Welding hint needed

[Punderhead]

Are you weaving the welder of just trying a straight pass?

I'm only an apprentice, so the pros can correct me, but I believe the correct technique for an internal 90degree weld is to weave a half moon.

E.g. If you are welding left to right across the screen go like this.
((((((((((((((((((((((
Pause for a half second before you start the next half moon.
It should be easier with the v to the bottom as you said, however if you have. It sitting with one side vertical you will need to spend a little bit longer burning the rod onto the high side.

Hope this makes sense and helps

Cheers