Consensus on exhaust collector ring color

[peebeep]

So you are saying that colouring is due to heat staining of steel alloy in those rings?

Sorry about mishap to your name!

 

 

Yes, the silver doped airframe (with the red prop spinner) has a collector colour that has very little evidence of heating and you can see clearly that it's not copper. The other pics are of the Shuttleworth Gladiator that has quite a coppery hue to the collector on account of it running probably for hundreds of hours, but it's heat not the material that gives rise to the colour.

 

 

For anybody building Airfix Beaufighters that might be puzzled with the paint instructions calling for black collectors, that's because later on in the war Coastal Command was painting them with heat resisting black paint.

 

 

I'm not at all fussed about mishaps with my screen handle. I changed my account to my real name but the software still uses the original screen handle.

[dogsbody]

These are new, unused collector rings, at the Bristol engine factory during WW2.

They are not made of copper, but from some steel alloy. When heated up by the 800F+ degree exhaust gases, they soon become heat-stained and turn a brownish colour. How stained depends on how many hours of engine running time they go through.

Some flying restored aircraft:

Chris

[SD45elect2000]

I hope this is close enough. I used a copper color over the silver color then highlighted it with violet and clear red. I tried to leave the cooler areas silver but it is hard to see in photos. The Beaufighter kit calls for black paint, I assume stove black, so I painted a light black over the silver copper finish. we'll see how that photographs.

Randall

[Ratch]

Re-activating this old thread.

[dogsbody]

The Bristol exhaust collector ring was a dull, metallic colour when manufactured. When fitted to an engine, it gradually turned a brown shade, from the heat. Later in the war, the rings were sometimes painted over with a black, heat resistant paint.

 

 

 

 

 

Chris

[SD45elect2000]

When I build my Stirlings it is possible then to have the collector rings different shades depending on the age of the ring?

Randall

[Valhalla]

11 hours ago, Ratch said:

Re-activating this old thread.

Thanks for resurrecting this Ratch. There's some really interesting information there.

Ian

[Dominic Thomas]

Perhaps another thing to bear in mind is the lighting conditions when the reference photo was taken. 

I think photos of this aircraft appear earlier in this post. Here the rings appear darker and more matt, perhaps due to darker conditions at the time of the photo. 
I use Humbrol 55 Metallic Bronze. It’ll do for me. 

Might be a bit bright but I can work on that. 

[Ratch]

Note that the inner edges on the Blenheim appear to be grey.

[peebeep]

2 hours ago, Ratch said:

Note that the inner edges on the Blenheim appear to be grey.

It's parts of the ring that don't get sufficiently hot to cause heat discolouration. 

[dogsbody]

1 hour ago, peebeep said:

It's parts of the ring that don't get sufficiently hot to cause heat discolouration. 

Yes, as in the diagram, in my posting above.
 

 

 

 

 

Chris

[A J Rimmer]

An interesting topic. I'd be tempted to paint my rings a steal colour, and then give them a wash with a brown/bronze wash or ink to get the heat stained colour. 

[SD45elect2000]

On 27/08/2024 at 05:41, A J Rimmer said:

An interesting topic. I'd be tempted to paint my rings a steal colour, and then give them a wash with a brown/bronze wash or ink to get the heat stained colour. 

That’s worth a try. The issue is keeping the silver parts silver and not washing the entire collector ring. 
Randall

[dogsbody]

On 27/08/2024 at 03:41, A J Rimmer said:

An interesting topic. I'd be tempted to paint my rings a steal colour, and then give them a wash with a brown/bronze wash or ink to get the heat stained colour. 

I have this Citadel set of inks:

plus these Tamiya pastels:

 

 

 

CHris

[A J Rimmer]

Might be worth having a go Chris.