Sailnet had a great article in their newsletter on replacing your teak handrails with teak railings. Why would you want to do that? Well if your handrails haven't been well cared for or have been sanded down every year and varnished for 20 years then they may be thinning a bit and lack the original strength intended to support you when you grab a hold instead of fall off the boat. I agree with the author; this looks like a very easy DIY project.