Author Topic: 2nd time pies with my DIY WFO (Read 3436 times)

jon7821 · « **Reply #20 on:** July 10, 2012, 12:02:26 PM »

Guys, thanks so much for all the suggestions. The good news is that i have access to a nearly endless supply of kiln dried hardwoods. I work for a company that makes high-end wood doors, so we throw away about 2 cubic yards of hardwood cut ends, usually about 6"L x 8" w at 1" thick every day.

pizzaneer · « **Reply #21 on:** July 10, 2012, 12:14:44 PM »

Sweet! Free fire!!

You can thank us by becoming amazing with your awesome modded grill. Your little girls will grow up thinking their Daddy's the smartest man on the planet.

Looking forward to following your build progress and your further pizzas!

Jet_deck · « **Reply #22 on:** July 10, 2012, 12:37:09 PM »

A computer fan is all you really need. 3 CFM is plenty for a fire this size

jon7821 · « **Reply #23 on:** July 11, 2012, 10:43:57 AM »

Sooo, last night i got out my arsenal of cutting tools, and i cut down a sheet of 1/4" plate steel I had lying around. Suffice it to say, cutting 1/4" plate without a torch or plasma is NO FUN. but, got it done, and took the lid off my grill to mount it and then.... Realized that the 14 gauge stamped steel lid is really not designed to support the weight of a 25 pound lump of steel. I didn't feel like completely frankensteining the lid to make the steel fit and have appropriate support, as i still want to be able to de-pizza this thing and use it to smoke ribs and such (i know, we can talk about flavor contamination in another post).

Bottom line, i am somewhat back to the drawing board on a mechanism to get the heat down to the surface of the pie. One thing i was contemplating is reversing the orientation of my deck, so that the wire basket section is over on the left side of the grill, then filling about 50% of the basket with a full fire brick split. Leave about two 4x4" squares of the basket open for air flow. Then, build the fire on the right hand side, completely on top of the fire bricks. Lastly, take the chimmney and replace it with a longer section of 3" OD automotive exhaust pipe, and lower the bottom of the chimmney down to 2-3 inches from the hearth. I have done that before with dryer vent for smoking, and it forces the entire volumn of the lid (dome) to fill with smoke before it will escape from the chimmney. Maybe the same concept would work with the heat from the fire, thus "filling" the dome more completely with heat, rather than just having it rush right out the top thru the stack.

Craziness, or does it have any merit?

pizzaneer · « **Reply #24 on:** July 11, 2012, 11:13:33 AM »

"Mommy, why is Daddy swearing at the grill?"
"Never mind, honey. He's being a man."

That must have been a frustrating moment! All that work to cut a big piece of steel!

I'm still going to promote my idea as submitted earlier. I don't think a cordierite slab will weigh as much as a steel slab. (I could be wrong about that. If so, Scott will correct me.)

Regardless, the setup you describe will simply repeat the setup that you already have, and asked for help improving.

The single most important factor that you are going to continue to lack if you can't mount a thermal mass in your lid is top heat for the pizza. If that is the case, then it's time to consider other methods to achieve that goal.

You could use a system of air directors and a strong forced-air supply. This technique is crucial to the success of the LBE's design. For that, the setup I proposed earlier still stands, with one change. The slab on top would be replaced with a lighter-weight steel sheet, with bolted-on bent metal to force the hot air down to the pizza. (Make it removable so you can use the grill for it's normal items.) You still need the movable block to change the route of the hot air from the firebox.

Michael130207 · « **Reply #25 on:** July 11, 2012, 12:13:21 PM »

I believe that when it comes to grill pizza it is a balance between thermal mass and heat generation. As Scott has pointed out, too much thermal mass on a grill just wastes time and fuel. But too little mass won't allow you to keep steady temps. What I find works well on my grill is to use a cordeite stone on the bottom instead of fire bricks. It heats up quickly and has enough thermal mass to do a nice ny style pie. I think it is important not to cover the entire surface with fire brick to allow for air flow. For the top I think air flow and low ceiling is much more important than thermal mass at these temperatures. I use a full size sheet pan, 18 inches by 26 inches, you can purchase online for about $10. I used a hole saw and cut a 1.5" hole in the center to encourage hot air flow across it. I prop it up with a couple half split fire bricks on either side. I also elevate my stone 1 inch up from the grate with some ceramic feet that came with my green egg. That gives be a gap of about 3.5 inches. My setup heats up in 30 min to 625F and produces some nice top browning but no leoparding. give about a 4 minute bake. I'll post some pictures tonight of my setup.

jon7821 · « **Reply #26 on:** July 11, 2012, 12:58:34 PM »

Thanks guys. Going to hit it again tonight to get that dome dropped.

Michael130207 · « **Reply #27 on:** July 11, 2012, 08:42:41 PM »

Here are the pics of my setup with the sheet pan and the pie I baked tonight. I probably should have got it hotter. I only preheated it 20 min with stone temp of 550F, 4 min bake.

jon7821 · « **Reply #28 on:** July 11, 2012, 08:47:03 PM »

Michael,

That looks great. I am actually on my way outside to mod my grill right now. I'll post pics later tonight. Thanks for your pics, it gives me hope!

norma427 · « **Reply #29 on:** July 11, 2012, 10:54:28 PM »

Jon,

I also tried different pizzas in my BBQ grill with different set-ups if you are interested. Some start around this link, but there are others in that thread. http://www.pizzamaking.com/forum/index.php/topic,11133.msg102003.html#msg102003

Norma

jon7821 · « **Reply #30 on:** July 11, 2012, 11:54:01 PM »

So, tonight my mission was to drop the dome (and keep it under a million pounds, removable, etc). So, i went to my metal supplier and got a sheet of 18 gauge sheet metal and set to work. My grill is 20" inside the lid from front to back, so i cut a piece that was 24x28w. That would have dropped the dome to about 5.75" total (1 have 1.25" of deck height). Based on the feedback here, that seemed too high. So, out it came and i trimmed another 2" off, total dims 22 deep 28 wide. I think that works, dropped the dome to about 3.75" at its peak.

So, me being without dough at the moment, I just did a test fire to check heat behavior. I started a small fire with my (endlessly free) oak splits, and waited. Started at 8pm, then by 830 had a good fire going. It's tough to see, but the flames really tracked well down the new low dome, about 2/3 of the way to the chimney side.

In the end, i ran the fire for about an hour without any coals underneath, and only had the fire on the far right fire basket (save for a few minutes where i moved some sticks to the middle of the hearth). Here are the specs:

Dome got much hotter, with some readings coming in 900+ (probably a direct reflection off the flame, but its only 3.5" up, so it won't be far from a pie).

Deck hit about 700 right next to fire, 600 in middle 400 on far left.

I will make some dough tomorrow and do another bake on sunday and let you know how it turns out.

thanks again for all the feedback and support.

petef · « **Reply #31 on:** July 12, 2012, 03:44:21 AM »

I agree with Michael, in that you need to get more heat from the heat source under the hearth into the top area. Considering your current frame design, the easiest way is to cut the corner bricks on the diagonal to create 4 vents that will allow more heat to flow into the top area. Those vents along with your fire in the top tray might do the trick.

Your last mod to lower the dome seems to me like the perfect height based upon my recent project to create a pizza oven for my Weber Genesis gas grill.

---pete---

jon7821 · « **Reply #32 on:** July 15, 2012, 09:41:05 PM »

Tonight was the first bake after this last week's oven mods (lowered the dome to about 3.5" above deck). Definitely an improvement, though still work to be done. Made slight change to my dough too, upping salt to 2.5% and upped yeast just a bit also. Pies tonight were pepperoni, margherita, fig and prosciutto, and a pesto with SDT and feta. Fig pie had good flavor, but i over stretched and go the crust really thin. Actually caught that one on fire too (not really paying attention). It was only ok, but the others turned out pretty good. Still need some work on flour control so as not to get so much uncooked flour on the pies. First two also had some launch difficulties, got them to look like near perfect footballs thought

Take a look and give me your thoughts.

scott123 · « **Reply #33 on:** July 15, 2012, 09:56:48 PM »

Wow! Did I say that I didn't think you could get a Neapolitan bake time out of this? This doesn't happen much, but I think I might have been wrong

Seriously, though, that's a good looking margherita. It's not as leoparded as much as it could be, but I'd still qualify it as Neapolitan.

Some additional char on the undercrust should be an easy fix, right?

Bake time?

jon7821 · « **Reply #34 on:** July 15, 2012, 10:07:29 PM »

Scott, these baked at just over three minutes. I am really excited with the improvements with the results, and I'm anxious to try again. I need to take my "dome drop" sheet all the way across to the left side, then tie the chimney in to that dropped dome. I am really hopeful to get back at it, though I am starting to doubt I'll get bake times down to the 90 second range. But..... I will melt my face off trying

scott123 · « **Reply #35 on:** July 15, 2012, 10:17:01 PM »

Jon, I think it's time to revisit the steel plate. You had mentioned the top of the lid not being able to support the plate, but I think if you drilled 4 holes in the side and ran bolts all the way across, it should support the plate just fine. When it comes time to use the grill for other things, put 4 small bolts in the holes to block them.

jon7821 · « **Reply #36 on:** July 15, 2012, 10:31:59 PM »

I've been thinking about that too. One think I need to figure out first is a better way to cut the 1/4" plate. My last effort was, well just that EFFORT. Papa needs a cutting torch. Never thought pizza making would drive me to get a new tool, but blessings come in many forms!

scott123 · « **Reply #37 on:** July 15, 2012, 10:43:34 PM »

I have a lot of respect for people willing to cut things that are tough to cut. After my two experiences with soapstone, I'll be happy if I never have to cut anything again.

Don't give up on that plate, though. The extra thermal mass might be just enough to put you over the top.

Chicago Bob · « **Reply #38 on:** July 15, 2012, 11:01:50 PM »

Jon, that is a fine look'in 3 min. Margarita....your set-up is getting dialed in quickly. Congratulations!

Michael130207 · « **Reply #39 on:** July 16, 2012, 10:53:54 AM »

Those pies look awesome!

I haven't done any calculations, but I suspect until you get up to really hot temps >1000F, that the heat transfer to the top of the pie comes more from hot air (convection) than from radiation. That might be an interesting back of the envelope calculation, might have to dust off an old heat transfer text book for that one.

I think you will get more improvement from Pete's suggestion of cutting the corners off the floor to get more hot air onto your ceiling than from adding the steel plate. I would at least try it first as cutting the bricks is a lot easier than cutting the plate. Although cutting steel plate with a torch sounds like a lot of fun, at least for the first couple minutes.