Scratches, cracks or silicone?

shoelaceike · Jul 28, 2018

I just purchased a new Aqueon 90 gallon with overflows. After I set it all up, I noticed what looked like scratches on the bottom near the bulkhead. I believe the bottom is tempered. Im wondering if they are simply scratches, or could they be stress cracks if there is such a thing on tempered glass? I contacted Aqueon and they said it looks like a silicone smear and there is nothing to worry about. From what I can tell its definitely not silicone and at best is just surface scratches. I just find it to be an odd place for scratches. The return standpipe was difficult to get in and im slightly concerned they can be stress cracks if that is even possible.

I'm looking for someone with experience in glass or making tanks. Pics below. TIA

shoelaceike · Jul 28, 2018

Reeferdood · Jul 28, 2018

Looks like scratches to me... I have seen silicone streaks but that is usually at the end of a bead......

shoelaceike · Jul 28, 2018

Thanks. They look like that to me as well only they are in an odd place. The bottom was covered in cardboard when I picked it up from the store

KrisReef · Jul 28, 2018

The first picture I saw silicone, and I can’t figure out pic 2.
My eyes are not so good. I tempered glass in a factory years ago. If it’s got cracks it’s a problem.
Hairline cracks look like a dark line. If it is tempered glass it should completely fail when put the glass under pressure. Tempering puts stress on the faces of the plate that cause the entire plate to crumble when it breaks (if the plate is properly tempered).

Fill it out side and you should know pretty quickly if it’s going to fail.

shoelaceike · Jul 28, 2018

Thanks. The tank is currently filled. Im like 99% sure its not silicone. The tank has been running for 2 days now

WetPets · Jul 29, 2018

You can check if it is silicone with a razor blade. Just watch the seal. I have at least a few people a year bring a tank back just after selling it thinking it has a crack that ends up being silicone.
In your case it does look like scratches. Can you feel them with your fingernail.

shoelaceike · Jul 29, 2018

Its in a hard to get to area and I don't want to mess with a razor blader over there due to the proximity of the seal. Im really quite sure its not silicone.....if its cosmetic scratches, I dont mind. I jusg want to make sure they are not stress cracks...I could feel them with my nail.

WetPets · Jul 29, 2018

I do not think they are stress cracks when aquariums crack it is generally one crack from one edge of a panel to the other. The bottoms are tempered the one time that I cracked the bottom the whole piece turned into pieces about 1/4" each. I also had a side panel that was tempered and I did not know. I tried drilling it and same effect it all let go it held as one piece but cracked all over about every 1/4".