Which flavor of Power Grab to reinforce magnets?

Hi All,

Thanks to the generosity of FestYboy who donated a working tweeter, I now have two excellent sounding Monitor 5B speakers. I want to keep them sounding good, so I am going to glue the magnets tomorrow before I play them much. The consensus on the forum seems to be that Loctite Power Grab is a good product for the job. However my local Lowes carries both the general purpose and the express heavy duty construction grade. The general purpose does not list aluminum as one of the materials that it bonds to while the heavy duty does, although it does not list steel. I wonder though, if there is yet another version such as the Power Grab Ultimate construction adhesive (not carried by Lowes) that I need to use. Input would be greatly appreciated.

Best,
Jay

Comments

  • pitdogg2
    pitdogg2 Posts: 24,474
    I've used both. I like the stuff in the 6oz hand squeeze tube. A little more expensive but much easier to work with instead of the caulking gun tube.
  • Viking64
    Viking64 Posts: 6,646
    The one I used was Power Grab Express All Purpose.

    5uq1n1cn4132.jpg
  • Viking64
    Viking64 Posts: 6,646
    DSkip wrote: »
    Whichever tastes best is the flavor I usually go with.

    :p

    That is risky. You should read the label for calories, fat content, gluten content, and peanut allergy information. :p
  • DrJay
    DrJay Posts: 10
    When reading the tube carefully, the PG construction grade heavy duty says "one surface must be porous" This concerns me. Thoughts? Real world experience?
  • Just grab some Power Grab (pun intruded) and go at it. The all purpose would be my choice if available. If not, use whatever is on the shelf.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

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  • DrJay wrote: »
    When reading the tube carefully, the PG construction grade heavy duty says "one surface must be porous" This concerns me. Thoughts? Real world experience?

    Got me... I use JB Weld on mine.
    "Make a man a fire and he'll be warm for a day. Light
    a man on fire and he'll be warm for the rest of his life."


  • I used the clear Power Grab as long as it was available. Then it was onto the construction grade. You will find other uses for what you have left over around the house.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • pitdogg2
    pitdogg2 Posts: 24,474
    edited December 2017
    TNTsTunes wrote: »
    DrJay wrote: »
    When reading the tube carefully, the PG construction grade heavy duty says "one surface must be porous" This concerns me. Thoughts? Real world experience?

    Got me... I use JB Weld on mine.

    I did also on my first go around. The power grab is so much easier to get in place less messy and has a longer work time.

    Ok both power grabs heavy duty and all purpose both say one surface must be porous. So its a wash. Many have used this with good results. I used heavy duty once just because i grabbed one from the bin and the heavy duty was in the wrong bin. I just went ahead and used it. Now mind you i certainly didn't go banging around after it was dry to see if that "1 surface must be porous" had merit.
    You should be fine
  • I'm a fan of epoxy or even Liquid Steel.
  • audioluvr
    audioluvr Posts: 5,420
    Powergrab sets up hard but brittle it will not hold up like you hope. liquid steel is much better but JB weld will bond them together permanently regardless of differentiating metals, materials, expansion/contraction due to heat and cold. It's best to put on in thin layers though as it will flow for hours after placement. If you wet a finger you can use it to smooth out surfaces.
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  • Nightfall
    Nightfall Posts: 10,042
    edited December 2017
    The self dispensing one worked good for me. I exchanged the caulk style ones, too difficult to manuever inside the speaker cabinet.

    pg_ca_ex_all_p_pp.png
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • txcoastal1 wrote: »
    Slapaho wrote: »
    Liquid Steel.

    Isn't Liquid Steel that hair gel Jesse uses??

    And probably other places. It can be formed to just about shape so long as you work quick enough. I used to use that stuff everyday making internal engine case mods. Pretty neat stuff. I still like real epoxy best for securing Polk magnets and plates.
  • txcoastal1
    txcoastal1 Posts: 13,124
    Slapaho wrote: »
    txcoastal1 wrote: »
    Slapaho wrote: »
    Liquid Steel.

    Isn't Liquid Steel that hair gel Jesse uses??

    And probably other places. It can be formed to just about shape so long as you work quick enough. I used to use that stuff everyday making internal engine case mods. Pretty neat stuff. I still like real epoxy best for securing Polk magnets and plates.

    ???
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  • DrJay
    DrJay Posts: 10
    I love to experiment and was concerned about the requirement for one porous surface of the PG general purpose and construction grade. Power grab Ultimate (red tube) specifically states that it is recommended for aluminum and steel. So, I glued up identical pieces of aluminum with each "flavor" and found that adhesion and bond strength were MUCH greater with the Ultimate. It costs a bit more and is very hard to pump out of the tube, but it is what I will use. It is in a whole different class of performance IMHO.
  • Nightfall
    Nightfall Posts: 10,042
    All three Amazon reviews are 1/5 stars?

    https://www.amazon.com/Loctite-Power-Grab-Ultimate-Construction-Adhesive-Ounce-Cartridge-1989550/dp/B071WLR64P/ref=sr_1_2?ie=UTF8&qid=1513653247&sr=8-2&keywords=loctite+power+grab+ultimate
    Product so thick it took three men and a boy to force product thru tube. Material looked like a tube of four year old dry puddy.
    Joke instant grab my butt wasn't sticking in an hour
    Product nozzle was craft and exposed to air. It was unusable (almost dry) upon delivery.

    Let us know how it works out for you when you're actually doing the magnets.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • lawdogg
    lawdogg Posts: 449
    Had the best luck with a 2-part epoxy.
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
  • Viking64
    Viking64 Posts: 6,646
    I had a hell of a time getting the stuff out of the squeeze tube on my first cabinet. The more pressure I squeezed with, the more it just went backwards into the tube. By the end of the first cabinet, I had no more strength in my normally strong fingers. On the second cabinet, I folded the tube to prevent the goop from going backwards and it flowed out of the tip like a ***** after 8 beers and a ***** on her *****.
  • Viking64
    Viking64 Posts: 6,646
    Profanity? That reads as: "It flowed out of the tip like a leaky beer stein after 8 beers and a bottle of wine on her tablecloth."
  • Nightfall
    Nightfall Posts: 10,042
    Man, I hate how beer steins start leaking after only 8 beers. They really should make them last longer, enough with the Chinese beer steins!
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • DrJay
    DrJay Posts: 10
    Hi Guys,
    Well, I glued up the magnets today using the PG Ultimate and it was easy to work with using a medium duty caulk gun. It is harder to squeeze out than the other 2 PGs, but not super hard. It can easily be smoothed with a finger and cleans up readily with alcohol.
    I think the bad reviews came from folks who got tubes that had exceeded their shelf life. I don't know if any more magnet reinforcing is in my future, but if there is, I will definitely use PG Ultimate, it is easy to work with and my tests suggests it has more than 5X the strength of the other versions of PG when used on metal.
    BTW this is a great forum, highly informative and fun.