diff --git a/code/__HELPERS/mobs.dm b/code/__HELPERS/mobs.dm
index 1ca1fe01036..13ee3c9e5ef 100644
--- a/code/__HELPERS/mobs.dm
+++ b/code/__HELPERS/mobs.dm
@@ -372,6 +372,27 @@ This is always put in the attack log.
 	if(progress)
 		qdel(progbar)
 
+#define DOAFTERONCE_MAGIC "Magic~~"
+GLOBAL_LIST_INIT(do_after_once_tracker, list())
+/proc/do_after_once(mob/user, delay, needhand = 1, atom/target = null, progress = 1, attempt_cancel_message = "Attempt cancelled.")
+	if(!user || !target)
+		return
+
+	var/cache_key = "[user.UID()][target.UID()]"
+	if(GLOB.do_after_once_tracker[cache_key])
+		GLOB.do_after_once_tracker[cache_key] = DOAFTERONCE_MAGIC
+		to_chat(user, "<span class='warning'>[attempt_cancel_message]</span>")
+		return FALSE
+	GLOB.do_after_once_tracker[cache_key] = TRUE
+	. = do_after(user, delay, needhand, target, progress, extra_checks = CALLBACK(GLOBAL_PROC, .proc/do_after_once_checks, cache_key))
+	GLOB.do_after_once_tracker[cache_key] = FALSE
+
+/proc/do_after_once_checks(cache_key)
+	if(GLOB.do_after_once_tracker[cache_key] && GLOB.do_after_once_tracker[cache_key] == DOAFTERONCE_MAGIC)
+		GLOB.do_after_once_tracker[cache_key] = FALSE
+		return FALSE
+	return TRUE
+
 /proc/is_species(A, species_datum)
 	. = FALSE
 	if(ishuman(A))
diff --git a/code/game/mecha/mecha.dm b/code/game/mecha/mecha.dm
index 1704fecd7a1..aa0c9495cbe 100644
--- a/code/game/mecha/mecha.dm
+++ b/code/game/mecha/mecha.dm
@@ -43,8 +43,6 @@
 	var/lights_power = 6
 	var/emagged = FALSE
 
-	var/list/repairers = new
-
 	//inner atmos
 	var/use_internal_tank = 0
 	var/internal_tank_valve = ONE_ATMOSPHERE
@@ -778,22 +776,16 @@
 
 	else if(iswelder(W) && user.a_intent != INTENT_HARM)
 		var/obj/item/weldingtool/WT = W
-		if(health<initial(health))
-			if (WT.remove_fuel(0,user))
-				if(!(user in repairers)) // Can only repair it once at a time
-					repairers += user
-					user.visible_message("<span class='notice'>[user] starts repairing some damage to [name].</span>", "<span class='notice'>You start repairing some damage to [name]</span>")
-					playsound(user, WT.usesound, 50, 1)
-					if(do_after(user, 15 * WT.toolspeed, target = src)) // Takes 1.5 seconds to repair
-						if (internal_damage & MECHA_INT_TANK_BREACH)
-							clearInternalDamage(MECHA_INT_TANK_BREACH)
-							user.visible_message("<span class='notice'>[user] repairs the damaged gas tank.</span>", "<span class='notice'>You repair the damaged gas tank.</span>")
-						else
-							user.visible_message("<span class='notice'>[user] repairs some damage to [name].</span>", "<span class='notice'>You repair some damage to [name]</span>")
-							health += min(20, initial(health)-health)
-					repairers -= user
-				else
-					to_chat(user, "<span class='warning'>You are already repairing [name]!</span>")
+		if(health < initial(health))
+			if(WT.remove_fuel(0,user))
+				user.visible_message("<span class='notice'>[user] starts repairing some damage to [name].</span>", "<span class='notice'>You start repairing some damage to [name]</span>")
+				if(do_after_once(user, 15 * WT.toolspeed, target = src, attempt_cancel_message = "You stop repairing [name]."))
+					if(internal_damage & MECHA_INT_TANK_BREACH)
+						clearInternalDamage(MECHA_INT_TANK_BREACH)
+						user.visible_message("<span class='notice'>[user] repairs the damaged gas tank.</span>", "<span class='notice'>You repair the damaged gas tank.</span>")
+					else
+						user.visible_message("<span class='notice'>[user] repairs some damage to [name].</span>", "<span class='notice'>You repair some damage to [name].</span>")
+						health += min(20, initial(health) - health)
 			else
 				to_chat(user, "<span class='warning'>The welder must be on for this task!</span>")
 		else