This is my first post here. Some images below of my build. This was done from re-purposed metal. The inside is mostly 3mm (1/8) metal. The insulation is rockwool and the outer frame is 1.5mm aluminium. The insulation is throughout, even in the doors. Now one might ask why such an insulation (for context I live in Malta and we have +15C weather most of the year. The insulation improves 2 things 1. Fuel consumption (wood) and 2. Temperature Stability. The smoker works perfectly and it has exceptional flow, putting your hands above the stack is like a fan. Below are some tips for anyone considering a similar build:
1. Temperature control is achieved with the main firebox door. This might sound strange, but the more you open the door the lower the heat input into the chamber. The reason this occurs is that the door allows fresh/cool air to be mixed into the hot air coming from the fire and thus it actually lowers down the temperature. For the most part, to get to 225F its around 2/3 open. To get to 350F (smoking potatoes/wedges mostly) you need to fully close the door and leave the side vent open. Stack is fully open and I only close the stack after the cook to limit water ingress.
2. Wood - I mainly used Oak and Eucalyptus. Yes if you search online you might see many hints towards not using this wood but, if its seasoned well (dried for 2 years) its a very good fuel and gives good flavor. Consumption is around a log the size of a pint beer can every 30 minutes approx, so its quite good.
3. The firebox is slightly large for such a small fire (its possible because of the insulation). This allows you to be able to mix in the fresh air because you can place the fire on the back side of the fire box and allow fresh air to 'bypass' the fire.
4. I use small flat bars to keep the aluminium in place but for the most part, it does not touch the main body (limiting heat loss through convection). Where Aluminium meats the main body I use fire cement to seal and, after it cracks, I used high temp silicone to seal. The cement serves as a 'connector' with low thermal conduction and the sealer seals off water.
Hope this helps some members who are considering such a build.
In case you are wondering what the square next to the thermometer is, its a piece of metal to hold the digital thermometer since it has a magnet behind and it does not stick to Aluminium.
Cook Chamber is 24"x18"deep by 32" and firebox is 18"x 18"x18"
1. Temperature control is achieved with the main firebox door. This might sound strange, but the more you open the door the lower the heat input into the chamber. The reason this occurs is that the door allows fresh/cool air to be mixed into the hot air coming from the fire and thus it actually lowers down the temperature. For the most part, to get to 225F its around 2/3 open. To get to 350F (smoking potatoes/wedges mostly) you need to fully close the door and leave the side vent open. Stack is fully open and I only close the stack after the cook to limit water ingress.
2. Wood - I mainly used Oak and Eucalyptus. Yes if you search online you might see many hints towards not using this wood but, if its seasoned well (dried for 2 years) its a very good fuel and gives good flavor. Consumption is around a log the size of a pint beer can every 30 minutes approx, so its quite good.
3. The firebox is slightly large for such a small fire (its possible because of the insulation). This allows you to be able to mix in the fresh air because you can place the fire on the back side of the fire box and allow fresh air to 'bypass' the fire.
4. I use small flat bars to keep the aluminium in place but for the most part, it does not touch the main body (limiting heat loss through convection). Where Aluminium meats the main body I use fire cement to seal and, after it cracks, I used high temp silicone to seal. The cement serves as a 'connector' with low thermal conduction and the sealer seals off water.
Hope this helps some members who are considering such a build.
In case you are wondering what the square next to the thermometer is, its a piece of metal to hold the digital thermometer since it has a magnet behind and it does not stick to Aluminium.
Cook Chamber is 24"x18"deep by 32" and firebox is 18"x 18"x18"