temp issues on my snp

Discussion in 'Charcoal Smokers' started by ravenclan, Sep 19, 2009.

  1. I have done some of the mod's on snp,[​IMG] like the extension on my chimmney and i also put a sheet metal the lenght of the smoker bottom "with holes to allow heat and smoke to move" but at the end closest to the firebox i still have a temp difference of 50 degree's from the box end to the other end. I made sure the sheet metal is even in the bottom and also tried to lift the far end higher in hopes that the heat will move to the colder end faster. i hope to smoke tomorrow morning and i am stuck with the difference in temp.

    any ideas [​IMG]?????

    Thanks in advance !!!!!!!!
  2. forluvofsmoke

    forluvofsmoke Smoking Guru OTBS Member

    Are you speaking of tuning plate surface temps, cook chamber temps, or cooking grate temps?

    On your tuning plate, did you leave a gap of about 2" on the vent end?

    I found that it has to be able to flow across relatively freely to get even temps all the way through. With holes drilled in the tuning plate, it only allows a small percentage of convection (heated air/gases) to pass upwards through the plate, the rest of the heat is radiant (through the plate metal).

    I have my tuning plate fitted level and tight on the firebox end and front-to-back. I use long stem turkey fryer therms with the tips resting directly on the tuning plate. These were installed through small holes drilled just below cook grate level in the front of the cook chamber. I can monitor the tuning plate temp very well. The fire box end is always 50-70* hotter than the vent end with a gas burner, and about 30* hotter with a charcoal fire with mine.

    As for the chamber and grate temps, have you checked both ends for even readings?

    Grate temps are what you really need to know. Chamber therms are a baseline to go by after checking grate temps and comparing with the chamber therms, so you know what the difference in readings are.

    Depending on what you are seeing for temps, you can go alittle further with the tuning plate by drilling a few more small holes in strategic locations where ever the cooler spots are, to even out the grate temps more. Don't drill too many at once, or it can foul up the process. It took me a long time to get mine relatively close, ~10-15* front-to-back, and ~15-20* left-to-right. Trust me, this takes time, patience and lots of oven rack therms to save some time (I have 10). 20-30 minutes between each temp check with using a chamber therm for a baseline.

    There is a good side to having uneven grate temps though...if you have birds to smoke you can put them on your hot spot and run the butts/briskets, etc. on the cooler areas for slower cooking. [​IMG]

    I tossed out what I could think of based on what you gave for info so far...come on back if you need more/better info.

  3. pineywoods

    pineywoods Smoking Guru Staff Member Administrator Group Lead SMF Premier Member

    I'd suggest going to "search" at the top of the page once you click on that click on "advanced search" then under "key word" type in "tuning plates" and click where it says "search entire posts" and click on "search titles only" then drop down and click on "search now" this will bring up several threads on tuning plates that should help. Good luck with getting the temps more even I hope the info helps
  4. smokin' dick

    smokin' dick Smoking Fanatic

    Not the best pics, but these may help. This is my Silver Smoker, similar to yours I think. The first pic of the chamber has five 1/4" x 5" x 16" steel plates spaced slightly apart. Fire box is to the left. This gives me even temps across the chamber with NO meat in it. When the meat goes in, typically ribs, the side away from the fire box cools dramatically. I now use just three plates keeping the right side open with no plates. The ribs go above the open area. Works great.

    Another thing people do is put a baffle at the fire box to try and direct heat down and under the tuning plates. Also, since the fire box end is so hot, put a bread pan full of water on the grate to soften the effect of the heat there.

    Good luck in smoke!
  5. papad

    papad Smoke Blower

    Just finished modifying mine and am smoking some ribs right now. I'm noticing just what you're talking about. I've been able to hold steady temps, but I still have a difference of about 40-50 degrees from one end to the other. I've been sitting out there thinking about doing just what you said and removing the end plate and leaving the far end wide open to see if that will even it out more.
  6. tasunkawitko

    tasunkawitko Master of the Pit OTBS Member

    hi, raven - the bottom line is that the sheet metal is simply too thin. here are some suggestions for "quick and dirty fixes" until you've got the $$$ to build or have a good, thick manifold built.

    1) get at least four bricks (or a couple of firebricks, if you can find them) and put them 2x2 at the "east" end of your SnP (the same end as the chimney). these will retain heat at that end. and do a lot to help equalize the temperatures. it will take a little longer for your SnP to come up to temperature, but it is worth it.

    2) get two or three heavy, old blankets, fold them so that they fit on top of the SnP smoking chamber and use them. make sure that nothing "hangs down" near the fire box. it is ok if there is some hanging down on the front, back, or "east" end. it looks redneck as can be, but it is worth it.

    in the meantime, start doing some research on a good design for a manifold that will work for you - quarter-inch steel plate is recommended as this will hold heat all day long.

    good luck!

  7. fire it up

    fire it up Smoking Guru OTBS Member

    I can vouch for that, out of nowhere once a rainstorm showed up while I was smoking, it was a small one but the only thing I could do (short of dragging the sNp on the porch and using fans to blow everything out the front door, not recommended [​IMG]) was to throw a few towels over the top and it was really amazing how well a few simple towels helped to insulate the smoke chamber.
  8. ddave

    ddave Master of the Pit OTBS Member SMF Premier Member

    Smokin' um Richard [​IMG] and I have basically the same setup it appears.[​IMG]

    A baffle and 3 tuning plates. These are 1/8" steel and the tuning plates are 10", 8", and 6" wide.

    This is an important point to realize. You can work your brains out to get even temps empty but as soon as you put some meat in there, the flow and temperature profile are going to change.

    You also have to be careful that in your quest to redirect the heat you don't block too much of it. That's what I did when I was using 4 tuning plates.

    This was my original setup but I went to 3 plate because 4 was just blocking too much of the heat. I was having problems with draft and temp.

    I like the plate with rows of holes idea but haven't made one yet. I have a drawing though.


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