Need a new one.
Not only do they spoil, but they're one time use. They don't absorb much, but that micro percentage that avoids vacuuming. Same to the filter component, absorbs just a list bit of crap.
Solder does not hold under expansion and contraction, it's used in plumbing because water temperature doesn't change much. And a little cold and that cracks in peoples houses all the time.
If you don't braze, you have will leaks, problems, cracks, failures, and possibly worse.
No, a system needs one filter.
But don't open it until your ready to install.
If you use proper procedures, then between capillary changes you won't have to change it out. That's why you use a purging gas and you work at a decent pace. Not unbraze it and leave it for 3 weeks.
It sounds like your really trying to do this on the cheap.
You should reavaluate your budget, cheaping out on tools and parts will not end well. Especially if your already taking a massive budget cut in using propane.