First offset build! Have some questions.

[mp4]

https://smokerbuildermfg.com/blogs/news ... PVOnMgzsE8

Pete's the man!

[thejm]

hey guys,

Got another update for you.

I have made a lot of progress on the smoker design and have started getting my material list together for the build. Below is a video of me flying around my current design. I still have to model the firebox door latch, top cooking rack, shadow plate, the CC door stops (more horseshoes), drain pipe, frame, etc. but its definitely coming along.

EDIT: youtube link updated, should be visible now

https://youtu.be/qAUCbVXM7Mw

Speaking of the drain pipe, what kind of pipe do most people use for this? I want to go with around a 2" pipe but don't know if there is a recommended type (galvanized, stainless, etc). and how do they attach it to the tank? Cut a hole in the tank and weld an adapter on there?

When i design the frame for the tank to sit on and eventually design the trailer, do I need to design it so the tank is slightly angled towards the drain? or will it drain fine being perfectly level?

How much vertical room is recommended between the top and bottom cooking grates?

I also purchased another 250 gallon tank to use for the firebox. Going to cut it in half so i have a 36" long by 30" in diameter cylinder.

Lastly, I found a screaming deal on a plasma cutter! I was planning on using my friends but his broke down. I ended up getting the Thermal Dynamics Cutmaster 52 new.

https://www.esabna.com/us/en/products/p ... ter-52.cfm

I will update the thread when i have made more progress. I am hoping to start the build in the next 2-3 weeks.

[towtruck]

Nice start!

[Dirtytires]

A 2 inch steel pipe is fine. I used a schedule 40 threaded pipe. Cut one end and weld it to the bottom of the baffle plate (or tank if building a traditional offset). You can then screw the ball valve (or pipe cap) on the threaded end. Standard steel is fine, absolutely nothing galvanized and no need to spend the money on stainless.

Cook chamber should sit level. Some will use the angle of the tank to help regulate temps but always start with a level pit. The grease is not going to (run) anywhere as it will basically stay where it falls. Pretty easy to scrape it out after the cook (with a wide putty knife), especially if the tank is still warm.

Most people like between 5-6 inches between racks if they can get it. Basically figure out how high your biggest piece of meat is and work from there. They can be different and nothing is wrong if it works for you. You might even get a third shelf in with that big of a tank.

And plasma is cool. You will never regret the purchase. Just make sure your air is clean and dry....install a second filter!

[thejm]

A 2 inch steel pipe is fine. I used a schedule 40 threaded pipe. Cut one end and weld it to the bottom of the baffle plate (or tank if building a traditional offset). You can then screw the ball valve (or pipe cap) on the threaded end. Standard steel is fine, absolutely nothing galvanized and no need to spend the money on stainless.

Cook chamber should sit level. Some will use the angle of the tank to help regulate temps but always start with a level pit. The grease is not going to (run) anywhere as it will basically stay where it falls. Pretty easy to scrape it out after the cook (with a wide putty knife), especially if the tank is still warm.

Most people like between 5-6 inches between racks if they can get it. Basically figure out how high your biggest piece of meat is and work from there. They can be different and nothing is wrong if it works for you. You might even get a third shelf in with that big of a tank.

And plasma is cool. You will never regret the purchase. Just make sure your air is clean and dry....install a second filter!

Thanks for all that info. I was just looking into those moisture traps. Which one do you have? Some are $20 and some are $200.

[dacolson]

I use 2. A water separator at the tank connection and a small cheap desiccant at the tool connect. Speedaire filter w separator and I picked the desiccant up at HD. I still get some moisture so I’m thinking about upgrading to a Deliquescent dryer.

[Dirtytires]

I run a regulator/filter at the air compressor and a fairly nice speed air filter/dryer at the plasma inlet. The price will determine what the drying/filtering capacity the filter has with the more expensive ones typically doing a better job. I would check out the recommendations from your plasma cutter and then at least meet them.

[thejm]

Hey so I have made more progress! I got a piece of steel rolled to form a 26" diameter by 36" long cylinder! This will be the inside liner for the firebox.

I have also looked at the inside of both propane tanks and the insides are quite rusty. How much do they need to be cleaned up before they are ready to have their first piece of meat on them? This is the inside of one of the tanks. I am guessing i have a looooong date with my angle grinder and a wire wheel ahead of me but any tips are appreciated!

[Dirtytires]

The cleaner the better but remember you will have a little oil burned on to seal it so perfection is not completely imperative.

I hate wire wheels as they throw dust everywhere. My preference for rust is a paint stripping wheel. They do a great job a and are a little cleaner. A bit expensive and you have to watch your pressure or they wear out pretty quick.

Another alternative is a medium/coarse flap disk. I like an 80 grit.

Either way, you need a mask inside a pipe.

[dacolson]

I’ll hit it with my pressure washer first. As high pressure as possible. Gets all the loose crap off.

[thejm]

I’ll hit it with my pressure washer first. As high pressure as possible. Gets all the loose crap off.

Thats a great suggestion. Ill have to try that when i get to the CC. The picture i posted above is the inside face of the outer cylinder of the insulated firebox. I cut a 36" section from one of the 250 gallon tanks i bought. I spent the evening with a fan, an N95 mask, goggles and my grinder with a wire wheel on it. I made a lot of progress. I realize the inside of this part will be sealed and wont come into contact with food but still wanted to clean it up a bit.

I am not sure if the pictures will do it justice but most of the rust came off. When i do the CC, ill probably give it 2 of these treatments or maybe do 1 with the wire wheel and another with a flap disk.

When i get some time, ill post more about how I cut the tank and my next steps.

[dacolson]

Sweet. Everyone appreciates pics and info on how other people do their fab work. Especially big awkward cuts like that.

[thejm]

I said this thread would be a build log and have made a fair but of progress over the past few days as I eluded to in my last post.

I bought both tanks with valves off so they had been airing out for a long time so there should be no propane left. To take an extra precaution, I filled the tanks up with water and dish soap and let them sit for a few days.

Both tanks are 250 gallon models but the tank closest to the camera (tank 1) has a full half sphere as the end cap while the other one (tank 2) has a 'flatter' end. I am using tank 1 as the CC and am cutting tank 2 up to use as the outside wall of the insulated firebox.

I bought a 4' by 8' piece of 1/4" plate from a local metal supplier that also cuts plate. I had them cut it into a 36" by 82 7/16" piece. The inside wall of my firebox is 26" ID so the 82 7/16" dimension comes from 26.25" (half way between the ID and the OD) times pi to get the circumference. I then had it rolled.

I will be the first to admit that I am new to metal working. I have made a few things like a welding cart and a fire pit but I am no expert so you might see some amateur mistakes.

Now that I have the inside of the firebox taken care of, my next task was to cut tank 2 to create the outside wall. This was a challenge as I needed to make 2 cuts to create a 36" cylinder. My primary concern was making a cut thats exactly perpendicular to the sidewalls e.g. not a slightly oval cut. I bought a framing square and another longer measuring stick and clamped them together to form a 90 degree measuring tool with both sides being long enough to make the cuts i need. I put the blue end against the long side of the tank and put the silver end against the rough center of the end cap. This allowed me to rotate this tool about the end cap and mark a common distance (reading from the blue stick) on several points of the side wall to form a 'perfect' circle.

Then I took a piece of 12' long by 1/8" thick by 1.5" stock that I am planning on using to create my door straps and weld it to the tank along the marks I just made. I made the first cut with my plasma cutter using that metal stock as a guide and then used the same method to make a cut 36" from the first taking into account the width of my plasma cutting guide. I knew that if the blue measuring tool was pressed flat against the side of the tank, that the other side must be perpendicular, making my cut perpendicular, not skewed like I was afraid of above.

After checking the cuts, I am +/- 1/8" in most all places with the occasional 1/4" spot. I should note that though I did use a guide, this is literally my first time using a plasma cutter! Not too shabby for a first cut IMO.

Next I cut the valves out of the 36" cylinder with my plasma cutter. I traced the holes on a piece of cardboard, cut it out with scissors, then transferred it to the remaining section of the tank and cut it out to use to fill in the holes.

Here is the 36" cylinder:

Here is the remaining part of the tank with the transferred shapes cut out of it.

I fit the cut outs in the cylinder and welded it in place filling the outline in to create a smooth surface.

You can see the inside of them here:

Next step:
I bought some regular metal nails to weld onto the outside of the inside wall of the firebox. I will tack enough of these in place to hold the Kaowool insulation in place long term. Ill then cut out the ends of the firebox out of another 8' by 4' piece of 1/4" plate and weld them in place.

Ill post more pictures when i make more progress!

[dacolson]

This is great. Nice write up. Are you welding the end cap back on the new smaller tank?

[thejm]

This is great. Nice write up. Are you welding the end cap back on the new smaller tank?

Hey thanks! Im going to need to cut more shapes out of that section for when I cut the valves out of tank 1. Other than that, that part is kinda scrap at this point.

My neighbor wants the end cap to use as a fire pit. Other than that ill probably sell or dump it.

[Big T]

It looks like you're off to a great start! Don't worry about making mistakes, we have all screwed something up along the way.

[Dirtytires]

So true....metal can be cut and re-welded tho.

And that means the first attempt is “practice” and NOT a mistake!!!

Looks like you have things worked out pretty well and are off to a great start.

[thejm]

So true....metal can be cut and re-welded tho.

And that means the first attempt is “practice” and NOT a mistake!!!

Looks like you have things worked out pretty well and are off to a great start.

Thanks! Thats one of the things I like best about metal working. I love being able to cut something off and re-weld it.

In the process of creating that blue welding cart that you can see in one of the pictures I became a certified expert at grinding!

I saw a decent improvement in my fab and fitting skills when I made this firepit for my brother.

I am hoping to have clean lines and consistent welds on this smoker. I am still trying to figure out how I am going to cut the CC to fit the firebox on it. I think I am going to have to cut a little but at a time until I have a perfect fit rather than trying to calculate what the exact cut might look like. My instincts tell me that the tanks probably have too many invisible imperfections to make a perfect cut the first time.

Ill probably mark the approximate cut on the CC end cap, cut conservatively, look at the fit, cut a little more, etc. until I get a great fit.

[Dirtytires]

You are on the right track. Cut small and keep inching towards what you want.

[thejm]

Hey guys, I have another question. I think i want to avoid painting the smoker because i like the original patina that the tanks have developed over the years. I like the old worn look of them but i want to somehow protect the metal from getting any rustier than it currently is. Can i use something like https://smile.amazon.com/gp/product/B00 ... 1d6b1bfbee on the outside of the tank without affecting/poisoning the food inside? Is there another product that works better than this?

PS I am planning on wire-wheeling the rusty spots on the outside before i spray anything on there to help it adhere.

[dacolson]

Surface prep is key. I used that exact paint on my last build. Stripped the paint, then went over it with a 3M surface prep pad/pneumatic grinder. It was a ton of work but I love the way it turned out. after I painted it I baked the paint on with a weed burner so I could hit surfaces that wouldn't normally get too hot during a cook.

[thejm]

Surface prep is key. I used that exact paint on my last build. Stripped the paint, then went over it with a 3M surface prep pad/pneumatic grinder. It was a ton of work but I love the way it turned out. after I painted it I baked the paint on with a weed burner so I could hit surfaces that wouldn't normally get too hot during a cook.

Oh awesome! Do you have a pig of your build?

EDIT: mind must have been on smoking pigs...i meant pic not pig.

[dacolson]

viewtopic.php?f=13&t=7536&start=175

At the bottom of the page are the pics of the finished trailer.

[thejm]

viewtopic.php?f=13&t=7536&start=175

At the bottom of the page are the pics of the finished trailer.

I like the build! Almost reminds me of a steampunk design.

[dacolson]

Definitely a retro design. It was a super fun build but man did it take forever.