Are these silicone seams normal?

[pixelhustler]

The outer part is a seam that actually bonds the panels looks good, but I haven’t seen a seam like this before. It’s an IM tank

 

[KrisReef]

Photo looks like foam rubber, not silicone. Interesting picture, I don't know how IM does their seams but it looks fairly uniform for the most part except in the corner gap. If the space between glass is filled, then a silicone seal should hold water.

Interesting picture, btw.

 

[EricR]

I think my eyes might be fighting an optical illusion here.
Is that the INSIDE bottom corner?

 

[TheBear78]

It looks like an armoured seal?
Is it quite hard or soft? As above, it looks like foam but a harder plastic could be made to look like this.

 

[pixelhustler]

I think my eyes might be fighting an optical illusion here.
Is that the INSIDE bottom corner?

Yup, it’s inside. It’s a used tank and I think the algae on the glass is filtering light, which reflects on the silicone as a speckled pattern. I guess my only concern was the beads don’t connect to the corner. Both front corners look like this, so I’m guessing it’s by design. I’ve just never seen a corner with disconnected beads.

 

[EricR]

Yup, it’s inside. It’s a used tank and I think the algae on the glass is filtering light, which reflects on the silicone as a speckled pattern. I guess my only concern was the beads don’t connect to the corner. Both front corners look like this, so I’m guessing it’s by design. I’ve just never seen a corner with disconnected beads.

Like mentioned in post #4, it's gotta be just some kind of armor over the actual silicone,,, no?

 

[pixelhustler]

Like mentioned in post #4, it's gotta be just some kind of armor over the actual silicone,,, no?

It’s the actual silicone bead, no armor. The silicone is smooth though. In the picture, it looks like some sort of textured foam because the sun was shining through the dirty glass and reflecting the film algae texture onto the silicone.

 

[Rjukan]

That's so weird, I would have bet money it was textured or some kind of foam over the silicone. Curious what the outside corner looks like.

 

[X-37B]

I had one corner on the back of my im 170 that looked the same.
I filled it in with black silicone and it should be fine.
Mine is an ext and I also filled in with a bead of silicone inside the overflow where its attatched to the tank.
A gap was seen between the acrylic and the glass. A few have had the acrylic pull off and it may or may not have been from overflow water constantly flowing over it.
I would clean and fill it in with some silicone and you should be good to go.

 

[EricR]

It’s the actual silicone bead, no armor. The silicone is smooth though. In the picture, it looks like some sort of textured foam because the sun was shining through the dirty glass and reflecting the film algae texture onto the silicone.

The fact that it's not all continuous is the funky part to me.
Kind of looks like someone might have done different sections or maybe multiple layers at different times -- if so, that seems weird to me but I'm not an aquarium builder.