I've been using Cetol many years.
UV is the biggest problem.
Covering rails or any exposed areas will allow years of protection.
I just finished recoating after 8 years.
But I stripped the old stuff off, and wiping down the wood with Acetone first just prior to application.
Stripping is pretty straight forward, I use the Banco scraper, with a carbide blade, triangle shape, also any tough areas? Use a heat gun to warm the area.
Do NOT thin Cetol, use natural, or lite if you want less tinting.
Remember the tint is to protect from sun UV.
Be sure to wipe with acetone until no more yellow color( Teak oil) shows on the rag.
Be sure to coat out of the sun, and place that coat on within an hour to assure no oil rises ot of the wood.
I've done alot of Britework and Cetol is the easiest.
