Part 4: Pigments and Powders

For this last part of this virtual demonstration I’m going to cover what you do once you have cleaned the airbrush and gone back to your model to finish it off.  Unfortunately due to the current mess we are living with I am going to have to rely for the most part on writing about it rather than being able to show you pictures of the finished product.

My tools of the trade here are the trusty Filbert brush and weathering powders, aka pigments.

If you look at the photos from the airbrushing lesson you will notice two things; first the “dirt” is probably a bit too even and uniform in appearance for true realism, and second there are none of the highlights (and lowlights) you might expect to see on, for example, the footsteps of the coach.  You rectify this by applying weathering powders over the airbrushed paint layer, but how do you successfully apply them? 

Well, the one thing you DON’T do is what I did the first time I tried!  My first attempt at using powders involved applying Humbrol powders to a mineral wagon and – without the benefit of a tutor – I simply dipped my ordinary brush into the jar and then applied it to the model.  Big mistake!  I wound up with way too much powder on the model, couldn’t get it off and almost gave weathering up as a bad job.  However, thanks to Mick Bonwick at Missenden Modellers I have learnt how to do it properly.

So, how do you do it properly?  Well, the first photo shows a PLASTIC bottle of a very finely ground powder – Ammo pigment “European Earth”.  The bottle is open. 

The second photo is a view of the lid of the bottle taken from above.  If you look at it carefully you will see there is a SMALL quantity of powder in the lid.  What I did to get this small quantity of powder in the lid was simply to bang the bottle hard on the table.  Explanation: Static electricity!  If you take a fine powder in a plastic bottle and agitate it (read as: bang it on the table) it takes on a static charge and a small amount of it will get attracted to the lid of the bottle.

If you dip the Filbert brush into this small amount of powder you will wind up picking up just the right amount of powder to use for the next step in the process.  However, you need to be using a very finely ground powder for this to work properly, there are a number of powders on the market that are, frankly, too coarsely ground to be able to make the light application that is needed.

So, dip your Filbert and with a small amount of powder lightly flick it across the things you want to highlight.  High points on the axle boxes, springs, coach steps and so on.  It is a matter of taste exactly where you place it, there is no right or wrong answer, what you are doing is creating an impression by breaking up the uniformity of the airbrushed layer of dirty paint rather than slavishly following a set formula. 

If you feel that you have put too much powder on or find that you have left a build up of powders on the model the way to remove it is NOT to attack it with the brush as this will only make matters worse.  The simplest way I find to get it off is to run up the spray booth extractor fan again and then with the airbrush (but no paint) simply blow the excess powder off into the spray booth filter. 

The final secret here: DO NOT OVERDO THIS FINAL APPLICATION…  Many a good weathering job has been ruined by an over-zealous final application of powders.

So choice of colours?  Well I typically have three colours handy:

  • A darkish rust colour
  • A lightish rust colour
  • A light dusty colour

Start dark and work towards the light.  The springs on any vehicle will be rusty, brush a bit of dark or heavy rust in here.  Next push a bit of dark rust onto various bits of the underframe, nothing too uniform, just pick up some of the highlights – or should that be the depths of the lowlights?  You decide. 

Now move to the lighter rust colour.  This can be used to represent dirt as well as rust.  Pick up one or two of the springs, maybe run some along the truss rods on the frame.  HAVE A LOOK AT A COUPLE OF PHOTOS!

Finally the dusty colour.  There will be places all over the lower area of any vehicle where people will be clambering up or down to access it while it is stationary and not alongside a platform, use the light dust powder to represent the wear that might be seen on the steps and running boards where the guard’s feet fall on these step points. 

And very finally, just look at the overall effect you have created; ask yourself, is there scope to just break up the evenness of the effect you have created a little more?  Just dust a little more of any of the colours you have used over the area you think could be broken up some more.