Any help with weathering white rooves?

[MrWolf]

I know this is probably a tired old question, but can any of you share your thoughts on how best to give those infernal white rooves a suitably varied weathered finish? I have quite a few to do and it is mostly stock that would be a bit long in the tooth. Also, I don't as yet possess an airbrush, it's something that I just don't use with my regular artwork. Perhaps I should get one, but that opens the which one? can of worms!

[burgundy]

Get a soft pencil. Rub it on your finger and then smear your finger across the roof. Repeat until you have a suitably varied weathered roof.

Hope this helps. If it does not, it should wash off (both you and the roof).

Best wishes

Eric    

[MrWolf]

Thanks, never thought of graphite. I have a rainforest worth of 6B pencils.

[Siberian Snooper]

I just brush on roof dirt paint Railmatch 2403 or Lifecolor UA 722  with a little thinners, it's better to use thin coats and build up layers, until satisfied and allow each layer to dry before applying the next one. I also add a little cream or dark grey to add a bit of variation. Oh and brush across the roof rather than lengthwise as this is the way the rain would wash it off.

 

 

[MrWolf]

That I will be trying, I have used washes in the past to good effect and the first thing that you are ever taught about the use of colour at art college is never, ever use pure black or pure white. Even if you are painting something that is in reality black or white, it doesn't scale down and looks plain wrong.

[bécasse]

The darkening on the prototype was more the result of a chemical reaction (hydrogen sulphide in the atmosphere converting some of the lead oxide in the paint to black-ish lead sulphide) than of the effects of soot, etc. Rain would have had a washing effect on soot deposits but rain actually helped the chemical reaction. The net result is that the "weathering" should be reasonably consistent over the whole roof although soot, etc deposits would tend to gather just above any rain strips and around ventilators.

[richbrummitt]

8 hours ago, Siberian Snooper said:

I just brush on roof dirt paint Railmatch 2403 or Lifecolor UA 722  with a little thinners, it's better to use thin coats and build up layers, until satisfied and allow each layer to dry before applying the next one. I also add a little cream or dark grey to add a bit of variation. Oh and brush across the roof rather than lengthwise as this is the way the rain would wash it off.

 

 

 

I work largely as above with paint from alternative sources. I also brush paint the roof first with the final brushing side to side only. This gives some texture for the washes (mid grey paints) that follow to sit in. When applying the washes I blot them with tissue or kitchen paper and build up gradually to reduce the appearance of lines. Sometimes I dry brush a bit. I use acrylics so that I can work fairly quickly between coats and change things by washing with water if it all goes wrong (obviously before it dries). 

 

Here's an example of various levels of dirty rooves done this way.

[NCB]

I take cans of Halfords white and grey acrylic undercoat, and spray them alternately, using several light passes. Doing it while the paint is wet means that the droplets tend to merge, so the result is reasonably smooth, and you can use more of one or the other to vary the shade. Here are GWR V4, V12 and V14 vans:

You can also apply the odd light wash afterwards if you want to.

Nigel

Edited February 13, 2020 by NCB

[MrWolf]

Thank you all, this is exactly the level of scruffiness I have been looking to achieve. I have a number of vehicles to go at, so I had better get the workbench cleared and work on them as a batch.

[Compound2632]

9 hours ago, bécasse said:

The darkening on the prototype was more the result of a chemical reaction (hydrogen sulphide in the atmosphere converting some of the lead oxide in the paint to black-ish lead sulphide) than of the effects of soot, etc. Rain would have had a washing effect on soot deposits but rain actually helped the chemical reaction. The net result is that the "weathering" should be reasonably consistent over the whole roof although soot, etc deposits would tend to gather just above any rain strips and around ventilators.

 

This also implies that white may not be the most appropriate base colour to start from - a dark grey tending to black may be better for a van that has been some years in service. 

 

A couple of photos at Hockley Goods Station:

https://www.warwickshirerailways.com/gwr/gwrhd691b.htm

https://www.warwickshirerailways.com/gwr/gwrhd756.htm

seem to me to show a variety of uniform dark shades; in the first picture the one recently-painted white roof sticks out like a sore thumb.

[57xx]

On 12/02/2020 at 19:05, MrWolf said:

Also, I don't as yet possess an airbrush, it's something that I just don't use with my regular artwork. Perhaps I should get one, but that opens the which one?

 

I would say that, yes, now could be the time to take the plunge and get an airbrush. As Becasse has pointed out, the chemical reactions in the paint would cause a more uniform colour change. I find using an airbrush to get that base tone better than brushing. You can then use washes on top of that for any dirt gathering in nooks and crannys like rain strips or vents.

 

Also don't forget that "clean" white roofs were a lot more common than people make out, so don't go overboard making them all really dirty. Just have a browse through Britain From Above and you will find plenty of pics like the one here.

[NCB]

Indeed. There's a well-known pic of Old Oak Common carriage sidings, in the 1930s I think, where there quite a lot of white roofs, not many really dark, and most in between.