Removal of 'rare earth magnets

[cajal]

Hi,

I am looking for suggestions on how I could remove rare earth magnets which are embedded in the four corners of my router table insert plate rebate. They are there to enable the fine levelling grub screws in the insert plate to be stablized.

I want to rout out the existing rebate to accept a larger and thicker Incra or JessEmm insert plate but the magnets will not facilitate this process whilst they are in situ.

I have considered drilling a small hole up from the underside of the table to enable me to knock the magnets out with a drift.

Any other ideas please???? I would rather not drill the table unless absolutely necessary

Regards

cajal

[Al Rogers]

Would it be possible to drill a hole in the magnets and pull them out with a screw extractor? I suppose it depends on how firmly they are fixed in place. Just a thought.

[Théière]

What is the material the magnets are set into? This would have a big effect on any recommendation.  If they are held in with epoxy glue like Araldite etc which is common, heat will soften the glue and allow easy removal, if you can use heat of course without damaging other parts.

[alittlebitfrench]

If you heat them up they could lose their magnetic field. A soldering iron might do it.

[Théière]

[quote user="cajal"]

I want to rout out the existing rebate to accept a larger and thicker Incra or JessEmm insert plate but the magnets will not facilitate this process whilst they are in situ.

[/quote]

I doubt they are held in with their magnetic force although it is possible so using  heat to remove the magnetism isn't going to work as cajal want's them out to increase a rebate which to me suggest non ferrous plate.  The use of a soldering iron would soften the glue though.

[Jonzjob]

Cajal, a photo would be a great help.

As for heating the magnets, you would have to get them very hot to destroy them, especially rare earth jobbies.

It sounds as if they may well be seated in plastic as you are talking about routing and not milling the surface.

[cajal]

Hi,

Thanks for the selection of suggestions and ideas. A lot of thinking going on 'outside the box'

The

composition of the table top is thermoset phenolic plastic laminate

covering 40mm MDF.  I suspect the magnets are glued in with an

Araldite/pu brand of glue which could possibly be softened with the use

of a decent powered hair dryer or heat gun (on low setting) held well

away from the table.

Unfortunately drilling these magnets is a big 'no no'.  Any holes you may find in neodymium is there because it was cast that way and not machined. Drilling them produces a powder of tiny particles of metal,

which is flammable!

I'm sure the combination of heat and a screw extractor in a drilled hole would have done the trick.

I will try the applicatipn of heat but the 'then problem' will be getting a hold on them as they sit in a counterbored hole at the bottom of the rebate. So it is looking as though I will have to drill, carefully, from underneath for the push out method as opposed to the pull out method from above.

Once again to you all, thanks. I very much appreciate your input.

Regards

cajal

[Théière]

cajal, I imagined as they are magnets you'd soften the glue with a soldering iron or hot air gun (small nozzle held close for quick heat up locally) Then a piece of iron stuck to the magnet by the magnet and lift them out?

[Jonzjob]

No photos? I like photos they are worth a thousand thingies.

If you can soften the adhesive with heat then it should be possible to get 2 small screwdrivers, one each side, and lever them out. After all, that's the hole they went in by and I doubt that they are an interference fit? failing that, a small hole on opposing sides and the small screwdrivers??

I agree with the drill/easyout method would be difficult. Rare earth magnets are VERY hard!!

[Théière]

Would you need to lever them out? with softened glue approaching any where near a rare earth magnet with one screwdriver should surely be an "attractive" proposition [geek]