Is JB Weld is the only thing available for preventing magnet shift?

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Mystery
Mystery Posts: 2,546
edited January 2021 in Vintage Speakers
Recently, I'm cleaning (well, trying to) my basement as I had lot of free time.
I had couple of monitor 4's, 4.5's etc... tucked in the corner in basement.
I remembered all of them were working when I stored them few years ago.
Now, two of them woofers have the stupid dreaded magnet shift and makes tweeter like sound with no movement.
So pissed off! What a waste! Hope Polk is using better glue on their newer models.
Anywho, now I need to keep others from the same fate.
Is JB Weld the only thing? If yes, which type of JB weld is good for magnets?
This cold-weld steel reinforced?
https://www.amazon.com/J-B-Weld-8265S-Cold-Weld-Reinforced/dp/B0006O1ICE/
or Kwik-weld?
https://www.amazon.com/J-B-Weld-8276-KwikWeld-Reinforced/dp/B0006O1ICY/
or Steelstick putty?
https://www.amazon.com/J-B-Weld-8267-S-SteelStik-Reinforced/dp/B000786GLM/
...
What about two part epoxy or metal epoxy that Harbor Freight sells?
Any other recommendation?

Klipsch RB81, KG3.5, B&W DM602.5, Polk.
Subwoofers: Klipsch RW10, Triad ProSub Bronze.
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  • Jazzhead
    Jazzhead Posts: 530
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    I used PC-7 epoxy. It's thick enough (at room temperature) that you can blade it on without mess/sagging. It's bombproof once it cures.
    Polk Audio first generation RTA-12s; 12 inch Polk Stands; DHS Speaker Service upgraded crossovers w/ Sonicap/Mills; the "westmassguy anti-lobing mod" (hyperdamped outer drivers/mirror imaged); tweeter anti-diffraction mod; Cardas binding posts; Neotech UPOCC internal wire; foam-lined inner driver baskets; xschop phase plugs; deleted fuses; Hurricane nuts; Sonic Barrier; Dynamat Xtreme
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    Dedicated 20A/10 AWG circuit; Furutech GTX-D (G) outlet; Furutech eTP80; Shunyata Research Venom Defender; Synergistic Research Orange fuses
  • Gardenstater
    Gardenstater Posts: 4,212
    edited January 2021
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    I used this stuff and would use it again. It adheres tenaciously to metal and ceramic/glass and I like that it is clear. One drawback is it only seems to come in the large tube. I squeezed (squoze?) it into a syringe to make it easier to apply, especially to back edge of magnet. Doesn't shrink a lot but does some, through solvent evaporation.

    There's so many suitable choices!

    nvrg84akbret.png
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Mystery
    Mystery Posts: 2,546
    edited January 2021
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    But how do you know if that prevented magnet shift?
    Some drivers never shift whether you epoxy glue or not.
    Did anyone test after applying epoxy by dropping or shaking the speakers or something in that manner?
    Or is it just a trust on whatever glue you chose?

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • VR3
    VR3 Posts: 28,160
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    Not sure I would recommend shaking or dropping speakers, ask @treitz3
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • Mystery
    Mystery Posts: 2,546
    edited January 2021
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    VR3 wrote: »
    Not sure I would recommend shaking or dropping speakers, ask @treitz3

    I know. What I was saying was for test purposes if anyone did a test with any drivers using different glues to confirm if they prevent magnet shift or not.
    Doesn't make sense to drop the one you just put epoxy on from a nice speaker.
    This issue came like 15-20 years ago and just wondering if anyone tested glue/epoxy properly or not with test speakers.
    Even someone who put certain epoxy and had a bad drop or accident that pretty much guaranteed magnet shift but didn't also would help.

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 24,669
    edited January 2021
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    One thing is for sure, if you do not use it you can come home to a shifted magnet having never dropped or bumped. All this is doing is helping whatever adhesive is left under the magnet to not allow it to shift to the best of our ability. It will be much harder for the magnet to shift if it must jump this barrier we put around the magnet. Can it still shift if it's dropped sure it can.
  • Mystery
    Mystery Posts: 2,546
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    pitdogg2 wrote: »
    One thing is for sure, if you do not use it you can come home to a shifted magnet having never dropped or bumped. All this is doing is helping whatever adhesive is left under the magnet to not allow it to shift to the best of our ability. It will be much harder for the magnet to shift if it must jump this barrier we put around the magnet. Can it still shift if it's dropped sure it can.

    Okay so there is no official or non official test done.
    I think around 10 years or so ago I did apply two part epoxy on few Polk drivers but those speakers are long sold.

    But looking at the recent magnet shift on the speakers, I'd epoxy any vintage Polk I run into.
    In conclusion, put something, doesn't matter what, as long as it's epoxy or metal weld to help prevent magnet shift and cross fingers.

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • Mystery
    Mystery Posts: 2,546
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    pitdogg2 wrote: »
    Hmm... That's much cheaper than the epoxy.
    Does this work as good as JB Weld for metal like magnets?

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 24,669
    edited January 2021
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    I feel it works better it's much easier to get in the magnet spaces you can build it up easier it doesn't run. You just caulk a big bead around your magnets and then you smooth out with your finger press it in and smooth it down and it it locks everything in place. it's well regarded here a lot of us have started using it I did JB weld on my first ones I'll never use it again.
    a8c8g0ax0044.jpg
    v2j72ro4jnw7.jpg

  • Mystery
    Mystery Posts: 2,546
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    pitdogg2 wrote: »
    I feel it works better it's much easier to get in the magnet spaces you can build it up easier it doesn't run. You just caulk a big bead around your magnets and then you smooth out with your finger press it in and smooth it down and it it locks everything in place. it's well regarded here a lot of us have started using it I did JB weld on my first ones I'll never use it again.

    Okay, I just read the description and it does mention metal but says at least one of the surfaces must be porous.
    Is Polk magnet or frame porous?

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • pitdogg2
    pitdogg2 Posts: 24,669
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    Do a search we've been over this time and time again. It works and holds or you can keep going over and over it in your head forever.
  • xschop
    xschop Posts: 4,753
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    I use Power Grab in the hand tube. I've even had to glue SL5000 tweeter magnets with good results.
    Don't take experimental gene therapies from known eugenicists.
  • lawdogg
    lawdogg Posts: 450
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    Mystery wrote: »
    Okay so there is no official or non official test done.
    I think around 10 years or so ago I did apply two part epoxy on few Polk drivers but those speakers are long sold.

    But looking at the recent magnet shift on the speakers, I'd epoxy any vintage Polk I run into.
    In conclusion, put something, doesn't matter what, as long as it's epoxy or metal weld to help prevent magnet shift and cross fingers.

    I did my own destructive testing (throwing them on the concrete garage floor) and found Loctite power grab shifted very easily. I've only used epoxy ever since and epoxy has never shifted.

    kfxdmqsyu2ne.jpg
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
  • Mystery
    Mystery Posts: 2,546
    edited January 2021
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    lawdogg wrote: »
    Mystery wrote: »
    Okay so there is no official or non official test done.
    I think around 10 years or so ago I did apply two part epoxy on few Polk drivers but those speakers are long sold.

    But looking at the recent magnet shift on the speakers, I'd epoxy any vintage Polk I run into.
    In conclusion, put something, doesn't matter what, as long as it's epoxy or metal weld to help prevent magnet shift and cross fingers.

    I did my own destructive testing (throwing them on the concrete garage floor) and found Loctite power grab shifted very easily. I've only used epoxy ever since and epoxy has never shifted.

    kfxdmqsyu2ne.jpg

    Yes thanks.
    I'm leaning towards epoxy but thinking if Loctite PL Max is better.
    It mentions metal and stainless steel.
    I have about a dozen and I think 3 of them are frozen. :(

    https://www.loctiteproducts.com/en/products/build/construction-adhesives/loctite_pl_premiummaxconstructionadhesive.html

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • lawdogg
    lawdogg Posts: 450
    edited January 2021
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    Good luck and enjoy the process! I'm sure you'll be able to get it done!
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
  • audioluvr
    audioluvr Posts: 5,461
    edited January 2021
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    I use Loctite Powergrab Ultimate. I tested it by throwing my speakers out a second floor window. Still play great but they look like hell
    Gustard X26 Pro DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables
    Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)


    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
  • VSAT88
    VSAT88 Posts: 1,234
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    I used nothing at all early on and ...Magnets shifted.
  • Mystery
    Mystery Posts: 2,546
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    VSAT88 wrote: »
    I used nothing at all early on and ...Magnets shifted.

    Of course that's why the thread is here.
    Question is about what to use among many choices.

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.
  • Gardenstater
    Gardenstater Posts: 4,212
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    I think if one didn't want to use epoxy or what I suggested above for whatever reason (mess, don't have any handy etc), one could use this prior to filleting in with some other adhesive as a 2nd insurance at a later time:

    21vyehcyfnp1.png
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • audioluvr
    audioluvr Posts: 5,461
    edited January 2021
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    Polyurethane isn't really that strong IMHO. You want something that bonds/ welds everything together. I would test it by placing two pieces of scrap metal together then running a bead around the perimeter. Once cured try to get the two pieces to move
    Gustard X26 Pro DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables
    Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)


    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
  • Gardenstater
    Gardenstater Posts: 4,212
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    The one I last brought up is a type of super glue (cyanoacrylate). The one Mystery was speculating about is a Silane (SiH4) Modified Polymer, which combines the highly elastic properties of Silicone with high mechanical strength of Polyurethane. Not sure I would want to use anything that is elastic where you want to protect from dislodgement due to impact.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • bigmontana
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    I recently used Loctite Instant Mix epoxy to do the magnets on my 2B's. It was readily available and I found it easy to apply cleanly. I used maybe half of the 14ml tube to do 4 magnets, so I would expect you could get 8 to 10 out of it. That was also applying a full bead all the way around the magnets, which in hindsight was probably overkill.
    mm8ka1pvz49j.png
  • hytekrednek
    Options
    only the one side of magnet is epoxied, correct? I saw the pic here of one done that had glue on both sides of the magnet. That look to be very tough to do without making a huge mess.
  • Gardenstater
    Gardenstater Posts: 4,212
    edited January 2021
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    Both sides, without a doubt. You can do one side, let it cure a bit, then flip the speaker over and do the other side, so gravity works for you instead of against you.


    bigmontana - I'm glad you chimed in because I think that stuff may be ideal and I forgot who had posted it before.

    https://www.ebay.com/p/536442390
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • bigmontana
    Options
    The static mixer that comes with the Instant Mix epoxy makes it easy to get to the bottom side of the magnet.
    7hl4ryw5khql.jpg

    You do have to work somewhat quickly or the epoxy will start to thicken inside the mixer. Don't stop for a break until you're completely done!
    I did the top side of all four magnets and then immediately did the bottom sides starting with the first one again. No issues with dripping or slumping.

    I was able to find it at my local Target: https://www.target.com/p/loctite-47-fl-oz-epoxy-5-min-instant-mix/-/A-14767197#lnk=sametab
  • hytekrednek
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    very helpful! Thank you
  • drumminman
    drumminman Posts: 3,396
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    I used JB Weld original formula for all the mw’s in my 2.3tl’s, RTA-12c’s and CRS+’s and had no issues. It takes a while to dry, but it will not fail.
    I had a good supply of nitrile gloves and paper towels on hand to immediately remove any excess.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • TennMan
    TennMan Posts: 1,266
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    I used JB Weld. I have no doubt about it's strength but it was messy to apply. If I had it to do again I would use clear two part epoxy.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
    • Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    • Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
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    • SDA CRS+ · Hidden away in the closet
  • Mystery
    Mystery Posts: 2,546
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    Okay I went back to what I used 8 years ago, two part epoxy.
    It hardens like rock and when it is applied at multiple places, even if it's not adhesive like original glue, it'll block movement.

    Klipsch RB81, KG3.5, B&W DM602.5, Polk.
    Subwoofers: Klipsch RW10, Triad ProSub Bronze.