Cannot get rid of these tiny lines with unions

[SwitchedDreams]

Hello,

I’ll keep it simple.
I’m trying to make a car, and I make the lights out of unions.
I align parts to make the shape, but for the rear lights, this happens:

I tried to use ResizeAligner to fix this, but it doesn’t matter how long I do it for, it just won’t work.

[Crazedbrick1]

Can you send screenshots of the part before being unioned?

[grimmerschool2 (PartyNoob)]

You can use GapFill to fix this. Here’s this video on how to fix:

[SwitchedDreams]

Thanks, I managed to fix it using gap fill!

[RMofSBI]

Then mark @grimmerschool2 with the solution as it was their suggestion that worked for you.

[SwitchedDreams]

I did, got removed for whatever reason. Fixed now.