Magnetic real live rock

[cmholl]

I was doing some thinking and I'm wanting to take some pieces of my live rock, grind a flat spot on the back and insert magnet so I can place them throughout the tank on the glass. What my question is... Are magnets corrosive in saltwater. If so, could I coat the magnets in an apoxy and will that dissolve in saltwater.

 

[flower]

Quote:
Originally Posted by cmholl http:///t/394836/magnetic-real-live-rock#post_3514447
I was doing some thinking and I'm wanting to take some pieces of my live rock, grind a flat spot on the back and insert magnet so I can place them throughout the tank on the glass. What my question is... Are magnets corrosive in saltwater. If so, could I coat the magnets in an apoxy and will that dissolve in saltwater.
Hi,
I assume you meant that "will NOT" dissolve in saltwater....LOL
Anyway, yes to the question of if it is corrosive. Also yes to epoxy...you will have to pour epoxy on the rock section first and let it dry solid... then put the magnet in place, and epoxy it again to seal it. The clear thin resin that takes a hardener is what I used when I sealed some wood pieces to make my own decor...your rock idea sounds awesome.
You will have to get some really strong magnets, because it has to hold through the glass on the tank, and the epoxy enough to hold your rock in place. It would make an awesome build project to take pictures of as you go...

 

[sweatervest13]

Quote:
Originally Posted by Flower http:///t/394836/magnetic-real-live-rock#post_3514460
Hi,
I assume you meant that "will NOT" dissolve in saltwater....LOL
Anyway, yes to the question of if it is corrosive. Also yes to epoxy...you will have to pour epoxy on the rock section first and let it dry solid... then put the magnet in place, and epoxy it again to seal it. The clear thin resin that takes a hardener is what I used when I sealed some wood pieces to make my own decor...your rock idea sounds awesome.
You will have to get some really strong magnets, because it has to hold through the glass on the tank, and the epoxy enough to hold your rock in place. It would make an awesome build project to take pictures of as you go...

Check this out. It is not live rock but a fake base rock that will become just like LR in your tank. The magnets are already sealed up and ready to use.
http://lmgtfy.com/?q=aqua-Mags+LLC
HTH's

 

[sweatervest13]

Sorry Flower,
I meant to reply quote to the OP's message. Either way some pretty cool stuff.
I thought I had read a thread here a couple of years ago where a member was making fake LR with magnets for frag racks. I tried to do a quick search but could not find it right away, and not enough time to search deeper.
LR with magnets is a very cool way to acclimate sensitive corals to lights. You can put your frags on the LR and slowly move it up in the tank to get them used to the brighter lights. Kinda cool!!

 

[flower]

Quote:
Originally Posted by sweatervest13 http:///t/394836/magnetic-real-live-rock#post_3514465
Sorry Flower,
I meant to reply quote to the OP's message. Either way some pretty cool stuff.
I thought I had read a thread here a couple of years ago where a member was making fake LR with magnets for frag racks. I tried to do a quick search but could not find it right away, and not enough time to search deeper.
LR with magnets is a very cool way to acclimate sensitive corals to lights. You can put your frags on the LR and slowly move it up in the tank to get them used to the brighter lights. Kinda cool!!
Fake live rock is a little tricky to make, but I agree it would work just as good...the OP wanted to shave off an end to be smooth and attach a magnet. LOL...When I had coral I would have given my eye teeth for such a thing....I did see a plastic version held with suction cups...and I looked at that real hard, but I knew it wouldn't hold up.
But you know what, after a little thought....making a back wall that is held by magnets in sections...I would pay for such a thing. I love the look of a back wall, and one held by magnets would allow me to work around equipment, and angle the rock the way I want....Wheels turning....Hey Cmholl...what would you charge for such a thing?...LOL

 

[cmholl]

Fake live rock is a little tricky to make, but I agree it would work just as good...the OP wanted to shave off an end to be smooth and attach a magnet. LOL...When I had coral I would have given my eye teeth for such a thing....I did see a plastic version held with suction cups...and I looked at that real hard, but I knew it wouldn't hold up.
But you know what, after a little thought....making a back wall that is held by magnets in sections...I would pay for such a thing. I love the look of a back wall, and one held by magnets would allow me to work around equipment, and angle the rock the way I want....Wheels turning....Hey Cmholl...what would you charge for such a thing?...LOL
It really wouldn't be that much work. I already have the blade to cut the rock. I would just need to get the magnets and the epoxy to coat them. Glue them on and let them sit. I've been looking at magnets and Home Depot has some that hold 25lbs. So with the glass and epoxy I would say it could hold 10 lbs. these magnet are only 3 inches in diameter. With someone that supplies the rock and the magnets it would probably only be $15 for labor.... The most time would be letting everything dry. But yes, I'm doing my first rock this weekend. I'll post pics of the progress!

 

[acrylic51]

Shaving the rock is a breeze with a diamond cutting wheel on a hand grinder........As far as epoxy should be super easy to do. I'd epoxy the magnet first and then bore my hole into the rock if needed or wanted.....The epoxy coating doesn't have to be super thick, but you need to guarantee there aren't any pinholes or you'll have disaster on your hands shortly......Then epoxy the magnet to the rock work.....I would suggest pouring a thin layer of epoxy on your rock work where the magnet will be attached....Pouring a thin layer allowing it to cure and then roughing it up a bit will give a super strong adhesive surface for the final bonding.....Just my .02

 

[flower]

Quote:
Originally Posted by acrylic51 http:///t/394836/magnetic-real-live-rock#post_3514582
Shaving the rock is a breeze with a diamond cutting wheel on a hand grinder........As far as epoxy should be super easy to do. I'd epoxy the magnet first and then bore my hole into the rock if needed or wanted.....The epoxy coating doesn't have to be super thick, but you need to guarantee there aren't any pinholes or you'll have disaster on your hands shortly......Then epoxy the magnet to the rock work.....I would suggest pouring a thin layer of epoxy on your rock work where the magnet will be attached....Pouring a thin layer allowing it to cure and then roughing it up a bit will give a super strong adhesive surface for the final bonding.....Just my .02
I agree, the epoxy itself makes a bond like steel. But I still think you need really strong magnets to be able to hold through glass, the epoxy isn't all that thick but doesn't acrylic tanks have thinner walls, then a glass tank? So tank type and thickness should determine the strength of the magnet to use. The ones I have for my power heads is so strong I can't hardly pry them apart...but when I put it on my 90g glass tank it holds, but can be pulled apart pretty easy.

 

[acrylic51]

Definitely going to have to do a check on the magnets....Probably order them online. I've been curious about how to decipher a magnets holding power translates to what thickness material it can penetrate......

 

[cmholl]

I'm a crane operator and I mess with giant magnets all day. The ones we have pick up plate steal. The way we measure how much one can hold is for inch of metal the power of the mag is cut down about 10%. I know we're talking about regular mags but I think we could use this as a guess. It also depends on how you distribute the rock. If you one one big mag that has a grab strength of 25lbs in the center of the rock, you would get 50lbs o grab strength with 2 15lbs mags on each end of the rock because the center mass of the rock becomes obsolete. That's how we judge what mags to use for what job I'm having to lift at work.

 

[cmholl]

Like I said, I'm going to buy magnet this weekend and I will go to a fish store that my friends parent own and test the grab strength of the mags thru different thickness glass. I can measure this buy pulling down on the mag with a fish scale. Another thing to think about is if you have two mags that are 25lb grab. One on the inside and one on the outside you would have 50lbs of grab. Just have to be careful when lining up the two not to have them crack the glass

 

[pinky327]

thats a really interesting idea!

 

[novahobbies]

Dude. Mine look SO much better. Just ask Siptang.

 

[cmholl]

They look nice, but they also look like painted plastic. I don't recall seeing anyone posting any pics of there's so where did the " mine look SO much better" come?

 

[novahobbies]

It was a JOKE....hence the laughing face..... ;-)
And I just noticed! Someone DID put a link to a sale page up (which was what prompted my comment) but it looks like the mods removed it. Heh.

 

[novahobbies]

And just fyi, these are with two neodymium mags, each 1.5 inches diameter and 1/4 inch thick. The internal mag is embedded in urethane resin, while the outer one is bare. It would be safer to encapsulate the outer mag in silicone rubber if I was actually producing these...it would prevent someone from accidentally smacking it against the glass. If you cut your own rock (easy to do as I see you have rhe tools) you'll be fine as long as you encapsulate the inner mag in epoxy or urethane resin. Personally I'm a fan of polyurethane resin, but that's just MO...

 

[cmholl]

Wasn't trying to be an a$$. Sorry. Was just asking. Are yours plastic

 

[2quills]

Have you guys tried the epoxy coated magnets that that I've seen sold online? I believe they're not very expensive at all. Might cut down on some of the cure time by only having to go with one coat in order to bond them with the rock but it's just an idea...haven't tried it myself.
I know that you can buy some of that soft fuzzy material that has an adhesive backing on it similar to what youd find on the exterior part of a mag float for your outer magnets. Just some thoughts.

 

[acrylic51]

Hmmmm I'd need something in the 200lb pull down range for 1".......

 

[novahobbies]

cmholl, no worries! To answer your question...yes, these are painted prototypes of something I was designing, and they're cast from urethane resin. There are two in those pictures, one painted in a natural "coraline" look, and another with brighter tones that was a little more toylike.
2quills, I know the epoxy coated mags you're talking about. Those are the ones I used. IMO the epoxy coating on the magnets is too thin to be considered safe for long term use. The magnets will be better suited to tank use if they're embedded in either more epoxy or resin. The epoxy coating that comes on most mags is just an "anti-chipping" coating...more or less.
Shawn, I agree you're going to need some serious pulling power to firmly hold through 1 inch acrylic. You should also use magnets for both side...will help a lot.