My last boat had teak. It was all weathered and had a few poorly repaired cracks. I took a stiff brush to them at first, them sanded to like 400 grit in 3 stages. Did this by hand, careful to get inside all slats. It's tedious but a good winter project. Have a few beers and get it done. Then once all sanded, blew off with air, sanded, more air, then oiled about 5-6 coats until it stopped sucking it all in. For the cracks, I removed the old screws that were holding the broken pieces together, got a waterproof wood glue at home depot, glued, clamped and put several stainless screws though when there would not be seen. I was happy with the result, just a quick brush and oil every month or two after that. My supra has a fiberglass platform which I don't care for. No character. If I ever come across a teak platform that will fit I'll probably change it out.
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Don't see any pics of when it's done, but you get the idea.