3 Simple Techniques to Achieve Realistic Rust Effects

In this guide I will show you three simple techniques to achieving a realistic rust effect using acrylic paints, texture paste and Humbrol weathering powders. These methods can be used to weather flat or 3d surfaces, such as the 3-d printed anchors I have used in my examples, and you can apply as much or as little as you like to vary the amount of rust.

INGREDIENTS:

• AX170-OO (Large) Anchors for Harbour and Ship Detailing
• Humbrol Weathering Powders 9 Pack
• Acrylic paint 
• Winsor & Newton Sand Texture Gel
• Small paintbrushes
• A suitable reference photo

TECHNIQUE 1 - ACRYLIC PAINT ONLY

I have used the following colours of acrylic paint for this method because they are the closest I had to the reference photo I was using  (although of course you can use whichever colours you prefer) -  Payne's grey, burnt umber, burnt sienna, Venetian red, yellow ochre.

The first colour to apply to the object you are weathering  for rust is always Payne's grey (which is a dark blue-grey colour and much less harsh than black, although you can use black if that's what you have to hand), and should be quite a thin coat. Once that's dry, build up the other colours using a stiff, blunt ended brush ( I cut the end off my bristles with a craft knife to get the shape I wanted) and apply a very small amount of paint at a time using a stippling effect and allow to dry between coats.

 Layer the colours from dark to light and back again, finishing with a very sparse dry brushed layer of Payne's grey. (To dry brush, dip your (bone dry) brush in the paint and then wipe most of it off onto some paper 🤨. Sounds bonkers I know but it works! Build up the layers of colour a tiny bit at a time)

This will give a finish with no texture to speak of but is very good if you are weathering a flat surface or one with only light rusting.

TECHNIQUE 2 - SAND TEXTURE GEL AND ACRYLIC PAINT

Begin with a coat of texture gel on it's own (apply quite a thick coat in areas to give a lumpy appearance if you like), allow to dry and then stipple on acrylic paint using the same technique as Method 1 above.

To achieve an even rougher surface you can mix each paint colour with some texture gel and apply the same way; I usually go for a ratio of 50/50 paint - texture gel. Allow to dry between coats.

The image below is my finished piece, and as you can see is very different from the method using just acrylic paint. I definitely favour this result!

METHOD 3 - ACRYLIC PAINT AND HUMBROL WEATHERING POWDERS

Apply a first (thin) coat of Payne's grey and allow to dry. then, using the stippling method as before, put on your paint in layers but this time apply a weathering powder to each layer WHILE THE PAINT IS STILL WET.  Match each weathering powder to the nearest paint colour, here's what I used -

Weathering Powder Colour                     Acrylic Paint Colour

Dark Earth                                                            Burnt Umber

Dark Rust                                                              Burnt Sienna

Iron Oxide                                                             Venetian Red

Light Rust                                                              Yellow Ochre

Sand                                                                          Yellow Ochre

Try out different combinations and see what works for you. I highly recommend using separate brushes for paint and powders otherwise you will end up with tubes of powdery paint and pots of painty powder!

You can be quite generous with the powder, especially if you combine it with a fairly this layer of paint.

The final layer will be dark rust, and it gives a good contrast when you apply it onto the lightest layer.

I really hope you have fun with these techniques, and I look forward to seeing what you achieve!