Is there any way to resize a part on a loop without breaking its weld?

Basically I want a brick with a SphereMesh to get bigger using a loop, but it always breaks its weld, no matter what I do. Here is the (current) code:

while wait() do
		script.Parent.Mesh.Scale = script.Parent.Mesh.Scale + Vector3.new(0.4,0.4,0.4)
		script.Parent.Size = script.Parent.Size + Vector3.new(0.4,0.4,0.4)
end

while wait() do
script.Parent.Mesh.Scale = script.Parent.Mesh.Scale + Vector3.new(0.4,0.4,0.4)
script.Parent.Size = script.Parent.Size + Vector3.new(0.4,0.4,0.4)
W = Instance.new("Weld")
W.Part0 = --Whatever is your Part0--
W.C0 --Whatever is your Part0--.CFrame:inverse() 
W.Part1  = --Whatever is your Part1--
W.C1 = --Whatever is your part1--.CFrame:inverse()
W.Parent = --Whatever is your part1--
end