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Gluing magnets

Rennie Heuer

Rennie Heuer

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I need to glue a few rare earth magnets in place in wood. I've used some CA in the past with about a 20% failure rate. For some reason it just doesn't hold well. Could be the ca I'm using.

I've also seen people use epoxy and hot melt. Anyone have experience in this and have a sure fire go to glue?
 
Part of the challenge I've had is that they're often really smooth which I think might have contributed to your CA glue failure modes.

I've mostly take to burying them in epoxy (basically a very thin epoxy plug around them) which at least captures the upper curves on them to trap them in place.

I've seen some folks claim success with lightly roughing them to give the glue more grip, but haven't really tried that enough to say how well it actually works, plus most of them are coated in just a thin metal film so I've always been wary of going through that (maybe that's ok?).
 
I would use a high quality 2 part epoxy - BUT - A shiny smooth surface is the enemy of any adhesive.
I would GRIND a VERY rough surface for the epoxy to adhere to, even to the point to grind away the chrome coating.

Clean the surface with DNA then DO NOT touch the glue surface

Chance of success - maybe somewhat OK - but not in tension. In compression a really good chance. In shear - if the magnet is in a pocket, then a good chance. Using Lord Adhesives - very good chance of success - but not in tension.


OK - this is not inexpensive
It is the best I have ever found
I have used it for 10-12 years on signs
Wood - Metal - PVC - HDU
I bonded PVC to Aluminum and tried to break it apart
By hand - not possible
Pry with hammer and big screwdriver - the PVC broke - but the glue joing did NOT fail completly
You need a dispenser.
If you want a cartridge I will ship one to you at what I paid for it, but you still need a dispenser. The dispensers are generic and maybe Borg has them. McMaster is killer on shipping cost.
I have also used some or the borg cartridges with good luck.
If I need to bank on success - Lord Adhesives is my goto.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com
 
Leo Voisine said:
I would use a high quality 2 part epoxy - BUT - A shiny smooth surface is the enemy of any adhesive.
I would GRIND a VERY rough surface for the epoxy to adhere to, even to the point to grind away the chrome coating.

Clean the surface with DNA then DO NOT touch the glue surface

Chance of success - maybe somewhat OK - but not in tension. In compression a really good chance. In shear - if the magnet is in a pocket, then a good chance. Using Lord Adhesives - very good chance of success - but not in tension.


OK - this is not inexpensive
It is the best I have ever found
I have used it for 10-12 years on signs
Wood - Metal - PVC - HDU
I bonded PVC to Aluminum and tried to break it apart
By hand - not possible
Pry with hammer and big screwdriver - the PVC broke - but the glue joing did NOT fail completly
You need a dispenser.
If you want a cartridge I will ship one to you at what I paid for it, but you still need a dispenser. The dispensers are generic and maybe Borg has them. McMaster is killer on shipping cost.
I have also used some or the borg cartridges with good luck.
If I need to bank on success - Lord Adhesives is my goto.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com
Click to expand...
Looks like good stuff! My magnets will be in tension, but only once in their shinny round little lives. These are going in those corner shelves I'm working on. Theoretically, the shelf will be pushed into place once, the magnets will click, and might never see the light of day again... unless the new owner wants to show off my clever idea for hiding the mounting screws. :rofl: It needs to hold firmly but might never be subjected to any forces that might pull them from there countersunk surroundings. I just don't want them jumping out of their hole as the shelf is put in place.

Corner Shelves1c.jpg
 
In some of my projects I use a lot of rare earth magnets. I tried CA and it is almost guaranteed to fail after a certain amount of time. CA crystallizes and those crystals will shatter with a good bump.

I now use a little dab of epoxy 5 minute glue. I also scratch up the side that will be glued. To date I have not had a failure with the epoxy. I had many CA glued magnets fail within 2 years.

Your project may not be as subject to bumps and knocks as my smaller items so the failure rate may not be as conspicuous.
 
For that job, ohh ok.

I think rough up the glue surface like I said above. Super clean with DNA.

The loctite 2 part is pretty good. I use a fair amount.

That will work well. Lots of other strength in there as well.
 
The magnets being recessed into a Forstner hole helps. Most CA does not do well in porous material. In a hurry? DAP Rapid-Fuse is your friend here. If I have 24 hours before use I have come to prefer E-6000 for magnets. I have never had a failure with Rapid Fuse or with E-6000 when the magnet is recessed into a "cup" in the wood. The E-6000 remains somewhat flexible (not rubber-like, more like UHMW consistency) so wood movement is a non-issue.
 
When I took a bowl turning class at Marc Adams, the instructor of my class hated CA glue and said in less than 20 years there would be many pieces of art fall apart due to CA failure. For permanence, I prefer 2 art epoxy and of course rough up any smooth surface. Now Brent's suggestion, that is amazing!! Never seen that before, Thanks Brent!!!
 
I've used the magnet cups on a few things, and it seems like they just wont fail. Love the mechanical nature of it. I use magnets a fair amount in my 3d printing and I won't try to glue them in on that either, I'll embed them in a .2mm layer of plastic to ensure permanence.
 
WOW. Great replies.

Jim, was not aware of that tape and might be just the thing for me. I'll look into this. I might try the tape and epoxy in a trial and see which I prefer. I have cups for the magnets, but there is not enough room for them in the edge of the shelf and not enough depth in the groove for the screw.
 
Rennie Heuer said:
Jim, was not aware of that tape and might be just the thing for me...
Click to expand...
I've used a lot of it for various tasks over the past ten years or so. Can't recall ever having a failure so long as I did my part and prepped properly.

When it was first marketed Fastcap was promoting it for use in edge banding. I used it to band an oak ply tabletop with 1/8" stock back then and it's still holding tightly. My niece has a 15 gallon aquarium on the table, so I'm pretty sure the edging has even gotten wet over the years.
 
Those came out great. Judging by the art items, wall border, and nic-nacs the client has a strong A&C preference. I dig the Dali clock too. Cool stuff!
 
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