Aluminum Panel RF Smoker Build

[mbasaraba]

Well I am new, been reading and watching some of the builds and now have planned mine out.

28 x 28 x 48 volume smoker with RF.

I have ready access to TONS of 1/8-1/4 inch aluminum panels and can cut any shape I want on my CNC Plasma so this is the material I will be working with. I also have TIG and MIG welders and tube bender (for the legs) for putting it together.

I used the Calculator to figure out what size fire box I would need as well as the opening needs of the firebox to cooking area opening and pipe length and intakes for the fire box.

I do have a question about these intakes on the fire box. I plan on cutting round holes for the intake but was thinking of taking some pieces and cutting them as a half tube around these openings. It is the actual openings that matter and not what is over them that matters or does it play a part in how the draft functions?

Here is the quick model I put together that I will be using as a reference for the different panels I will program for cutting on my CNC.

 

[daveomak]

Mb, morning and welcome to the forum...... You might reconsider using aluminum for the smoker.... The possibility of it melting are pretty good.....  

Dave

 

[mbasaraba]

Melting? Aluminum has a melting point of 1221 degrees. Do a lot of people heat up their smokers that hot? 

 

[piaconis]

It's not just the melting point. Heat retention will be bad as compared to steel. Plus, you need to consider that the aluminum may not melt at the temp inside your firebox, but it will lose strength as it heats, so your failure point will be much lower than the melting point.

 

[daveomak]

[h3]Mb, morning..  here are some interesting temps.... Note the temp of a candle flame...   Dave[/h3][h3]Heat[/h3]
Main article: Heat

Fires give off heat, or the process of energy transfer from one body or system due to thermal contact.
[h4]Typical temperatures of fires and flames[/h4]

• Oxyhydrogen  flame: 2000 °C or above (3600 °F)[sup][7][/sup]
• Bunsen burner  flame: 1,300 to 1,600 °C (2,400 to 2,900 °F)[sup][8][/sup]
• Blowtorch  flame: 1,300 °C  (2,400 °F)[sup][9][/sup]
• Candle  flame: 1,000 °C  (1,800 °F)
• Smoldering  cigarette:
  • Temperature without drawing: side of the lit portion; 400 °C  (750 °F); middle of the lit portion: 585 °C  (1,100 °F)
  • Temperature during drawing: middle of the lit portion: 700 °C  (1,300 °F)
  • Always hotter in the middle.

[h4]Temperatures of flames by appearance[/h4]
The temperature of flames with carbon particles emitting light can be assessed by their color:[sup][10][/sup]

• Red
  • Just visible: 525 °C  (980 °F)
  • Dull: 700 °C  (1,300 °F)
  • Cherry, dull: 800 °C  (1,500 °F)
  • Cherry, full: 900 °C  (1,700 °F)
  • Cherry, clear: 1,000 °C  (1,800 °F)
• Orange
  • Deep: 1,100 °C  (2,000 °F)
  • Clear: 1,200 °C  (2,200 °F)
• White
  • Whitish: 1,300 °C  (2,400 °F)
  • Bright: 1,400 °C  (2,600 °F)
  • Dazzling: 1,500 °C  (2,700 °F)

 

[mbasaraba]

Thank you for the insight. Since the material is only costing me $14, the cutting costs me $0 and my time is free I think I will build it anyways. At least it will be a test run on my first build and since I will have the plans saved I can always invest in making it out of steel once I get the actual building bugs worked out.

 

[mbasaraba]

Have there been measurement of themp of the heat that enters the cooking chamber? curious if the fire box cpuld be made of steel and the cooking chamber from aluminum since it should be far less heat.

 

[piaconis]

You may want to consider making some design allowances to keep the heat source out of direct contact with the box (i.e. a charcoal/wood basket made from expanded steel with steel stand-offs, etc).  Good luck with your build!

 

[daveomak]

Mb,....  At least you can cut the metal with a skill saw.. The build should go pretty fast... I love building stuff out of aluminum....  Please take pics of your building process....  we love watching builds....  Dave

PS: I'm in for the build.... 

..... 

 

[piaconis]

You're problem that you'll run into using steel for the firebox and aluminum for the cooking chamber is that they expand/contract at different rates, so you will likely need to use a gasket to mate the two, as opposed to welding them together.  A good interlock design with a rope gasket may work well as an expansion joint.

 

[piaconis]

*Your...ugh.  I hate when I modify what I'm typing and mess up the grammar.

 

[mbasaraba]

Mb,....  At least you can cut the metal with a skill saw.. The build should go pretty fast... I love building stuff out of aluminum....  Please take pics of your building process....  we love watching builds....  Dave

PS: I'm in for the build.... 

..... 

Skill Saw?? 

I am a bit more high tech in my shop. ;) I have a CNC Plasma. Here is a video of the initial run on the machine. I had forgot my G code for firing the torch so had to do it manual on this video but has since cut hundreds of parts.

I should have stated that this is a home made CNC I made myself. Might not be top of the line but I hold a .005" positional tolerance (square root of x squared plus y squared dimension in both axis = position divided by 2) and a .005" profile tolerance. Pretty good for a home made job. 

Here is what the cut pieces made. It is a 3 Tier LED light for the back of my buddies 65 Chevy Van. I put spacers and LED lights between each layer. 

 

[shoneyboy]

 

[daveomak]

Mb, afternoon....  Well.... Your home-made CNC beats the dog-doo out of a skil-saw....   Dave

 

[dewetha]

I not sure Aluminum is food safe. I know we all use aluminum foil but i'm guessing raw aluminum is different. do a quick google search on FDA and aluminum. a few bucks isn;t worth the health risk and a sheet of 14 guage black steel isn't that much. just my .2ct but i would look into it.

 

[kolre33]

Melting? Aluminum has a melting point of 1221 degrees. Do a lot of people heat up their smokers that hot? 

HA ha ha,So u think you are like a aluminum.I think i am a cobalt,What is it's melting point ...huh

 

[boomhower]

You're problem that you'll run into using steel for the firebox and aluminum for the cooking chamber is that they expand/contract at different rates, so you will likely need to use a gasket to mate the two, as opposed to welding them together.  A good interlock design with a rope gasket may work well as an expansion joint.

If a steel box and aluminum cook chamber is used, it will have to be a flanged/bolted connection.  Steel and aluminum can not be welded together. (Although there are some electroplating/ brazing techniques that can be used to join these two materials.)

Boom