Chipped the edge of my 40g rimless 😭

[Fishstery]

Made a massively stupid late night mistake. I needed to reset the soil in my buce collection tank and tapped the edge of the tank with a glass pyrex measuring cup (I'm getting a plastic one today).

I started working around 11pm after my mom duties were done for the evening, and work continued well into the early morning so I was pulling an all-nighter to get this done. In the heat of my exhaustion, I was absentmindedly going through the motions of refilling the tank when it happened.

Now I have a pretty sizeable scallop chip in the top front panel of a tank that is only a few months old. This is the first time I've ever chipped one of my tanks. Thankfully it's smack dab in the middle of the panel, so i'm not terribly worried as scallop chips rarely splinter or spread into a crack. I have the water level an inch below it to reduce any pressure stress, and am going to buy a windshield repair kit and attempt to fix it since the shard came off in a mostly solid piece that I was able to recover.

Once I get the kit and free time, I'll post pictures of the repair process to document here. I know this is probably a somewhat controversial idea, but luckily this tank is in my tiled floor basement which has an adjacent unfinished room with a floor drain. Of course I would rather not have the tank spontaneously spring a leak, but taking that into consideration and the fact that the glass is 10mm thick for 40 gallons of water, it's not worth the money or hassle to replace right now.

 

[JayP]

Probably not an issue as far as mechanical stress, but if you're like me, it'll drive you crazy seeing it all the time. Hope the repair kit does a good job.

 

[Fishstery]

Probably not an issue as far as mechanical stress, but if you're like me, it'll drive you crazy seeing it all the time. Hope the repair kit does a good job.

This is my take on it as well. I know the repair won't do anything for structural integrity, but I think the risk is minimal anyway as that part of the tank is under the least amount of stress. The spot is definitely bothering me so that is why I am going to attempt to repair it. It won't be invisible, but it will be far less of an eyesore.

 

[Koan]

I think the risk is minimal anyway as that part of the tank is under the least amount of stress

You're not alone, this just happened to another member last week

Post in thread 'Just chipped the glass. Do I need to immediately drain and replace?'

Aug 22, 2026

This question gets asked a lot.

Remember that the glass panes of your rimless aquarium are constantly subjected to flex stresses. Bending stress from the weight of the water, and thermal expansion stress from the heat differentials between the water temperature and your air temperature changing over time.

Here's an interesting discussion about edge chips in terms of the risk of cracking and shattering :

Glass Breakage and Pre-Existing Damage

Each year hundreds of people are injured or killed by glass breakage, whether by falling through glass, or by having glass fall on them.

chicagowindowexpert.com

"Chips, flaws and scratches act as “stress concentrators”. To best understand this, take a piece...​

• Koan

• 

 

[Fishstery]

You're not alone, this just happened to another member last week

Post in thread 'Just chipped the glass. Do I need to immediately drain and replace?'

Aug 22, 2026

This question gets asked a lot.

Remember that the glass panes of your rimless aquarium are constantly subjected to flex stresses. Bending stress from the weight of the water, and thermal expansion stress from the heat differentials between the water temperature and your air temperature changing over time.

Here's an interesting discussion about edge chips in terms of the risk of cracking and shattering :

Glass Breakage and Pre-Existing Damage

Each year hundreds of people are injured or killed by glass breakage, whether by falling through glass, or by having glass fall on them.

chicagowindowexpert.com

"Chips, flaws and scratches act as “stress concentrators”. To best understand this, take a piece...​

• Koan

• 

Yeah I saw that post, it's incredibly unfortunate as it happened at the very end of me completing the soil replacement, and it was very late (or early depending on how you look at 5am), so I wasn't able or willing to turn the tank around so the chip is at least on the back side. I had just put in 5 grueling hours of removing over 100 bucephalandra rhizomes between 60+species , removing and replacing the soil, then planting them back without getting my ID's messed up. My substrate is sloped upwards in the back, so to turn my tank around I'd have to go through that entire process over again and I say hell na to that

 

[Fishstery]

Started the repairs tonight, though my cat knocked the glass shard off my tank the other night which then broke the edges off

Instead of having a shard that perfectly fit the chip, I now had to work with a shard that was missing the edges on either side.

First I used glass bonding glue to secure the shard in place and let it cure for 24 hours. Tonight I used JB Weld Windshield Saver Kit to fill in the cracks which worked well, however the resin was far too low in viscosity to be able to fill in the portions of the chip that are missing thanks to my cat.



It's good to be an aquagirl, as I had a UV light handy that I usually use for gel manicures

Here's what I have now, a vast improvement over a massive chunk taken out of my glass. You can see the air bubbles that formed in the resin that weren't able to fill all the way.



While I could have bought another windshield kit and filled the holes in that way, it probably would take multiple layers of fill, cure, repeat. Instead I decided to buy some ultra clear, high viscosity UV resin for crafts. It should arrive tomorrow, so I'll update tomorrow evening. The plan is to fill the gaps with the thick resin, reuse the orange cure sheet that came with the JB Weld kit to keep the resin level with the glass surface, then clean up any excess by scraping it with a razor blade. When it's finished I think it will still be pretty visible, but at least the tank will be whole again and far less of an eyesore.

 

[Naturescapes_Rocco]

Honestly looks better than without the repair, nice work.

 

[Fishstery]

The repairs are complete! There are some tiny air bubbles in the resin, but at least it is much less noticeable in photos.


Here's photos of the process I used to fill the missing chunks, it was pretty simple. I globbed resin in to both areas with missing chunks of glass, then used a razor blade to scrape the excess down so it was flush with the glass. After that, I used a final very thin layer to get a uniform appearance on the affected area. I just used scotch tape to tape around the edges of the chip so I could apply the resin a bit heavier. After I cured it with the cure sheet in place, I used a razor to score along the tape edges so when I peeled them, the resin would not lift with the tape.


Lastly, here are the other two products I used: the glass bonding glue and the UV Craft resin

 

[Fishstery]

A final photo to display what it looks like IRL:


In conclusion, I would say that chip repair is 100% possible and in my opinion worth it, as long as the only issue with the damage is that it is aesthetic and not structural. This can certainly be done if you aren't able to recover the missing shard of glass, however if you have the shard it will make the repair much easier and neater. If the shard had been left undamaged and whole, this repair would have been near invisible and would have just required the windshield chip repair kit.