I have dock located on a brackish (salt/fresh water mix) body of water. It is built with appropriate (for the area) pressure treated lumber, though I am not sure of the exact type of preservative.
I want to build a lower level platform to make it easier to access canoes, kayaks, and smaller watercraft, similar to what is shown here:
What kind of fasteners and hangers should I use? I have been looking at various types of Hot Dipped Galvanized (HDG), Zmax, and stainless. Stainless is my first choice, but a couple of questions arisen. The stainless hangers are not as heavy duty (18 gauge), in so far as their load carrying capability is, as some of the HDG or Zmax (16 or 14 gauge) products. But the stainless parts would work with approximately 4X margin, while the heavier parts would have 6X or 8X margin.
Also, with the stainless parts, I am limited to using stainless 3-1/2" nails, as structural screw-type fasteners do not seem to be available in stainless. I cannot use any sort of galvanized fastener with stainless. With the HDG or Zmax hangers, I can use the appropriately finished structural screw type fasteners.
Any thoughts on whether I should go with stainless or the HDG/Zmax products?
EDIT 1 - Existing dock hardware
FYI, the dock is built with all galvanized hardware - large nails (no bolts or screws); nothing stainless. The boat lift (not shown in this picture) uses stainless hardware for the pulley and cable system.
The dock went through the proper permitting process when it was built, which included a professional survey, local jurisdiction approval, Dept. of Natural Resources approval, and (I think) Army Corp of Engineers approval (standard for anything on the waterfront around here).
Edit 2 - Decision
I decided to go with the thinner stainless steel (316) hangars, with SS nails, instead of one of the thicker, galvanized versions.