My first build! 275gal Oil Tank Reverse Flow

[garretthall29]

I have finally started my first build. I wanted to put up some pics of the start of the process, but I also have a couple questions. How far above the firebox opening should I put the RF plate? What thickness of steel is recommended for said plate? Also how far above the plate should my bottom grate

photo 1 (3).JPG

• garretthall29
• Apr 21, 2014

be?

photo 2 (3).JPG

• garretthall29
• Apr 21, 2014

 

[garretthall29]

Anyone have any advice???

 

[daveomak]

I've been trying to picture the total project.... see exactly what your plans are and figure what may work better.....

Draw us something so we have a starting point..... Scan as a picture and save to file to post on here....

Dave

 

[garretthall29]

My end result will look something similar to this picture below I found on google, only mounted on a trailer. In the original pics if you can see the blue chalk line below where the door cut outs are, that's where I planned to have the RF plate with the opening into the firebox 2 inches below that. Now I am kind of second guessing everything I drew out.

 

[daveomak]

The RF plate location and height looks good..... Be sure, on the end opposite the FB to leave and area equal to the area under the RF plate for the heat/smoke to make a 180 degree turn to head to the stack...
I've been in discussion with another member about how to get some heat to the lower racks when there is a large volume above the RF plate....
Something I suggested, the revues are still out.......


.......click on pic to enlarge......

GarrettHall29.jpg

• daveomak
• Apr 24, 2014

 

[garretthall29]

Dave, do you mean if there is 13" from the bottom of the chamber to RF plate that I need to leave that same distance at the end of the plate? That's interesting idea for redirecting. Are guys/gals having problems getting enough heat to the lower rack with the RF design?

 

[daveomak]

Some have that temp. difference issue.... Most folks use it to their benefit.... From end to end of the lower cooking grate, temps are close to even if the smoker was designed OK.... It's when you get lots of room above the RF plate... 2-3 racks.... that's where temps. are different...

 

[garretthall29]

Would you recommend a thermometer at the top grate and one at the lower?

 

[daveomak]

I would recommend...... Once you get the smoker up and running.... Put a remote thermometer on the grate where the meat is located that you are cooking.... Have a dial thermometer mounted on the door or somewhere handy.... Make notes when you cook on the Door therm and the meat rack therm..... There will be a difference of 10-30 degrees..... note that difference and the therm location on the rack...... that difference should remain fairly constant over time unless you change the configuration of the smoker...

ie. if the rack therm says 230 and the door therm says 190.... next cook bring the smoker to 190 and you know the rack is 230....

 

[garretthall29]

I hope you don't mind if I pick your brain Dave!  Should I use 1/4" for the RF plate? Also, my RF plate will be 13" from the bottom of the tank so does that mean it needs to have a 13" space at the end of it? I wasn't sure if thats what you were saying in your ealier reply.

 

[daveomak]

Since the bottom of the CC is round, and takes up less area, the space on the end of the RF plate could be 9-10" or so... If the area at the end of the RF plate is less than the area under it, that will become a choke point for the air/heat flow... The air/heat is trying to take a 180 and that is a point of friction/resistance, as it is....

1/4" plate is good for an RF plate... has thermal mass, spreads heat evenly.... You can bolt or what ever angle iron to the CC walls and set the RF plate in there... maybe a tack weld or two and you are good to go.... Since the smoker is convection/gravity there will be minimal leakage ....

 

[garretthall29]

I am getting ready to start cutting my plate for the firebox and the dimensions I come up with off of the Feldon calculator seems on the big side. 27x27x28. Any suggestions?

 

[daveomak]

1/3 the volume of the CC... for the FB.....