If it's only for tacking stuff together and you already have Argoshield light then I'd just give it a go.
It wouldnt be worth getting a completely new bottle.

Ensure all pieces are spotlessly clean. The biggest issue is wire feeding and speed. Alloy wire is soft, so can easily bunch up inside the tube. And you need to fire in a lot of wire.

IMO use the thickest wire your system can handle, and keep the torch tube as straight as possible so there is less chance of the wire doing strange things.