Magnetic frag mounts

vdituri

vdituri

Well-Known Member
Home Depot has some that they labeled as The strongest ceramic magnets available.
I've used them to mount xenia frags to, but will have to watch for any signs of rust or other leakage from them.

So far so good.
 
Origami2547

Origami2547

Member
Matt, I'm going to revive this thread to ask for some additional DIY info. Hope you're around to help!

First, I'm guessing that the larger magnets you've used are the epoxy-coated 3/4 x 1/8 neodymium N42 discs shown here? K&J Magnetics - Products

What's the thickness of the glass on the tank that you're showing in the pictures? (I'm trying to determine the pull strength that you're getting after separation.)

Here's a nice page that gives you some magnet calculations (such as pull strength). I've found it helpful and thought maybe other's might, too.
Calculation Tool-Kit
 
panmanmatt

panmanmatt

Well-Known Member
Yes, those are the larger magnets that I amusing. In the pics above it is on a 29 gallon tank with 1/4" glass. That was just for the pics. I am currently using it on my Oceanic 70 gallon with 3/8" glass and it is holding just fine using 2 sets of magnets. I ust made one for a friend of mine for his 120 gallon with 1/2" glass and used 3 sets of magnets. I am delivering it tomorrow so once I gr some feedback on it I will post it here.

The only problem I found with these magnets is that the epoxy is very thin and brittle. It chips very easily if you let the magnets slam together. I just mixed up a small amount of 2 part epoxy and brushed a thin layer on the magnets after I assembled the racks.
 
Origami2547

Origami2547

Member
I'm guessing that maybe you've seen Daniel's design over at mag-racks.com? He uses black egg crate now, which is visually low-key - he used to spray paint his black with Krylon Fusion. I think he encapsulates his (uncoated neodymium) magnets in clear casting resin, also using the resin as the adhesive that bonds the magnets to the egg crate. A little research showed that one technique used to encapsulate the magnet is to drill appropriately spaced holes in a plastic cutting board and using duct tape to seal off one side of the hole. This makes "wells" that you can partially fill with the resin/hardener mix before dropping in the magnet and setting up the egg crate for bonding.

I think that your epoxy paint approach would be cheaper for small quantities since casting resin is kind of expensive.

Thanks for the answers. I've been kind of wrestling with, should I build my own magnetic frag racks, whether I should use 1/8" or 1/4" discs.
 
pinantanjohn

pinantanjohn

Member
panmanmatt said:
I'm not sure about the nickel. I would imagine that it will eventually rust in saltwater.

You get 2 part epoxy from a craft/hobby store and coat the magnets in that just to be safe.
Click to expand...

Stainless Steel is in part nickel, about 40 to 60 percent. There is a material that is called stellite that is 60% nickel and 40% chrome that is used in marine pumps. It doesn't corrode at all.

If the coating is pure nickel, it will be inert.

Not sure about the magnets though, I have some Ne-B/Fe (Neodymium/Boron/Ferrite) magnets that will scramble your DNA or smash your bones if you aren't careful. Ever see the ones on Mythbusters, Jamies monsters? Don't think you need that kind of power. Old speakers will have good magnets that will do the job and not contaminate the tank. Just clean all the goo off them, it's petroleum based. Old hard drives and hobby motors have good strong magnets in them too. These are just a strange shape.

Peace...
John
 
Jeremy0322

Jeremy0322

Active Member
I was wondering if anyone had any other information about this, im gonna revive the thread and see if there has been anything else found out about building these?
 
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