Air Problem

[golfpro2301]

I just ran into an unusual problem with my fridge. I just finished remodeling her in the last month and still getting to know how she operates. Unfortunately my firebox door does not seal perfectly. there are a few small gaps that I plan on fixing next week. I have a 1.5" ball valve for air intake as well as 2 small 3/4" valves on each side for my guru fans. I have my firebox setup to burn the "s" pattern. I would dump  two lit chimneys on one side after I preheat with weed burner. temp would get to 250 but as soon as I close the door the temp would drop. this is with all dampers open. If I leave door open or slightly cracked the temp would shoot up past my target of 250 which is expected. Here is where I am thrown tho. when I went to shut it down last night I closed all air dampers and had firebox door closed. After about 5 minutes of everything being shut down the temp started rising and went all the way to 370* and stayed there for 2 hours. I am no expert on how air moves but this is weird.

 

[southern swine]

Is this on your old fridge?

 

[golfpro2301]

No it is on new version. This is the only picture I have of it. This was right after I completed it.

new fridge.jpg

• golfpro2301
• Mar 16, 2015

To give you an idea on design. There is a welded in water pan between the firebox and cook chamber. There is a 1" gap around all edges of the water pan. There is then heat deflectors above water pan to divert heat and smoke back to center and away from walls. The 1.5" valve on the right is air damper. I have two guru adapters underneath each shelf on the side. Outside of the door leaks this is the only air inlets.

 

[southern swine]

How far is your water pan from charcoal basket? I had a vertical cooker once I built that had weird temp swings. I had to move water pan up a little. With iout it cooked fine. It's just a suggestion. I know the water pan needs to be there. I think mine was 2 inches all the way around.Have you cooked without the Guru's? We ran into a similar problem with a Liberty at last competition. It was real windy cook temps were all over the place. We pulled the Guru's off adjusted ball valves and she stayed at 245 all night. Not trying to confuse you, just trying to help.

 

[golfpro2301]

I appreciate the help. Not confusing at all. My Guru would not work at all last comp. I plugged it in and no readings and fans wouldnt work so I sent it back and have not received it back yet. The only thing I am using to attempt to control temps it ball valve. From top of charcoal basket to water pan there is roughly 4-5". There is 1" between water pan and back and front walls and 1.5" on the sides. I decided to run it dry today with sand in the water pan. Pre heated with weed burner and dumped 1 full chimney in the charcoal basket with the maze burn pattern. All air dampers were open. The preheated smoker was at 240* I closed the door and temp dropped down to 215*. opened door and let the temp come back up to 230-240ish and closed the door. Temp dropped again. Started getting frustrated so I closed down all dampers and started working on hot water heater for the trailer. About 45min later I went over and the temp was at 375*

 

[southern swine]

Is it insulated? How much charcoal does your basket hold? Can you light your basket the minion method or is it like a charcoal basket on a Liberty?

 

[golfpro2301]

It has 2" around firebox and 1" everywhere else. It is kaowool rated to 2300 degrees. doors have 5" each of insulation. Basket holds 20lbs of charcoal and I burn it in a maze pattern but it has been skipping rows. I didnt leave a gap between pieces of metal. I used to use bricks and I know that works. I removed all gasket material tonight and grinded down to bare metal on inside of firebox door. I loaded up the edges with 1.5 tubes of silicone and put saran wrap over it and closed the door. This should make air tight. I am going to test again wed using the same method recommended with the vault. Charcoal along the sides and back. I used roughly 6-8lbs of charcoal today which is what I had left in the old blue bag. It topped out at 400*. all vents were closed during this as well. I went out about 5 hrs later and it was still at 200. I rolled it in the garage about 8:30 to do the silicone and I touched the sand in the water pan. Holy **** it was hot. I now know why it held heat for so long. We will see what happens on WED and I will update you. I am hoping to have my guru back by the end of the week.

 

[southern swine]

You sound like your on the right path. Let me know what happens.

 

[golfpro2301]

So the silicone sealed the firebox but still having issues. I have been around alot of pits but this is throwing me. Preheated smoker today with weed burner. After I was done I shut the door and smoker was at 250* Lit one full chimney and while is was getting going I put a small row of charcoal on backside of firebox. It was roughly 3" wide. I jumped lit chimney on far side of firebox right next to air damper. I left door open to let it go for a bit. Shut the door and after 5 min it dropped 30*. Opened the door up and the smoker slowly went back to 250*. shut the door and temp dropped again. let it open and let it get back up then shut the door. At this point I was pissed so left it closed and started welding up a side handle for the fridge. After about an hour I looked and it was holding steady at about 235. This is with air vent wide open. a few min later it was at 250. So I closed the vent to where there was barely any air getting in. and off it went to 300*. I shut it down completely and it maintained 300 for 2.5 hours. after 5 hours it was at 250. My only guess that the water pan with the sand in it is taking forever to heat up and that is the delay. Any suggestions?

 

[southern swine]

Have you got your Guru's back yet? I know it's supposed to cook at 250. Try your Guru's before you make any other changes. If still problems,the only other change I would make is to go up one size ball valve. Go from 1 1/2 to 2 inch if necessary. Let me know what happens with Guru's.

 

[golfpro2301]

Havent gotten them yet. Should get them Mon. I am off wed so thats when I will test. I am going to silicone the crap out of every possible gap mon night and let it cure 48 hours. Will preheat the metal more than I did before and focus more on firebox and water pan with sand. Usually is 250 after preheat but see if I cant let it get to 300. Then will add the charcoal. 

 

[southern swine]

Sounds good. In our Liberty pit we put a coffee can in one corner of firebox start coals then pull coffee can out and let it start that way. Let the coals work there way towards back. Seal it good and see what she does without Guru's. When's your next Competition?

 

[golfpro2301]

Next comp is April 11th. Its a local pro event with no Brisket. So I usually just throw a couple of butts in the memphis and let her run all night. Ill do the ribs in the refer. If I dont feel comfortable with temp control by them I will take my two jim bowie as backup to do ribs and chicken on. Firebox should be completely sealed now. I went over the door again after the first time cured. Also sealed around the water drain pipe where I forgot weld around I just found out. The only other thing I can think of but dont know if its plausible is if it is drawing air from small gaps in cook chamber door down under heat diverter, around water pan, and then into firebox. I really think I am not preheating it enough. I used 2.5 sheets of 1/8" on the inside so it will take a while to get heated up. Going back over notes and it looks like after 45min is when temp takes off. probably takes this long to get all metal heated. I am going to light 1 chimney in the front corner and put unlit coals across the back. I wont connect the two until the smoker gets fully heated then I will add the last bit of unlit that will connect the two strands and see how the guru manages it. Starting to wish I left it the old way with the side firebox. It was a perfect stick burner.

 

[southern swine]

I think with it topping out at 300, you can control temps with Guru. I've been thinking about the way the temp swing were when the firebox was not sealed ,do you think it was causing a draft making the coals burn hotter? If you can get temps to 275 to 250 with Guru it will be a good Brisket cooker.

 

[golfpro2301]

Got gurus back today. It turned out both probes were melted somewhere in the center. Now I got fresh probes. I went back over every possible crack in the door with silicone as well as the water pan pipe that might have a few leaks around the edges. I am going to fire it up on Wed. I see that I am losing some of my seasoning on the back side of my racks so going to re season them and cook some ribs with a mix of rib tickler and a local rub. I am going to pre heat the hell out of it. I will put charcoal around the back of charcoal pan and dump 1 chimney in front left next to air damper. Once it gets up to temp I will add unlit charcoal to connect the lit coals and the row in the back. We will see how this works out.

 

[southern swine]

Sounds good. I think it should do better with the Guru's. I think that it's just hard to get up to temps. Let me know what she does. I'm getting ready myself for a Competition coming up.

 

[golfpro2301]

So I was able to fire it up this morning and test out the guru's. I preheated smoker quite a bit. focused alot on water pan,sand, and firebox. Seemed like once that got hot last time is when temps started going up. after pre heating I closed the door and the temp was at 300*. I lit half a chimey and once that got going I dumped in the charcoal pan and set gurus to 250. turns out half a chimney is too much cause that created 270* temps. Not to worry I removed half the lit coals  and closed her back up. It took about 30 min before most of the steel cooled a bit but it settled in at 250* I was actually getting excited. It stayed at 250* for about 2 hours. I decided to run to Home Depot to get a new sprayer for rib spritzing. When I got back I heard the guru alarm going. Went over and noticed it was at 320*. Could understand why and then I noticed a large gap on the top right corner of the firebox door. Turns out the hinges are bending quite a bit once they get hot. The door dropped about 3/4" which created a large gap in the door letting in a lot of air. So I know that is why the temp shot up. I plan on welding on a ledge to have the door close on top of and it will support the weight. this way there is no way of it to drop down while cooking and create a gap. Once I get thru competition in two weeks I will remove hinges and door seal then lay fridge flat on ground and re attach everything so it is good. 

 

[southern swine]

I'm so glad you figured it out I have staying up at night thinking about it. I knew it was getting air just didn't know where. Do you cook Comps in Louisiana region Alabama or Mississippi? Let me know if that fixes it. I got a line on a fridge you still need one?

 

[golfpro2301]

Not yet. I am going to start drifting over that way in the next year or so. I decided I am done with conversions I am going back and forth on a vault or backwoods. If I can find a used one I would get it but I might just build my own. Just waiting to get dimensions on the vault so I can make an exact replica. if you know of anyone that is selling either brand cooker please let me know.

 

[southern swine]

Me and my brother are building a Backwoods clone. We got a Liberty we Compete with love it a real Backwoods is garbage. Their cheaper to build. I know of a Rebel a guy was thinking about selling. You looking for a hog cooker or Ribs and Pork Brisket type of cooker?