Can you weld unions?

I've been trying for ages now, using scripts I've made and also trying welding plugins, but I can't find how.

My current script

local w1 = Instance.new("Weld")
	w1.Parent = script.Parent.PLT 
	w1.Part0 = w1.Parent
	w1.Part1 = script.Parent.C 
 
	local w2 = Instance.new("Weld")
	w2.Parent = script.Parent.PLT
	w2.Part0 = w1.Parent
	w2.Part1 = script.Parent.A 
	
	local w3 = Instance.new("Weld")
	w3.Parent = script.Parent.PLT
	w3.Part0 = w1.Parent
	w3.Part1 = script.Parent.J 
	
	local w4 = Instance.new("Weld")
	w4.Parent = script.Parent.PLT
	w4.Part0 = w1.Parent
	w4.Part1 = script.Parent.Part	
end