Fire Box - Insulated or Not Insulated

[jarjarchef]

So I started a thread some time ago and it kind of fell to the side due to health issues. http://www.smokingmeatforums.com/t/115761/first-build-info-gathering

We are all up and running now after surgeries and other health issues. I am going to use the propane tank after all and we are going to mount it to a trailer, even if we need to build from scratch. Father in law is not worried about the build. He just got a couple new toys for trade for doing some work. He has a Miller 230 MiG welder and a plasma cutter (not sure of the details but it cuts very nice lines)

I am going to flush the tank out over the next couple weeks before we do any cutting.

So here is the question that will determine what material I need to buy. I am not insulating the cook chamber and I have seen builds done both ways with the fire box insulated and not insulated. What is the best way?

If it was uninsulated I figure 1/4" plate will work and reinforce the insides for heat warping.

But if I insulated it, what is the best size of metal to use?

Any and all help is very much appreciated.

 

[jarjarchef]

Any thoughts to insulating the fire box or not? What are the pros and cons?

 

[ribwizzard]

Looks like your in Florida like me, I think its overkill in our weather. But im sure that you would use less fuel. and the paint would not burn off like it does on ones that are not insulated. Cant see it making any difference other than that.

 

[jarjarchef]

Thank you for the response.

I was planning on using this primer for the entire build. http://www.tcpglobal.com/spraypaintdepot/high-heat-primers.aspx

I was thinking of using this high heat paint for the fire box and main tank. Then the other heat paint for the trim and other areas.

http://www.tcpglobal.com/spraypaintdepot/high-temperature.aspx

Might cost a bit more, but looks like they will work. Most wood and chacole fires don't get over 1000 degrees. The high heat is rated for 2000 degrees, figure that will give me a bit of padding even with the long duration of the cooks.

I would really like to get the paint in non aerosol, but have not seen much nor looked real hard. Figure that part is some time away. But am leaning towards the aerosol primer to at least put something on the metal as i finish parts to protect against rust.

Just my thoughts. But I am not an expert and did not stay at a Holiday Inn Express...

Jeramy

 

[ribwizzard]

Ive bought some high dollar paint over the years from different manufactures and now just use Rustoleum BBQ high temp paint from Home Depot. $16.00 for a quart and you dont need any primer. I sandblast the unit to white metal first and this stuff holds up very well. Good thing is, anytime down the road, if you need to touch it up, stop by Home Depot and get a spray can of it and it will match right up.

 

[sqwib]

Don't paint the firebox, season it.

 

[ribwizzard]

Wouldnt you have dirt and all always stuck to the outside? And worry about it rusting?

I season the inside of mine, but the fire always burns it all off right away.

 

[diesel]

IMHO.. If you have the money and time I would insulate.  I did w/ my firebox and it holds temp very well.  All I did was use 1 ince square tube in the middle of the plates.

 

[sqwib]

Wouldnt you have dirt and all always stuck to the outside? And worry about it rusting?

I season the inside of mine, but the fire always burns it all off right away.

no rust and it really doesn't collect much dirt.

These are the only 2 photos I could find.

20100918802.jpg

• sqwib
• Aug 31, 2012

20101017259.jpg

• sqwib
• Aug 31, 2012

 

[ribwizzard]

well it looks pretty clean, how long has it been in use?

 

[jarjarchef]

I am fully with the seasoning avenue, but I am concerned with the rust. I know if seasoned correctly it won't. But we get a lot of direct sun and then rain. I have seen cast iron loose their seasoning and rust even being stored in a storage unit.

The insulation question is where I am really stuck. Most smokers I see are not. I also know that their is a big plus to the cook chamber being insulated, the heat retention. But if the fire box is and the cook chamber is not, does it make a difference enough to warrant the time and labor involved?

 

[ribwizzard]

I just really dont see it making that big a difference on the just the firebox as far as cooking goes. On the smoke chamber, yes, but not the firebox. Plus, wouldnt you like to be able to use the top of the firebox to cook your beans and stuff on?

 

[bruno994]

I've painted and seasoned my firebox, holding up well so far.  It does collect dust and dirt, because mine is parked outside all the time.  As far as insulating the firebox, in Central Florida, you won't need it, but it will save you alot of fuel.  Get all the heat produced by the fire heading into the chamber and not through the walls of the firebox.  Personal preference...

 

[rubbin butts]

I agree with ribwizard, if you are going to spend the time and money, insulate the cook chamber. The firebox wont make much difference. If your concerned with rust, just spray the outside with cooking oil each time you finish cooking.

 

[ribwizzard]

Now, let me say, I like to put my firebox about 1/3 under the cooking chamber, this saves me alot of fuel. I have had horizantal smokers with the fire box way out there and they sucked up the wood. Maybe if they would have been insulated, they would not have been so bad.



See how 1/3 is under chamber, and with reverse flow plate it kept chamber at even temp

 

[bruno994]

Personally, insulating a tank style pit is going to be a chore or the very least quite difficult to be able to insulate and still keep the thing nice to look at.  If you want a completely insulated cooker (smoker, pit, etc), go with a Backwoods Chubby, Pitmaker Vault or some other vertical cabinet style smoker.  They are fuel friendly, space savers and look good.  Your choice of paint on the outside, because it doesn't have to be high heat. 

I like the idea of the 1/3 under the chamber, Ribwizzard, I made the opening from firebox to chamber on mine a bit larger than the calculator called for, I use my exhasut to control the temps as my intakes pretty much stay the same from the time I reach 225, until I'm done cooking.

 

[ribwizzard]

I agree Bruno994,

I feel the reverse flow type smoker is more designed around a tank or pipe style cooker, that why I wanted to build one to try it out.  Most of my smokers have been verticle just for the reason of being insulated and more fuel efficient. Even then, though, I never had the fireboxes insulated or really had the need.

 

[bruno994]

No need for insulation here in Texas either, but the ones who have insulated their fireboxes, say they are very fuel friendly.  I framed my firebox with 1" tubing so that if I decided to later, it wouldn't be such a chore. 

 

[ribwizzard]

What kind of wood you Texans using over there?

 

[jarjarchef]

I like the idea of putting it about 1/3 under.

I have used a pitmaker vault they are very fuel friendly and put together well. Just not the style and price I am looking for.

At this time the biggest cost for me will be the metal to fabricate with. I have a boat trailer to mount it on and the cook chamber tank. I am very much into RW build he is working on. If you have not looked at it you should.