what's the strongest long lasting glue ? :)

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andre tchmil

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I need to glue a neodymium magnet on a thin (1 mm)  steel plate .
What do you recommend giving the fact that the steel plate will vibrate heavily ?
Sorry if this is the wrong forum but as an early member I thought I give it a shot here :)

 

Dualflip

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Some sort of flexible epoxy, like the ones used on hobby model RC aircraft, those things vibrate like a MF and yet they keep all the pieces together.

https://www.motionrc.com/collections/epoxy


Not sure if it works that great on metal thou..  Maybe try this epoxy made for metal parts

https://www.loctiteproducts.com/en/products/build/epoxies/loctite_epoxy_metalconcrete.html
 

Tubetec

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I dont think you'll want any flexibility if its forming part of a pickup system for vibrations.
What might be worth trying is bond the magnet to the plate with super glue , this wont be very strong ,but it will make a good close physical contact which will transfer the vibes , you might then suplement it with two part epoxy around the edge for extra strenght.
You would be as well to roughen the metal surfaces with some emery paper where the epoxy bond is otherwise even though the glue itself is strong the bond wont be great .  A gentle roughening of the surface creates more surface area and thus gives the glue more 'grab' . Any tendency towards flexibillity probably wont allow your high frequencies pass into the pickup as well .

The idea for the superglue comes from how the nut is mounted on a guitar neck which is all about allowing string vibrations pass into the body.
 

andre tchmil

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Tubetec said:
I dont think you'll want any flexibility if its forming part of a pickup system for vibrations.
What might be worth trying is bond the magnet to the plate with super glue , this wont be very strong ,but it will make a good close physical contact which will transfer the vibes , you might then suplement it with two part epoxy around the edge for extra strenght.
You would be as well to roughen the metal surfaces with some emery paper where the epoxy bond is otherwise even though the glue itself is strong the bond wont be great .  A gentle roughening of the surface creates more surface area and thus gives the glue more 'grab' . Any tendency towards flexibillity probably wont allow your high frequencies pass into the pickup as well .

The idea for the superglue comes from how the nut is mounted on a guitar neck which is all about allowing string vibrations pass into the body.

Good comment but my intention has nothing to do with vibration pickups for an audio system.
 

Dualflip

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andre tchmil said:
Ok , in what kind of proportion, and just mix the two together ?

Don't worry to much about it, just make a paste by adding superglue to the baking soda, dont make it very wet thou...you want to mix it directly in the surfaces you are going to paste together, it dries quickly AF.
 

Tubetec

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Ive used the baking soda trick , not so much for its adhesion ,but more as a gap filler .
Its  best built up in layers , so first a drop of super glue in the gap , then sprinkle on the baking soda , another drop of glue then another sprinkle of powder , build things up then sand it back to where you need it . Ive seen a similar technique used on guitar necks with hollows  worn in fingerboards except instead of baking soda wood dust is sprinkled over the glue , its usually done in conjunction with a re-fret.

Sorry Andre , I'd assumed you were making a reverb plate , what is it your making?
 

rackmonkey

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While cyanoacrylate  (super glue) does adhere well to metal, it’s brittle and thus has low shear strength. Shear strength will be the limiting factor of an adhesive where vibration is an issue. Over a relatively short period of time, with a heavy neodymium magnet plus vibration, it’s likely to fail, especially if the magnet will be positioned vertically (perpendicular to the force of gravity).

Consider using the attached PDF chart on adhesive properties. The basic rule is to select an adhesive that is compatible with both materials you are gluing. Then narrow down to the best choice based on adhesive properties. This chart doesn’t have test numbers for properties like shear and tensile strength, etc, but those can easily be found online.

For this application, my inclination would be a 2 part epoxy or perhaps a 2 part acrylic adhesive.
 

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andre tchmil

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rackmonkey said:
While cyanoacrylate  (super glue) does adhere well to metal, it’s brittle and thus has low shear strength. Shear strength will be the limiting factor of an adhesive where vibration is an issue. Over a relatively short period of time, with a heavy neodymium magnet plus vibration, it’s likely to fail, especially if the magnet will be positioned vertically (perpendicular to the force of gravity).

Consider using the attached PDF chart on adhesive properties. The basic rule is to select an adhesive that is compatible with both materials you are gluing. Then narrow down to the best choice based on adhesive properties. This chart doesn’t have test numbers for properties like shear and tensile strength, etc, but those can easily be found online.

For this application, my inclination would be a 2 part epoxy or perhaps a 2 part acrylic adhesive.

That is good info !
 

JohnRoberts

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andre tchmil said:
I need to glue a neodymium magnet on a thin (1 mm)  steel plate .
What do you recommend giving the fact that the steel plate will vibrate heavily ?
Sorry if this is the wrong forum but as an early member I thought I give it a shot here :)
Adhesives for use inside speakers have made great advancements over the years (including high temperature use).

McMaster carr has many options rated for use on steel.

https://www.mcmaster.com/adhesives/for-use-on~steel/

JR
 

Whoops

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Dualflip said:
Some sort of flexible epoxy, like the ones used on hobby model RC aircraft, those things vibrate like a MF and yet they keep all the pieces together.

https://www.motionrc.com/collections/epoxy


Not sure if it works that great on metal thou..  Maybe try this epoxy made for metal parts

https://www.loctiteproducts.com/en/products/build/epoxies/loctite_epoxy_metalconcrete.html

Both are good ideas.
The Epoxy used by the RC aircraft people are pretty hardcore,
this product is really stong:

https://www.motionrc.eu/collections/epoxy/products/zap-z-poxy-5-minute-epoxy-4-oz

also the Loctite Epoxy Metal is pretty nice, it cures in a metallic finish so it will have a better look, than the yellowish color of other Epoxy.

Sanding the surfaces and cleaning with acetone or alchool is also really important for the process

boji said:
+1

Scuff up metal and then clean with acetone for best adhesion.
 

boji

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Also there's good ole' JB weld.  It's quite good at bonding dissimilar materials in a high-vibration environment (used in aftermarket automotive repair industry for years). Should be able to pair a magnet and prepped steel plate with ease.
 

Whoops

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Just to advise everyone to never buy this Epoxy from UHU,
It's called "Fast Fixed 2 Liquid Metal"

It's plain crap, worst epoxy I ever used, and no it doesnt fix metal parts

index.php

 

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