crack in bulkhead hole

[LuckyReefer]

so i recently got a used 125 drilled aquarium and changing out the bulkheads i noticed a small chip where the holes drilled, my other tanks are all hob overflows so im unsure is this going to create an issue down the road? should i just be more diligent with the silicone when putting new bulkheads in? its not where you can see it i noticed the bulkhead came off i just wanted to be sure before i have a leakage..

 

[Timfish]

From what I see it looks like a chip from when the bit broke though when drilling. I would just goop up the bulkhead fitting like you're thinking with some silicone.

 

[Troylee]

It’s not gonna hurt anything! Scrape that area clean with a blade before installing the bulkhead and I wouldn’t use silicone as the seal doesn’t seal properly..

 

[Timfish]

It’s not gonna hurt anything! Scrape that area clean with a blade before installing the bulkhead and I wouldn’t use silicone as the seal doesn’t seal properly..

That's interesting, can you give more info? I started using silicone on bulkheads back in the early 90s and haven't had issues.

 

[Troylee]

That's interesting, can you give more info? I started using silicone on bulkheads back in the early 90s and haven't had issues.

A properly installed bulkhead does not require silicone… plain and simple lol.. it has a better chance of leaking with goops of silicone than it does using the seal it comes with..

 

[Formulator]

so i recently got a used 125 drilled aquarium and changing out the bulkheads i noticed a small chip where the holes drilled, my other tanks are all hob overflows so im unsure is this going to create an issue down the road? should i just be more diligent with the silicone when putting new bulkheads in? its not where you can see it i noticed the bulkhead came off i just wanted to be sure before i have a leakage..

I’ve drilled several tanks and sumps myself and found it nearly impossible to avoid chips like that. As long as it isn’t cracked, you’ve go nothing to worry about. The bulkhead will seal just fine. Also agree that silicone is unnecessary and more likely to cause a problem than it is to help anything.

 

[Timfish]

A properly installed bulkhead does not require silicone… plain and simple lol.. it has a better chance of leaking with goops of silicone than it does using the seal it comes with..

I’ve drilled several tanks and sumps myself and found it nearly impossible to avoid chips like that. As long as it isn’t cracked, you’ve go nothing to worry about. The bulkhead will seal just fine. Also agree that silicone is unnecessary and more likely to cause a problem than it is to help anything.

In theory that sounds great! But what has been your actual experience? As I mentioned earlier I've been using silicone on bulkheads for about three decades now on dozens of setups and have not had the issue you are insisting will happen nor do I see how it can happen. Are you speaking from exerience or is it just a hypothetical. If you are speaking from experience what are the specifics?

 

[Troylee]

I’ve never used silicone and never had a leak! I have fixed many tanks where people used silicone and they leaked! That’s my experience.

 

[BillB83]

This is fine and shouldnt cause you any issues at all

 

[Timfish]

I’ve never used silicone and never had a leak! I have fixed many tanks where people used silicone and they leaked! That’s my experience.

And I've fixed tanks where bulkheads leaked and aquarists hadn't use silicone. Based on what I've seen I could make the argument a bulkhead has a greater chance of leaking if silicone isn't used. Are you saying it's a 100% chance, 50% chance, 10% chance?

The reason I used silicone the first time was in the middle of a tank move replacing an old bulkead with a new one the new one had a defect and with animals sitting in buckets the expediant fix was to use silicone. I've seen setups where the hole was drilled oversized for standard bulkheads and silicone provided additional insurance. I've found gaskets that are very loose on bulkheads and silicone helped keep the gasket in place installing the bulkhead in tall narrow overflows. And I've seen chips like the OP posted large enough a gasket wouldn't seat well.

 

[BillB83]

And I've fixed tanks where bulkheads leaked and aquarists hadn't use silicone. Based on what I've seen I could make the argument a bulkhead has a greater chance of leaking if silicone isn't used. Are you saying it's a 100% chance, 50% chance, 10% chance?

The reason I used silicone the first time was in the middle of a tank move replacing an old bulkead with a new one the new one had a defect and with animals sitting in buckets the expediant fix was to use silicone. I've seen setups where the hole was drilled oversized for standard bulkheads and silicone provided additional insurance. I've found gaskets that are very loose on bulkheads and silicone helped keep the gasket in place installing the bulkhead in tall narrow overflows. And I've seen chips like the OP posted large enough a gasket wouldn't seat well.

Are you using silicone on the inside of the glass ? under the gasket ? or are you like filling in the small gap in the threads ?

 

[Timfish]

Are you using silicone on the inside of the glass ? under the gasket ? or are you like filling in the small gap in the threads ?

Most of the time I'll put the gasket against the flange side of the bulkhead fitting, then run a thick bead of silicone around the bulkhead next to the gasket. Randomly, this sequence is reverse for no particular reason. I've run into holes that are oversized for standard bulkhead fittings a couple times and the bulkhead fitting and the hole will get enough silicone so the nut squeezes some out.

 

[Formulator]

In theory that sounds great! But what has been your actual experience? As I mentioned earlier I've been using silicone on bulkheads for about three decades now on dozens of setups and have not had the issue you are insisting will happen nor do I see how it can happen. Are you speaking from exerience or is it just a hypothetical. If you are speaking from experience what are the specifics?

I wasn’t insisting there would be an issue, just suggesting that it is absolutely unnecessary and theoretically could cause an issue if the silicone were applied inconsistently for example. In this hypothetical, one could imagine a glob of silicone creating a channel for water to pass through by making an un-level un-smooth surface for the true rubber seal of the bulkhead to seal against.

At the very least it is a waste of your time and silicone.

 

[Troylee]

I wasn’t insisting there would be an issue, just suggesting that it is absolutely unnecessary and theoretically could cause an issue if the silicone were applied inconsistently for example. In this hypothetical, one could imagine a glob of silicone creating a channel for water to pass through by making an un-level un-smooth surface for the true rubber seal of the bulkhead to seal against.

At the very least it is a waste of your time and silicone.

My thoughts exactly but not gonna argue! To each their own!

 

[Timfish]

I wasn’t insisting there would be an issue, just suggesting that it is absolutely unnecessary and theoretically could cause an issue if the silicone were applied inconsistently for example. In this hypothetical, one could imagine a glob of silicone creating a channel for water to pass through by making an un-level un-smooth surface for the true rubber seal of the bulkhead to seal against.

At the very least it is a waste of your time and silicone.

As a hypothetical that may seem reasonable on the face of it. Having used silicone dozens of times it certainly isn't the reality I've seen. And with the vagaries I've seen over the decades the investment of a minute or two and a few cents of silicone is worth it even when it doesn't simplify installation as I pointed out above.

 

[Formulator]

As a hypothetical that may seem reasonable on the face of it. Having used silicone dozens of times it certainly isn't the reality I've seen. And with the vagaries I've seen over the decades the investment of a minute or two and a few cents of silicone is worth it even when it doesn't simplify installation as I pointed out above.

To each their own. I’ve never had a problem without the use of silicone. 8 year old tank with 3 1 inch DIY holes, sump with 3 holes, and fuge with 1 hole.

 

[Timfish]

To each their own. I’ve never had a problem without the use of silicone. 8 year old tank with 3 1 inch DIY holes, sump with 3 holes, and fuge with 1 hole.

I've installed plenty of bulkheads without silicone also. And in a perfect world probably would never have needed silicone. But apparently my world isn't as perfect as yours and I've found using silicone to be cheap insurance.

 

[X-37B]

I use my finger to smear a light amount of silicone to the gasket. Install bulkhead and tighten lightly. In 24 hours you can remove the bulkhead and the gasket remains. I have done it this way for 30+ but know many who dont who have no issues.
You need very little.

 

[JayM]

I know I’m late to the party, but if bulkheads were intended to be sealed with silicone, the bulkhead manufacturers would specify for you to do so and save money on supplying gaskets.

 

[cilyjr]

I’ve drilled several tanks and sumps myself and found it nearly impossible to avoid chips like that.

Tape the side you are not drilling. Use something thick and sticky, not painters tape. That way when there's just a thin piece of glass that the drill is working to cut, the adhesive of the tape keeps it in place and allows the drill to finish boring. This will allow you a nicer chip free hole.