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500 Gallon Fat Tank Reverse Flow Build
- Thread starter moody cue
- Start date
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weldwizzz
Newbie
- Nov 28, 2016
- 10
- 10
What do you mean about cutting 1/4" sheet down the metal to make 76" for the firebox? Also, from the picture, it looks like your bottom rack is raised expanded and not flat expanded. I'm just curious about this. Any info would be great.
I use 1 1/4x1/8" angle for guides and racks on nearly all my smokers.
I cut a sheet of 1/4" down the center so it makes 76" for the firebox. Yep the firebox is huge on these.
Sheets of steel are 172" wide (they are here in Argentina anyway) so I try to make the least cuts posible by cutting it straight down the center length ways.2./ Same kinf of expanded metal on all the racks, one is just reversed.
Also go easy on welding the expanded, it only needs to hold the weight of the meat.
Many folks weld the crap out of it and in the process the racks bow from shrinkage. ( block of wood on floor and jump on rack if this happens)
Also go easy on welding the expanded, it only needs to hold the weight of the meat.
Many folks weld the crap out of it and in the process the racks bow from shrinkage. ( block of wood on floor and jump on rack if this happens)
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weldwizzz
Newbie
- Nov 28, 2016
- 10
- 10
I have never understood why America felt the need to ignore the metric system and instead adopt the confusing inch system which is also referred to as the "standard" system. REALLY!!? I don't see anything standard about it! Now, to make things worse our cars are made with both inch and metric systems! What a terrible idea!
moody cue
Newbie
The below is from Dave Omak's tutorial, the opening at the end of the RF plate should be the same as the area under the RF plate. I don't recall if the end cap on this tank has the same arc as the body of the tank, but if it does then it would be as simple as going with the same radius measurement from the end of the RF plate to the CC wall on the end cap, as the radius you have on the area from the RF plate to the bottom of the CC.
Before sandblasting....
After sandblasting.....ALSO......
I need to know what the dimension needs to be from the end of the RF plate to the inside of the cooking chamber needs to be. I can't find any data on this. Help is greatly appreciated
Calculations for a standard design, reverse flow smoker..
Volume of the Cook Chamber.... Use the Inside Diameter of the tank... All smoker calculations are based on the volume of the Cook Chamber....
Diameter X Diameter X 0.7854 X Length = Volume in cubic inches / 231 = Volume in gallons
Volume in cubic inches X 0.004 = FB/CC opening in square inches
Volume in cubic inches X 0.004 = Area under the RF plate in square inches
Volume in cubic inches X 0.004 = Area required at the end of the RF plate in square inches
Volume in cubic inches X 0.33 = minimum volume of the Fire Box
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moody cue
Newbie
Well the fabrication has come along much more slowly than initially anticipted but making good progress now.
moody cue
Newbie
Another pic showing the doors.
You may want to brace where the hinges attach to the door. You are welding to the edge of the flat bar which is not very strong. It will bend or crack. Looking goodAnother pic showing the doors.
moody cue
Newbie
Thanks for the suggestion on the hinges. We added braces to mitigate the stress issue on the flat bar.
Today we tried mounting the assembled smoker onto the trailer and ran into a couple of problems.
1. When positioning on the trailer so that the firebox door is behind the fenders where it will clear when opened the center of gravity is rear of the center line of the axles. Thus, causing negative tongue weight.
2. There is some room to move the smoker forward and still have the firebox door clear the fender (or maybe even modify the fender slightly). However, the ashtray will not clear the fender (or tires). So I'm thinking I may have to scrap the ashtray idea. But I still don't think we can get it forward enough to be centered over the axles and have the door clear the tires.
3. Intake holes are partially covered by the rear cross member. But I think this will become a moot point if we're able to figure out a way to move the smoker forward on the trailer.
4. Right now the bottom of the firebox is even with the bottom of the axles, which puts the top cooking shelf at 69" off the ground. Honestly, I'm not all that concerned with the height as I'm a pretty tall guy at 6'4". But still it would be nice to have it a little lower. I just get nervous dropping the firebox lower than the axles and running into clearance issues while hauling the trailer.
My initial thoughts are that I'm going to have to move the firebox door to the rear (i.e. Opposite the CC/FB opening) so we can move the smoker forward to get it centered over the axles and avoid the door clearance issue we currently have with the FB door being obstructed by the trailer fender/tire. There's enough room to cut a new door between the upper and lower air intake holes. Then We'd have to seal up the side of the firebox where the door is currently by welding the door into place.
I'm not really seeing an easier solution at the moment. Any thoughts?
Today we tried mounting the assembled smoker onto the trailer and ran into a couple of problems.
1. When positioning on the trailer so that the firebox door is behind the fenders where it will clear when opened the center of gravity is rear of the center line of the axles. Thus, causing negative tongue weight.
2. There is some room to move the smoker forward and still have the firebox door clear the fender (or maybe even modify the fender slightly). However, the ashtray will not clear the fender (or tires). So I'm thinking I may have to scrap the ashtray idea. But I still don't think we can get it forward enough to be centered over the axles and have the door clear the tires.
3. Intake holes are partially covered by the rear cross member. But I think this will become a moot point if we're able to figure out a way to move the smoker forward on the trailer.
4. Right now the bottom of the firebox is even with the bottom of the axles, which puts the top cooking shelf at 69" off the ground. Honestly, I'm not all that concerned with the height as I'm a pretty tall guy at 6'4". But still it would be nice to have it a little lower. I just get nervous dropping the firebox lower than the axles and running into clearance issues while hauling the trailer.
My initial thoughts are that I'm going to have to move the firebox door to the rear (i.e. Opposite the CC/FB opening) so we can move the smoker forward to get it centered over the axles and avoid the door clearance issue we currently have with the FB door being obstructed by the trailer fender/tire. There's enough room to cut a new door between the upper and lower air intake holes. Then We'd have to seal up the side of the firebox where the door is currently by welding the door into place.
I'm not really seeing an easier solution at the moment. Any thoughts?
ok,
You know where the balance point is already on the smoker by where you are lifting it from. It has to go a long way ahead to get to the center between the axles, so the doors are not going to work how they currently are.
Don't worry about a rear crossmember. cut the chasis and weld it straight to the cooker and firebox. You cooker is way stronger than that box section and will act as a chassis.
On a 500 gallon I am building I only have 8" of ground clearance at the back, but doesn't worry me. It is 1/4 steel plate, so when it hits the ground just gas it and drag it. You are going to hurt anything.
if the chassis is sturdy enough you can extend it at the front of the trailer and add some more stuff to help balance the weight.
You know where the balance point is already on the smoker by where you are lifting it from. It has to go a long way ahead to get to the center between the axles, so the doors are not going to work how they currently are.
Don't worry about a rear crossmember. cut the chasis and weld it straight to the cooker and firebox. You cooker is way stronger than that box section and will act as a chassis.
On a 500 gallon I am building I only have 8" of ground clearance at the back, but doesn't worry me. It is 1/4 steel plate, so when it hits the ground just gas it and drag it. You are going to hurt anything.
if the chassis is sturdy enough you can extend it at the front of the trailer and add some more stuff to help balance the weight.
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moody cue
Newbie
So we moved it as far forward as we can (to the point where the firebox is up against the rear axle) and that gets us close to center and gives me about 110 lbs of tongue weight. That weight distribution might work out great actually. Because I will likely load 200-400 lbs of wood in the rack on the front of the trailer. I believe ideal tongue weight is roughly 10-15% of the total weight of the trailer. My best estimate is that the trailer and smoker is somewhere around 3,000 lbs, as such we would potentially need upwards of 400 lbs of tongue weight. Which is about where I'll be with the steel framework for the wood rack yet to be built on the front end of the trailer and a load of wood.
As for the FB door, we're kicking around the idea of cutting the existing FB door vertically in half, then install hinges on the inside of that seam. The door will fold in half as it opens past the fender. Or another option is going with double sliding doors. I just don't want to have to completely change the configuration of the firebox if I don't have to.
As for the FB door, we're kicking around the idea of cutting the existing FB door vertically in half, then install hinges on the inside of that seam. The door will fold in half as it opens past the fender. Or another option is going with double sliding doors. I just don't want to have to completely change the configuration of the firebox if I don't have to.
Rings Я Us
Smoking Guru
Lol @ block n tackle crane thingy to lift only the door . [emoji]128514[/emoji]
moody cue
Newbie
So we decided to go with the folding door for the firebox so that the door will clear the fender with the smoker moved forward over the axles. This was preferable to having to cut a new door on the rear of the FB[emoji]128522[/emoji]. My only concern is the potential affect on the hinges on the inside seam of the door from heat exposure on the inside of the firebox. But I'm thinking it will be fine.
Also, once we added everything to the FB and CC it added more weight and still have a problem with tongue weight. To add tongue weight we are putting in a 3/16" plate to serve as a floor for the wood box on the front of the trailer.
Also, once we added everything to the FB and CC it added more weight and still have a problem with tongue weight. To add tongue weight we are putting in a 3/16" plate to serve as a floor for the wood box on the front of the trailer.
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moody cue
Newbie
The rear frame work doesn't weigh that much so even cutting that off and welding the frame directly to the FB isn't going to help us immensely with th tongue weight. So we decided to leave the rear framework intact. We ended up putting side plates on the front of the trailer for the wood box and went with 3/8" plate on the floor which helped quite a bit as we are now at 200 lbs of tongue weight.
Almost done at this point, just have handles to weld onto the doors and get her painted! We will be talking to the powder coaters next week about a high heat resistant powder coating but not sure how much that type of product will cost. Has anybody experimented with powder coating versus a standard heat resistant paint?
Almost done at this point, just have handles to weld onto the doors and get her painted! We will be talking to the powder coaters next week about a high heat resistant powder coating but not sure how much that type of product will cost. Has anybody experimented with powder coating versus a standard heat resistant paint?
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