Pass II

code/game/objects/structures/door_assembly.dm

@@ -174,7 +174,7 @@ obj/structure/door_assembly
 					if(!src || !WT.isOn()) return
 					user << "\blue You dissasembled the airlock assembly!"
 					new /obj/item/stack/sheet/metal(src.loc, 4)
-					del (src)
+					qdel(src)
 		else
 			user << "\blue You need more welding fuel."
 			return

code/game/objects/structures/stool_bed_chair_nest/stools.dm

@@ -58,7 +58,7 @@
 	origin.loc = get_turf(src)
 	user.unEquip(src)
 	user.visible_message("\blue [user] puts [src] down.", "\blue You put [src] down.")
-	del src
+	qdel(src)
 
 /obj/item/weapon/stool/attack(mob/M as mob, mob/user as mob)
 	if (prob(5) && istype(M,/mob/living))
@@ -66,7 +66,7 @@
 		user.unEquip(src)
 		var/obj/item/stack/sheet/metal/m = new/obj/item/stack/sheet/metal
 		m.loc = get_turf(src)
-		del src
+		qdel(src)
 		var/mob/living/T = M
 		T.Weaken(5)
 		return