Fixes #9744.

code/game/objects/items/weapons/tools.dm

@@ -261,6 +261,8 @@
 
 //Removes fuel from the welding tool. If a mob is passed, it will perform an eyecheck on the mob. This should probably be renamed to use()
 /obj/item/weapon/weldingtool/proc/remove_fuel(var/amount = 1, var/mob/M = null)
+	if(!welding)
+		return 0
 	if(get_fuel() >= amount)
 		reagents.remove_reagent("fuel", amount)
 		if(M)
@@ -291,7 +293,7 @@
 	var/turf/T = get_turf(src)
 	//If we're turning it on
 	if(set_welding && !welding)
-		if (remove_fuel(1))
+		if (get_fuel() > 0)
 			if(M)
 				M << "<span class='notice'>You switch the [src] on.</span>"
 			else if(T)