What You Need:Duct Tape or Guerilla Tape.
One can of Plastic Dip or Tool Dip (not the spray type).
A one inch, cheap paint brush. You will throw it away.
Old pair of gloves. You do not want Plastic Dip on your hands.
Newspaper or an old towel. You do not want Plastic Dip dripping on the floor etc.
The Procedure:Empty your daypack.
Start taping the holes from the inside of the daypack first.
Note: If the holes are huge, this is probably not going to work.
Next, tape the holes from the outside, bottom of your pack.
Now, take your pack outside (the smell from the wet Plastic Dip is bad)
Paint the bottom of your pack with plastic dip. Really brush it on thick.
Let it dry ~ 30 minutes, maybe longer if in a humid climate.
Apply a second coat of Plastic Dip.
Watch the video
The Plastic Dip will protect the bottom of your pack without making the bottom of your pack rigid.