Sanding and wetting and cleaning, oh my!
Bart, I had the same problem with the teak on my boat, i'm not sure of the overall condition of your teak other than greying, but mine was many many years neglected and needed more than just brightening, I chose to refurbish the wood. Basically a friend and I spent a lot of our free time over a couple of weeks on a fairly simple process,,the first step is to sand the wood, wet it ( to soak in and swell the wood ) repeat, repeat, then repeat with finer grit sandpaper, repeat, then finer grit paper, repeat, etc... until I ended up with glass smooth teak,then hit it with teak cleaner, then teak brightener, then a sealer. it looks beautiful and I get a lot of complements on it. unfortunately it's a lot of work, and be sure to allow the wood to dry thoroughly between sandings and before sealing.In the long run I'm much happier than I would have been if I'd bought new teak instead. Good luck with it, whatever you plan to do.