magnets?

mr.maroonsalty · #1 03/29/2007, 11:23 AM

Can someone post me to a link? I have questions about converting suction cups to magnets. I'm thinking rare earth magnets for their power set in epoxy so not to corrode.

TouchemAllTommy · #2 03/29/2007, 11:45 AM

someone posted this link awhile back..i just bought some last night:
http://www.kjmagnetics.com/proddetail.asp?prod=RX054E

barbra · #3 03/29/2007, 01:38 PM

Here is the thread that deals with the conversion:
http://archive.reefcentral.com/forum...oto=nextnewest

nugg91 · #4 03/29/2007, 01:39 PM

it gets expensive but i had a buddy just use regular magfloats

Driftwood · #5 03/29/2007, 01:39 PM

I recently made some DIY magnet holders.

I used casting resin and neo or rare earth magnets and they work great. Pictures:

I used disposable tupperware containers and followed the two layer casting directions on the resin container. I imagine you could do the same thing with epoxy...

Good luck!
Dave

mr.maroonsalty · #6 03/29/2007, 02:11 PM

Thanks all! Couple quik questions: do I need the 58# magnets or will the significantly less expensive 35# force magnets hold say a maxijet 1200? Where can I find casting resin?

Driftwood · #7 03/29/2007, 02:19 PM

I got mine at a craft shop, Michaels in Augusta, Maine. I also got my magnets there. I have no idea how strong they are, I paid $3.99 for four of the magnets. I could tell they would work when two packages of the magnets were hard to pull apart.

You could also take apart an old computer hard drive and steal the magnets out of there, those suckers are STRONG!

Dave

mr.maroonsalty · #8 03/29/2007, 02:57 PM

Quote:

Originally posted by Driftwood
I got mine at a craft shop, Michaels in Augusta, Maine. I also got my magnets there. I have no idea how strong they are, I paid $3.99 for four of the magnets. I could tell they would work when two packages of the magnets were hard to pull apart.

You could also take apart an old computer hard drive and steal the magnets out of there, those suckers are STRONG!

Dave

Just to give me an idea, how many magnets are you using to hold that PH and roughly how big are they?

Driftwood · #9 03/29/2007, 03:15 PM

There are two in each side of the magnet holder. They are smaller then a penny. The $3.99 package came with all four of the magnets I used.

Dave

mr.maroonsalty · #10 03/29/2007, 03:29 PM

Many thanks!

dhnguyen · #11 03/29/2007, 05:51 PM

These work very well and you wouldn't have to encase them in anything.

http://www.kjmagnetics.com/proddetail.asp?prod=BX0X06BR

dhnguyen · #12 03/29/2007, 06:03 PM

These will work too

http://www.gaussboys.com/ndfeb-magnets/D3006.html

mr.maroonsalty · #13 03/29/2007, 08:19 PM

Two more questions then: can I get away using one magnet and a piece of metal? how to fix the magnet to the inside of the suction cup if not encased?

Driftwood · #14 03/30/2007, 08:19 AM

Glue it to the powerhead. If the magnet is strong enough it should hold to a piece of metal on the other side.

Dave

miwoodar · #15 07/26/2007, 09:42 AM

Quote:

Originally posted by dhnguyen
These work very well and you wouldn't have to encase them in anything.

http://www.kjmagnetics.com/proddetail.asp?prod=BX0X06BR

dhnguyen -

Do you konw if anyone has had good experiences with these? They are epoxy coated with a pull force of ~34lbs and 1/6th the price of the other link.

http://www.kjmagnetics.com/proddetail.asp?prod=DC2E

Siffy · #16 07/26/2007, 10:31 AM

Anyone know if rare earth are the type used inside mag floats? I'm wondering if they're actually the best choice due to the way they work. I can't think of the term to describe it, but basically force is an inverse function of distance and with rare earth magnets the force drops off very quickly. More so than other magnet types. Many of them don't produce a force over an inch. On larger tanks with glass with a thickness > 1/2" the actual force will be much lower than the advertised pull strength.

Chrismo · #17 07/26/2007, 10:35 PM

The rare earth magnets I got from KJ have a tonne of force at an inch distance. They hold my maxi-mod on very well.

If a magnet has a pull force of 34 pounds and it is stuck to another same magnet. The pull force is added together to be 68 pounds. That drops down a lot though the glass, but still enough to hold.

In fact, I have attatched rocks/corals to my maximod to disguise it a bit and the magnet holds them up to.

miwoodar · #18 07/26/2007, 10:41 PM

Awesome - Thanks!

dhnguyen · #19 07/27/2007, 02:24 AM

Quote:

Originally posted by miwoodar
dhnguyen -

Do you konw if anyone has had good experiences with these? They are epoxy coated with a pull force of ~34lbs and 1/6th the price of the other link.

http://www.kjmagnetics.com/proddetail.asp?prod=DC2E

They SHOULD be strong enough to use. However, the expoxy coating seems a bit too thin IMO and could chip or crack easily if you're not careful.

Haven't used these myself though.

Siffy · #20 07/27/2007, 04:43 AM

Quote:

Originally posted by Chrismo
The rare earth magnets I got from KJ have a tonne of force at an inch distance. They hold my maxi-mod on very well.

If a magnet has a pull force of 34 pounds and it is stuck to another same magnet. The pull force is added together to be 68 pounds. That drops down a lot though the glass, but still enough to hold.

In fact, I have attatched rocks/corals to my maximod to disguise it a bit and the magnet holds them up to.

Which magnets are you using?
http://www.kjmagnetics.com/proddetail.asp?prod=DC2E ?
How many are you using per side to hold up your maxi-mod?

workn4frags · #21 07/27/2007, 07:48 AM

Has anyone had problems with the Mags. interfering with the impeller/mag. motor?

Chrismo · #22 07/27/2007, 10:54 AM

I'm just using one. but it is a big one with 180 pounds of force. ($13) I tried glueing a bunch of smaller ones to the maxi jet but it was way harder than I expected. After you glue one magnet down, the next magnet wants to stick to it, or push it away. So you have to let each magnet dry really well before glueing the next one.

One more thing to note: In your glass cleaning magnets they actually have two magnets of opposite polarity mounted together in that plastic. Like this [+ - ]
This allows the magnets on the inside of the tank(wet) stay aligned with the magnets on the outside(dry).

If you use only one magnet, then spinning the outside one will not spin the inside(wet) one.

One more problem I faced... the back panel of the maxijet which I epoxied my magnet to can pop off. You need to glue the back piece on better. The magnet is stuck to the back panel more than the back panel is stuck to the maxijet.

I used a 2 ppart marine expoxy/paint to seal my magnet to keep the water from touching it.

Chris

Quote:

Originally posted by Siffy
Which magnets are you using?
http://www.kjmagnetics.com/proddetail.asp?prod=DC2E ?
How many are you using per side to hold up your maxi-mod?