Water drainage holes in railing ? Advice appreciated...

I am putting together 11m of (outdoor) balcony railing.

Spindles are 20mmx5mm strips (hot dip galvanized)
connected to rails by 5/32" screws and bolts (galv)
Rails are 20mmx20mm square profile bars, 2.5mm thick. Cold galv.
connected to Posts by 1/4" nuts and bolts (galv)
Posts are 30mmx30mm square profile bars, 3mm thick. Cold galv.
will be anchored ~ 200mm deep in existing concrete

I am painting everything with a phenolic primer then DTM (metal) paint.

And now the questions
I am looking for corrosion resistance.

1. Should I drill drainage holes at either side of each rail ? (welded the bolts tight, some zinc has been burned off inside)
2. Should I take the time to seal the ends of the rails ? ie look for plastic plugs, or squirt some silicone in - or really take the time and weld them shut.. Would moisture not enter in any case via the screw/nut holes ?
3. Should I drill drainage holes at concrete level for the posts ? Should I take care to somehow fill the bottom of the posts when anchoring, to prevent water potentially collecting in a cavity below the existing level of the concrete ?

Thanks for any input...

D.

Plastic plugs for the ends. Silicon if you want as an extra no harm doing so.
A clear lacquer over all joints with the bolts/screws.
Hot dipped stuff should be fine, but a lacquer coat never hurts.

Thanks.

The screws, nuts and bolts are being primed and painted along with all the rest...
Do you think drainage holes are not really necessary?

D.

Alarm said:

Plastic plugs for the ends. Silicon if you want as an extra no harm doing so.
A clear lacquer over all joints with the bolts/screws.
Hot dipped stuff should be fine, but a lacquer coat never hurts.

Click to expand...

Not if its sealed anyway.
Drainage holes will also allow ingress.
You see holes on hot dipped tube as it has to allow the air to escape when dipped, also a way of securing to the hangers.

Are the screw and nut holes not a point of ingress ? I assumed some moisture would penetrate there...

Alarm said:

Not if its sealed anyway.
Drainage holes will also allow ingress.
You see holes on hot dipped tube as it has to allow the air to escape when dipped, also a way of securing to the hangers.

Click to expand...

Why I mentioned using the silicon and lacquer.