CA glue and magnetism

[Bill PhinnParticipant @billphinn90025]

I’ve encountered a problem that is new to me.

I’ve just replaced the fibre linings on my bench vice’s six inch detachable soft jaws because they were worn out. I used nitrile rubber instead of fibre. Each soft vice jaw has four neodymium magnets set into the back, two of these being original and two being ones I added for extra holding power. Their hold on the cast iron vice jaws has always been excellent.

…Until now. After using CA glue to stick the nitrile linings to the jaws I find that there is virtually no magnetism in any of the eight magnets – so little that even an M8 BZP hex nut stuck directly to one of the magnets will slide off under gravity.

Can anyone explain this and suggest whether the magnetism of the magnets will return?

[Clive FosterParticipant @clivefoster55965]

Most odd.

I’ve used CA glue to stick neodymium magnets to various things, including alloy jaws, with no apparent effect on the magnetic strength.

Clive

[DiogenesParticipant @diogenes]

I’d guess that way you have arranged them is causing them to cancel out each others fields?

Maybe you need to re-align your poles..?

[Robert Atkinson 2Participant @robertatkinson2]

+1 for poorly arranged poles. CA adhesives are excellent for gluing magnets due to their thin glue lines.

Robert.

[SillyOldDufferModerator @sillyoldduffer]

Very strange, no way should glue mess up a magnet.  If the magnetism has gone, won’t come back on it’s own.  Replace the magnets.

Maybe something happened to them whilst the fibre was being replaced.  Dropped, or got hot somehow?   Heat and mechanical shock are both very bad for magnets.  Neodymium magnets being made of sintered powder are mechanically weak – are they in good physical condition?

Eclipse used to warn against disassembling their older chucks.  The problem was due to Alinco, then best magnetic alloy, except the flux needed to be managed. Not likely to be Bill’s problem – Neodymium should be fine.

I blame Gremlins!

Dave

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