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BLOCK OFF PLATE BONANZA ! SEE PICS!

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by WoodButcher80, Nov 19, 2008.

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  1. WoodButcher80

    WoodButcher80 Feeling the Heat

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    ok guys, after i come up hungover from Columbus Ohio to see the greatest blowout this saturday, i plan on tackling the rest of my block off plate . from the pics below, you can see i had the right tools for the job. .
    now, ive listened to many peoples opinions on what to use to cut out the damper frame to fit your pipe through(in my case 7" round) .
    ignore it all. get yourself an angle grinder , 4.5" or whatever, and get thin cut off blades from the depot for 2$ each(itll only take one and you cant cheap out on these things). get your goggles and cloth mask and away you go! i cut throught the steel frame and brick in about 60 seconds. then , luckily, i had an air hammer chisel and blasted away the remaing sharp chunks of brick.

    anyways, i just bought 4' of Kaowool (from http://www.anvilfire.com/sales/pages/index.htm) and its 1" thick and 2' wide.

    heres my question. as you can see below, i have custom cut a block off plate from 30gauge hvac metal, and i have TWO of them to smoosh together. i was thinking, should i put one layer of kaowool like a blanket in between the two riveted pieces of metal like a sandwhich , OR should i lay a layer on top of both sheets of metal, thus the kaowool would be closest to the chimney cap?

    if thats the case i was wondering how this stuff will stay put on the block off plate. i figure glue will melt.
    i was DEFINITELY gonna take this stuff called 3M FIREBLOCK (anyone use this?) caulk and put it on the sides and the rest of the wool and line the edges of the metal so no air can creep in on the sides where it meets the brick. the fireblock cault is supposed to expand slightly when fire hits it to seal better, but i think they mean dirt flame.
    then i was gonna just tack the plate in place to hold it.

    what you guys think? rivets or a better solution? where to put the wool blanket?

    thanks in advance! :)

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  2. WoodButcher80

    WoodButcher80 Feeling the Heat

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    more pics of block off

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  3. iceman

    iceman Minister of Fire

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    sounds a little overkill but if it makes you sleep better do it!

    you cam use the wool and stuff allaround the damper opening and pipe.
    then install blockoff plate and use furnace cement where the pipe goes through the plate
    but before that stuff the rest of the wool up there.
    use some tapcom screws to get a good hold on the blockoff plate then use hitemp silicone or what ever your choice to seal any gaps
    whatever you do post more pics!!!! we like pics!!!!!!!
  4. burntime

    burntime New Member

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    Looks identical to what I did but I ended up using 2 pieces of metal and screwing it together. You will definitely be happy. Like iceman said...put some rock woal above the block off plate as well.
  5. Chardler

    Chardler New Member

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    I was considering using the 3M firestop sheets for a blockoff plate too. They have the putty and caulk as well for sealing up the cracks and spaces. I am hesitant only because I'm not sure how much gassing off that material will produce each time it gets hot and i don;t want to be smelling it all the time. I know how it works...expanding when exposed to heat and fire, but if it's exposed to it on a regular basis, how will it perform? Will it degrade over time or become a health hazard?
    Has anyone else ever utilize this stuff for a blockoff plate?
  6. ksting

    ksting New Member

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    Why did you cut out that hole in your damper? You could have just ovalized your liner, pulled it through, and then knocked it back round again to connect to the stove. That's how mine is and I haven't had any issues so far.
  7. Hogwildz

    Hogwildz Minister of Fire

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    How you did it is perfectly fine.
    However, even though you re-rounded it after it is through the old damper. It is still oval at the damper. Which may or may not cause some small problems when brushing the liner out while cleaning.
    The other factor is, depending on how much you cut out, it can give you a straight shot onto the stove, rather than a bend to bet it to meet the stove outlet.
    This is the reason I cut mine out. Makes for easier cleaning & inspection sighting. What I would have done it I was him, since he already cut some of the damper out, is cut some more out, eliminate the offset all together, and have a nice straight run right to the stove outlet.
    There is not set science to liner installation, so each person does as they see fit, or how the imagine in their mind.
    And most of us are newbs and doing it for the first time. I helped another member run his liner and made a nicer block off plate for him, then I made for my own. But, I had one under my belt already and had an idea of how to improve the original design. As long as its done safely and works properly, in the end that is what matters most.
  8. ksting

    ksting New Member

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    Actually, I have an additional flush mount kit installed on my Freedom which pushes it all the way to the back of my fireplace. The installer didn't even know about it until I ordered it. It's almost as flush as the Declaration which is what I really wanted but couldn't get it to fit without knocking out bricks. Anyway, it's a stright shot through the damper other then the oval at that point so I'm pretty satisfied. My only issue is that I don't have a block off plate at the bottom. I wish I had the installers put one in but it's too late now I guess. My stove likes to run hot anyway, so a little heat going into the dead air space in my chimney isn't really affecting my output at all. I have to run the blower anyway with it pushed so far back in there. Don't see any other reason for adding the block off plate unless you want to stop additional heat from being lost up in there. Am I correct in my assumption??
  9. Hogwildz

    Hogwildz Minister of Fire

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    Block off plate also seals off in the event of the liner rupturing due to a chimney fire( not that this is common), it would help keep any fires from back drafting back into the home. Sort of a fire barrier.
    Not saying that will happen or at all, but when there is potential, the extra effort is worth it in my book. Second point, again not major if your happen with performance already, but some members have felt same as you, perfectly happy with performance & heat output, but on the very coldest of days/nights (below 20 degrees) they found they noticed a difference of the heat output due to less heat loss up the chimney and absorbed and transferred to the outside through the masonry. Of course this is mostly a problem with exterior chimneys.
    Lower block off plate is not required by code, but is merely an extra barrier to retain heat to the inside of the home & extra added protection in case of chimney fire gone real bad.
  10. WoodButcher80

    WoodButcher80 Feeling the Heat

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    Snowbelt of NE Ohio - Chardon

    thanks for all your replies. as for the aforementioned questions, well start with the one quote above. the only reason im doing it is that i have an external short stack and i dont want all my heat being used to heat up the chimney stack facing outside. heat always moves to where cold is, i am told. and i want the first place to being radiating in my family room! also, some say its good to have one down low to contain a fire in the chimney if there would be an accident.

    as for not ovalizing the pipe.... well, thats simple. if im gonna get dirty, may as well do it right. i also have the tools handy!

    also, if im gonna spend 365$ on a liner, i want it to be the correct surface area size for my stove, and in my case its a 7" round pipe.i also want the minimal amount of curves in the liner. if i would have squished it through a damper - mind you the damper opening was 4.5" wide - it would have impacted the nice draft i am seeking.

    the BEST way to think of it is a drinking straw. if your sipping your soda from a straw and pinch the middle of the straw so its a little more half the diameter of original size, your gonna mess with the draw, or flow, or DRAFT :) ya like that analogy? lol. anyways, im never gonna use the damper ever again, and if i sell the house i can get a chimney cap damper up on the roof. whoop di doo .

    and no, this is not overkill to me. if im back there and im spending the $$$ and time to do it, im gonna do it right. whether its the liner OR the block off plate...ive heard too many people on this forum say they wish they would have done a block off the first time, etc etc. just my 2 nickels.....
  11. Hogwildz

    Hogwildz Minister of Fire

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    HA, I forgot to add the demolition factor. I took great joy in the demolition I performed to get it just the way I wanted to.
    There is something about hacking away at stuff that gets my blood going. Always been that way. Add the feeling of a job well done when accomplished,
    priceless.
  12. WoodButcher80

    WoodButcher80 Feeling the Heat

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    ill cheers to that! that air chisel is a blast to use! and only 15$ ! ive been tryin to find stuff around the garage to use it on. its great!

    getting back to the other unanswered question, has anyone used this 3M fireblock stuff? if it expands and contracts all the time i dont think i want it... i got a tube but am willing to try something else that will withstand the heat if need to .
  13. Hogwildz

    Hogwildz Minister of Fire

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    I have never used the 3M stuff.
    Where exactly are you planning to use it?
  14. WoodButcher80

    WoodButcher80 Feeling the Heat

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    i have enough kaowool to outline the entire outer edges of the block off plate and the to lay on top of it as well. knowing that, should i put a 2" strip that will run in between the block off sheet and the smoke chamber brick its resting on? is this a bad idea? should i just jam the metal plate where it needs to go and put only kaowool around the liner hole i made in the sheet metal and resting at the top of the block off plate? i would think i dont need to use the kaowool smooshed in between where it buts up to the smoke brick, and just put it on top, seeing how the wool wouldnt entirely AIRTIGHT SEAL the edges, as the firestop or another caulk would.

    did a quick search for fb 136 caulk on the site and found an old post:
    http://www.hearth.com/econtent/index.php/forums/viewthread/1057/#8297



    to help, and if you care, ive posted what they say on their website :

    product description:

    3M™ Fire Block Sealant FB 136, a one component, water-based,
    non-combustible draft, smoke and fireblocking sealant,
    designed to resist high temperatures and smoke passage in
    non-rated construction.
    3M™ Fire Block Sealant FB 136 meets ASTM E-136, current
    2003 International Building Code (IBC), 2003 International
    Residential Code (IRC), 2003 International Residential
    Mechanical Code, 2003 International Fuel Gas Code and
    NFPA 5000 draft, smoke and fireblocking requirements.
    3M™ Fire Block Sealant FB 136 features superior adhesive
    strength, caulk rate, and no-sag application, plus a halogenfree
    formula.
    3M™ Fire Block Sealant FB 136 can be installed with a standard
    caulking gun, pneumatic pumping equipment, or it can be
    easily applied with a putty knife or trowel. 3M™ Fire Block
    Sealant FB 136 will bond to concrete, brick, metals, wood,
    plastic, and cable jacketing. No mixing is required.



    APPLICATION :

    3M Fire Block FB 136 is ideal for use in residential (single, twofamily
    and combustible) construction in areas that require sealing
    to maintain the integrity of a fireblock. 3M FB 136 can be easily
    applied with a standard caulking gun, pneumatic pumping
    equipment or simply a putty knife and/or trowel. It adheres to
    virtually any material, including wood, masonry, metal and plastic.
    It is gray in color and applies like conventional caulk.
    • Wires, Cables & Conduit
    • Plumbing
    • HVAC Ducts & Vents
    • General Construction Gaps
    • Chimneys & Fireplaces
  15. Hogwildz

    Hogwildz Minister of Fire

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    I personally would put the kawool on top of the block off plate. And then put the block off plate in place. And stuff kawool around the liner where it passes through the block off plate (depending o how large the gap is).
    If the gap is small enough, you can use the furnace cement around the liner where it passes through the plate to seal it off. If gap is larger, stuff kawool or as I used, a stove door rope gasket as a filler for the gap.
    I left mine as so. You could then use furnace cement or the 3m stuff to seal over the filler. All a matter of preference. I can say, that a larger gap will not hold the furnace cement well on its own. The cement tends to crack and fall out if trying to seal a large gap. Hence why I used the rope gasket as our wise ol Brethrem Bart pointed out some time ago.
  16. WoodButcher80

    WoodButcher80 Feeling the Heat

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    ok guys ,heres the final pics! i had to cut and cut some more of the leftover shroud welds to get my arm in and around to connect the cast iron insert boot connector on top of the stove. had to buy a hex head on the one side cus i couldnt get a flathead screwdriver vertical to tighten it down! tight tolerances. i put 10sq ft of Kaowool above the sheet metal blockoff plate and around the 7" liner. then used tapcon screws in the corners to hold it in place. after that , i sealed around the blockoff plate with a 3M fireblock sealant. aint nothing gettin past it! theres apic below of the ROUGH installation of the blockoff plate before i cut the kaowool and made it nice.

    i am gonna make a shroud out of 3 pieces of sheet metal riveted in the corners . as you can see , the paint is rough because i wire wheeled it and steel wooled it to prep it for paint . thinking about stove bright russett color http://www.northlineexpress.com/itemdesc.asp?ic=5SA-8102

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  17. WoodButcher80

    WoodButcher80 Feeling the Heat

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    12 degrees out, TURNED OFF THE OIL FURNACE AT 62DEGRESS on the thermostat ...... 4HRS LATER.... all 2000 sq ft was 68 degrees and then some! the room with the Baker in it was too hot. and no, i didnt over fire it. :) not too bad for a slab-based room surrounded by 3 outside walls and an exterior 17' chimney! nothing was going for this colonial's houses hearth location, but i think attention to detail in the install , a whole heap of help from you'all , and an ounce of obsession is what did it!

    finally , a fire pic!

    (with the door open, youll see a steel 1/2" thick plate in the front of the firebox. this is a coal/wood stove with shaker grates and all. the plate is used to keep the coal away from the door/window (my glass is on order! ) . . . just figurin someone woulda asked. .. .

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