I've used it to stick things together (which have yet to come apart), to repair broken items of virtually all materials (ditto on the not-coming-apart), and, of especial interest to the OP, I hope, I've used it to patch holes, and I can attest that after years of exposure to the elements, said holes are still waterproof and the lexel is still unclouded.
Ok, NOW I'm sounding like a paid endorser...(maybe I should contact the company).