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Wood Pellet Stove Convection Blower Rubber Gasket Material to reduce vibration and noise-Cut to Fit?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Don2222, Jun 18, 2012.

  1. Don2222

    Don2222 Minister of Fire

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    Hello

    A few months ago I purchased a brand new replacement Magnum MF3541 230 CFM convection Blower. I was very impressed with the thick rubber gasket glued to the mounting flange to prevent vibration and noise. Since then, I looked alot for something similar and inexpensive.

    The room fan gasket does not need to be extremely high temperature like the exhaust fan does and rubber is a better choice to reduce noise and absorb vibration!

    I may have found it at Lowes. I found what is called a "Rubber Packing Sheet" in their plumbing department to make your own gasket! Click on pic below!

    They have sheets 6x6x1/16 and 6x6x1/8. I purchased the 1/8 inch thick because it seems as thick as the Magnum. Lowe's Part number is PP25547 also has # 31448 above bar code.
    http://www.lowes.com/pd_31448-143-PP25547_0__?productId=1082957&Ntt=rubber packing sheet&pl=1&currentURL=&facetInfo=

    According to this web site it has a hardness of Durometer = 75
    http://www.sealsales.com/gasketmaterial/Redrubber75.shtml

    Amazon.com also sells this in 12x12x1/8 sheets for $11.78 per sheet
    Since my gasket was 4x4-3/8" I could get exactly 6 gaskets from it. That would be $1.96 per gasket. So Lowe's is cheaper this time!
    http://www.amazon.com/Rubber-Sheet-Thick-Width-Length/dp/B000MAJ10I/ref=pd_cp_hi_1

    It does not state the thermal max but it is red and I know red rubber is good to approx 195 Deg F

    Has anyone tried this material? How does it work?
    So for $1.38 it is worth a try!

    As you can see in the second picture, the old Magnum MF3541 Convection Blower Gasket is a Rope Gasket. See Blue Arrows below. However the new Magnum MF3541 Convection Blower Gasket is Rubber. See Yellow Arrows below. This is the new trend to absorb vibration and reduce noise. The rubber gasket on the MF3541 is not a sticky silicon rubber gasket.

    Attached Files:

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  2. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    There is at least one convection blower that uses a neoprene rubber gasket.
  3. smoke show

    smoke show Guest

    wrong answer.

    just sayin.
  4. Don2222

    Don2222 Minister of Fire

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    Hello

    Well, I just made the gasket and threw it on. Running the stove full tilt on the highest heat setting my infrared gun measures only 103-104 Deg F on the right top of the convection blower. That is the hottest part that the red rubber gasket covers. So it looks like it will work fine and it does reduce noise and vibration some.

    See pics below. Just traced the flange with a pen and used a utility knife to cut out the pattern!

    Attached Files:

  5. smoke show

    smoke show Guest

    must be invisable pics.
  6. Don2222

    Don2222 Minister of Fire

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    Hi Smoke

    Had an error uploading so I had to save the post and then edit again and upload!

    Can you see them now?
    What were you saying about using a rubber gasket? This red rubber is a harder and higher temp rubber.
  7. smoke show

    smoke show Guest

    yes.
    I was just ribbing the old bear.
  8. Don2222

    Don2222 Minister of Fire

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    Oh, OK

    I do like the red rubber better because when I put the blower back on, the red rubber holds the screws in the holes really well so I can put the blower up to the hole and screw it right in!

    Also it is a really nice Re-Usable gasket. :)
    smoke show likes this.
  9. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Hey smoke,

    I just wanted Don to know that rubber gaskets have been stock in some cases.

    I got some silicon rubber sheet gasket material that is good to 500::F and replaced my convection blower gasket with it, I'm not a neatnik in my gasket making as I just cut the gasket out with scissors and made a small hole with a nail through the gasket in each corner. Then I was able to use the gasket to hold the bolts while putting the blower snorkel on. One needed fewer hands that way.

    Don,

    I think another way to tame the noise is to not use any gasket at all (yep you heard me right). It drastically changes the resonant frequency of the assembly, at least that is what I've been told. I'd worry about temperatures if the blower was actually close to the firebox because the little bit of insulation value a gasket provides would be gone.

    Motors and electronics do not play well with heat.
    smoke show likes this.
  10. Don2222

    Don2222 Minister of Fire

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    Hello Smokey
    I just wanted to make sure the red rubber was ok and it sure is!
    I am sure the Silicon rubber sheets are much higher in their temperature rating but they cost a little more and may not be necessary!
    This would be good for $14.71 only $2.45 per gasket and rated at 525 Deg F ! Nice
    These 12x12x1/8" Silicon ORANGE rubber sheets are a little softer than the red rubber with Durometer = 70A on the hardness scale. That is good. Would not want to go much less.
    http://www.amazon.com/dp/B005JFRB7Q/ref=biss_dp_t_asn

    Yes, I know rubber gaskets come stock now, that is why I added the pic in the 1st post to show how Magnum has upgraded!

    That new gasket I made did help. Now the big rattle is coming from the black case not being secured properly to the motor frame before it warms up! So I will see if the new blower US Stove is sending me this week is better.
  11. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Don,

    If there are any crimps in there anywhere those frequently are not fully set. and can cause all sorts of funny (or not) noises.
  12. Don2222

    Don2222 Minister of Fire

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    Yes, lots of crimps! ! What do you suggest to fix?
  13. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    See if any (of the metal the crimps are supposed to hold in place) are loose and adjust (sorta like, maybe it might help a bit) if so. You'll figure it out being an engineer and all (just leave the slide rule out of it).
  14. Don2222

    Don2222 Minister of Fire

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    Hi Smokey

    Yes, I did figure out something. I took the blower out and hit the crimps with a hammer and a nail set! The nail set is hard small and gets right in there to complete the crimp! The case does not move the slightest!
    I made a video of the issue and in the process of the upload.


    So there are 3 fixes
    1. Change the Lytherm Convection Blower Flange gasket to either Red Rubber (195 Deg F) or High Temp Silicone Orange Rubber (525 Deg F) Since the flange gets only 104 Deg F on the highest heat level either will work.
    That reduces vibration and insulates against transmitting stove heat to the blower.
    2. Tighten the shock mountings that bolt the Fasco motor to the Squirrel Cage (3 Screws with red rubber washers)
    3. Tighten the black motor housing the the grey motor frame by hitting the crimps with a hammer and nail set!

    Here is a couple stills of the crimp fix

    Attached Files:

    SmokeyTheBear likes this.
  15. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    What, really, now where did I put my Pickett (yes folks Smokey has a deep dark secret he has a slide rule or two) ;-) .
  16. Don2222

    Don2222 Minister of Fire

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    Hello

    This is one difference between the Red Rubber Gasket:

    Lowe's price is$1.38 for 6x6x1/8 and hardness of Durometer = 75
    They have sheets 6x6x1/16 and 6x6x1/8. I purchased the 1/8 inch thick because it seems as thick as the Magnum. Lowe's Part number is PP25547 also has # 31448 above bar code.
    http://www.lowes.com/pd_31448-143-PP25547_0__?productId=1082957&Ntt=rubber packing sheet&pl=1&currentURL=&facetInfo=

    and the Orange Silicon Rubber Gasket:

    This would be good for $14.71 only $2.45 per gasket and rated at 525 Deg F
    These 12x12x1/8" Silicon ORANGE rubber sheets are a little softer than the red rubber with Durometer = 70A on the hardness scale. That is good. Would not want to go much less.
    http://www.amazon.com/dp/B005JFRB7Q/ref=biss_dp_t_asn

    Some Silicon Rubber gaskets stick to the blower flange and may be harder to get off.
    Specifically the silicon from the tube because it has not cured. The all ready cured silicon rubber sheets like the orange one above will not stick!

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