Offset smoker 250 Franklin style.

[stijntje113]

I have announced the built of a 250 gallon offset smoker. Bought it for 50 euro and the goal for the smoker was to make it a real low budget built.
Almost everything is bought second hand.
I have started the build but I have q question that came up.

First some pictures from the steps till now. (excuse my writing I'm not native english speaking)

































For the firebox I've bought 3 metal plates from the scrap yard 250cm x 125 cm 4 mm thick. (for 100 euro)
One is used as bottom.
















Starting to grind out the dors of the from. (FB & warmer)
The dimensions of the complete block are 74 X 74 X 125 cm. The firebox will be 65 cm high.

And that is also what is my main question. If you see the troath opening from the FB to the CC, it is about 2 cm from the top.
For a smooth airflow do I need to extend it to the top completely?



As outlet/exhaust I have a pipe 16 cm wide and about 100 cm high. According to the calculator it is ok but if you keep the principle of Franklin in mind with the higher airflow do you think it will be sufficient?

[Rodcrafter]

As for the throat opening, you are close enough to not cause a turbulent air flow. I wouldn't change it since you are where you are in the process. As for the stack size and length, I know the calculator works. That doesn't mean you can't make it longer, just consider putting a choke of some kind on the top of it so you can reduce the airflow if you find that it is needed. All wood doesn't burn the same, some needs more draft than others.

jm2cw

[Big T]

[stijntje113]

Thanks!

I can easily make the opening higher. (think I'm going to do that)

I will leave the exhaust as is. If it doesn't work I can extend or replace it.

Thanks for the tips! If you've got any more..!

[stijntje113]

Some new pictures.

After weighing the trailer I decided to cut off the warming box. Also better for the ballance
The trailer was about 450 kg without the firebox etc. Maximum allowed is 650 kg.

I will also change the grid. I think the holes are to small and will not let the hot air flow through fully.

[ajfoxy]

Nice build pics. Thanks for sharing.

[Rodcrafter]

Can you step back and take some more pics walking around your build it looks interesting, but the close up pics make it hard to put together.

[Dirtytires]

Good progress. Thanks for sharing.

Good call on the warming box....always better to be within weights or it will constantly give you issues.

[Big T]

Sweet

[stijntje113]

Here are some overview pictures.

Thing still to do:
Attach the firebox
Bend the door a little bit because it doesn't fully close.
Make some counter weighs
Attached new grate to the frames.

[Rodcrafter]

[stijntje113]

If any has suggestions/tips.. Please let me know!

I'm doubting how to bend the door a bit. Think I need to remove it completely. Tried it with straps but they snapped due to the sharp edges.
Saw some tips with chains etc. The gap is small, about 5 mm.

[Dirtytires]

Much easier on the ground but can be done in place. Try putting a scrap piece of angle under the strap.

I had great success with a bottle jack and a section of chain. Just go slow and realize it’s under a lot of pressure. Make sure your chains/straps can handle it.

[MattJ]

Nice build so far. You might want to consider extending the trailer tongue.

[AndrewPalmer71]

Much easier on the ground but can be done in place. Try putting a scrap piece of angle under the strap.

I had great success with a bottle jack and a section of chain. Just go slow and realize it’s under a lot of pressure. Make sure your chains/straps can handle it.

Agreed! Wear head, eye, ear and body protection. That door will be under an immense amount of pressure while using the Jack and chain method. And you can easily overdo it, so take it slow.

And, when you get fed up, just build you a set of cabinet doors!

Sent from my SM-J727V using Tapatalk

[Big T]

[stijntje113]

Thanks for the advise!

Trailer tongue will not be extended. With the current set up I haven't touched the construction part of the trailer. (would like to keep it that way)

Hope to get some time this weekend for bending the door, will keep you informed.

[Squiggle]

[stijntje113]

I have tried to bend the door a little bit, started with it still attached but I have removed it and put it on the floor.
I'm not sure if I have really bend to door (it was though) but after re-attaching the door and welding the hinges again it looks like there are less gaps.








Also created something to put water bins in. Hope this will work like a buffer and would also spread the heat a bit better.

[Big T]

That's something that you don't see everyday

[Rodcrafter]

That water pan idea may work, I’m a little concerned about the air flow. I wonder if it will restrict it.

On the door fit issue. I use 1/2” rope and a toggle latch, it seals great. Just a option.


Making memories!

[stijntje113]

If the water pans block the flow They can be removed.

I think with the door is good how it is now. I will add some sealing to it to make sure it is airtight.

[stijntje113]

I have attached the firebox.
Also placed new iron on the grids. (think this will work better)
I was really happy with the gap between the firebox & CC. Only thing is that I cannot weld upside down so I need to check if somebody can lift it off and then turn it upside down.















Clean smoke coming out of it..


Smoke a pork loin besides it. Also baked a steak on the firebox, turned out great!


I noticed that my wood pieces are to small. I think it will burn better if I will use larger logs.

[Rodcrafter]

Looks great!

As far as the wood, I agree splints work better. About the size of your fist is a good rule of thumb.

You may want to make a fire basket so you don’t have to try to control how the wood lands on the rack.

jm2cw


Sent from my iPhone using Tapatalk

[stijntje113]

Looks great!

As far as the wood, I agree splints work better. About the size of your fist is a good rule of thumb.

You may want to make a fire basket so you don’t have to try to control how the wood lands on the rack.

jm2cw


Sent from my iPhone using Tapatalk

I was thinking about larger logs. (more arm sized) Because for my feeling these are to small and quickly burn out.
Firebox is 75x75x75 cm.

I have made a rack for good airflow but indeed, a basket works probably better.

One of the "issues" that I currently have is that I don't have thermometers installed. Therefore not sure how "big" the fire needs to be.
I have some tell tru's that I want but shipping to Europe is 60 dollar or something. Therefore I hope to get to the US soon (for work)