Why dose't this work? (.Value = ""..part.Position.."") Please Help

So im trying to make a "Save Blocks" Script, but i came across this problem.

when I run the script/press the button, inside Player, theres a Value called Save and in Save theres a Value Called Part, and inside Part theres a Value called pos, but pos has no value, so im gessing that .Value = ""..part.Position.."" is wrong. Can someone explain why it wont work?

local Gui = script.Parent
local Player = Gui.Parent.Parent.Parent
local Char = Player.Character
local part = game.Workspace:FindFirstChild("Part")

function onClicked()
	
	local save = Instance.new("StringValue", Player)
	save.Name = "Save"
	
	while true do
		wait()
		if part ~= nil then
			local savepart = Instance.new("StringValue", save)
			savepart.Name = "Part"
			
			local savepartpos = Instance.new("StringValue", savepart)
			savepartpos.Name = "pos"
			savepartpos.Value = ""..part.Position..""
			
			local savepartrot = Instance.new("StringValue", savepart)
			savepartrot.Name = "rot"
			savepartrot.Value = ""..part.Rotation..""
			
			local savepartsize = Instance.new("StringValue", savepart)
			savepartsize.Name = "size"
			savepartsize.Value = ""..part.Size..""
			
			part:remove()
		end
		
	end

	
end

Gui.MouseButton1Click:connect(onClicked)

If you want a string representation, you should just use tostring(part.Position).

Concatenation has to be specifically defined -- it doesn't automatically turn objects into strings when concating with a string. Since it wasn't for Vectors, you get an error.

It makes a lot more sense to use Vector3Values, though, since that way you can actually get the value back later without doing an excessive amount of work.