Offset Problem

[tieman]

I have been reading and getting information from the site for years. Do not post much and although I like building offset smokers (11) I have an heating issue with one I just got completed. It is just a 48 inch grill on a trailer I made built similer the the Lang 48 with some of my personal touches, I put 2 temp guages on it and there is 60 to 75 degrees difference in the 2 guages.
I used the sizing calculater on this site to creat my vents, stack height, etc. The guages are new Tel-Tru's which I always use, so I dont think it a guage problem although I have not checked it. I did switch ends and the one is still allot hight than the other. The last one was exactly like this one and it works perfect.
When using the calculater it said to use a 24 inch stack when using a 4 inch pipe. The 4 inch scheduled 40 pipe is actually a 3.5 inch ID. With stack size that is recommended be the OD or ID? Any info would be appreciated...thanks

[k.a.m.]

tieman, when figuring stack height calculate the ID. The calculator is figuring the internal volume of the stack. On a cooker your size I would use a minimum 4" ID.
I hope this helps.

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Always remember slow and steady wins the race.

Hybrid Cooker

[tieman]

I will change it out, but what puzzels me is the one I had before this one was exactly like this one and cooked great.
Thanks for the info

[k.a.m.]

tieman, was your temp difference in the first hour or after she was totally warmed up? It could be a variable of things like the weather that day was it windy and or wet and humid? Cookers will perform in weird ways from day to day.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[daddywoofdawg]

Are your tuning plates or RF plates the same and in the same place?May not be getting the heat to the other side.
_________________
Good BBQ is all smoke and beers!
The Dawghouse Custom vertical Gasser
Custom Made offset smoker
Char grill smoker
Weber kettle

[tieman]

Yes my RF plate is extactly the same place as the previous build, Exactly the same length.... everything is the same. I did check the ID of the stack and it is 4 inches and that is how I ran it through the calculater.
As KAM says the outside temperture make a tremendous difference. Wind yeah I live on a hill and have plenty of it. I will usuall pull it in the shop with the overhead open to find a nice break from the wind. KAM to answer your question are consistantly 40 to 60 degrees apart from strat to finish. I find myself cooking on the end where the heat come out and as you know one should not have to do that?
I thought maybe I was loosing excessive heat from door leakage but did some work on it and did not make any difference.
I havent nor will I give up but a little frustrated with this one. I keep saying this is my last build but someone will come along and make me a good offer I cant refuse and here we go again.lol

[Maniac]

just a stupid? did you switch your therms to see if they had the same reading when switched?
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RF Smoker
20" disc
uds

[tieman]

If you would have read my first post you would know that I did switch ends with the therms and got the same results.

[Maniac]

sorry don't know how i missed it
_________________
RF Smoker
20" disc
uds

[1MoreFord]

Let me ask some questions.

How is the pit pitched? Nose up? Nose down? RF's have a personality that way or so I've been lead to believe.
_________________
Joe

[k.a.m.]

[tieman]

I dont guess I quite understand the question? But curious as to what you mean.

[1MoreFord]

[tieman]

Thank you for the reply and yes since the one I built is on a trailer its easy to raise the nose either up or down which like you say does make a difference. I wished I had bit the bullet and had my take rolled useing 1/4 inch plate instead of 3/16. Just no cutting corners if you looking for a good cooker. Damn steel is so expensive. thanks