Drilled sump crack

[MGarvo2]

Need some experienced perspective, please? I successfully drilled 2 of my 3 40G Breeders I’m using for my sump/refugium. I was placing the bulkhead on one, over tightened it, and it cracked. Then to make matters worse, while inspecting the other drilled tank, it has a crack also! Both cracks originate from the holes and are about 1.5-2” long. I loosened the bulkheads and applied silicone around the lip of the holes/bulkheads to ensure a better seal, and tightened them a bit less but still firmly. I siliconed the hell out of the inside and outside of both cracks, and both sure seem pretty solid. Next obvious question,… am I crazy to want to still use them? Also, the pics have a couple small spots where it appears the cracks have extended, but it is only silicone which I scraped off after taking the pics.

 

[SteveMM62Reef]

I only have experience repairing cracks in metal. To stop the crack from spreading, had to figure out where the crack ended at. Drill a hole in the crack end, and Weld the hole and Crack back. Otherwise it would keep spreading. I would think glass would be similar. I have a chip, in the top rim of my 120 Gallon. To keep it from spreading, I Cleaned it with 99% Isopropyl, heated it with a heating pad.Cleaned again and heated. Glued the Chip with Thin Super Glue. I measured the Chip, and took pictures of the Caliper. So far it hasn’t moved. BTW, This is the best Aquarium Non-Aquarium item, I’ve ever gotten. It’s on Amazon.

SHONSIN Absolute Scale Digital Caliper, 6"/150mm Caliper Measuring Tool, 0.0005"/0.01mm Resolution, IP54 Waterproof Stainless Steel Micrometer Vernier Caliper, Large LCD, Extreme Accuracy​

 

[Seymo44]

I understand the want to use the tanks, but I personally would not use them. These tanks will eventually leak or burst. You might get 3 years of use, or you might get 3 hours.

If you decide to replace the tanks, keep the broken ones. You can either buy new glass to replace the broken panel, or you can take one panel off of one and replace the broken one on the other.

 

[SteveMM62Reef]

I took another look at your setup. It’s going o be a pain to keep up with the Salt Tracking and Spray. Where you go from one aquarium, down to another aquarium, you need a “T” Fitting. The lower end needs to be below or right at the normal water level. You need a breather tube going up from the “T” Loosely Cap it and drill progressively larger holes in the caps, until the gurgling stops. Don’t glue the cap as you need to be able to clean the cap and down tube occasionally.

 

[WestMI-Reefer]

I accidentally cracked mine when drilling it. I mixed a 2 part epoxy and applied that heavily over the damaged area. Epoxy gets a great bond to glass. Its not pretty but its behind the overflow weir box so its unseen. It has held up fine.