diff --git a/code/game/objects/items/stacks/rods.dm b/code/game/objects/items/stacks/rods.dm
index 5ab56ea942b..790815844be 100644
--- a/code/game/objects/items/stacks/rods.dm
+++ b/code/game/objects/items/stacks/rods.dm
@@ -43,7 +43,6 @@ var/global/list/datum/stack_recipe/rod_recipes = list ( \
 
 		if(WT.remove_fuel(0,user))
 			var/obj/item/stack/sheet/metal/new_item = new(usr.loc)
-			new_item.add_to_stacks(usr)
 			user.visible_message("[user.name] shaped [src] into metal with the welding tool.", \
 						 "<span class='notice'>You shape [src] into metal with the welding tool.</span>", \
 						 "<span class='italics'>You hear welding.</span>")
diff --git a/code/game/objects/items/stacks/sheets/glass.dm b/code/game/objects/items/stacks/sheets/glass.dm
index 3881915f99d..c12fa7dc3a2 100644
--- a/code/game/objects/items/stacks/sheets/glass.dm
+++ b/code/game/objects/items/stacks/sheets/glass.dm
@@ -42,7 +42,6 @@
 		if (V.get_amount() >= 1 && src.get_amount() >= 1)
 			var/obj/item/stack/sheet/rglass/RG = new (user.loc)
 			RG.add_fingerprint(user)
-			RG.add_to_stacks(user)
 			var/obj/item/stack/sheet/glass/G = src
 			src = null
 			var/replace = (user.get_inactive_hand()==G)
diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index 3feb6b0dff3..a18fb047f3d 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -133,7 +133,6 @@
 		if (R.max_res_amount > 1)
 			var/obj/item/stack/new_item = O
 			new_item.amount = R.res_amount*multiplier
-			new_item.add_to_stacks(usr) //try to merge with existing stacks on current tile
 
 			if(new_item.amount <= 0)//if the stack is empty, i.e it has been merged with an existing stack and has been garbage collected
 				return
@@ -196,21 +195,27 @@
 		src.amount += amount
 	update_icon()
 
-/obj/item/stack/proc/add_to_stacks(mob/usr)
-	var/obj/item/stack/oldsrc = src
-	src = null
-	for (var/obj/item/stack/item in usr.loc)
-		if (item==oldsrc)
-			continue
-		if (!istype(item, oldsrc.type))
-			continue
-		if (item.amount>=item.max_amount)
-			continue
-		oldsrc.attackby(item, usr)
-		usr << "<span class='notice'>You add new [item.singular_name] to the stack. It now contains [item.amount] [item.singular_name]\s.</span>"
-		if(oldsrc.amount <= 0)
-			break
-	oldsrc.update_icon()
+/obj/item/stack/proc/merge(obj/item/stack/S) //Merge src into S, as much as possible
+	var/transfer = get_amount()
+	if(S.is_cyborg)
+		transfer = min(transfer, round((S.source.max_energy - S.source.energy) / S.cost))
+	else
+		transfer = min(transfer, S.max_amount - S.amount)
+	if(pulledby)
+		pulledby.start_pulling(S)
+	S.copy_evidences(src)
+	use(transfer)
+	S.add(transfer)
+
+/obj/item/stack/Crossed(obj/o)
+	if(istype(o, src.type) && !o.throwing)
+		merge(o)
+	return ..()
+
+/obj/item/stack/hitby(atom/movable/AM, skip, hitpush)
+	if(istype(AM, src.type))
+		merge(AM)
+	return ..()
 
 /obj/item/stack/attack_hand(mob/user)
 	if (user.get_inactive_hand() == src)
@@ -228,34 +233,10 @@
 	return
 
 /obj/item/stack/attackby(obj/item/W, mob/user, params)
-
-	if (istype(W, src.type))
-		if(zero_amount())	return
+	if(istype(W, src.type))
 		var/obj/item/stack/S = W
-		if (S.is_cyborg)
-			var/to_transfer = min(src.amount, round((S.source.max_energy - S.source.energy) / S.cost))
-			S.add(to_transfer)
-			if (S && usr.machine==S)
-				spawn(0) S.interact(usr)
-			src.use(to_transfer)
-			if (src && usr.machine==src)
-				spawn(0) src.interact(usr)
-		else
-			if (S.amount >= max_amount)
-				return
-			var/to_transfer as num
-			if (user.get_inactive_hand()==src)
-				to_transfer = 1
-			else
-				to_transfer = min(src.amount, S.max_amount-S.amount)
-			S.amount+=to_transfer
-			if (S && usr.machine==S)
-				spawn(0) S.interact(usr)
-			src.use(to_transfer)
-			if (src && usr.machine==src)
-				spawn(0) src.interact(usr)
-			S.update_icon()
-
+		merge(S)
+		user << "<span class='notice'>Your [S.name] stack now contains [S.get_amount()] [S.singular_name]\s.</span>"
 	else
 		..()
 
diff --git a/code/game/objects/items/stacks/tiles/tile_types.dm b/code/game/objects/items/stacks/tiles/tile_types.dm
index 63b826797ef..27424a95a17 100644
--- a/code/game/objects/items/stacks/tiles/tile_types.dm
+++ b/code/game/objects/items/stacks/tiles/tile_types.dm
@@ -40,7 +40,6 @@
 
 			if (mineralType == "metal")
 				var/obj/item/stack/sheet/metal/new_item = new(user.loc)
-				new_item.add_to_stacks(user)
 				user.visible_message("[user.name] shaped [src] into metal with the weldingtool.", \
 							 "<span class='notice'>You shaped [src] into metal with the weldingtool.</span>", \
 							 "<span class='italics'>You hear welding.</span>")
@@ -54,7 +53,6 @@
 			else
 				var/sheet_type = text2path("/obj/item/stack/sheet/mineral/[mineralType]")
 				var/obj/item/stack/sheet/mineral/new_item = new sheet_type(user.loc)
-				new_item.add_to_stacks(user)
 				user.visible_message("[user.name] shaped [src] into a sheet with the weldingtool.", \
 							 "<span class='notice'>You shaped [src] into a sheet with the weldingtool.</span>", \
 							 "<span class='italics'>You hear welding.</span>")