diff --git a/concrete.lua b/concrete.lua
index 75add9e..f9af08c 100644
--- a/concrete.lua
+++ b/concrete.lua
@@ -77,8 +77,8 @@ minetest.register_abm({
 	interval = 5,
 	chance   = 5,
 	action = function(pos)
-		minetest.get_node_timer(pos):start(15*60) -- concrete takes half an hour to cure at best
--- 		minetest.get_node_timer(pos):start(5) -- fast cure for debugging
+--		minetest.get_node_timer(pos):start(15*60) -- concrete takes half an hour to cure at best
+ 		minetest.get_node_timer(pos):start(5) -- fast cure for debugging
 	end
 })
 
diff --git a/craftitems.lua b/craftitems.lua
index 877002b..99ca4e2 100644
--- a/craftitems.lua
+++ b/craftitems.lua
@@ -1,112 +1,19 @@
  
-
+--[[
 minetest.register_craftitem(":bitumen:bitumen", {
 	description = "Bitumen",
 	inventory_image = "bitumen_bitumen.png",
 	on_place_on_ground = minetest.craftitem_place_item,
 })
+]]
 
 
-
-	
-	
-	
-	
--- these are temporary until the piping system is done
-minetest.register_craftitem(":bitumen:synthetic_crude", {
-	description = "Synthetic Crude Oil",
-	inventory_image = "bitumen_synthetic_crude.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:lube_oil", {
-	description = "Heavy Lubricating Oil",
-	inventory_image = "bitumen_lube_oil.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-minetest.register_craftitem(":bitumen:fuel_oil", {
-	description = "Fuel Oil",
-	inventory_image = "bitumen_fuel_oil.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:diesel", {
-	description = "Diesel",
-	inventory_image = "bitumen_diesel.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:kerosene", {
-	description = "Kerosene",
-	inventory_image = "bitumen_kerosene.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:gasoline", {
-	description = "Gasoline",
-	inventory_image = "bitumen_gasoline.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:jet_fuel", {
-	description = "Jet Fuel",
-	inventory_image = "bitumen_jet_fuel.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:lpg", {
-	description = "LPG",
-	inventory_image = "bitumen_lpg.png",
+minetest.register_craftitem("bitumen:galv_steel_sheet", {
+	description = "Galvanized Steel Sheet",
+	inventory_image = "bitumen_galv_steel_sheet.png",
 	on_place_on_ground = minetest.craftitem_place_item,
 })
 
 
 
 
-	
-	
-minetest.register_craftitem(":bitumen:lpg_regulator", {
-	description = "LPG Regulator",
-	inventory_image = "bitumen_lpg_regulator.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
--- these may need to just be tools
-minetest.register_craftitem(":bitumen:small_lpg_bottle", {
-	description = "Small LPG Bottle",
-	inventory_image = "bitumen_small_lpg_bottle.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:gas_can", {
-	description = "Plastic Gas Can",
-	inventory_image = "bitumen_gas_can.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-
-
-
-minetest.register_craftitem(":bitumen:brass_ingot", {
-	description = "Brass Ingot",
-	inventory_image = "bitumen_brass_ingot.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:brass_dust", {
-	description = "Brass Dust",
-	inventory_image = "bitumen_brass_dust.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
-minetest.register_craftitem(":bitumen:carbon_steel_ingot", {
-	description = "Carbon Steel Ingot",
-	inventory_image = "bitumen_carbon_steel_ingot.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-minetest.register_craftitem(":bitumen:carbon_steel_dust", {
-	description = "Carbon Steel Dust",
-	inventory_image = "bitumen_carbon_steel_dust.png",
-	on_place_on_ground = minetest.craftitem_place_item,
-})
-
diff --git a/crafts.lua b/crafts.lua
index cbc8ae8..cd17064 100644
--- a/crafts.lua
+++ b/crafts.lua
@@ -187,11 +187,57 @@ minetest.register_craft({
 })
 
 minetest.register_craft({
-	output = "bitumen:oil_drum 27",
+	output = "bitumen:oil_drum 3",
 	recipe = {
-		{"default:steelblock", "default:tin_ingot",   "default:steelblock"},
-		{"default:steelblock", "",                    "default:steelblock"},
-		{"default:steelblock", "default:steelblock", "default:steelblock"},
+		{"default:tin_ingot",   "default:tin_ingot",   "default:tin_ingot"},
+		{"default:steel_ingot", "",                    "default:steel_ingot"},
+		{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"},
 	}
 })
 
+
+-- tanks
+minetest.register_craft({
+	output = "bitumen:galv_steel_sheet 3",
+	recipe = {
+		{"", "", ""},
+		{"", "", ""},
+		{"default:steel_ingot", "default:tin_ingot", "default:steel_ingot"},
+	}
+})
+
+minetest.register_craft({
+	output = "bitumen:cylinder_tank 1",
+	recipe = {
+		{"default:galv_steel_sheet", "default:galv_steel_sheet", "default:galv_steel_sheet"},
+		{"default:galv_steel_sheet", "",                         "default:galv_steel_sheet"},
+		{"default:galv_steel_sheet", "default:galv_steel_sheet", "default:galv_steel_sheet"},
+	}
+})
+
+
+minetest.register_craft({
+	output = "bitumen:cylinder_tank_top 1",
+	recipe = {
+		{"", "bitumen:intake",        ""},
+		{"", "bitumen:cylinder_tank", ""},
+		{"", "",                      ""},
+	}
+})
+
+minetest.register_craft({
+	output = "bitumen:cylinder_tank_bottom 1",
+	recipe = {
+		{"", "",                      ""},
+		{"", "bitumen:cylinder_tank", ""},
+		{"", "bitumen:spout",         ""},
+	}
+})
+
+minetest.register_craft({
+	output = "bitumen:galv_steel_sheet 4",
+	type = "shapeless",
+	recipe = {"bitumen:cylinder_tank_cracked"},
+})
+
+
diff --git a/cylinder_tank.lua b/cylinder_tank.lua
index 44463fb..76cf1d8 100644
--- a/cylinder_tank.lua
+++ b/cylinder_tank.lua
@@ -1,12 +1,63 @@
 
 
+
+local function check_tank_foundation(bpos)
+	local meta = minetest.get_meta(bpos)
+	local height = meta:get_int("height")
+	
+	if height < 1 then
+		return
+	end
+	
+	local d = math.ceil(height / 5)
+	
+	return bitumen.check_foundation(
+		{x = bpos.x - 2, y = bpos.y - 1 - d, z = bpos.z - 2},
+		{x = bpos.x + 2, y = bpos.y - 2    , z = bpos.z + 2},
+		{
+			["default:stone"] = 1,
+			["default:desert_stone"] = 1,
+			["default:steelblock"] = 1,
+			["bitumen:concrete"] = 1,
+		}
+	)
+end
+
+
+-- check poor foundation
+minetest.register_abm({
+	nodenames = {"bitumen:cylinder_tank_bottom"},
+	interval = 30,
+	chance   = 10,
+	action = function(pos)
+		if not check_tank_foundation(pos) then
+			--print("tank failure")
+			
+			local meta = minetest.get_meta(pos)
+			local fill = meta:get_int("fill")
+			local height = meta:get_int("height")
+			
+			if height < 2 then
+				-- no middle segments
+				return
+			end
+			
+			local fillh = math.ceil(fill / (9 * 60)) 
+			
+			local y = math.random(1, fillh)
+			minetest.set_node({x=pos.x, y=pos.y+y, z=pos.z}, {name="bitumen:cylinder_tank_cracked"})
+			
+		end
+	end
+})
+
+
 local function try_add_fluid(tpos)
 
 	-- find the bottom node
 	local tmeta = minetest.get_meta(tpos)
 	local rbpos = tmeta:get_string("bpos")
 	if not rbpos then
-	--print("no bpos")
 		return
 	end
 	
@@ -15,8 +66,6 @@ local function try_add_fluid(tpos)
 	local npos = {x=tpos.x, y=tpos.y+1, z=tpos.z}
 	local tnet = bitumen.pipes.get_net(npos)
 	if not tnet or not tnet.fluid or tnet.fluid == "air" then
-	--print("no tnet")
-	--print(dump(tnet.fluid))
 		return
 	end
 	
@@ -29,12 +78,10 @@ local function try_add_fluid(tpos)
 	
 	-- check for full
 	if fill >= capacity then
-		--print("empty")
 		return
 	end
 	
 	if fill > 0 and fluid ~= tnet.fluid then
-		--print("wrong fluid to take")
 		return
 	end
 	
@@ -43,7 +90,6 @@ local function try_add_fluid(tpos)
 	
 	local taken, tfluid = bitumen.pipes.take_fluid(npos, remcap)
 	if taken == 0 then
-		--print("none taken")
 		return
 	end
 	
@@ -54,7 +100,6 @@ local function try_add_fluid(tpos)
 	end
 	
 	fill = fill + taken
-	--print("cyl tank fill: " .. fill .. " ("..tfluid..")")
 	
 	bmeta:set_int("fill", fill)
 end
@@ -66,7 +111,6 @@ local function try_give_fluid(bpos)
 	local npos = {x=bpos.x, y=bpos.y-1, z=bpos.z}
 	local tnet = bitumen.pipes.get_net(npos)
 	if not tnet then
-		--print("no bnet")
 		return
 	end
 	
@@ -78,7 +122,6 @@ local function try_give_fluid(bpos)
 	
 	-- check for empty
 	if fill <= 0 or fluid == "air" then
-		--print("tank empty " .. fluid .. " " ..fill)
 		return
 	end
 	
@@ -86,12 +129,10 @@ local function try_give_fluid(bpos)
 	
 	local pushed = bitumen.pipes.push_fluid(npos, fluid, math.min(fill, 64), lift)
 	if pushed == 0 then
-		--print("none pushed")
 		return
 	end
 	
 	fill = math.max(fill - pushed, 0)
-	--print("cyl tank fill: " .. fill .. " ("..fluid..") [push]")
 	
 	bmeta:set_int("fill", fill)
 end
@@ -102,8 +143,6 @@ end
 -- tank data is stored based on the bottom position
 local function init_tank(tpos, bpos) 
 	
-	--print(dump(tpos))
-	--print(dump(bpos))
 	
 	local fluid = "air"
 	local tnet = bitumen.pipes.get_net({x=tpos.x, y=tpos.y+1, z=tpos.z})
@@ -117,16 +156,16 @@ local function init_tank(tpos, bpos)
 	}}
 	local tmeta = minetest.get_meta(tpos)
 	tmeta:from_table(tmetad)
-	--print(dump2(tmeta:to_table()))
 	
-	local cap = (tpos.y - bpos.y) * 60 * 9
-	--print("capacity: ".. cap)
+	local height = tpos.y - bpos.y
+	local cap = height * 60 * 9
 	
 	local bmeta = minetest.get_meta(bpos)
 	local bmetad = {fields = {
 		capacity = cap,
 		fill = 0,
 		fluid = fluid,
+		height = height,
 		tpos = minetest.serialize(tpos),
 	}}
 	bmeta:from_table(bmetad)
@@ -135,6 +174,30 @@ local function init_tank(tpos, bpos)
 end
 
 
+local function find_bottom(pos)
+	
+	local p = {x=pos.x, y=pos.y, z=pos.z}
+	
+	while 1==1 do
+		-- find the bottom and check the fill
+		
+		local n = minetest.get_node(p)
+		if n.name == "bitumen:cylinder_tank_bottom" then
+			return p
+		elseif n.name ~= "bitumen:cylinder_tank" 
+		   and n.name ~= "bitumen:cylinder_tank_cracked" 
+		   and n.name ~= "bitumen:cylinder_tank_top" 
+		   
+		   then
+			return nil
+		end
+
+		p.y = p.y - 1
+	end
+
+end
+
+
 local function can_dig_tank(pos, player) 
 	--if 1==1 then return true end
 	-- check owner
@@ -145,21 +208,14 @@ local function can_dig_tank(pos, player)
 --	if player:get_player_name() ~= owner then
 --		return false
 --	end
-
-	local p = {x=pos.x, y=pos.y, z=pos.z}
 	
-	while 1==1 do
-		-- find the bottom and check the fill
-		local n = minetest.get_node(p)
-		if n.name == "bitumen:cylinder_tank_bottom" then
-			local meta = minetest.get_meta(p)
-			local fill = meta:get_int("fill")
-			return fill <= 0 
-		elseif n.name ~= "bitumen:cylinder_tank" and n.name ~= "bitumen:cylinder_tank_top" then
-			return true
-		end
-		
-		p.y = p.y - 1
+	local n = find_bottom(pos)
+	if n == nil then
+		return true
+	else
+		local meta = minetest.get_meta(pos)
+		local fill = meta:get_int("fill")
+		return fill <= 0 
 	end
 	
 end
@@ -177,9 +233,9 @@ minetest.register_node("bitumen:cylinder_tank", {
  	node_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
-			{ -1.7, -.5, -1.2, 1.7, .5, 1.2 },
-			{ -1.2, -.5, -1.7, 1.2, .5, 1.7 },
+			{ -1.3, -.5, -1.3, 1.3, .5, 1.3 },
+			{ -1.5, -.5, -1.1, 1.5, .5, 1.1 },
+			{ -1.1, -.5, -1.5, 1.1, .5, 1.5 },
 -- 			{ -8.2, -.5, -.2, -7.8, 10, .2 },
 -- 			{ -.2, -.5, -8.2, .2, 10, -7.8 },
 -- 			{ 8.2, -.5, -.2, 7.8, 10, .2 },
@@ -189,13 +245,68 @@ minetest.register_node("bitumen:cylinder_tank", {
  	collision_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
  	selection_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
+		}
+ 	},
+	paramtype2 = "facedir",
+	groups = {cracky=1, level =2},
+	sounds = default.node_sound_wood_defaults(),
+	
+	on_construct = function(pos)
+-- 		local meta = minetest.get_meta(pos)
+-- 		if placer then
+-- 			local owner = placer:get_player_name()
+-- 			meta:set_string("owner", owner)
+-- 		end
+-- 		meta:set_float("fluid_level", 0)
+-- 		meta:set_float("capacity", math.floor(3.14159 * .75 * 9 * 9 * 9 * 64))
+-- 		meta:set_string("infotext", "0%")
+		
+		--bitumen.pipes.on_construct(pos)
+	end,
+	
+-- 	on_destruct = bitumen.magic.on_destruct,
+	
+	can_dig = can_dig_tank,
+})
+
+
+
+minetest.register_node("bitumen:cylinder_tank_cracked", {
+	paramtype = "light",
+	drawtype = "nodebox",
+	description = "Cracked Cylinder Tank Segment",
+	tiles = {
+		"default_tin_block.png",
+	},
+ 	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -1.3, -.5, -1.3, 1.3, .5, 1.3 },
+			{ -1.5, -.5, -1.1, 1.5, .5, 1.1 },
+			{ -1.1, -.5, -1.5, 1.1, .5, 1.5 },
+-- 			{ -8.2, -.5, -.2, -7.8, 10, .2 },
+-- 			{ -.2, -.5, -8.2, .2, 10, -7.8 },
+-- 			{ 8.2, -.5, -.2, 7.8, 10, .2 },
+-- 			{ -.2, -.5, 8.2, .2, 10, 7.8 },
+		},
+ 	},
+ 	collision_box = {
+		type = "fixed",
+		fixed = {
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
+		}
+ 	},
+ 	selection_box = {
+		type = "fixed",
+		fixed = {
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
 	paramtype2 = "facedir",
@@ -232,9 +343,9 @@ minetest.register_node("bitumen:cylinder_tank_top", {
  	node_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.5, -.5, -1.5, 1.5, .0, 1.5 },
-			{ -1.7, -.5, -1.2, 1.7, .0, 1.2 },
-			{ -1.2, -.5, -1.7, 1.2, .0, 1.7 },
+			{ -1.3, -.5, -1.3, 1.3, .0, 1.3 },
+			{ -1.5, -.5, -1.1, 1.5, .0, 1.1 },
+			{ -1.1, -.5, -1.5, 1.1, .0, 1.5 },
 			{ -1.2, -.1, -1.2, 1.2, .2, 1.2 },
 			{ -.7, -.1, -.7, .7, .4, .7 },
 			{ -.1, .1, -.1, .1, .5, .1 },
@@ -243,13 +354,13 @@ minetest.register_node("bitumen:cylinder_tank_top", {
  	collision_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
  	selection_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
 	paramtype2 = "facedir",
@@ -309,31 +420,31 @@ minetest.register_node("bitumen:cylinder_tank_bottom", {
  	node_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.5, .0, -1.5, 1.5, .5, 1.5 },
-			{ -1.7, .0, -1.2, 1.7, .5, 1.2 },
-			{ -1.2, .0, -1.7, 1.2, .5, 1.7 },
-			{ -1.2, -.2, -1.2, 1.2, .1, 1.2 },
+			{ -1.3, .0, -1.3, 1.3, .5, 1.3 },
+			{ -1.5, .0, -1.1, 1.5, .5, 1.1 },
+			{ -1.1, .0, -1.5, 1.1, .5, 1.5 },
+			{ -1.0, -.2, -1.0, 1.0, .1, 1.0 },
 			{ -.7, -.4, -.7, .7, .1, .7 },
 			{ -.1, -.5, -.1, .1, .1, .1 },
 			
 			-- legs
-			{ -1.4, -1.55, -1.4, -1.3, 0, -1.3 },
-			{  1.3, -1.55, -1.4,  1.4, 0, -1.3 },
-			{ -1.4, -1.55,  1.3, -1.3, 0,  1.4 },
-			{  1.3, -1.55,  1.3,  1.4, 0,  1.4 },
+			{ -1.25, -1.55, -1.25, -1.15, 0, -1.15 },
+			{  1.15, -1.55, -1.15,  1.25, 0, -1.25 },
+			{ -1.25, -1.55,  1.15, -1.15, 0,  1.25 },
+			{  1.15, -1.55,  1.15,  1.25, 0,  1.25 },
 			
 		},
  	},
  	collision_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
  	selection_box = {
 		type = "fixed",
 		fixed = {
-			{ -1.7, -.5, -1.7, 1.7, .5, 1.7 },
+			{ -1.5, -.5, -1.5, 1.5, .5, 1.5 },
 		}
  	},
 	paramtype2 = "facedir",
@@ -402,13 +513,47 @@ minetest.register_abm({
 
 
 
---[[
-minetest.register_craft({
-	output = 'bitumen:sphere_tank_constructor',
-	recipe = {
-		{'default:steelblock', 'default:steelblock', 'default:steelblock'},
-		{'default:steelblock', 'vessels:steel_bottle', 'default:steelblock'},
-		{'default:steelblock', 'default:steelblock', 'default:steelblock'},
-	}
+
+-- leaking
+minetest.register_abm({
+	nodenames = {"bitumen:cylinder_tank_cracked"},
+	interval = 10,
+	chance   = 5,
+	action = function(pos, node, active_object_count, active_object_count_wider)
+		
+		local p = find_bottom(pos)
+		if p == nil then
+			return
+		end
+		
+		local meta = minetest.get_meta(p)
+		local fill = meta:get_int("fill")
+		
+		local fillh = math.ceil(fill / (9 * 60))
+		local dh = pos.y - p.y
+		-- fill level is below the crack
+		if fillh < dh then
+			return
+		end
+		
+		-- choose a random place to leak
+		local airs = minetest.find_nodes_in_area({x=p.x-2, y=pos.y-1, z=pos.z-2}, {x=p.x+2, y=pos.y, z=pos.z+2}, {"air"})
+		if not airs then
+			return
+		end
+		
+		local ap = airs[math.random(#airs)]
+		local l = math.min(fill, math.min(64, math.random(5, 30)))
+		
+		local fluid = meta:get_string("fluid")
+		minetest.set_node(ap, {name=fluid})
+		minetest.set_node_level(ap, l)
+		
+		meta:set_int("fill", fill - l)
+		
+	end,
 })
-]]
+
+
+
+
diff --git a/init.lua b/init.lua
index 434673d..a4e405b 100644
--- a/init.lua
+++ b/init.lua
@@ -41,7 +41,46 @@ end
 
 
 
+local function vmin(a, b)
+	return {
+		x = math.min(a.x, b.x), 
+		y = math.min(a.y, b.y), 
+		z = math.min(a.z, b.z), 
+	}
+end
+local function vmax(a, b)
+	return {
+		x = math.max(a.x, b.x), 
+		y = math.max(a.y, b.y), 
+		z = math.max(a.z, b.z), 
+	}
+end
+
+bitumen.check_foundation = function(p1, p2, accept)
+	local low = vmin(p1, p2)
+	local high = vmax(p1, p2)
+	
+	--print(dump(low) .. "\n" .. dump(high))
+	for x = low.x, high.x do 
+	for y = low.y, high.y do 
+	for z = low.z, high.z do 
+		local n = minetest.get_node({x=x, y=y, z=z})
+		if accept[n.name] == nil then
+			return false
+		end
+	end
+	end
+	end
+	
+	return true
+end
+
+
+
+
+
 -- first initialize the internal APIs
+dofile(modpath.."/craftitems.lua")
 dofile(modpath.."/magic_nodes.lua")
 dofile(modpath.."/blueprints.lua")
 dofile(modpath.."/pipes.lua")
@@ -63,6 +102,13 @@ dofile(modpath.."/cylinder_tank.lua")
 dofile(modpath.."/sphere_tank.lua")
 dofile(modpath.."/refinery.lua")
 
+
+
+-----------------------------------
+--                               --
+-- * * * * * LOOK HERE * * * * * --
+--                               --
+-----------------------------------
 -- where players should look for information
 dofile(modpath.."/crafts.lua")
 dofile(modpath.."/ore_gen.lua")
@@ -96,6 +142,14 @@ minetest.register_node("bitumen:glass", {
 	end,
 })
 
+
+
+
+
+
+
+-- igore this; test for structure algorithm
+
 local support = {}
 
 minetest.register_abm({
diff --git a/sphere_tank.lua b/sphere_tank.lua
index f2d3958..c9a02ac 100644
--- a/sphere_tank.lua
+++ b/sphere_tank.lua
@@ -1,37 +1,6 @@
 
 
-local function vmin(a, b)
-	return {
-		x = math.min(a.x, b.x), 
-		y = math.min(a.y, b.y), 
-		z = math.min(a.z, b.z), 
-	}
-end
-local function vmax(a, b)
-	return {
-		x = math.max(a.x, b.x), 
-		y = math.max(a.y, b.y), 
-		z = math.max(a.z, b.z), 
-	}
-end
 
-local function check_foundation(p1, p2, accept)
-	local low = vmin(p1, p2)
-	local high = vmax(p1, p2)
-	print(dump(low) .. "\n" .. dump(high))
-	for x = low.x, high.x do 
-	for y = low.y, high.y do 
-	for z = low.z, high.z do 
-		local n = minetest.get_node({x=x, y=y, z=z})
-		if accept[n.name] == nil then
-			return false
-		end
-	end
-	end
-	end
-	
-	return true
-end
 
 
 
@@ -74,7 +43,7 @@ minetest.register_node("bitumen:sphere_tank_constructor", {
 		
 		if fields.build then
 			-- tanks can only be built on thick foundations
-			local ret = check_foundation(
+			local ret = bitumen.check_foundation(
 				{x = pos.x - 9, y = pos.y - 3, z = pos.z - 9},
 				{x = pos.x + 9, y = pos.y - 1, z = pos.z + 9},
 				{
diff --git a/textures/bitumen_galv_steel_sheet.png b/textures/bitumen_galv_steel_sheet.png
new file mode 100644
index 0000000..6200b75
Binary files /dev/null and b/textures/bitumen_galv_steel_sheet.png differ