make a magnet food safe by coating?

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SanPancho

SanPancho

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want to figure out if its possible to get a ring magnet and coat it so its food safe. found this post below, but it went no where from what i can tell.


Food Safe Coating Ideas for Neodymium magnets

anybody know of a diy plastic dip thats food grade? the 100% silicone caulk seems like it would work if cant find plastic, yes? either the high temp stuff or just regular kitchen/bath caulk at 100%.

open to other ideas as well.
 
wont work. the magnet itself needs to be coated for this application
 
how robust does the coating need to be? many waxes are food grade, but would wear off pretty easily.
 
Might help if the application (and operating temperature) were known.
But if the usage isn't extreme I'd be looking towards a food safe epoxy coating...

Cheers!
 
hadn thought of wax as an option, although I’d worry that it’d make clean up a pain. And on the chance the wax coating was hit or pinched I’d be leery of letting the magnet Become exposed to the beer


day_trippr said:
Might help if the application (and operating temperature) were known.
But if the usage isn't extreme I'd be looking towards a food safe epoxy coating...

Cheers!
Click to expand...

we’re talking about uncarbed beer. Anything from room temp to cold crash temp, although cold is most probable. I got a few hits about epoxy but none that mentioned food safe.
 
yeah, but you gotta be careful that they're compatible with metal. this one, and many others, are not. so what i should have said is food safe and bare metal compatible.

more i think of it though, more im leaning towards just coating that sucker in silicone since it is soft and rubbery. epoxies are hard and somewhat brittle in thin coatings, seems much more likely to develop small cracks and leaking. plus i'd assume it'd need a few light coatings to build up a covering.

so im definitely leaning towards silicone. gotta wait for magnets to show up. so just need to decide if its the high temp stuff i have left over from sealing up my kettle, or the clear stuff for kitchen/bath use.
 
So what is your application? I use mine like the post you stated where the magnets are used to keep a dry hop bag at the top of the fermenter until I want to drop it into the beer. having the magnets sealed in food saver vacuum bags works just fine. I take a bit of vacuum bagging, use the seal function to create columns a touch wider than my magnets, drop a magnet in each column, then vacuum and seal the bag. Cut carefully through the middle of the seals to have a bunch of tiny food safe magnet baggies. With the magnets I have one on the outside and one on the inside can easily keep over a pound of material suspended above my beer in the fermenter until I am ready to drop it in.
 
Its a ring magnet. It has a hole in the middle where i need to run tube. Vacu seal bags wont work.
 
I work in an industry that uses many magnets, but sadly nothing requiring food grade coatings. Most of what we use is Black Epoxy (or a slightly modified variation) or Nickel Plated.

Here is a good resource of the typical coating and plating for magnets: Magnet Plating and Coating Options - Amazing Magnets

I would think the ABS or Teflon / PTFE coatings would be the best for food grade. That or a two piece "cup type" stainless steel sleeve around the ring magnet while also allowing a through hole.

Since this is adding a coating after sourcing the magnet, I bet some fully-cured food grade viscous epoxy or silicone would work. It would probably be easier to be able to dip it into a liquid. I found this guide on a magnet manufacturer when they dip magnets into rubber: K&J Magnetics - Rubber Coating Neodymium Magnets
 
SanPancho said:
yeah, but you gotta be careful that they're compatible with metal. this one, and many others, are not. so what i should have said is food safe and bare metal compatible.
Click to expand...
It says that it is compatible with metal " Clear Adhesive For Wood, Metals, Ceramics, Glass, Plastics "

If it really isn't for some reason, then could you coat with something like fingernail polish, and then epoxy?
 
the issue is that all of that stuff is rigid, and therefore more likely to crack and even chip. a soft plastic or silicone will be much more resistant to cracks/chips/etc. and that seems much safer to me. even if it'll be a bit more difficult to apply initially.
 
i remember as a kid magnetizing metal? what about rubbing your magnet on a SS washer? then using the washer?
 
the 300 series stainless metals are generally not magnetic, or very weakly so. doubt it would have any effect
 
Yeah, for stainless steel one would be stuck in the ferritic SS class, and I'm not sure how that type stands up in the face of pH in the 4s...

Cheers!
 
well i thought it was worth mentioning. i remember thinking it was cool if i rubbed some non magnetic metal with a magnet, it got magnetic.
 
Magnetic flux is generated by an electric field coil, usually wrapped around core material but that's not actually required...

Cheers!
 
SanPancho said:
Its a ring magnet. It has a hole in the middle where i need to run tube. Vacu seal bags wont work.
Click to expand...
Well it seems you have an application that you don't want to let out of the bag. As a young man I worked in the family painting business. We did all types from residential to commercial. I have sandblasted very large steel tanks that contained the syrup for making Coke (the drink). We then painted the tanks with an industrial food grade epoxy primer and then a few coats of the finish food grade epoxy paint. Epoxy is very tuff and resists abrasions and chemicals. Epoxy does not do well in UV light.
Also, look in to the coating used on stir bars they're magnets.
 
Last edited:
Ok, I just googled and found this.
Stir bars are typically coated in PTFE, or, less often, in glass; the coatings are intended to be chemically inert, not contaminating or reacting with the reaction mixture they are in.

Prost
 

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