anchor.diff:  
   /obj/structure/tank_frame/proc/add_plating(mob/living/user, obj/item/stack/stack)
   	. = FALSE
  +	if(!stack.material_type)
  +		balloon_alert(user, "invalid material!")
   	var/datum/material/stack_mat = GET_MATERIAL_REF(stack.material_type)
   	if(!(MAT_CATEGORY_RIGID in stack_mat.categories))
   		to_chat(user, span_notice("This material doesn't seem rigid enough to hold the shape of a tank..."))
  
positive.code: 	if(!isturf(build_location))
  		return
  	var/obj/machinery/atmospherics/components/tank/new_tank = new(build_location)
  	var/list/new_custom_materials = list()
  	new_custom_materials[material_end_product] = 20000
  	new_tank.set_custom_materials(new_custom_materials)
  	new_tank.on_construction(new_tank.pipe_color, new_tank.piping_layer)
  	to_chat(user, span_notice("[new_tank] has been sealed and is ready to accept gases."))
  	qdel(src)
  
negative.code: #define TANK_PLATING_SHEETS 20
  
  /obj/machinery/atmospherics/components/tank
  	icon = 'icons/obj/atmospherics/stationary_canisters.dmi'
  	icon_state = "smooth"
  