a big job?

[OceanSprint]

There are rust streaks coming away from one point in my coach roof top wooden hand rail.

Would you take the whole hand rail off to fit new screws?

Surely they would not have used just one non stainless screw?

PS I guess I know what the answer is !

 

[DanTribe]

Sometimes a steel screw can be accidentally mixed with stainless ones, may not be noticed by the shipwright.
Anyway it's unlikely to heal itself, better to replace sooner than later.

 

[PlankWalker]

You may be able to tell by using a magnet to see if it's attracted, but a hand rail should be through bolted not screwed.

 

[David2452]

304 stainless which is often used above the waterline can produce rust streaks over time.

 

[OceanSprint]

304 stainless which is often used above the waterline can produce rust streaks over time.

What should I use to replace?

 

[aslabend]

What should I use to replace?

I used bronze screws from Classic Marine for fixing the handrails on my coachroof.

 

[vyv_cox]

What should I use to replace?

The solution to all corrosion problems, where possible, is to exclude the water. A 300 series stainless steel component will suffer crevice corrosion, particularly if it is permanently wet in timber. Using a sealant that keeps it dry should solve the problem.

Many examples at http://coxengineering.sharepoint.com/Pages/Crevice.aspx