what glue do i use to stick magnets to ss

[aboard_epsilon]

Nothing to do with magnet motor

I want to make SS covers for lead-screws on a car lift ...that is outside.

thought that these rare earth magnets are the right approach ans easiest way to do the job..

Will epoxy two pack glue stick magnets to stainless steel .

The covers, will just be in use when the lift is not being used ..

The covers will be just 18 guage SS with a return lip on them



All the best.markj

[Evan]

Epoxy is the best for one particular reason that isn't obvious. Most glues are based on plastic resins of various types and have a large coefficient of expansion with temperature. If the glue is a type that polymerizes to a hard solid such as cyanoacrylates it can fracture and fail with changes in temperature. Epoxy resin however has almost exactly the same coefficient of linear expansion as steel.

[aboard_epsilon]

ahh.......... but the trouble in the UK is ..not all epoxies are the same

I've had some that cured and was like your candy sweets ..or Blackpool rock to the uk'ers..........you can break it with very light taps of hammer ...like boiled sugar.

there are some on ebay with countersunk holes in them ...but unrealistic prices compared to the others

so what would be ideal ...

neodymium 20mm diameter with hole and coutersink..quantity 40...at under a tenner UK.

if not its back to the glues

all the best.markj

[bob ward]

I would be thinking of one of the polyurethane adhesives. Sikaflex have an external variety in their large range.

[aboard_epsilon]

what's the best grade of this Sikaflex stuff Bob...

I've looked on ebay...about the only place cheap ...and I'm lost .so many different ones.....all have numbers and letters

all the best.markj

[Duffy]

Here in Canada, Lee Valley Tools produce, (and sell,) steel cups that are designed to hold those magnets, thereby increasing their attractive force. These are supplied, with matching washers, if desired, both drilled and countersunk for flathead screws. They actually work, and if you didnt want to wait delivery, it would not be very difficult to machine up a few. I think the clearance on the magnet is only about .005", and the bar stock seems to be the "next size up," ie 1" for a 3/4" magnet. The cups could probably be installed with pop rivets with a little preplanning.

[davidh]

the magnets would leave the cover to be open for the thickness of the magnets anyway, another approach that may be thought about:
drill and tap the lip on the hoist frame three places (top, middle and bottom) and install bolts using threadlocker to keep them just a bit more than the thickness of the stainless cover, away from the lip.

match drill and slot the stainless cover with the slot being larger diameter hole on the bottom of the slot to let the bolt head slip thru it.

slip the cover onto the bolt heads and let the slots hold it in place. nice snug fit. . . .

as always, just my humble thoughts with coffee in the a.m.

[aboard_epsilon]

You're probably right David
I thought the magnets idea would make it simpler and less complicated ...now think about it ...what with the chance of the glue failing ...i could become "unstuck" with this idea
studs and wingnuts it is then ...
more pics







all the best.,,markj

[darryl]

I don't know if it still can be found, but I used some flexible epoxy once and it worked great. Ironic that you mentioned gluing magnets- that's what I did, but these were motor magnets- the typical pair of arc shapes in a steel can.

I just checked a test piece I made about 15 yrs ago- it's still flexible and didn't crack when I flexed it. If you were to use that or similar, it might be a good idea to coat over the surface of the magnet as well. The nib discs are already coated, but it won't hurt to add further protection to that. I've seen them peel and corrode- looks nasty.

I wasn't aware that epoxy had the same coe as steel- that's good to know.

[aboard_epsilon]

whoopy woo

Went out looking for a met fab business ..that had a bigger sheet metal folder than i had ........first business ...didnt have one big enough ......but we know where one is for sale ...

when i got to the destination,turns out it wasn't a metal folder

ended up buying a guillotine for £70

sort of heavier duty version of this ..I've wanted one for years !

http://cgi.ebay.co.uk/Edwards-Pedicu...QQcmdZViewItem

all the best.markj