Is this tank doomed (cracked, with pics)?

[GrumpyAlison]

I drilled my 75 and when I screwed the bulkhead on and I heard some weird grinding noises. Took it off and noticed some cracks in it. One is an actual crack, the other is a large chip near the edge of the hole.

I assume it would be dumb to actually use this and I should get a new tank? The crack doesn’t extend to the edge of the tank (barely to the edge of the bulkhead) but it seems like the kind of thing that has potential to get worse even though it’s near the top of the tank.

I’m just supper annoyed because I had to pay full price for a tank after petco broke my first one that was on sale and didn’t tell me until I went to pick it up after the sale (so I missed the sale).
And if I do need to get a new tank idk what to do with this one and I’m paranoid to drill it but I don’t want to drop another 200 on a tank and then also buy an expensive HOB Overflow. I’m just salty because I’ve punched at least 20 holes in tanks and never had a crack before If I need to get a new tank my boyfriend is going to be salty af...

I am also familiar with the rule about having the hole far enough from the edge. I did slightly mis measure this one but it’s still close to the distance it should be from the edge.

Thanks for your thoughts.

 

[KrisReef]

Not doomed, just destined to become a terrarium.

 

[lstmysock11]

Maybe you could get the reef ready version, Comes pre drilled in the bottom of the tank. Check with your LFS in your area or find a used one reef ready or Pre drilled.

 

[TerraFerma]

10 mins sounds a little fast to drill a standard 75. You can push harder once you get a little deeper but you have to slow down a lot when you start approaching the push through of the other side.

 

[GrumpyAlison]

10 mins sounds a little fast to drill a standard 75. You can push harder once you get a little deeper but you have to slow down a lot when you start approaching the push through of the other side.

It might have actually been longer. I wasn't really timing it but I went through a few songs and an ad break on spotify start to finish I normally don't press super hard at all because I'm paranoid and the drill was running pretty slow most of the time, but it was getting a bit dark towards the end so it's possible I misjudged where the edge was. Thanks for the thoughts!

 

[ca1ore]

Hmmmmn ...... the wisest course is probably to replace the tank ..... BUT .... I used a tank for many years with a comparable crack. Crack may run to the closest edge, but it's not guaranteed. Plus, in your case if it does run, there's not very far for it to go. If it were my tank, I would try to use it. I'd put a lot of silicone under the bulkhead/overflow.

One other thing to try, is to over drill/grind the hole beyond the crack. You'll have to play around with a larger bulkhead, if possible. But if you are going to trash the tank, maybe worth trying.

 

[GrumpyAlison]

Hmmmmn ...... the wisest course is probably to replace the tank ..... BUT .... I used a tank for many years with a comparable crack. Crack may run to the closest edge, but it's not guaranteed. Plus, in your case if it does run, there's not very far for it to go. If it were my tank, I would try to use it. I'd put a lot of silicone under the bulkhead/overflow.

I think I am going to replace it for peace of mind (my bf would be super unhappy if I flooded the basement and I'd feel terrible if my cheapness killed lots of stuff) but out of curiosity, are you talking like permanently silicone the bulkhead into the cracked hole?

 

[ca1ore]

are you talking like permanently silicone the bulkhead into the cracked hole?

Yes, bead of silicone on both sides of the gasket and tighten it down. Silicone will make it easy to overtighten the nut, so be careful. Also note that over drilling a new hole is an option I have done a few times.

 

[GrumpyAlison]

Yes, bead of silicone on both sides of the gasket and torque it down. Also note that over drilling a new hole is an option also.

actually... the over drilling is really interesting... hum..... i might try that before scrapping the tank entirely... seems like worst case scenario would be cracking it more and maybe not getting to sell it for more if i really destrtoy the back pane.... thanks for that suggestion!

 

[ca1ore]

actually... the over drilling is really interesting... hum..... i might try that before scrapping the tank entirely... seems like worst case scenario would be cracking it more and maybe not getting to sell it for more if i really destrtoy the back pane.... thanks for that suggestion!

Yeah, you might completely kill the tank, but probably not. As I said, I have over drilled holes on a few occasions to save a tank. Same general best practices - bit in good shape, some kind of guide, take your time and lots of water.

 

[GrumpyAlison]

Yeah, you might completely kill the tank, but probably not. As I said, I have over drilled holes on a few occasions to save a tank. Same general best practices - bit in good shape, some kind of guide, take your time and lots of water.

Indeed. I just measured the crack and it seems like a 2.5" hole would barely cover the crack/chip. Does that seem like an issue/should I get a slightly oversized bit, or just go super slow & careful?
I'm also kind of nervous because the redrilled hole would take me closer to the edge of the tank but spending like $10 on a new drill bit over buying a new $200 tank is def appealing... You have renewed my hope in DIY for now Like I'm legit so much happier right now XD Thanks!

 

[ca1ore]

You don't have to to it so that the material removed is a perfect ring, you can keep one of the existing edges and just remove a crescent .... if that makes sense. Even if you do go a bit closer to the edge, what's the downside really if you were going to bin the tank anyhow.

 

[GrumpyAlison]

That does make sense - it's basically what I was already considering actually
And yeah - logically I realize it doesn't make a lick of difference if I explode the tank, but emotionally I'm now invested in it again XD I'm going to order a new saw today and cross my fingers until it gets here.
Thanks again - I have no idea why I didn't think of over drilling the thing to begin with.

 

[GrumpyAlison]

THE OVER DRILLING WORKED!!!!
Took me 49 mins to punch the hole in but it’s the cleanest hole I’ve ever put in a tank before!!
Only down side is it’s pretty close to the top bracer so getting the bulkhead on might get a bit dodgy :/ but that’s fixable. Worse case scenario I have the materials available to cast myself a new bulkhead with a more streamlined profile.
Thanks so much for everyone’s thoughts!!
I’m gonna frame the stupid crescent piece with the crack.

 

[MnFish1]

I drilled my 75 and when I screwed the bulkhead on and I heard some weird grinding noises. Took it off and noticed some cracks in it. One is an actual crack, the other is a large chip near the edge of the hole.

I assume it would be dumb to actually use this and I should get a new tank? The crack doesn’t extend to the edge of the tank (barely to the edge of the bulkhead) but it seems like the kind of thing that has potential to get worse even though it’s near the top of the tank.

I’m just supper annoyed because I had to pay full price for a tank after petco broke my first one that was on sale and didn’t tell me until I went to pick it up after the sale (so I missed the sale).
And if I do need to get a new tank idk what to do with this one and I’m paranoid to drill it but I don’t want to drop another 200 on a tank and then also buy an expensive HOB Overflow. I’m just salty because I’ve punched at least 20 holes in tanks and never had a crack before If I need to get a new tank my boyfriend is going to be salty af...

I am also familiar with the rule about having the hole far enough from the edge. I did slightly mis measure this one but it’s still close to the distance it should be from the edge.

Thanks for your thoughts.

Just like was mentioned by someone on another thread. Buy a second piece of glass 1/4 inch thick - cover the bottom and re-silicone (leaving the old bottom in place. Just make sure you cover the whole bottom.

PS - I only mentioned this to help someone else with a similar problem - I see that you re-drilled it

 

[dhnguyen]

All is not lost on that tank though. You can patch it up by siliconing on a glass patch to cover the hole and the cracked area. Then at least you can still used it for a frag tank or a sump.

 

[dhnguyen]

I personally I don't put a lot of trust in HOB overflows. They are bound to fail sooner or later.
I've used enough of them in the past and eventually they always fail and always when you're out of town. Speaking from experience here.