First offset build! Have some questions.

[thejm]

I have another progress update! In short, the firebox has been built.

I am going to share what i did that worked and what didn't work to help anyone who reads this in the future.

When I got the plate rolled to form the inside of the firebox, i had them tac weld it closed. I started off fully welding the seam. to make room for the weld and to get better penetration, I ground a groove in the plate. Now this piece will be exposed to the most heat of any other piece of the built so I wanted to make sure the welds were strong. this is why i decided to weld both sides of the seam.

Not super proud of how these welds look but they should be more than adequate for the task. I also need to remember to weld through other welds, not stop at them. I am somewhat new to MIG welding but I can see myself improving over time.

Outside of the Seam:

Inside of the joint:

After this I knew i needed to cut the ends of the firebox out of the 4' by 8' sheet of 1/4" plate i bought. I have the plate on some basic furniture rollers which made moving it around really easy.

I bought the Thermal Dynamics Deluxe Cutting Guide Kit from Cyberweld which was really expensive but I gotta say, it makes cutting circles out very easy. I don't know how else i would have made this cut. I would highly recommend it if you have the budget for it.

https://store.cyberweld.com/decugukit.h ... 7..zTnkDvL

I purposely cut this to be 29.75" in diameter since the OD of my outer wall of my firebox is 30" diameter. This left me with a bit of room to make a nice outside corner weld when the time comes to weld that up (see below).

I am continuing this post into another one so i can upload more pics.

[towtruck]

Nice so far...

[dacolson]

Nice work on the bevels. You can grind over those tacks as well to make it easier to weld over. I agree on those big circle cuts. Very difficult w/out a circle cutting guide like that. Outside corner welds are my favorite. Looking great.

[thejm]

My next task was to weld the inner wall of my firebox to the plate i just cut out.

I centered the cylinder on the plate, made sure it was level with my garage floor (where the plate was sitting), tac'ed it in place then welded it solid. I only welded the outside of this joint though. this should be more than fine. I do want the insulation in between the inner and outer wall to be in an airtight environment so i welded the entire circumference.

I forgot to take a picture of the finished weld but i was really happy with how it came out. Not that anyone will be able to see it anyway...

Next step was to test fit the inner and outer wall. They fit perfectly with exactly 1.5" of clearance for the insulation.

After suggestions here and some research, i decided to go with 8# ceramic blanket insulation. I found some on ebay here:
https://www.ebay.com/vod/FetchOrderDeta ... noapp=true

At first i taced the outer wall to the plate and tried to stuff the insulation and that didn't work at all. since i have 1.5" thick insulation and only a 1.5" gap, it wouldn't fit.

I then got the bright idea of laying the assembly down so the gap on top was much larger than the gap on the bottom and stuffed the insulation in 1 section at a time. For anyone doing this in the future, i would suggest buying insulation thats 1/4 "to 1/2" smaller than you have space for it. I wish i would have bought 1". it would have saved me a lot of time and effort. Now that its done though, i am happy with how it turned out

I would do 1 section, roll the tank 90 degrees, repeat until I had the whole thing done. Here is the final product.

This also served to align and center the outer wall over the plate and the inner wall.

[thejm]

Welding the outer wall to the bottom plate gave me some issues. Due to some imperfections in the first cut i made in tank 2, i had a gap up to 1/4" in some places between the plate and the outer wall. in some places, i inserted a filler metal strip to fill this gap and in others i welded a bunch of tacs and then welded over those to form 1 solid weld all the way around.

PS i apologize for the butt picture. I am recording the build with a mounted camera and its the only shot i got of the tacs.

Next I cut out another circle of the same size as above for the other end of the firebox and welded it in place. I am really happy with how this came out! The firebox is now built!

Next step is to start thinking about aligning the firebox with the CC and making the cut to join them. My next update probably wont be for about a week or so as I'm going out of town in the next couple days.

[dacolson]

[Big T]

Nice work!

[Dirtytires]

Really nice job on the firebox. Lotta work doing it round.

[ajfoxy]

Looking good!

[thejm]

Another build update!

Now that the firebox is built, I prepared to make the cut in the CC (tank 1) for the firebox to fit into.

I knew i needed to get the tank level which involved laying a level on top of tank 1 and knew that the valve holes would get in the way of that so started off by cutting all the valve holes out of tank 1 with my plasma cutter. My plan was to go ahead and patch them the same way I patched the holes I cut in tank 2 (now part of the firebox), by cutting pieces from the remaining part of tank 2. I cut the first piece from tank 2 using a template and it fell in the hole it was patching in tank 1. I had no way of fishing it out since I hadn't cut any large holes in this tank yet so i decided to hold off on patching these holes until I made a substantial cut.

Next, my goal was to get the CC high enough so that i could roll the firebox over to it to attach it. I took some 4x4s that I had laying around, cut them, and screwed them together so they would raise the tank to the correct height. In my case I raised it so the bottom was 21" above the ground. This gave me 15" for the firebox and 6" for the cart for the firebox to ride on. You'll notice that i also used some metal scraps on one end of the tank to get it level. This gave me a great sturdy way to move the tank around where i knew it would stay level.

I repeated the same process with the firebox as youll see below. This firebox is over 500 pounds as it sits and it is no fun to move around by yourself. I have managed by using jacks and wedges but still have to man mode it to flip it from rolling to standing up. If you are reading this i would definitely recommend building your smoker with 2 people!

I used my floor jack to raise and lower the tank.

You can see the holes i patched on top of the firebox here (mentioned above).

Next I found the exact top of the CC and firebox using a combination square i picked up at Harbor Freight. Its surprisingly great for as cheap as it was. I used a chalk line to mark it. I should note that i obviously used a level attached onto the ruler part of the square.

I found the center of the CC by using my framing square and projecting it out 15 inches (radius of the CC tank). I did this from several locations and got a shape that looks like this.

Drawing2-Layout1.pdf

(2.79 KiB) Downloaded 28 times

Now that the top of both the firebox and CC are marked, i used a laser level to align them. This allowed me to correct the alignment of the firebox left/right and also correct for any angles. The firebox is already level and at the correct height so this gave me the ability to accurately transfer the face to the CC.

Now if you recall, the cut I need to make into the CC is a 2 part cut. The bottom portion of the cut is straight vertical 7.5" from the start of the end cap and the top portion is a projection of the firebox onto the end sphere of the CC. The top of the firebox sits at the center point of the CC end sphere. Check post 1 for more details about how i aligned the firebox.

You can see what im talkin about below:

I will continue this in the next post.

[thejm]

With the firebox pushed against the CC and aligned, I used a 48" metal ruler to project the top edge of the firebox onto the end of the CC. I dont have pictures of this but basically, I laid the ruler parallel to the blue level you saw on the firebox above and pushed it until it hit the end cap. Because the ruler is metal it actually made a visible mark on the end cap that i could later reference. Keeping it roughly parallel with that level, i rotated it around the firebox until i had a mark from one side of the end cap to the other.

Next step is to mark the bottom vertical portion of the cut. This got complicated because i wanted to make sure the cut was exactly square so that my firebox didn't sit at an angle and wanted to make sure that both sides of my cut lined up perfectly with each other. I also wanted to avoid cutting too much material off one side. Filling those gaps in is no fun and it never looks as good as a clean joint.

I tried several things to get my marks to be square but found this worked best. The basic principal i used is described in the below PDF. It is looking from the top down at the tank and the laser.

Drawing2-Layout2.pdf

(33.1 KiB) Downloaded 49 times

You can clearly see that if the laser isnt aligned correctly, you'll see different measurements from the bottom and side of the tank. I should note that i am using the end cap weld that came with the tank as a datum to measure from. B is obviously greater than A. B is the rulers i have set up below the tank and A is the ruler i hold at the side of the tank.

Once i had the laser in the correct position, i marked the location of the laser on the tank with a few arrows. I also marked the location of the laser level itself. Youll see later why i did this.

I now had marks on 1 side of the bottom of the CC and repeated the same process with the other side making appropriate marks as needed and also marking the location of the laser level itself.

I still wasn't confident that my marks were going to line up exactly and create a clean cut. After marking the tank with some soapstone, my lines were still about 1/4" off. I attribute this to the weld that i was using as my datum. it varied in width some.

Not to brag but as an amateur fabricator, I think this next step was a 400IQ move on my part.
To correct this, i moved the laser level to its original location using the mark i made and got it aligned again. In doing this i made sure that the laser hit where it was sitting on the opposite side of the CC. if there was any skew to the laser alignment, I wouldnt be able to make all 3 rulers line up and have the laser hit its opposite point. I got a standing mirror that we have in our guest room and shined it so it reflected the laser exactly back at the laser level. This gave me confidence that the mirror was not skewed at an angle.

Lastly, i tilted the mirror back so it reflected the laser onto the opposite side of the CC than the laser level was on.

What do you know, the laser lined up perfectly with the marks on both sides and on the bottom of the end cap. I markd the laser with a sharpie stopping where it hit the scratches i made earlier on both sides.

Now all that was left to do was to cut it out!

I purposely cut it a little conservative and so I had to get after it with a grinder to clean things up. I pushed the firebox in and it fit! I also checked the measurements of the cut according to my 3D model and was accurate within a 1/4" in both directions which means that my throat area will be also match the model!

I still have some grinding and realigning to before its ready to tac and weld in place but I am very happy with how the cut came out! Its starting to look like a smoker!

Next steps:
I have heard a lot of people say that when they cut their CC doors, they warp a bit, becoming more concave and i would like to avoid this. thats why I want to weld some braces on the door closest to the firebox before i even cut the door. I will poke my head inside the CC from the hole i just cut out and weld these on. They dont have to be perfect but want to get some in. Then i will make hinges for that door, cut it out and repeat the process for the second door.

[thejm]

More pics of the firebox and the CC.

[Cole Leffert]

[Dirtytires]

Great write-up. Looks like all the hard stuff is behind you now!

[Big T]

[hogaboomer]

Well dang! Lasers and mirrors and shit!

I need to up my game.

[dacolson]

I love the write up. Gotta bookmark this one. Good detail on that throat cut. Very nice work.

[hogaboomer]

That laser stuff is above my pay grade.

[tinspark]

The mirror idea was pretty cool. I could just see one of my mastiffs running into the broom propping it up and breaking the Mrs. mirror.
Looks like it is coming along nicely! Good layout techniques!

[thejm]

Thanks guys I appreciate the compliments. My goal is for this thread to become somewhat of a resource for guys starting their first build especially since its from the perspective of someone just getting into metal working and building their first smoker!

[thejm]

Hey Guys,

I am starting the process of designing the trailer for this smoker and am looking for some advice from those of you that have built trailers for their smokers. However i design it I am going to use 2" by 4" by 1/4" steel tubing. This should be plenty strong enough for my applications.

My smoker will be about 1,330 pounds fully built without any supports or frame.

A few specific questions:
1. In looking at the weight of my trailer and my smoker, i am planning on using a single 3500 pound axle rather than tandem axles but i see a lot of smoker trailers with tandems. Has anyone else come across this? Is there a good reason to go tandem? Just seems expensive and more tires to replace.

2. Is it imperative to have your smoker centered (left to right) on the trailer? I am looking at having mine biased about a foot to the door side of the smoker to give me easier access to the meat especially the meat in the back. This will also give me enough room for a firewood storage box on the other side. Will this make the trailer pull poorly?

If you have built a trailer post a pic below!

[Big T]

I don't think that a tandem axle is a must have for a smoker of this size as long as you don't start adding a lot of things to the trailer. There have been plenty of them built on single axle trailers over the years without any issues. If you were going to be pulling it long distances on a regular basis a tandem axle would probably be the way to go because I think it would ride a lot smoother. My 24 X 48 with a WC is on a single 3500lb axle and it bounces pretty bad when going over bridges at high speed which puts quite a load on the springs. I believe that Frank has replaced the springs on Mack 2 or 3 times and it's on a single 3500lb axle. As for your 2nd question, I've seen several smokers built on the forum that were offset and I only recall one person having any problems. His trailer leaned to the heavy side because of the load on the leaf spring. I believe that he put the next size spring on that side and it corrected the problem. If you check out the Mack build I believe that there are some good pictures of the trailer build on the thread.

[dacolson]

My 2nd build was a trailer on a single axle. My build was a 80 gallon tank w/ a warming chamber and a 33 gallon charcoal grill on the back side. I built it offset from center, which is part of the reason I built the grill on the back side. My suggestion is if you are going to build it offset of center, build the other side with walls so you can store things and offset the weight. Logs, coolers, beer, etc. Chances are you'll bring enough crap to even the load.

[thejm]

I don't think that a tandem axle is a must have for a smoker of this size as long as you don't start adding a lot of things to the trailer. There have been plenty of them built on single axle trailers over the years without any issues. If you were going to be pulling it long distances on a regular basis a tandem axle would probably be the way to go because I think it would ride a lot smoother. My 24 X 48 with a WC is on a single 3500lb axle and it bounces pretty bad when going over bridges at high speed which puts quite a load on the springs. I believe that Frank has replaced the springs on Mack 2 or 3 times and it's on a single 3500lb axle. As for your 2nd question, I've seen several smokers built on the forum that were offset and I only recall one person having any problems. His trailer leaned to the heavy side because of the load on the leaf spring. I believe that he put the next size spring on that side and it corrected the problem. If you check out the Mack build I believe that there are some good pictures of the trailer build on the thread.

I do plan on towing the smoker about 3 hours away to my grandmas house for thanksgiving so i might consider a tandem. They really aren't that much more expensive, they just interfere more with getting to the cook chamber. Thats my biggest hurdle at this point. I am using the standard 10%-15% tongue weight rule and it seems no matter how i design it, the wheel falls at the back half of the CC (which makes sense since the smoker is the majority of the weight of the trailer assembly). I am working on trying to move the smoker over so that the wheel is somewhat tucked under/beside the smoker.

[thejm]

So i laid out my 2 CC doors yesterday and have started making the hinges with my bender and some 1/2" rod I bought. I am trying to do what I can to prevent warpage of the doors so my plan is to:
1. Weld supports on the inside of door 1 (closest to firebox, firebox is NOT attached at this point)
2. Make and install hinge for door 1 and door 2.
3. Cut door 1 out.
4. Weld supports on the inside of door 2.
5. Cut door 2 out.
6. Wirewheel inside of CC.

After this, I was going to turn the tank with the doors open and facing up and burn it out. Is it a good idea to burn it out? Should i be worried about the heat causing the tank to warp and the doors not fit? Since this is all 1/4" material i wouldnt think this would be a concern but want to ask you guys with more experience.