How would I go about adding welding to this script?

I have made a building system and I want parts to get destroyed and have it fall down and the current script all works I just want to have the parts weld together when they are placed. Here is the script

local rf = game.ReplicatedStorage.MouseTarget
Build = game.ReplicatedStorage.Build

rf.OnServerEvent:Connect(function(Player, MouseTarget, TargetSurface)
	if MouseTarget.Parent.Parent.Owner.Value == Player.Name then
		local B = Build:Clone()
		B.Parent = MouseTarget.Parent.Parent.Blocks
		if workspace.CanBuild.Value == true then
			if MouseTarget.Parent.Parent.Name == "Plot1" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot2" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot3" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -113 or MouseTarget.Parent.Parent.Name == "Plot4" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -118 or MouseTarget.Parent.Parent.Name == "Plot5" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -113 or MouseTarget.Parent.Parent.Name == "Plot6" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot7" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 or MouseTarget.Parent.Parent.Name == "Plot8" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 or MouseTarget.Parent.Parent.Name == "Plot9" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 then
				if TargetSurface.Name == "Top" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y + 2, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y + 4, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Left" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X - 2, MouseTarget.Position.Y, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X - 4, MouseTarget.Position.Y, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Right" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X + 2, MouseTarget.Position.Y, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X + 4, MouseTarget.Position.Y, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Back" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z + 2)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z + 4)
					end
				elseif TargetSurface.Name == "Front" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z - 2)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z - 4)
					end
				elseif TargetSurface.Name == "Bottom" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y - 2, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y - 4, MouseTarget.Position.Z)
					end
				end
			end
		end
	end
end)

here is what I tried to do to weld it but it didn't work

local rf = game.ReplicatedStorage.MouseTarget
Build = game.ReplicatedStorage.Build

rf.OnServerEvent:Connect(function(Player, MouseTarget, TargetSurface)
	if MouseTarget.Parent.Parent.Owner.Value == Player.Name then
		local B = Build:Clone()
		B.Parent = MouseTarget.Parent.Parent.Blocks
		if workspace.CanBuild.Value == true then
			if MouseTarget.Parent.Parent.Name == "Plot1" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot2" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot3" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -113 or MouseTarget.Parent.Parent.Name == "Plot4" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -118 or MouseTarget.Parent.Parent.Name == "Plot5" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -175 and MouseTarget.Position.X < -113 or MouseTarget.Parent.Parent.Name == "Plot6" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -31 and MouseTarget.Position.X < 31 or MouseTarget.Parent.Parent.Name == "Plot7" and MouseTarget.Position.Z > -35 and MouseTarget.Position.Z < 27 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 or MouseTarget.Parent.Parent.Name == "Plot8" and MouseTarget.Position.Z > 37 and MouseTarget.Position.Z < 99 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 or MouseTarget.Parent.Parent.Name == "Plot9" and MouseTarget.Position.Z > -107 and MouseTarget.Position.Z < -45 and MouseTarget.Position.X > -103 and MouseTarget.Position.X < -41 then
				if TargetSurface.Name == "Top" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y + 2, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y + 4, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Left" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X - 2, MouseTarget.Position.Y, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X - 4, MouseTarget.Position.Y, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Right" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X + 2, MouseTarget.Position.Y, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X + 4, MouseTarget.Position.Y, MouseTarget.Position.Z)
					end
				elseif TargetSurface.Name == "Back" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z + 2)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z + 4)
					end
				elseif TargetSurface.Name == "Front" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z - 2)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y, MouseTarget.Position.Z - 4)
					end
				elseif TargetSurface.Name == "Bottom" then
					if MouseTarget.Name == "Part" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y - 2, MouseTarget.Position.Z)
					elseif MouseTarget.Name == "Build" then
						B.Position = Vector3.new(MouseTarget.Position.X, MouseTarget.Position.Y - 4, MouseTarget.Position.Z)
					end
					wait(.05)
					B.Touched:Connect(function(part)
						if part.Name == "Part" or part.Name == "Build" then
							local  Weld = Instance.new("Weld")
							Weld.Parent = B
							Weld.Part0 = B
							Weld.Part1 = part
						end
					end)
				end
			end
		end
	end
end)