Roy,
I'm not replacing, but will be adding.
At the present I have metal toerails/T-tracks that over lap my deck-to-hull joint. After almost 30 years she seems to seep a little on the windy/rainy days.
So my plan it to pull the metal, re-install the fasteners, fill and glass over it all. Then add a mahogany (1" X 2")
water board (toerail) with a new T-track on top, staggering the fasteners between the old ones.
This should give it new strength, keep'r
water tight and create a stronger base for the
safety line stanchions, if you know what I mean!
I plan to to laminate 3/8" wide X 3/4" tall strips with DAP® Weldwood Resorcinol Glue (waterproof & stronger then epoxy) the shape of the curvature of the
hull, then laminate another 1/4" on top of that horizontally and radius the top edges to fair it in.
I could lacquer or
paint the wood but I can glass over that too. I haven't decided yet.
The problem with teak is it's hard to glue and to keep lacquer or
paint on it.
Some pictures of your old rail would help! That would give us a better idea of your set up and how we can make suggestions.