4" gate posts

[jgr2015]

Definitely galvanised!

As to condensation, my reckoning was that nothing I was going to do would completely seal the hollow section.

I thought of it as being like condensation forming in the hollow sections of a car as the air heats and cools. And over years, I figured it might well accumulate - that was my logic anyhow. The extra strength from the concrete fill is a bonus.

 

[Dave-sparks]

If they’re sealed top and bottom how can they fill up with condensation???

Unless you can completely dry the air inside them and make them gas tight, or something like that, then condensation will form in there.

 

[8ob]

Cant see it being a problem, oxide once formed is tougher than any paint. Before I built brick piers to hang my gates on they were hung on two lumps of 8" od steel pipe just concreted into the ground, no paint or protection and they were stiil good after twenty five years, pretty sure that layer of oxide was protecting them.

Bob

 

[Onoff]

I made a mistake I think with my 100x100x6 gate posts.

I got the steel free. After welding I set them at an angle and poured (new) oil down all 4 inside faces. Can't remember what but again it was free.

However...I then filled them with expanding foam.

They condensate ON THE OUTSIDE.

 

[waddycall]

Unless you can completely dry the air inside them and make them gas tight, or something like that, then condensation will form in there.

How are they going to get enough fresh moist air in them for it to be a problem?

 

[brightspark]

I was thinking of coating the buried section, it's the void I was more interested in, filling with condensation and filling up

fill them with concrete

 

[nickk]

If they’re sealed top and bottom how can they fill up with condensation???

Repeatedly warm/cold,just touch steel on a hot day,then after it cools , condensation forms,why exhausts rot from the inside.

 

[Luggsey]

I put electric gates on wood posts 10 years ago.
7x7" posts that I left standing in genuine creasote that soaked up 2'.
I then painted them to seal them and maintained them well.
Last year the gates fell to bits and one post disintegrated at the bottom.
Never ever using soft wood gate posts again!

 

[RWD3M]

I put electric gates on wood posts 10 years ago.
7x7" posts that I left standing in genuine creasote that soaked up 2'.
I then painted them to seal them and maintained them well.
Last year the gates fell to bits and one post disintegrated at the bottom.
Never ever using soft wood gate posts again!

Wow, that's a surprise. I've just replaced four 3 x 3 posts that support my pergola that I fitted about 25 years ago. This is one of them, the others were the same:




I only replaced them as I'm rebuilding the brickwork and had the opportunity.

They too were soaked in creosote for probably a week or so then fitted. They were never retreated as I had grape vine planted around them!

 

[brightspark]

Wow, that's a surprise. I've just replaced four 3 x 3 posts that support my pergola that I fitted about 25 years ago. This is one of them, the others were the same:

View attachment 298740View attachment 298741


I only replaced them as I'm rebuilding the brickwork and had the opportunity.

They too were soaked in creosote for probably a week or so then fitted. They were never retreated as I had grape vine planted around them!

just replaced my 2 3x3 gateposts after 35 years. i dipped them in proper creosote for a week in a bucket and they get coated every 3 years the fence posts are still ok

 

[waddycall]

Repeatedly warm/cold,just touch steel on a hot day,then after it cools , condensation forms,why exhausts rot from the inside.

I understand condensation. All I’m saying is that if they’re pretty much sealed top and bottom then there will be a limited amount of moisture in there with a limited amount of oxygen and it won’t be anywhere near enough to cause any significant corrosion.

 

[Onoff]

Looking at the tops of my gate posts and the expanding foam seems to have pulled away from the inside face of the box:

All I could think to do was cover it in lashings of Hammerite Underbody Seal With Added Waxoyl as I've some kicking about. Seems to form a decent "skin" over the foam and fills the gaps. When the cap stones go on I'll not be getting to this area again in a hurry.