Loctite Henkel Power Grab for speaker magnets

Schurkey

WHICH "Power Grab" product is the correct one for preventative securing of driver magnets? My understanding is that the "Power Grab" has superseded epoxy as the material of choice. As typical, Loctite/Henkel makes several products--and dispenser packaging--using the "Power Grab" name. In other words, "Power Grab" is not a product, it's a product LINE, with all sorts of specialized adhesives sold under that name.

• Loctite 1589158 9 Fluid Ounce Cartridge Power Grab Clear Molding and Paneling Construction Adhesive
• Henkel 68882 Power Grab All Purpose Clear Construction Adhesive, 6-Ounce, Clear
• Loctite 1589155 9 Fluid Ounce Cartridge Power Grab Clear All Purpose Construction Adhesive
• Henkel 841982 Loctite Power Grab All-Purpose Construction Adhesive (10 OZ)
• Loctite Power Grab Express All Purpose Construction Adhesive, 6 Ounce Squeeze Tube (2029846)
• Henkel-Loctite 2032666 9 oz. Power Grab Express Heavy Duty Construction Adhesive, Clear
• Loctite 1589157 Clear Power Grab Heavy Duty Adhesive Latex, 9 oz
• Loctite Adhesive Metal, Glass, Foamboard Clear Cartridge, Tube 9 Oz
• Loctite 1363138 10 Fluid Ounce Cartridge Power Grab Tub Surround Adhesive, White

There are more options than just what I've put in the list above--some of the differences are just the packaging--9 oz caulking-gun cartridge vs. 6 oz squeeze-tube, for example. The item in bold is what I'm likely to buy unless someone convinces me otherwise.

Another thought: Since the "Power Grab" is construction adhesive, there's probably competing products of similar quality from Liquid Nails, Red Devil, and thirty other brand names that would work every bit as well--but might have better availability in a particular local area. That would be just like the infamous "Mortite", which is a brand name for rope caulk, but any other rope caulk would work just as well--or just as poorly--as the Mortite brand name. My foray into rope caulk was with the Denis brand.

RandyCroissant

I used the clear molding adhesive with good results, it does take a few days to cure though! starts out white then turns clear. I put a bead around the magnet to basket joint then a thin bead around the top piece then smooth it with your finger a thin bead is best cleans up really easy, and looks good hope this helps.

westmassguy

http://www.homedepot.com/p/Loctite-6-fl-oz-Clear-Power-Grab-All-Purpose-Construction-Adhesive-1589346/203009271
I did a lot of research for an alternative to epoxy. I found the Loctite was the only clear acrylic that did NOT contain any silicone. All the other have trace amounts.

Randy, the Loctite all purpose dries in a bout 2-3 hours max.

RandyCroissant

Thanks Dave, I think I used the snail set but it worked just fine.

westmassguy

RandyCroissant wrote: »

Thanks Dave, I think I used the snail set but it worked just fine.

It's great stuff. The end result is a lot more professional looking than the JB Weld or Epoxy

gudnoyez

I've collected everything I need except for the crossovers (tax time) to tl my CRS+ anyhow is these the right power grab as I did a trim job in the man cave and got a extra tube of it. Is it the right stuff for the cabinets and magnets?

dkfreebird

That's the kind I used.I found it difficult to use the tube type in the speaker cabinets and went with the smaller squeeze type.

westmassguy

Yes, the "All Purpose" is the type I originally found. I keep a few tubes on hand at all time.

gudnoyez wrote: »

I've collected everything I need except for the crossovers (tax time) to tl my CRS+ anyhow is these the right power grab as I did a trim job in the man cave and got a extra tube of it. Is it the right stuff for the cabinets and magnets?

Yes, the "All Purpose" is the type I originally found. I keep a few 6oz tubes on hand at all time.

Schurkey

For the record, Menards is closing-out the Loctite Power Grab products. The local store has already sold-out of several products including the "All-Purpose" version, they've still got stock of the Heavy-Duty stuff, on sale and with rebate available. After rebate, it's a buck-and-a-quarter for a 9-ounce caulking gun tube.

No silicone in the HD version. MSDS shows Limestone, petroleum distillates, silicon dioxide, and quartz. So silicon, but no silicone. The final "e" makes all the difference.

ZLTFUL

I use this stuff for Polk magnets...

http://www.jbtoolsales.com/permatex-84109-4-min-multi-metal-epoxy-each/?gclid=Cj0KEQiAwNmzBRCaw9uR3dGt950BEiQAnbK9671nxKtIPeTYRwVAJCu2gDsG3CUnNS-CBCjvzBwlLOIaApSe8P8HAQ

It dries very rapidly, dries black and flows incredibly smooth so the bead around the magnets looks very clean.

Schurkey

Ooops. The Heavy-Duty stuff isn't appropriate for magnets, the list of applications says:
"Bonds wood, plywood, drywall, cork, foam board, ceramics, plaster, stone, brick, concrete, chip board, carpet, vinyl cove base, foam and much more (1 surface must be porous)"

Of course, neither the magnet nor the metal parts of the driver are porous.

leftwinger57

None of my magnets were ever secured either w/ epoxy or Locktite. Yes I had a x-over slip off it's stanchions but that didn't effect the magnets. What I did do to seal the cabinets was to use Liquid Nails and used a tube squeeze gun.To reach the farthest and hardest parts of the cabinets I attached some fish tank tubing to the tip to work it into ever corner and crevice. Since the 2Bs are done in totality and should not come apart again I'm leaving the magnets the way the are. From what I've heard here it's the moving/shipping of the speakers that more often cause magnet shift than actual playing time.
Footnote... the M7s I got did have the magnets glued up and apparently never let it cure to it's fullest time because some poly fill was stuck to both of the #6502 drivers. It was not a good job at all . They went through 5 owners before me and I did change out both drivers thanks to Polks warranty dept.

lawdogg

Just to confirm, the adhesive is applied around the circumference of the magnet-to-frame border after it has been re-aligned, but NOT between the magnet and the frame - correct?

RandyCroissant

lawdogg wrote: »

Just to confirm, the adhesive is applied around the circumference of the magnet-to-frame border after it has been re-aligned, but NOT between the magnet and the frame - correct?

This discussion is about preventing Magnet shift, not a repair for after an issue has occurred. There are threads on here for fixing a magnet shift, power grab is a non silicone based clear set adhesive that helps to prevent this MW killer It is an advised mod for older Polk MW drivers.

RandyCroissant

The adhesive is applied around the basket to magnet then smoothed with your finger, then around the magnet to top piece same thing smooth with your finger dries clear and looks good when your done.

waxman

I'm a little confused- reading Larry's write-up, he applied 8 distinct 'welds' of jbweld, not two continuous beads. Is the current recommendation just to do the entire circumference?

http://forum.polkaudio.com/discussion/98202/jb-welding-your-magnets-on-your-old-drivers

westmassguy

waxman wrote: »

I'm a little confused- reading Larry's write-up, he applied 8 distinct 'welds' of jbweld, not two continuous beads. Is the current recommendation just to do the entire circumference?

http://forum.polkaudio.com/discussion/98202/jb-welding-your-magnets-on-your-old-drivers

The method I developed is easy peasy, apply a bead in the groove where the front plate meets the magnet, and do the same for the back plate. Smooth it out with your finger tip, wipe off any excess with a damp sponge, set it aside, and let it dry for a few hours. No mess and looks very professional. Epoxies can get messy.

waxman

thank ya much Dave!

westmassguy

waxman wrote: »

thank ya much Dave!

Any time Brother

waxman

Dave do I have the second bead (the groove where the front plate meets the magnet) called out properly in your pic? Making sure I have this absolutely correct before doing this over the break.

westmassguy

You are correct, you get a star!

gudnoyez

As easy as 1,2, front plate and back plate, glad this thread came about. I just returned from Menards had to get a gallon of paint, I didn't buy any but they still had locktite power grab all purpose still on the shelfs.

Schurkey

OK, back for more advice. I have applied the "all purpose" Power Grab as suggested by westmassguy. I bought the 9-oz caulking-gun tube. Eight drivers, two circular beads per driver = sixteen fillets required. This used about 1 1/2 "inches" of the 9-oz tube. One caulking-gun tube of this stuff would do 24 drivers/48 fillets--except:

I wasn't expecting so much shrinkage as the stuff dried/cured. I thought I had a reasonable fillet of adhesive (when it was freshly-applied) but after a few hours, I'm seeing that the fillet has shrunk considerably. The stuff is not yet fully-cured, so I think it's going to shrink even more.

Should I apply a "second coat" to increase the thickness of the adhesive?

westmassguy

Schurkey wrote: »

OK, back for more advice. I have applied the "all purpose" Power Grab as suggested by westmassguy. I bought the 9-oz caulking-gun tube. Eight drivers, two circular beads per driver = sixteen fillets required. This used about 1 1/2 "inches" of the 9-oz tube. One caulking-gun tube of this stuff would do 24 drivers/48 fillets--except:

I wasn't expecting so much shrinkage as the stuff dried/cured. I thought I had a reasonable fillet of adhesive (when it was freshly-applied) but after a few hours, I'm seeing that the fillet has shrunk considerably. The stuff is not yet fully-cured, so I think it's going to shrink even more.

Should I apply a "second coat" to increase the thickness of the adhesive?

No. Power Grab cures by evaporation. If you smoothed out the bead with your finger, some of the adhesive was pushed into any small gaps between the plates and the magnet. This, plus the bead, are tough as nails once fully cured.

akajimmy

those pictures are exactly what I was looking for, thanks westmassguy!

westmassguy

You're welcome

westmassguy

Ken it's $5.00 for a 6oz tube.

westmassguy

You don't have Home Depot or Loews up there Ken?

txcoastal1

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aprazer402

When using Loctite Power Grab AP, should you do both sides of the magnet at the same time? Rather than let one side cure completely before applying to the other side. Since it shrinks some when curing by evaporation, if you do one side first, is it possible because of the shrinking of the adhesive, that this could pull a possibly already weakened magnet loose if only applied to one side at a time? Just thinking. Thanks.

westmassguy

aprazer402 wrote: »

When using Loctite Power Grab AP, should you do both sides of the magnet at the same time? Rather than let one side cure completely before applying to the other side. Since it shrinks some when curing by evaporation, if you do one side first, is it possible because of the shrinking of the adhesive, that this could pull a possibly already weakened magnet loose if only applied to one side at a time? Just thinking. Thanks.

You're over-thinking. I've done several dozen woofers, with no ill effects.