# cracked AC filter



## ScarletFire (Nov 4, 2012)

I'm cleaning some old used AC HOB filters, and I found that one of them have a cracked case. Is it possible to somehow fix this and it's still usable and not toxic to fish and plants? I was thinking about taping it from the inside, but I don't know if it's that good of an idea.


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## pyrrolin (Jan 11, 2012)

easy fix, silicon will do it, just let it cure for 48 hours, just be sure its just silicon and not stuff with anti mold and stuff.

GE silicon I is just fine, do not use silicon II as it has stuff that will kill your BB.


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## ScarletFire (Nov 4, 2012)

Is Perfecto Silicone Sealant okay? I don't want to end up buying the wrong item 

http://www.kensfish.com/moreinfo/perfecto-silicone-sealant-28-oz.html


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## Jackson (Jan 30, 2009)

I've fixed things like thins with super glue and a small piece of plastic. Patch it from the inside. I've never had an issue with a leak or dead fish from fixing it this way.

Silicone IME will just peel off over time.


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## pyrrolin (Jan 11, 2012)

that one is ok if it is 100 percent silicon and does not have any additives for mold and stuff. Silicon is what most people use to seal their aquariums, if it is good enough to seal my 90 gallon aquarium, which it is, its more than good enough for an AC filter


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## pyrrolin (Jan 11, 2012)

Just checked the link, yes that silicon is perfectly fine to use if you already have it. I bet its about $20, you can just buy the GE stuff for about 7 or 8 bucks. Its the same thing, you just pay more for the word aquarium.


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## Jackson (Jan 30, 2009)

pyrrolin said:


> that one is ok if it is 100 percent silicon and does not have any additives for mold and stuff. Silicon is what most people use to seal their aquariums, if it is good enough to seal my 90 gallon aquarium, which it is, its more than good enough for an AC filter


Silicone peels off of plastic and doesn't adhere to plastic the same way it does to glass. 
The silicone will peel off especially if its done from the inside.


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## wtac (Mar 17, 2006)

You have quite a few cracks and will take almost a lg tube of Weld-On 16 and reinforcement mesh to get it 100% sealed and "safe".

A new case is ~$30 where WO16 and mesh is ~$20-25. I'd buy a new/used case.

HTH


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## pyrrolin (Jan 11, 2012)

try using sand paper around the cracks where silicon will go and give it a try, but monitor it.

or just buy a new housing


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## ScarletFire (Nov 4, 2012)

Jackson said:


> Silicone peels off of plastic and doesn't adhere to plastic the same way it does to glass.
> The silicone will peel off especially if its done from the inside.


What kind of plastic do you suggest using? (things that come to mind include plastic bags, plastic wrap, plastic cups, ziplock bags)



wtac said:


> You have quite a few cracks and will take almost a lg tube of Weld-On 16 and reinforcement mesh to get it 100% sealed and "safe".
> 
> A new case is ~$30 where WO16 and mesh is ~$20-25. I'd buy a new/used case.
> 
> HTH


I'm looking at the MSDS because I saw that some hits on google say that it's hazardous: http://www.tapplastics.com/uploads/pdf/MSDS IPS Weld-On 16.pdf

Have you had any issues with using it?


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## Jackson (Jan 30, 2009)

What I used was a piece of a cd case and some super glue.
I let it cure for 48hrs and it worked for years until I broke it another time beyond repair. 
Sounds ghetto but it worked and was cheap.


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## Fishfur (Mar 4, 2012)

I'd be tempted to use super glue and something like a piece of jewel case too. Or two part expoxy, and they make both liquid and solid forms of this that are safe for fish and being submerged. The putty form would make a good barrier, the liquid should work too. I once repaired a simple corner filter that broke in half using ordinary epoxy, two part liquid and it lasted me another five years after that. No harm to the fish or the turtles in that tank. This was back in my school days, btw.

There is also a product out there that is extremely effective for repairs like this, because it comes with both a 'super' super glue and a 'welding powder', which fills in any cracks or holes and is rock hard in moments. Once cured it's not going anywhere. The powder I'd probably use on the outside, but since it's bound up with the super glue I doubt it would cause issues in a tank. But better safe than sorry, right ?
I've used it for a number of repairs and it's been superior to any other super glue. I'd have to look up the name though, it's not in every store yet.
Silicone, while a wonderful product for many things, is not going to last for a repair like this one. It will peel off and leave you where you started. And tapes have a lot of chemicals in them. Even if you used it outside, some of the chemicals would likely seep in via the crack. I'd not want to risk it.

Edit* That super glue product I mentioned is called Rapid Fix.. there's a lot of info online and places to get it. Costs about twenty bucks for one pack with two bottles, one of powder, one of glue, but it goes a heck of a long way and is very, very effective. I got it at the Hobby show last spring and it's been amazing. I used it to repair a cheese grater that was great to use but cheaply made. This stuff made it better than new and it's still working fine, as well as a number of other things.


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## wtac (Mar 17, 2006)

For just cracks on one surface plane, the CZ and plastic CD case will work fine, but on the curves, you will have to use the WO16 and imbed the mesh. Once the WO16 cure and the solvent evaporates, it is safe. WO16 is widely used in acrylic aquarium and sump repairs/hole patching.


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