Hold Out Achievement in Killing Floor 2
Hold Out
15Weld a Door to 100%
How to unlock Hold Out
When you walk up to a doorway, you have the option to close the door or weld it shut. To weld it shut, tap to close the door the hold to equip your welding tool. Then press and hold and until it reaches 100% and the achievement will unlock.
Note, the last 10% will go slower, but keep holding until it completely welded shot.