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  • question about magnetic sheeting

    Posted by Martin Pearson on November 29, 2016 at 3:57 pm

    Does anyone know if magnetic sheeting looses it’s properties over time ?

    Have to be honest & say that I haven’t made any magnetics for years but a customer asked me for a price for a set last week. I knew I had a roll of vehicle grade magnetic sheet so dug out the box to see how much was still on the roll.
    The material is still on the round cardboard core & kept in the same box that I originally received it from the supplier in but it doesn’t seem to want to stick to the side of the steel locker like it should πŸ˜†

    Just wondered if anyone had come across this before, I know as an engineer that certain types of magnet become less effective over time & I had to change the stepper motors on the CNC because the magnets in the original motors were failing but those motors were probably 40 year old πŸ˜† πŸ˜†

    Martin Pearson replied 7 years, 4 months ago 6 Members · 16 Replies
  • 16 Replies
  • Phill Fenton

    Member
    November 29, 2016 at 5:03 pm

    I didn’t think it did Martin and was recently asked this same question by a customer. I told them the magnets were permanent but now you have me doubting this. Interested to hear what the definitive answer is?

  • Martin Pearson

    Member
    November 29, 2016 at 6:19 pm

    Phill I was a bit surprised myself, going to either phone or email the supplier tomorrow & ask them about it. I bought this a few years ago, maybe 4 or 5 years I would guess & it has always been stored the way I received it from the supplier, I just use to cut what I wanted for a job off the roll & then put the remainder back in the box. If I hadn’t ever used any of it I might suspect that I had been sent a duff roll in the first place but since i used well over half of it when I originally ordered it & have never had any complaints about it that can’t be the case.
    It’s very cold in the unit just now so I even tried warming a piece of the sheet & the filing cabinet & it made no difference πŸ˜† πŸ˜†

  • Jasper McEwan

    Member
    November 30, 2016 at 11:25 am

    Martin, not sure if the below might help with the problem you are having..

    Would have thought magnetic should be the same across the board but might be best to check back with your original supplier, but these are ours…

    Magnetic sheeting won’t demagnetize over time providing that the material is not subject to temperatures over 80c or below -20c. So unless you keep your workshop in arctic temperatures you should be fine πŸ™‚

    I can’t see this next point being an issue, but magnetic material must be kept away from strong magnetic fields such as those emitted from electro magnets or neodymium magnets. These type of materials may demagnetize or reverse the polarity of magnetic sheet or tape, so should be stored and transported separately.

    What we say is that if these guidelines are kept to, then magnetic sheet will continue to perform perfectly well over time.

    Don’t know if that helps, but thought i would throw it in…

  • Martin Pearson

    Member
    November 30, 2016 at 11:47 am

    Thanks Jasper have emailed them & will see what comes back, it does get very cold in the unit during the winter as I don’t have heating as such & only put the portable heating on occasionally but not as cold as -20 (just feels like it sometimes πŸ˜† ) I did wonder if it was due to low temperatures but with you quoting -20 I can pretty much dismiss that as a reason.
    It isn’t stored near any other magnetic sources either so from what you have said it should still be OK.

  • Martin Pearson

    Member
    December 3, 2016 at 8:33 pm

    Quick update on this, I said that I had used quite a bit of this roll but it would seem that I never did, have to blame that on my illness as it does cause problems with my memory.

    Having had a look through a couple of note books & searched my email it would appear that I purchased a 10m roll in 2009 but never used any of it at the time, in 2014 I had a request for magnetics & made some up using this material & they wouldn’t stick to anything. Contacted supplier to be told that the material did not lose it’s magnetic properties over time but they didn’t replace the roll I had.
    I actually ended up buying some from a different supplier so I could get the job done & it looks like I am going to have to do the same again for this job.
    Probably should have thrown the roll out back then to save the problem arising again πŸ˜†

  • Phill Fenton

    Member
    December 3, 2016 at 11:22 pm

    That is so strange. How can a magnet lose its magnetism. There must be another factor involved to cause this surely

  • Robert Lambie

    Member
    December 3, 2016 at 11:24 pm
    quote Phill Fenton:

    That is so strange. How can a magnet lose its magnetism. There must be another factor involved to cause this surely

    Batteries? :awkward:

  • David Hammond

    Member
    December 4, 2016 at 7:10 am

    Strangely I did a magnetic sign and poster for a customer, rolled both up in a 3in postal tube and sent it by courier to them.

    Customer rang when he got it to say it wasn’t magnetic.

    Ended up reprinting it and sending it flat, and all was OK.

  • Simon Worrall

    Member
    December 4, 2016 at 7:38 am

    I learned at school that magnets can lose their magnetism if
    1. they are heated
    2. they get knocked about
    3. if they are put into a strong magnetic field.

    So it is entirely possible the roll was dropped in transit or went through a scanner of some sort.
    Heating is less likely without showing some distortion or coloration.

  • Martin Pearson

    Member
    December 4, 2016 at 11:22 am

    Simon what you say is True plus temperatures below -20 can also cause loss of magnetism but it is hard for me to believe that any of these factors have caused the problem. Distributors send out mag sheeting every day & no one has ever reported a problem that I am aware of, it’s true that couriers can be a bit harsh but from what I have read it requires quite a bit of bashing about or an extremely sever force to cause this to happen.
    As far as temperature goes it is stored in a box in my unit & so you can forget about the upper temperature πŸ˜† more likely to be caused by the cold but even though it gets cold in my unit in the winter it hasn’t been that cold that I am aware of it only felt that cold at times πŸ˜†
    It’s not stored near or around any strong electromagnetic currents that I know of & isn’t kept near any other magnets.

    David is the first Person I have ever known who has said that they have had a problem with mag sheeting, a google search doesn’t throw up lots of posts either so maybe this has happened more often than we suspect but just hasn’t been reported πŸ˜† πŸ˜†

  • Phill Fenton

    Member
    December 4, 2016 at 4:41 pm

    The electromagnetic pulse from a nuclear bomb exploding at 5000 ft can cause this. Make sure you don’t store your magnetic sheeting anywhere near where nuclear explosions are taking place.

  • Robert Lambie

    Member
    December 4, 2016 at 6:51 pm

    No wonder those magnetic panels we put on the Trident Submarine in Faslane kept slipping off…
    learn something new every day! :awkward:

  • Martin Pearson

    Member
    December 4, 2016 at 7:13 pm
    quote Robert Lambie:

    No wonder those magnetic panels we put on the Trident Submarine in Faslane kept slipping off…
    learn something new every day! :awkward:

    No that was probably down to the rubber acoustic tiles & 3 inch thick layer of old paint that was covering it πŸ˜† πŸ˜† πŸ˜†

  • Martin Pearson

    Member
    December 6, 2016 at 11:36 am

    This is the offending Roll, as you can see it’s not just a small offcut or the very end of the roll.

  • Phill Fenton

    Member
    December 6, 2016 at 12:30 pm

    Not being funny Martin – but are you sure you haven’t been shipped ferous sheeting by mistake? i.e not magnetic sheet material but material designed for magnets to stick to. It looks very similar.
    http://www.first4magnets.com/large-metr … -4mm-p3851

  • Martin Pearson

    Member
    December 6, 2016 at 1:38 pm

    Phill, that’s a good question but I have Ferro sheeting from the same company which I use to use to make custom magnetic boards for a transport company & although it is similar you can see the difference between the 2 materials. It also seems to have a slightly different feel to it.
    I did wonder that myself when I first discovered it wasn’t magnetic, says so in the notes I made at the time πŸ˜† πŸ˜†

    I am 99.9% sure this is magnetic sheeting & it does have a very (very) small amount of magnetism but not enough to even keep a very small piece stuck on the filling cabinet πŸ˜†
    It’s the usual gloss on one side matt on the other.

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