Secondary that can repair building to multiplicative from breakage from its lowest hp so if it has been lowest at lets say 40 out of 200 hp it will only be able to repair it to 120 hp (triple the amount of the hp its ever been at lowest) to repair the thing to its max potential repair amount it will take no matter what 3 seconds to do so, it will also be able to be used as a shortrange flamethrower that will have only 1 second afterburn but a bit higher damage because its higher concentrated fire and whatever yeah and will have a flamethrower type ammo which will fill up 5 for every 1 damage done to your buildings up to max 100 and using it for 1 second drains 8 ammo

the downside is your wrench repairs 10% slower to encourage you a bit more to use this thing to repair your buildings instead

Because you are welding with this you don't ADD any metal you just PUT METAL TOGETHER on your building it getting shot makes pieces of it fall off thus reduce its total material % and so you cant repair it to its best with this thing because that will require its entire highest previous material composition, though its a solid secondary for repairing and fighting off spies/scouts.