how me make a func brakeable close a door and show off a welding point over it and since welding they blow the door.

So lets see if I understand you correctly:

1. func_breakable closes a door
2. func_weldable appears on the door so it can be welded
3. welding the func_weldable will result in the door it's destruction (kill target from the trigger_relay?)
4. after a round restart the door should reappear

2 not possible as far as I know, since a func_weldable is enabled at the start of each round with the weld sprite visible.
4 is also not possible if you kill it with the trigger_relay. The only way I know of to make it invisible and accesable.

This is another aproach to your idea, but it with a twist.

1. func_breakable closes a door and opens up a hatch to show you a func_weldable
2. welding the func_weldable opens the door

All of these are reset at the restart of a round so no problem there.

Man I wish they made func_weldable toggleable and add the option to enable them during a round instead of standart enabled at the start of a round. Maybe I'm mistaken, but I haven found a way in doing that...

im a bit lazy with entities could be step by step?
in your function way of life?
break a hidraulic pipes->close door and show a manual input to unlock the door by welding;

func_breakable (the pipe):

target on break: door

func_door (the actual door):

name: door
delay before close, -1 stay open: -1

func_door (the hatch in front of the weldable):

name: door
delay before close, -1 stay open: -1


func_weldable:

target: door
and check it's flag: weld opens, not