What should I use to fix the outer screen door?
Answers:
Difficult to tell what the problem is? Guessing now, have you tried metal L brackets? Need to add some additional information to this question
Other answers:
Just buy another frame. They're not that expensive.
Just buy another frame. They're not that expensive.
Duct tape?
Why is the frame breaking so often? If it has a spring that slams it shut, you might try installing a gas shock like they have on storm doors.
I guess I would go buy a new door, reinforce the area that has been breaking with some nice long screws. Make sure you drill pilot holes first so as not to split the wood. Then try to correct the root cause of the problem. Perhaps the door is hung a little off center or is slightly too big for the frame? Make sure you hang the new door correctly and use a plane to shave any excess material from the door so that it fits.
Good luck!
DUCK TAPE!!!!