outlay, but big enough to learn and enter into a small commercial operation if the product takes off.  I certainly would upscale to a different location if it does so as to keep work and home seperate.  The oven is located in a shed on my property with enough space that a small bakery could be set up with required code equipment and facilities with minimal effort.  Enjoy the photo's that are to come.

 

sgregory's picture
sgregory

Here is more progress:

sgregory's picture
sgregory

And Some More Photo's

Faith in Virginia's picture
Faith in Virginia

Got a few questions.  What did you use for insulation under your floor?  Looks like you formed something up.  Also are you planning to add more butressing for your arch?

 

Questions, questions, questions.  sorry about that.   I have plans for a simular oven in the spring.

sgregory's picture
sgregory

The insulation layer is Noxcast 32 and pearlite.  Not poured yet is a lentil which will form the oven flue and oven front opening.  It will be Noxcast32, SS needles an reinforced with steel durawall trusses.  Yes there will be a frame or "harness" around the skews to compress the arch.  The Lintel needs to be installed first so that the tie rods can fit into it to keep the face flush.   It will have flaps for doors which will fit into the front facing on a frame.

Faith in Virginia's picture
Faith in Virginia

I am interested in the flap door as well but have not done any research on that aspect yet.  Are you going to make your own door or have it fabricated?  If you have any drawings of the door workings I would be quite interested.

What part of the world do you live in I would love to see your oven?

I already have my brick for my oven in fact I'm planing to have twins. ;-)  I have about 2,300 #1 wedge that measure 6x9 and a half pallet of #3 arch.  Now I just need the time to build them.

On my 42 inch Pomeii I used vermiculite/portland for the insulation layer under the floor.  My next oven I plan on using a combo of the vermiculite/portland and the insulation board.

Such a nice job on your oven...you will have something to be proud of.

 

sgregory's picture
sgregory

I Designed a flap door that easily lifts out and can be removed for firing.  Will probably have it fabricated at the local weld shop.   Same with the flue damper.  When I flesh out the details and have a working prototype I would be happy to share with you.

I thought of using portland in the insulating layer but my concern was that it would get too hot.  Would be alot cheaper!!!.  The Noxcast was a little stronger and won't degrade.  I figured that it would be seeing 500+ degrees potentially if used in a more continuous mode.

Live about an hour south of Buffalo, NY.

frenchcreek baker's picture
frenchcreek baker

Hi,

Thanks for sharing the details of your oven construction. Your photos are a welcome addition too and I am looking forward to following your progress.

As far as total cost, what do you project will be the final dollar amount for your investment?

I appreciate your in-depth knowledge. I have a dream to own an oven like yours. Would it be possible to get a copy of your plans? I am so impressed by your attention to details and research. I hope you have many happy years of baking in your oven ahead!

 

Cheers,

Anne

Faith in Virginia's picture
Faith in Virginia

I'm not familiar with Noxcast 32 I tried to look it up but could not find in on a google search.

I have not had any problems with my portland/vermiculite mix and I have had it get quite hot.  But like you said it could be a worry and that is why I will do a combo and put the insulation board on top of the portland/vermiculite mix.

South of Buffalo...bummer I would have loved to see the real thing but you are not in my typical travel routes.  I look forward to more pictures and your thoughts on that flap door.

Faith

sgregory's picture
sgregory

Nock and Son Refractories.  High Cement material.  3200 service temp.  Overkill but has the strength with a 2% SS needle addition and some steel work to not break.  Any high cement 50-60%alumina material would be good.

I will post what drawings I can.  Even though I drew and designed mine I would like to ask William Davenport for his blessing since he helped me and gave me insight to his designs and experiences.  The pictures are pretty easy to reverse engineer from though.

I figure about $2500 since I bought the fire brick at scrap cost.

sgregory's picture
sgregory

Here is a photo sequence showing the front beam and/or lentil.  You can see the flue and a channel for the compression rods of the vault harness.  Tomnorrow I will pull the forms and with any luck it will be right...

Again the castable is Nock and Son   NoxCast 32 with 2% Stailess needles and #4 rebar supported with durawall 10". 

To get and idea of dimension, the beam is 9"x64"x12".  The flue is 16" at top and 34" at bottom.

Faith in Virginia's picture
Faith in Virginia

Me thinks you will need the help of that good looking young man in the previous photos to help you get that in place.

Very impressed with your work.  Your not far from curing fires. Good luck with the fit.

Faith

sgregory's picture
sgregory

And the beam is free from is bounds.  Very pleased with it.  Material casts very well with no voids.  Will try to set it today once I do a clean-up.  The mess of building is a little out of control right now.

And yes my partner in crime has been essential in speed of construction.  He has an interest in it so who knows.

Faith in Virginia's picture
Faith in Virginia

Guessing that should weigh about 600 lbs.  Let me know how the lift goes.

sgregory's picture
sgregory

Beam weighs in around 650 lbs or so.  Lift went well using my tractor.  Need to get another bucket of mortar and it will be set permanently. 

A little tweeking, some mortar, insulwool and it will be set.  Thats for another day though.

sgregory's picture
sgregory

A Little update.  Beam is now set permanently and the refractory flue constructed.  I-Beams for harness completed and waiting for the tie rods to be threaded.  Hopefully have them tomorrow late morning and installed so as to remove the vault forms.  My friend is coming over tonight to measure for the stove pipe and roof penetration.  I will probably have him make the damper as well.  Enjoy the photos detailing the exhaust flue.  FYI it will be 8" diameter.

Faith in Virginia's picture
Faith in Virginia

Great pictures.  The size of your oven makes the flue look small.  You will be the first to know if it needs to be larger.  With curing fires you will get lots of smoke and will most likely come out the front.  That is pretty normal.  But once you are fully cured if you still have smoke out the door you can always make adjustments at that time.  Such a cool oven.

sgregory's picture
sgregory

Faith in Virginia, you are right in that the flue looks small in the photo's.  I think because there is a form holding the castable.  I guess I will find out soon enough as you said.  I based it off of some larger ovens and they had 8" so I hope my reverse engineering was correct. 

Received the tie-rods today so installed the harness.  Worked like a champ.  The vault forms are removed and it is now free standing.  A little clean up and it should be ready for fire.  The exhaust duct ( 8") comes Thursday.  I hope to have it installed by this weekend.   Then it is the other necesary work such as a face, sides, doors, and insulation.

sgregory's picture
sgregory

Had to try it for a few minutes.  Opened the doors on the shed and put a fan in.  Worked long enough to get the photo and claim success for the day!

Now for a shower to get the smoke smell out  ;-)

Faith in Virginia's picture
Faith in Virginia

Congratulations that is always a great feeling after hours of hard labor.   Kind of like when Dr. Frankenstein  hits his monster with that lightning....It's alive!!!

sgregory's picture
sgregory

This is the fourth curing fire.  Still pretty small and short in duration but enough that when I pushed the fire back I thought why not try to cook something!.   Nothing fancy, we ate toasted cheesy tortilla's.  took about a minute and it was done.   It would have cooked a pizza if I had some dough.  Will try that tomorrow. 

The oven is finally getting a little heat in it.  Not hot, just slightly warm to the touch on the outside.  I figure that by Saturday I will be in a good position to fire it pretty hard.  Possibly try to bake something once the damper gets in from the shop Saturday.  Duct is in and while not smoke free it is pretty good.

 

MangoChutney's picture
MangoChutney

What an amazing construction, and the fire is lovely.  How does one keep an oven like that fed with wood?

sgregory's picture
sgregory

Live in an area where wood is plentiful.  In particular slabs of off mills, clean hardwood pallets, culls and tops from lumbering operations.  Most of that is free or of minimal cost.  Premium firewood is also pretty inexpensive and can be used without cost prohibitive consequences.   What will be interesting is how much is required to get to temp, and how many bakes I get out of a firing. 

MangoChutney's picture
MangoChutney

I thought the burning wood in the pictures looked like scrap lumber.  I thought to myself that virtually no one has enough construction waste on their lot to feed such a behomoth for very long, but if you have the "waste" stream from a lumber mill to tap then you are set.

Many happy bakes to you.  *smile*

sgregory's picture
sgregory

There is some scrap lumber in the picture.  And your right, especially today there is very little scrap lumber available. 

sgregory's picture
sgregory

The was oven heated well today so I made some make shift doors and cooked pizza and bread.  I obviously rushed the dough a little but had great success for a first time.   I have no idea what the temps were as I havn't hooked up the thermocouple yet.  Enjoy the pizza and bread.  Talk about oven spring,...... wow!.

Hope you don't mind all the pictures,  I think they are worth a 1000 of my words ;-)

sgregory's picture
sgregory

A little Updating.

Here is the damper I had a friend make.  Sliding type designed to fit into brick flue and then transition to 8" Class Duct.  As you can see from the second photo it does the quite well.  For scale, the outside diameter of the Class A duct is 11 inches.

 

In the third photo you can see it fired up with outer skin on and with a insert I made for the opening.  The draft seems sufficient, however, there is an error in my design that allow smoke to escape on the edges.  The flue doesn't go wall to wall on the bottom of the beam.  A little chisel work at some point should take care of it but for now this temp fix is very effective.  I am waiting on some more thermocouple wire to arrive to be able to insulate the oven.  I plan on using vermiculate since I can get it pretty easily.

sgregory's picture
sgregory

The learning curve is steep!   I am starting to have some success now as I continue to work with the oven.  The key is in the timing ;-).  Based on my data, I am going to add another layer of brick to the vault and then insulate.  This will even out the energy storage top and bottom.  Probably will get 5-6 solid hearth bread loads out without too much issue by doing this.  I can get 3-4 out now and the temp in vault mass at the mid thickness point is only 320F!.  

Here are some of the better results to date.  Little tweeking to do as far as soak times and ultimate bake temps but starting to dial it in.

Now I need to go run 15 miles to burn off the calories!!!  Seriously.

MANNA's picture
MANNA

Everything looks great. Sorry, I havent contacted you yet. I havent been out your way. Question, how much money have you invested into this so far?

grind's picture
grind

That's some oven and great bread and pizza too.  Congrats.  Are you a bricklayer, or something?  I ask 'cause you make it look easier then it probably really is.

sgregory's picture
sgregory

As far as investment the oven is around 3,000.  That includes chimmney, insulation, and everything except the face brick.  Still havn't found the right stuff at a good enough price.  As far as the surrounding modifications to the barn, I havn't added it up yet.  Afraid to. 

No I am not a bricklayer by trade, however, I have some experience in refractory.  It isn't hard, just takes time and the desire not to rush it.  Helps to rent a good brick saw! 

Scott

JoshuaFinancial's picture
JoshuaFinancial

Wow, Scott that's really some accomplishment.   If only I had a place to put it, and if only our county health department wouldn't deffecate blue thunder, I'd pay you $6,000 without hesitation.     

sgregory's picture
sgregory

Your county health department sounds like mine.  You live close?

JoshuaFinancial's picture
JoshuaFinancial

Nah, Philly.  I suspect that all HDs share a personality profile.  

DebbieR's picture
DebbieR

I just found this thread----I Greatly enjoyed your pics of your new oven (and the amazing goodies that were baked in it!!)!!!  You're very talented! 

 

lumos's picture
lumos

Great record of your great project...and the beginning of your new journey.  Thank you for sharing.  It's really uplifting.

jackieosjunebug's picture
jackieosjunebug

Really great work. I hope to do similar some day.

sgregory's picture
sgregory

Well, it is finally warm enough for me to venture out to the barn and bakery.  Lit a fire a couple of days ago, and then started baking.  My good friend and I had some oustanding pizza for lunch today after our run.  First bread loafs are out as well and just as good

primer7's picture
primer7

Frick'n Awesome!

SylviaH's picture
SylviaH

pizza boxes today : ) just like you have for your fantastic looking pizza.  The shipping cost me way more than the boxes but they sure come in handy.  Now I just need a stamp.  Neighbors love getting a pizza and a box makes it sooo much easier for my pizza's to go.

Sylvia

carblicious's picture
carblicious

Simply impressive.  Incredibly jealous of your WFO.  The breads and pizzas look great.  You do need a custom logo/stamp for your pizza boxes.