SoA Forums

General Category => Army Research => Topic started by: eques on February 14, 2016, 08:33:15 PM

Title: Wearing out Magnets for Storing Figures
Post by: eques on February 14, 2016, 08:33:15 PM
Hi

I know magnets lose strength over time, but does anyone know if this is affected by the amount of exposure to metal, or does it happen anyway?

I prefer to magnetise my bases and then store them on metal, because that way I don't have to transfer them to another container for transport, but don't want to wear out the magnets unnecessarily.

Thanks in advance!

Harry
Title: Re: Wearng out Magnets for Storing Figures
Post by: Imperial Dave on February 14, 2016, 08:42:35 PM
I thought that magnets lose strength very slowly over time and to accelerate this you need heat and/or corrosion. My flexible magnetic bases are still holding 30 years after I first fixed them although I cant comment on how strong they are now compared to then
Title: Re: Wearing out Magnets for Storing Figures
Post by: Mark G on February 15, 2016, 06:19:19 AM
I have no issue with 15 years worth if steel paper bases on magnetic rubber lined boxes.
Title: Re: Wearing out Magnets for Storing Figures
Post by: Jim Webster on February 15, 2016, 07:29:23 AM
I must have units which have been on magnabase for over thirty years and there's no problems. The biggest issue is that the magnet can grip better to the toolbox than it can to the base, so I now don't rely on the glue on the strip, but add my own contact adhesive as well

Jim
Title: Re: Wearing out Magnets for Storing Figures
Post by: aligern on February 15, 2016, 11:26:45 AM
The biggest wear on magnets is generally other magnets. If you put them near other manets of similar r greater power with the magnetic field in a contrary direction it randomises the molecules in the original magnet and as they  become disordered the magnetism weakens. Same effect for heat which energises the molecules so they bounce around and drop out of order, but I rather doubt they get syuufficinetly hot in a box in your games room. As you most likely store your figures vertically and all aligned to the horizontal the magnetic fields are not competing so your magnetised bases shoud stay strong in the force.

Roy
Title: Re: Wearing out Magnets for Storing Figures
Post by: Andreas Johansson on February 16, 2016, 05:52:37 AM
Something else that weakens magnets is physical impact, but you'd probably worry about the figures before their bases on that score  :o
Title: Re: Wearing out Magnets for Storing Figures
Post by: Dave Beatty on February 24, 2016, 03:35:52 AM
Commercial magnets "wear out" (demagnetize) at about 1% per decade. This accelerates logarithmically as you approach the Curie Temperature for the particular type of material the magnet is made of. Once the Ct is crossed, the magnet immediately demagnetizes with catastrophic results for the unprepared. Very powerful magnets are often made of neodymium and have higher remanence, much higher coercivity and energy product, but a lower Curie Temperature than other types. But the lowest Ct I've seen is on the order of 600 degrees Fahrenheit so generally not a problem for the average gamer (the figures will melt much earlier than the Ct of your bases).

And yes, my day job is Rocket Scientist... ;)