1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Replacing the Wood Gun nozzle

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by muncybob, May 22, 2012.

  1. muncybob

    muncybob Minister of Fire

    Joined:
    Apr 8, 2008
    Messages:
    2,003
    Loc:
    Near Williamsport, PA
    Finally got around to doing the summer cleaning of the WG last night. The 3 season nozzle looks like it should be replaced before next heating season. I say looks like because the refractory is still in place and not falling apart but the nozzle "holes" are enlarged.

    So 2 questions....what would be the negative effects of using the nozzle where the holes are maybe 50% enlarged? ...and...has anybody replaced the 2 piece nozzle refractory? Appears to be an easy job?(dang, that's 3 questions).

    I did order the replacement nozzle last year but I am hopng the WG owner that replaced the refractory type nozzle with a steel one has good results as I'm hoping to not have to do this every 3 years.

    Helpful Sponsor Ads!





  2. Gasifier

    Gasifier Minister of Fire

    Joined:
    Apr 25, 2011
    Messages:
    3,137
    Loc:
    St. Lawrence River Valley, N.Y.
    Hey Bob. I was going to send you a message and ask you if you had done this yet. I have not had to replace yet. But was wondering the same thing. My nozzle apears to still be in pretty good shape. I have burned approximately 8 full cord of wood through the boiler since October 1 when the Gun came on line. And this has been a mild winter. I am going to order a new set for the nozzle before the summer is over and probably replace in the fall. My nozzle holes are enlarged as well. I lose my coal bed toward the rear faster than any place else and I think that is because the hole at the rear is the largest. I have thought about the steel plate, and about some of the "cement", but I think I am going to stick with the replacement nozzle this first time and see how the others make out. Could the "cement" cause any problems with the larger ceramics in the Wood Gun? If it did not work out to good and you wanted to go back to the replacement nozzle. For instance, could it be in the way for future replacement kit? Could it be hard to get it off of the large ceramics? I would hate to break the large ceramics for any reason. Those are expensive.
  3. infinitymike

    infinitymike Minister of Fire

    Joined:
    Aug 23, 2011
    Messages:
    1,697
    Loc:
    Long Island, NY
    Hey there fellow WG boys.

    I think, and thats all I do since I have only burned for 1 season, that having larger nozzle holes will just let more coals fall into the secondary chamber.
    Which means you may lose some efficiency in gasification and you may need to clean it more often.
    How much efficiency? The world may never know.
    But then again you may not lose any efficiency, gasification is achieved by the gases being pulled over the hot coals so if some of the hot coals are in the lower chamber you still might get some type of gasification. AHH what do I know?!

    What if you leave the nozzles the way they are and put a strip of stainless steel grating over the nozzles. You know the kind of grating used on metal stairs.
    It would be interesting how long that would last.

    Speaking of metal, what metal piece are you guys talking about? Is this something you can buy from AHS?
  4. muncybob

    muncybob Minister of Fire

    Joined:
    Apr 8, 2008
    Messages:
    2,003
    Loc:
    Near Williamsport, PA
  5. Gasifier

    Gasifier Minister of Fire

    Joined:
    Apr 25, 2011
    Messages:
    3,137
    Loc:
    St. Lawrence River Valley, N.Y.
    Hey Bob. Did you ever replace your nozzle? Just curious. Mine is still in pretty good shape, but the slots are getting a little bigger. Probably will be replacing the two pieces sometime early this season like November, December.
  6. infinitymike

    infinitymike Minister of Fire

    Joined:
    Aug 23, 2011
    Messages:
    1,697
    Loc:
    Long Island, NY
    Gasifier, wow, that seem awfully quick to be replacing them. I know you did burn all summer but I would have thought they would last longer. I guess I will have to inspect mine a little more carefully. Thanks.
  7. Gasifier

    Gasifier Minister of Fire

    Joined:
    Apr 25, 2011
    Messages:
    3,137
    Loc:
    St. Lawrence River Valley, N.Y.
    Don't need to be replaced just yet. But you can see the slots getting larger. Especially the further back you go. That seems to only mean you end up with more and larger ash in the ash pan. I do not think it is effecting performance too much. We will see. I am trying to remember what they told me about how many cord through and then replacement time. It was pretty low if I remember right. I have put approximately 10 full cord through it in one year.
  8. maple1

    maple1 Minister of Fire

    Joined:
    Sep 15, 2011
    Messages:
    4,009
    Loc:
    Nova Scotia
    Has anyone tried the grating (stretch metal?) suggestion?

    I would think it wouldn't stand the heat - but if some could be found that would, seems that would help almost any gasser nozzle/refractory last a lot longer by just laying a piece over the nozzle with some ashes in between and be real easy to do too. Or if not grating, something similar. I should go read that other thread...

    EDIT: After reading that again, I think I will keep fireplace grating in the back of my mind for a future trial, once I get up & going for a bit. Anything that could be easily done to protect the relatively vulnerable nozzle refractory without affecting performance should be worth checking out, I would think.
  9. skfire

    skfire Feeling the Heat

    Joined:
    Nov 15, 2010
    Messages:
    304
    Loc:
    NEPA
    Grating if it works, should be of high melting point, such as:
    High Carbon Steel(2,600f-2,800f), or
    Stainless alloys, such as 316L(2,500f)

    or if u can afford/find tungsten...yeeeeha (6,150f)..


    Scott


  10. avc8130

    avc8130 Minister of Fire

    Joined:
    Dec 6, 2010
    Messages:
    986
    Loc:
    God's Gift to Gassification
    I plan to take measurements of my ceramic nozzle when I get my WG in and plan to try some different options. I think a plain carbon steel should work just fine.

    AHS told me the nozzle would last 2-3 years and cost $80.
  11. Fred61

    Fred61 Minister of Fire

    Joined:
    Nov 26, 2008
    Messages:
    1,729
    Loc:
    Southeastern Vt.
    Bob,
    I replaced my center bricks on average about every 1.5 seasons. Two things that are of concern are:

    If the holes erode out too close to the shoulders on the main refractory you could erode them or weaken them from the intense heat.

    The second thing is that the larger holes will cause larger pieces of charcoal to enter the tubes. You have probably observed by now that not everything stops in the cyclone and ash pan. I had some pretty good sized chunks of charcoal go into the smoke pipe and burn in a short horizontal section of my single wall pipe. Hot enough to turn the pipe red and cause me concern that it would burn through. It also ignited the High temperature silicone sealant on the joints.

    I had not attributed the emission of sparks out of the top of my chimney to this situation but as I type this message, I'm thinking that it might be another thing to keep your eye on.

    If whomever made the bricks did a good job, it's only at most a 10 minute job to change them. If they are a little warped from the firing or have a high spot, you may need to lap them on a rough piece of concrete to grind off the high points.
  12. muncybob

    muncybob Minister of Fire

    Joined:
    Apr 8, 2008
    Messages:
    2,003
    Loc:
    Near Williamsport, PA
    Good info. No, I have not yet replaced the nozzle and a contemplating stretching it another season but after reading this I think I will replace it soon. I have never noticed anything other than smoke or steam coming from the chimney, nor do I want to. I'm really hoping somebdy comes up with a better alternative and reports it here within the next 3 years! :)

Share This Page