My first build, help me please! reverse flow

  • Some of the links on this forum allow SMF, at no cost to you, to earn a small commission when you click through and make a purchase. Let me know if you have any questions about this.
SMF is reader-supported. When you buy through links on our site, we may earn an affiliate commission.
Too big on the fire box is ok, but as JckDanls said, it's much easier to just make it the width of your RF plate.  This allows everything to match up.  The larger FB does allow for larger pieces of wood, but on a pit that size, you might not need more than a charcoal basket with some small splits or chunks to get a good smoking temp running in it.   
 
I'm on vacation waiting for my son to wake up from a nap so figured an update was due. I will NOT be winng welder of the year anytime soon!

Firebox warped when I started the door. No biggie.
 
Last edited:
What are you welding with? If it is a Mig/wire feed when was the last time you changed the liner? Tension set right?
 
Hmmm, liner? What do you mean? Tension? How do I know if it is right or not? Keep in mind I am 100% youtube (self) taught.
 
It looks like you are welding "flux core wire".... there is a liner inside the cable where the wire feeds.... between the drive wheels and the tip where the wire comes out... The drive wheels have an adjustment to apply pressure to the flux core wire so it feeds without slipping... The tip on the welding gun should fit the flux core wire "PERFECT".. if you are using 0.045 wire, the tip should be 0.045 tip.... the tip acts as a contactor for the current..... needs to fit perfect....
 
Yes, I am using flux core and I am using .035 wire with a .035 tip. Maybe I'll play with the tension a little bit. Thanks everyone. I wish welding came naturally to me but clearly it does not!
 
Bigger issue is the location of your hinge pivot line. It should be on the right side of the seam if you are going to put in a strip to seal off the door. You always want the hinge pivot point to the right side of the door gap as shown in your picture if you are going to add a flange for a good seal. Look up "Welding Tips and Tricks" on Youtube, he is good and goes into good detail. You get to see the puddle in his videos.
 
Miller should have the manual for your machine on there site. If the tension is to loose will create all kinds of nightmares. Keep in mind that the gaps need to be tight. You might want to lose the factory ground clamp. WI'll go out to the garage and get a picture of the one I like...
 
Forgot to mention, might want to search for the Welding Tips and Tricks site and sign up for his emails....they are VERY informative.
 
Thanks everyone. That is why I am here. I like to LEARN! I am intrigued about the ground clamp comment. Are you saying the clamp is no bueno? Man, if only I could take a welding class. The local community college told me years ago I would have to sign up for a complete certificate and I was not able to just take one or two classes. Lame. Thanks again. I will continue to read and study up but unfortunately without someone watching my welds and telling me what I am doing wrong I may never learn. I sure as shit will keep trying though.
 
Where are you Busmania? (you should fill out your profile) There may be a member near you that would be willing to come by and give you some hands on training. I doubt school is needed, just some stick time with someone experienced.

The welding clamp discussion is on the Welding Tips and Tricks website and youtube videos.
 
The ground is as important as the tip and gun..... clean metal and secure, tight gripping ground completes the electrical circuit..... rust, paint or a loose grip can screw up a weld pretty fast.....
 
Thanks everyone. When I get home from vacation I'll try a new clamp and find the miller user manual online and read it again.
 
Back from vacation, back to the smoker build.  I got the new ground and it has made a difference.  I am moving onto the CC so I will be switching to using regular mig welding with gas (no more messy flux core). 

Today I got some scrap for my chimney, it was all they had, will it be ok?  It is 2.75" inside diameter. The calculatotions shows me needing a 24" chimney.  I know it says 30" is ideal but will 24" be too short based on this 30" rule?

second question.  Because of the shortness of the tank, I am going to run the chimney out the side rather than run the tube down into the CC.  Do I calculate the 24" based on A or B in this drawing below?  Because my tools are somewhat limited, I will be building a box to attach to the side of the tank that is the same size roughly as the pipe.


Last question.  I was going to have the chimney hole on the side of the CC half way between the top of the CC and the cooking grate.  OK?  Should I go lower or higher? 

Thanks again.  I am working ont he CC door now and will have more pics soon. 
 
Disclaimer first....never built one of these yet....am in the planning stages.....but from everything I have read it would be in your best interest to adhere to what the calculations advise.....
 
Check with a muffler shop that works on trucks. They should have drops bigger than that really cheap. It may work @ 24, but if it doesn't, you will have to weld on another piece, not the end of the world to try since your tank is short and fat.
 
The pipe is plenty long. I got 6 feet of it. I guess my question is, do I go 24" like the calculations says or make it longer at 30"? Is going 6" longer than the calculator class for going to overdue it? Honestly I'd prefer shorter but if going 30" has any benefits, I'll go that route.

Also, upon pondering it more, I now realize I will count the volume in the side box as part of the overall exhaust volume.
 
Last edited:
There is a note on the Feldon's calculator page about chimney length recommending minimum length. Feldon's isn't correct for FB/CC opening for reverse flow, but the chimney recommendation for length is good. Using pure volume numbers is cool, but make sure you base it on pipe, not box tubing, the friction is not the same for the two. Chimneys should draw well and be based on the height above the top of the CC since that is the mass of air you want to move. If your chimney intake is below the top of the CC, you need to pull the hot CC air down to get it out, that is not natural, so it makes the chimney height "draw" more important. I would go with 30" in your case, the minimum suggested.
 
Last edited:
SmokingMeatForums.com is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

Latest posts

Hot Threads

Clicky