The first technique we tried is the old crimp and fold technique. For this use your needle-nose pliers to remove the fins on either side of a leaking tube. Cut the damaged part out using the dykes and use the needle-nosed pliers to crimp both ends of the now-severed tube closed. Use the pliers to fold the flattened tube over on itself three or four times. Be careful not to bend or crease the tube or you may just create more holes for leaks to find.