Matt's WFO Build

[ThisOldGarageNJ]

Re: Matt's WFO Build

Sounds like your doing okay.... do you mean the lower part of the dome isnt getting hot ??

Mark

[mluttropp]

Re: Matt's WFO Build

Sorry for all the typos and strange spelling errors. I have been using my iPhone to post updates and sometimes my fingers don't quite hit the keys correctly.

Mark, the lower third of the dome does get hot. It just does not get as hot as the top of the dome. I still have not insulated the dome and after a four hour propane burn the inside top of the dome was a bit over 550 degrees. However the floor and the lower 1/3 of the done were at 350 degrees. This us not all that surprising as hot air rises.

I am going to try to undulate the dome this weekend and get the temps up to 600 degrees or so.

I have a few cracks in the dome but they are still small and do not appear to go allbyhe way through.

Those of you that used the propane technique when did you go all out and get the dome up ti 800 or more degrees?

[david s]

Re: Matt's WFO Build

When I do mine the burner takes the oven to 250C in 24 Hrs but it all depends on the oven size and the burner capacity. Problems in pottery kilns with moisture cracks typically occur at around 300C and I guess it would be the same with our ovens (sorry you Neanderthals will have to convert to the ancient F) The bottom of the dome takes ages to get hot and if you start using wood you'll notice that a ring of black soot around the bottom takes a long time to go white. Take it slow the energy of the wood is being used to convert that moisture to steam.

[mluttropp]

Re: Matt's WFO Build

Thank you for the advice David. I will definately takevit slow.

This weekend I concentrated on getting the insulation on and starting the enclosure framing. Having never worked with metal studs I was amazed at howveasy they are tobwork with. The best part is that I could start early in the morning without waking everyone as you don't needvto use a loud saw.

as I framed things up I was reminded that nothing in my build is square or even centered. This is not to obvious at this point but I suspect the roof is going to be a challenge to get it to look right.

I will try to post pictures next weekend.

[mfiore]

Re: Matt's WFO Build

... I was reminded that nothing in my build is square or even centered.

Square and centered are overrated! (as are plumb, level, and symmetric)

[jmhepworth]

Re: Matt's WFO Build

Nothing on my oven is square, plumb, level or round. But it cooks pretty good.

[mluttropp]

Re: Matt's WFO Build

A lot has happened since my last post.

Before I started to frame the enclosure I placed 2 inches of insulation over the dome. The stuff is fairly easy to work with. A bit like normal fiberglass insulation but a lot easier to cut. If the effects on bare skin are any indication of what it will do to your lungs I would strongly suggest a mask when working with this stuff. In general the material does not move around all that much, but to really keep things in place over the long term I strapped it all down with metal strapping material. The ends are anchored to the hearth with concrete screws. A little trick with these is if the screw does not hold all that well brush a little of the concrete dust in the hole as you put the screw in, worked every time for me.

Framing the enclosure was a lot easier than I thought it would be. Those metal studs are fantastic to work with. After the first few cuts I decided that I would wear the gloves as it was getting annoying having to put band aids on all the time. In order to make the roof trusses all the same I made a quick and dirty jig that allowed me to crank all of them out in about an hour. After most of the framing was in place I was still not happy with the rigidity of the structure and it was a little out of plumb and a bit racked. To fix this I put in an angle brace in each of the corners that allowed me to tweak the structure back into plumb and true.

Next I put the roof sheathing on and trimmed out the rafters. Considering I have never done this sort of thing I thought it turned out rather well.

I have continued to use the propane burner to heat the oven up and keep it hot for 4 or 5 hours at a time. When I put the insulation on I was amazed at how well it worked and shocked by the steam that I saw escaping between a gap in the insulation. Fortunately after a couple of fires the steam appears to have stopped and the oven moves to higher temperatures much easier now. I decided to light a couple of good sized wood fires as the pyromaniac in me just could not wait any longer. Everything worked well, no significant cracks and I even got the top of the dome to turn white.

There are now too many pictures to post one at a time so check out my picasa link if you want to see the latest and greatest.

I am looking forward to that first pizza.

[ThisOldGarageNJ]

Re: Matt's WFO Build

hey matt,

If the effects on bare skin are any indication of what it will do to your lungs I would strongly suggest a mask when working with this stuff.

The one i used is water soluble,, Supposedly non harmful, but I still wore a mask.. sounds like your making good progress

Cheers
Mark

[Dino_Pizza]

Re: Matt's WFO Build

Great job Matt! I checked out your steel stud framing techniques on your web album and I think you've got a second career ahead of you .

The angle brackets you added look good and you'll be surprised how it all firms up when you screw on the plywood roof and siding. It looks like 1st pizza will be soon! Can't wait to see it. -Dino

[mluttropp]

Re: Matt's WFO Build

Thanks for the kind words Dino. I decided to crank up the fires this morning as I would like to get the oven closer to pizza temps before thanksgiving. We are shooting for a new years eve pizza party and I would really like to have had one or two successful pizza nights before the main event.

The interior of the oven is currently at 500 degrees or so and I noticed one hell of a crack along the back of the oven. It runs nearly completely top to bottom. I can't measure how big it is on the inside as the oven is rather hot, but it is definately visible. On the outside of the dome it is about two credit card thicknesses thick. Yikes. I am startting to panic a little bit. I decided to do a smoke test by closing the door to the oven and effectively smothering the fire. When I looked at the crack I did not see any smoke escaping, at least that is a good sign. I will continue to heat the oven and see what happens. Mostly because I dont know what else to do at this point. Should I be worried.

Thanks all

[Dino_Pizza]

Re: Matt's WFO Build

Don't worry Matt. Wait until it cools and you'll see the crack will close up again. I think that will be your one "big" crack and you'll never see it that big again for a couple of reasons:

1. You will get a few more hairline or even more invisible cracks when your oven is finished "curing" at the 700-800 degree range. I found that my top-to-bottom crack actually got smaller once I got to full oven temps a few days later and I think it's because the dome expands better and more evenly after all the hair-lines and heat-stress points figure out what the want to do. The bigger crack will always be the ovens 1st expansion area but that's all it will be and you don't have to think of it as a "crack".

2. Your insulation layer will "seal" it up.

If you see no smoke which you didn't, your good. I cut a swath of my FB blanket and laid it across my ovens crack and after a big smokey fire...ya, with my critical eye, I saw the faintest whisp of a Grey streak the next day on the blanket. I put some more Refmix on it, put on my blanket and its fine.

You're doing a great job, don't worry about the crack. -Dino

[jmhepworth]

Re: Matt's WFO Build

Your crack sounds just like mine. Its' fine. Really.

[mluttropp]

Re: Matt's WFO Build

Joe thank for the picture of your crack it does look a lot like mine. You know now that I am reading these sentences it is a real good thing we all know what we are refering to as in a different context this would just be wrong.

I have another question for all you experts out there. Has anyone covered the fancy high heat insulation with a layer of regular old fiberglass insulation? I was looking at the temperatures of the dome and under the insulation the dome surface was about 300 degrees. On the outside of the insulation it was 75 degrees. I was wondering if filling up the space between the 2 inch layer of high heat insulation and the wall of th enclosure would be a good idea or a bad idea. Any thoughts would be appreciated.

matt

[trockyh]

Re: Matt's WFO Build

Joe thank for the picture of your crack it does look a lot like mine. You know now that I am reading these sentences it is a real good thing we all know what we are refering to as in a different context this would just be wrong.


matt

Matt, that made me laugh!
Your oven looks great and I like how you are covering it.
Good job.

Tom

[ThisOldGarageNJ]

Re: Matt's WFO Build

Originally Posted by mluttropp
Joe thank for the picture of your crack it does look a lot like mine. You know now that I am reading these sentences it is a real good thing we all know what we are refering to as in a different context this would just be wrong.


matt

Matt, that made me laugh!
Your oven looks great and I like how you are covering it.
Good job.

Tom

tom & matt... I wasnt paying attentions till i read this... I just finished wiping the soda off my laptop from spitting it out..(seriously) that was funny
Thanks for the laugh guys

Mark