I've just used some accoya for a window, but I pinned (and glued) some of the internal beeding on with steel pins, mainly to hold while the glue cured. But I now realise my pins were steel rather than stainless, and I'm wondering if anyone knows the consequences of their corrosion. I drove the heads a few mm in and filled the holes, and the whole thing will have two layers of good quality primer and top coat, will rust show through eventually? I'm hoping not! There could still be time to replace the beeding but it would get messy....