WSM airflow on long smokes with ash build up?

Discussion in 'Charcoal Smokers' started by jerseydrew, Apr 13, 2013.

  1. jerseydrew

    jerseydrew Smoking Fanatic

    what do you guys do? as the bowl fills with ash it is harder to hit temp running full steam and i am thinking it is because there is so much ash. last night i started the smoker up at about 8:30 with an 18 lb bag. at 3 am i had to add another 9lbs of coal to keep it going. then today at about noon i had to add another 9 lbs of coals. and now as a result i have everything wide open and i am seeing ash fall out of the intake vents and the temp just wont go to where i want it to now. it gets close but just not there. 

    any tips on dealing with this for my next time around?
  2. fpnmf

    fpnmf Smoking Guru OTBS Member

  3. dward51

    dward51 Master of the Pit OTBS Member

    What type of charcoal are you using (type & brand)?  Some creates more ash than others and some also burns faster and hotter than others.  Also things like water pan with water vs empty pan or clay pot base will affect burn times.
  4. fwismoker

    fwismoker Master of the Pit

    Could be a stupid question but are you using a charcoal basket and the minion method?
  5. jerseydrew

    jerseydrew Smoking Fanatic

    Minion method. Water in pan. Kingsford comp briquettes. Low 40's temp all night with 7-10 mph winds.
  6. dward51

    dward51 Master of the Pit OTBS Member

    Kingsford comp should last a lot longer than that.  Could the wind have been blowing directly into the lower vents and have driven the temps up for a while?  That would burn through fuel quicker than normal.  But a minion method at 225* or so should last a lot longer than that (even Kingsford blue bag).  Using water would have moderated the heat spikes somewhat because of the physics involved to flash water at 212 to steam at 212* (and the tendency to want to stay as water), but I would not think it would burn through fuel like that.
  7. davidgibsonhm

    davidgibsonhm Newbie

    I think that its where natural lump charcoal is better, I get much less ash with lump. not trying to start a charcoal war I know some people are passionate about their charcoal. when I used brickets I had the same problem, they would sink into the ash and smother themselves out.
  8. teebob2000

    teebob2000 Meat Mopper

    You smoking a side of beef??  [​IMG]   That's a heck of a loooooooong smoke!  What's your cooking grate-level temperature?
  9. jerseydrew

    jerseydrew Smoking Fanatic

    i've used royal oak before and my only issue with it is that it burns so fast. you have to add so much fuel to it for a long smoke. i think i may start not using water in the pan. and running a little hotter to cut time down a bit. 
  10. I don't know much about WSM but don't their coal baskets have a crating where the ashes would fall through and land on the ash catcher, leaving the burning coals to keep on burning above it?

    and while I risk adding to the charcoal vs lump war, the only problem I have with lump coals is that there are more smaller pieces than the big ones, making the lump coals a bit more ineffective.
  11. jerseydrew

    jerseydrew Smoking Fanatic

    yes but on a long enough smoke the ash builds up in the bowl and will actually come up to the bottom of the grate and start smothering the fire.

    i have had the same experience with lump you get more gravel size pieces then actual lump pieces.
  12. dward51

    dward51 Master of the Pit OTBS Member

    One trick to help keep small pieces of otherwise usable charcoal from falling through the grate is to add a 2nd grate with the bars set 90* to the first.   I have the old style 18.5" WSM and the charcoal grate from the Weber 18.5" kettle is just the right size to fit inside the charcoal ring for the 2nd grate (Weber model # is 72501).  The old style 18.5" WSM has a 14.5" diameter charcoal ring and the #72501 grate is 14". The new style 18.5" WSM has a 15.25" charcoal grate, so the 72501 grate would probably still work, but they have another model that would be a better. The 22.5" WSM has a 17" diameter charcoal ring and the charcoal grate from a 22.5" kettle is listed as being 16.5" so it should work for a 22.5" WSM.  This 2nd grate also fills in the gap at the sides of the charcoal grate.  I got my 2nd grate or this mod at Home Depot.  It was an off the shelf stock item in 2005.

    I used some stainless steel wire to wire my charcoal ring and the two grates together as a single unit.  (Note the following photos are not mine, but illustrate my points).

    You can also cut a section of expanded metal lath to accomplish the same thing.  The bracket bolts are to make a handle so you can shake the ash off of the lit coals when it's time to reload or if you are saving the coals by choking off the oxygen and putting them out at the end of a smoke.  You can take the mid section off, grab the bolts with welding gloves, and give them a quick shake or two to clear the ash. Gives you nice fresh red hot coals to light a reload from.  I like to take a metal tool and gather the lit coals up in the center and fill in around them with unlit for a sort of minion method restart on a long smoke.  Once you practice it a few times, you can do the whole thing in under 30 seconds and you meat will not miss a beat.

    Last edited: Apr 14, 2013
    markbeer likes this.
  13. fpnmf

    fpnmf Smoking Guru OTBS Member

    I cannot understand what is going on that you use so much charcoal.....

    One 20 pound bag of KB lasts at least 3 smokes or right around 20-24 hours..

    20 pounds tends to be time to empty the ashes..
  14. dward51

    dward51 Master of the Pit OTBS Member

    I'm with Craig on this scratching my head trying to figure out why you are burning through Kingsford so fast.  Even an all night boston butt smoke with the water pan kept full should not use a whole bag, much less a 2nd bag like your original post.  I know the 22.5" uses more fuel than my 18.5" does, but that's crazy.

    You are not using lighter fluid are you?
  15. jerseydrew

    jerseydrew Smoking Fanatic

    no sir lighter fluid is a no no! this one had me scratching my head too. could it be i was trying to run at 250 with the water pan full?
  16. dward51

    dward51 Master of the Pit OTBS Member

    22.5" WSM?

    I know the 22.5" uses more fuel and goes through it quick than my 18.5" would. I would not think 250* with water in the pan would do that, but I guess it might.  Due to the physics of the phase change from liquid water to steam, it takes a huge jump in energy to go from water at 212* to steam at 212*.  And water wants to remain liquid.  That's why it makes a great heat moderator in a smoker running "low and slow".  All other things being equal, that has to be the reason, but it still sounds like a lot of fuel to me.

    Hopefully someone who runs water in their 22.5" WSM will comment on this soon.

    You may want to find a clay flower pot base for your WSM and try a trial run with that instead of water.  Wrap it with foil and sit it inside an empty water pan.  The pan will act as a heat shield from the direct heat of the charcoal. You want to find the largest diameter base that will just fit inside your water pan.  I used a 14" in my 18.5" WSM, but that won't help you if you have a 22.5"  I would think you want something in the 16-17" range.  The mass of the flower pot base will help moderate heat swings.  It does not work as well as water for bringing a spike back down as a flower pot base at 240* wants to stay at 240* whereas water wants to stay water and not steam so it can have a cooling effect if the heat source is throttled back.

    I know using the clay pot base in my WSM I use a lot less fuel than with the water in the pan.  I've run entire shoulders on a single fire ring full using the flower pot base and the minion method (no reload at all).  But again, I have the 18.5"
    Last edited: Apr 14, 2013
  17. dward51

    dward51 Master of the Pit OTBS Member

    Just a side FYI, but it takes 1 calorie of energy to raise the temperature of 1 gram of liquid water by 1* C.  However it takes 540 calories of energy to raise the temperature of that same mass of water from 100* C liquid water to 100* C steam (just to flash the water over to steam and not increase the temperature - this is called the latent heat of vaporization).  Conversely it takes 540 calories of energy out of the steam when it falls back to liquid water. That is why water makes such a great heat moderator in a smoker.

    This is a "small calorie" or a "gram calorie" and it is not the same as a Calorie which we see used in food ratings.  That type of Calorie is actually a kilocalorie or Calorie (large "C"alorie) which is 1,000 of the small calorie units.  The more common annotation of a small calorie is usually express in joules and a calorie is equal to 4.1868 joules of energy.
  18. fwismoker

    fwismoker Master of the Pit

    Smoking in 40 degree weather vs 60, 70 or 80 is a very big variable, wind and the where it is hitting the smoker is another. 
    Last edited: Apr 14, 2013
  19. fpnmf

    fpnmf Smoking Guru OTBS Member

    That is true...

    But 37 pounds of charcoal for one smoke??

    Something aint right...
  20. jerseydrew

    jerseydrew Smoking Fanatic

    I do have the WSM 22 i will measure and try clay base.

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