fully closing a steel support - problems?

[kingnero]

I'm fabricating 4 steel columns that will serve as a replacement for 4 wooden posts which support a roof similar to a carport.

It will need to be welded onto a baseplate (with bolt holes), and I intend to weld the upper end shut as well.

This won't be hot dipped nor powdercoated afterwards, only painted.
Should I worry about any moisture inside, as I'll do this at home, no special controlled environment nor the ability of drying the inside to a 100% dry.

The upper end will be protected for the rain by the roof.
So should I have weep holes, those at the bottom are more likely to see water entering from rain "ricoshet", and I can't really paint the inside. According to me I'd be better off without.

Your thoughts?

 

[bridgebuster]

Put a small weephole in the baseplate. Better safe than sorry.

 

[hokie66]

I would leave it sealed.

 

[kingnero]

I would prefer sealed too, but what would the "sorry" option mean?
If there was an initial small amount of water inside, how much would/could it corrode?
Rust = oxides, so once all the water is transformed into oxides, it should stop rusting, no?

 

[Compositepro]

Rust is a reaction with oxygen in air. Water just facilitates the reaction.

 

[Ron]

Keep it sealed. Slight corrosion inside will consume remaining oxygen and further corrosion will cease.

 

[MikeHalloran]

Sealed.
Extra paint near the bottom, or gutters and downspouts to deal with rain ricochet.



Mike Halloran
Pembroke Pines, FL, USA

 

[kingnero]

Thanks for your thoughts...
Sealed it will be.

I'll blow through the steel columns with a hair dryer for piece of mind...