Help with Welding?

I am trying to weld a multi-part sword together, but every Weld script I have found does not work with my sword, but it does with other tools (the one they came with).

Any help?

Weld Script 1

local previous
local part = script.Parent:GetChildren()

for i = 1, #part do
	if part[i].ClassName == "UnionOperation" or part[i].ClassName == "Part" then
		if not previous == nil then
			local weld = Instance.new("Weld")
			weld.Part0 = previous
			weld.Part1 = part[i]
			weld.C0 = previous.CFrame:inverse()
			weld.C1 = part[i].CFrame:inverse()
			weld.Parent = previous
			part[i].Anchored = false
		end
		previous = part[i]
	end
end

wait(3)

Weld Script 2

function Weld(a, b)
	local w = Instance.new("Weld")
	w.Part0 = a
	w.Part1 = b
	local CJ = CFrame.new(a.Position)
	local C0 = a.CFrame:inverse() * CJ
	local C1 = b.CFrame:inverse() * CJ
	w.C0 = C0
	w.C1 = C1
	w.Parent = a
end

function Get(A)
	if A.className == "Part" then
		Weld(script.Parent.Handle, A)
		A.Anchored = false
	else
		local C = A:GetChildren()
		for i=1, #C do
		Get(C[i])
		end
	end
end

function Finale()
	Get(script.Parent)
end

script.Parent.Equipped:connect(Finale)
script.Parent.Unequipped:connect(Finale)
Finale()

I know they are quite large, but I have not found any errors in them. Any help is appreciated.

TheArmoredReaper

EDIT : I am trying to link this to a for loop, allowing the script to weld as many parts as needed. Every part inside my model is a Union, thus its class name is UnionOperation.

If you are trying to find a script then why not use plugins.It works great and effecting.Search up welding/welder or auto-weld. Thats just tips other than that I can't figure this script out. BTW when getting all children you have to name every part the same thing as the part you want to get.

Alright if you wish to weld two parts together by their relative position then i recommend this

Inside a Script:

local weld = function(a, b)

	local w = Instance.new("ManualWeld")
	w.Part0 = a
	w.Part1 = b
	w.C0 = CFrame.new()
	w.C1 = a.CFrame:toObjectSpace(b.CFrame)

	return w

end

local Tool = script.Parent -- get tool
local Handle = Tool.Handle

for i, part in pairs(Tool:GetChildren()) do
	
	if part:IsA("BasePart") then
		if part.Name ~= "Handle" then
			weld(Handle, part)
		end
	end

end