I bought a new pair of breathable waders last summer (fishing store went out of business, so they were 60%off). I'm pretty rough on waders and would like them to last a while. I was thinking of cutting up an old pair of rubber waders and using that to add extra material to the knees of the new waders. I was going to use wader repair adhesive to glue them together. Are there any potential issues (I'm not worried about warranty, and I already look like a dork, so appearance isn't an issue either)? Anyone tried this? Any other alternatives?

Thanks!
Matt