Does my beam need touching up?

[carson321]

I had a rather large UC delivered a few months ago that is to be used as a beam to form a new opening at the back of my house for a single storey extension to be built off it. None of the surrounding brick/blockwork will be an externally exposed surface.

 

There are some patches of rust on the beam, these were basically there from point of delivery and are mostly from where it has been supported etc from moving it around. 

 

Will I need to touch these up with some red oxide before it is covered or will it not make any difference?

 

 

[JohnMo]

I would have had it galvanised. You still could.

 

It looks like paint was possibly simply painted after welding with little or no prep. It should have been blasted to Sa 2.5 spec and then painted. Depending on paint type most primers are an open film, so water gets below the paint surface and you get rust. An epoxy primer isn't so can be left in a primer state.

 

For me (others will say otherwise)

1. Get them/it galvanized 

2. Send to an industrial painter to be blasted and painted correctly.

[saveasteading]

36 minutes ago, JohnMo said:

others will say otherwise

No need to do anything, but touching up in red oxide will look better and avoid anybody questioning it.

If there is the slightest chance of dampness on ,say, padstones then some blackjack locally might be worthwhile.

 

Steel needs a lot of dampness combined with oxygen, to rust.

 A tip for appearance. Do any red oxide as local rectangles rather than splodges.

 

If you need any proof I can find photos of the columns on our project that were exposed to the weather for 30 odd years. 

Rust looks worse than it is, because the steel expands a lot when oxidising.

 

I'm assuming it will be out of sight.

 

On balance,  touch up in red oxide. Then decide whether to stick there ot paint it all in red oxide. 

 

[Super_Paulie]

we'll all be buried before that rust effects anything, just leave it and move on.

For info, this is my huge beam, i just cleaned it off, primer and painted it.

[saveasteading]

For anyone generally interested in steel, especially contractors.

 

My business was mostly big steel buildings, mostly portal frame.

The frames were supplied in red oxide as standard. They did not need paint other than touch-up or an optional decoratively.

A finished coat at the works was not wise as chains etc damage it.

 

Clients recognised it as ' cheap red oxide' and often chose that it needed full over- painting.

Then our supplier began to offer grey oxide.

This became our norm, and scraped bits were touched up after construction in the same paint.  Nobody ever said it was unacceptable.

 

However, for simple beams as above, red oxide is never questioned.