LED Aluminum Channel Gap Covering?

[Imatk]

I just installed some LED lights and channels down my stair case.

The problem I have is that where my cuts are made, there are thin gaps when the light illuminates.

They're barely noticeable when the lights are off, but when they're on you can see a thin piece of light where the two channels but up against each other.

I also have similar gaps where I mitered one of the corners.

I bought some white vinyl hoping to apply it to the gap and get read of the leak, but it shines right through the vinyl so I'd love to hear some suggestions on a fix.

Thank you!

 

[DIWdiver]

Gaffer's tape would be ideal, as it's designed for that. Black electrical tape would work pretty well too. Do you need something that isn't black?

 

[Imatk]

Gaffer's tape would be ideal, as it's designed for that. Black electrical tape would work pretty well too. Do you need something that isn't black?

Yeah I need something white, but I could use the electrical tape on the inside and cover the small gap with the white vinyl on the outside I suppose.

 

[DIWdiver]

They make white electrical tape. I have a roll.