Problems related to flat-bottom tank appearance

[STEVE LIU]

Hi everyone,
I have a question. I’ve noticed that many flat-bottom tanks have black lines after being painted.
I’m curious about how these occur. Are they caused by the welds (Welded joint )? If so, what is the reason?

 

[LittleInch]

Do you mean the vertical lines?

I strongly suspect these are where they are drain holes in the roof edge and this is where the water drops down, discolours the tank and allows some moss or organism to grow.

 

[STEVE LIU]

Hi everyone,
I have a question. I’ve noticed that many flat-bottom tanks have black lines after being painted.
I’m curious about how these occur. Are they caused by the welds (Welded joint )? If so, what is the reason?

Yes , I mean the black

Do you mean the vertical lines?

I strongly suspect these are where they are drain holes in the roof edge and this is where the water drops down, discolours the tank and allows some moss or organism to

Do you mean the vertical lines?

I strongly suspect these are where they are drain holes in the roof edge and this is where the water drops down, discolours the tank and allows some moss or organism to grow.

Yes, I was referring to the black vertical lines. it was just painted a little over a month ago, so seeing these evenly spaced black lines makes me curious about where they came from.

 

[LittleInch]

Rain.