CarolsHusband
SMF Supporter
Used to be "red lead" ( lead tetroxide) until the 90'S, and it wasn't the healthiest stuff to use. Though it wasn't actually banned most manufacturers now use iron oxide in red primer instead.
Rust
- Thread starter CarolsHusband
- Start date
That's the stuff. Remember lots of paint was lead based. Used lots of turpentine.
All bare metal ( with the possible exception of gold ) will oxidise when exposed to the air - the rate of oxidation also depends on the level of moisture and acidity in the air. "Rust" is the specific term used to refer to IRON oxide. Iron containing materials such as cast iron and steel will "rust" but at very different rates.
Even high quality steel products will form surface rust quite quickly - just look at the disc brakes of a car that has been standing unused outdoors for a few days but this will be bright orange surface rust which easily rubs off. Cast iron ( or some cast steel ) products will oxidise to a dark brown colour over a longer period of time - just take a look at drain grids or manhole covers in the street - this colouration doesn't easily rub off it just polishes.
Non-ferrous metals such as aluminium will oxidise differently - aluminium tends to become a dark grey, zinc and its alloys often form a light grey or white oxide, copper and brass tarnish to a darker colour and sometimes form a green "verdigris" colouration (but this takes a significant amount of time).
Often poorly finished, relatively thin, mild steel such as that on fenders or stowage boxes will show signs of rusting under paint layers - often due to the fact that paint has been applied over existing damage without adequate surface prep.
Tracks are often a tricky thing to get right - the closest most of us get to them is when we see museum exhibits or "gate guards"/monuments which usually do show deep oxidation ( light or even dark brown colouring ) with little or no abrasion visible. Working vehicles usually show some bare metal (depending on the track type) but this depends on the surface they are operating on.
Even high quality steel products will form surface rust quite quickly - just look at the disc brakes of a car that has been standing unused outdoors for a few days but this will be bright orange surface rust which easily rubs off. Cast iron ( or some cast steel ) products will oxidise to a dark brown colour over a longer period of time - just take a look at drain grids or manhole covers in the street - this colouration doesn't easily rub off it just polishes.
Non-ferrous metals such as aluminium will oxidise differently - aluminium tends to become a dark grey, zinc and its alloys often form a light grey or white oxide, copper and brass tarnish to a darker colour and sometimes form a green "verdigris" colouration (but this takes a significant amount of time).
Often poorly finished, relatively thin, mild steel such as that on fenders or stowage boxes will show signs of rusting under paint layers - often due to the fact that paint has been applied over existing damage without adequate surface prep.
Tracks are often a tricky thing to get right - the closest most of us get to them is when we see museum exhibits or "gate guards"/monuments which usually do show deep oxidation ( light or even dark brown colouring ) with little or no abrasion visible. Working vehicles usually show some bare metal (depending on the track type) but this depends on the surface they are operating on.
Graeme C.
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I worked at Barnbow tank factory in Leeds for 14 years, tank hulls & turrets are not dipped surprisingly! After being welded & machined they are shot blasted, then sprayed first with primer, then top coat. The armoured steel parts of a tank don't generally rust much, due to the metals that armoured steel is alloyed with making it rather more rust resistant, as well as being harder than mild steel.