Custom G-Gauge Rolling Stock – A Guide to Modifying Milk Tankers

Custom G-Gauge Rolling Stock – A Guide to Modifying Milk Tankers

With the run-up to Christmas, I had some time off work. I decided I’d like to spend some time kit-bashing some Newqida Tank Wagons. Kit-bashing, for those of your new to the term, involves modifying something built ready to be closer to what you want on your railway. This could be buildings, locomotives or, in my case, wagons.

I decided to try my own hand at bashing some wagons after being inspired by the incredible creations of other members on the G Scale Central forums. This is my first attempt at doing something like this and I learnt a lot in the process which I hope can help you too if you decide to try something similar.


I recently found a seller on eBay here in Germany that seems to have a good supply of Newqida stock. I was able to buy x4 tankers for around €75 (~£68). [Here is his page if anyone is interested. Not sure about international shipping charges]. These were the same tanker wagons I wrote a brief review of on a separate post.

The original wagon that will be modified.


For my fiancé and I, it has always been important to personalise the railway with nods the people, places and memories important to us. The broad theme/era is continental steam around the area of southern Germany, Austria and Switzerland. The plan is to convert 4 fuel tankers into milk wagons (or at least, my interpretation of them). They will each be liveried slightly different depending on what they represent.

  • Home Farm Dairy – is a dairy farm in Jersey, Channel Islands.
  • Goose Rocks Dairy – is an Ice Cream parlour in Kennebunkport, Maine, USA that my fiancé visited a lot of a kid
  • Jersey Dairy – the dairy processor for all of Jersey’s milk.
  • Starbucks – Because my fiancé loves it and it’s part of our Sunday morning dog-walk tradition

For the first two, I’ve mocked up some logos/text as they didn’t have any quality ones to hand and for Starbucks I took their logo from a quick Google search Finally, Jersey Dairy were kind enough to provide a vector file of their logo. I will print them on waterslide paper using a laser printer. I’ve tried this once before and it worked out well but I didn’t seal it resulting in them silvering (going white-ish) – lessons have been learnt!


Although the wagons were cheaper than the usual LGB or Piko stock, I still didn’t want to be wasteful. Before I started I scoured the G Scale Central forums for various posts on basic kit-bashing, spray-painting and decals augmented with a healthy amount of YouTube videos.

In all, there are 5 steps to follow:

  1. Disassembly
  2. Cleaning & Preparation
  3. Painting
  4. Decals
  5. Varnishing


1. Disassembly

Before we begin, disassemble the wagon to the smallest elements you need. In my case, I removed the chassis, tank, the panels and the access ladders. These were mostly held on by screws on the underside of the wagon. Also, be sure to remove small detailing such as the tap on the bottom nozzles and the cap that seals the top. The tap will remain black so doesn’t need painting and the cap and latch should be painted separately to ensure an even coat. For most of the modification, we’ll be focused on the tanker so put all the other pieces somewhere safe (and don’t just leave them on the dining table like I did…)

2. Cleaning & Preparation

In this stage, we’re going to do three main tasks:

  • Removing the existing lettering
  • Fixing the tanker sections together
  • Cleaning the surface

If you don’t remove the existing lettering, it will show through after painting, ruining the effect. There were a few methods listed online to remove the lettering including using car breakfluid, sandpaper and a fibre glass pen. I opted for the fibre glass pen as it seemed the most controlled and I was really happy with the results.

Use the fibre glass pen to scratch away the lettering. I found I had to keep rotating the pen pen to keep up its effectiveness and then tapping the end to remove some of the paint/plastic dust. You’ll see the pen scratching the plastic – don’t worry about this as the paint will cover the areas evenly leaving it smooth again. One thing to be careful of is the fakes that come up. Fibre glass causes splinters and I got a small bit stuck in my finger. Be sure to clear your work area well after you’re done.

You can just see in the picture above the join between distinct section on the left and middle (where the trim comes to a +). A mistake I made on my first couple of attempts was not fixing theese different sections of the tanker together. The result was very small gaps that the paint dripped in to. A fix for this is either using a glue-gun or plastic cement (as you find in model kits) to seal the sections together.

Finally, give the body a through wash. I used warm, soapy water in a sink to wash off the body to ensure there was no dirt and dust prior to painting.

3. Painting

This was perhaps the stage I was most nervous about having never spray painted anything before. However, once you’ve got the basics this is a really effective way to paint your models quickly to a reasonably high quality.

It’s important to note that spray painting is not appropriate for detailing. It’s a way to cover a large surface area quickly and evenly when you want to recolour. If you’re painting on a dark or vivid colour with a lighter colour (like I did with green to white/cream) – it will take several coats to complete.

Before applying any paint, you need to spray the surface with a Primer. This gives the spray paint something to adhere. The same advice for spray paint applies to primer – a couple of thin coats in long fluid motions. Be sure this is done and dried before proceeding with the paint.

The main piece of advice I have here is go slow and be patient. Many thin layers will look much better than one (or two) thicker layers. This is because there is less risk of the paint running and globing together (which is even more likely on cylindrical shapes like a tanker wagon)


  • Protect your mouth/nose and do this is a well ventilated area!!
  • Shake the can for at least 30seconds first
  • Don’t use a cold can of spray paint – ensure it is room temperature
  • Spray a test blast on cardboard/plastic before hand to ensure the paint is flowing smoothly
  • Spray from approximately 30cm (~12inches) away from the target
  • Move the spray can smoothly in long, fluid movements length ways across the target before repeating perpendicularly
  • Press down fully on the nozzle, a light press and result in the can spluttering leaving visible drops
  • Place the target on a slightly raised surface
  • Keep the layers thin
  • Again, keep the layers thin
  • Leave to dry inside where it is warmer and there is less risk of dirt (or bugs) sticking to the paint

There are many fantastic (and short) videos on YouTube that will help you visualise the technique so watch a few before attempting if you’re new to this.

In my first attempt, I made two big mistakes:

  1. My layers were too thick (I was excited and impatient)
  2. I was painting outside in the cold (~0°C) and leaving them there to dry.

These mistakes together resulted in the paint grouping and dripping down the side of the wagon (think about the condensation on the outside of a beer glass in summer.) This was easy enough to get off but definitely resulted in more time and effort. If you do make the same mistake as me, you can use fine grit sandpaper to smooth off the markings. This can take a while to smooth out. Once you have, wipe over with a damp cloth to remove any dust and continue to apply (thiner!) layers of paint.

How to correct your mistakes – sandpaper and few more layers of paint.

For the Starbucks tanker, I wanted to get a little more creative and have the body be white and a dark green on the belly of the tanker as well as the seals similar to the picture below:

I decided to do this by first painting the whole taker white and using painters tape (masking tape) to protect the areas I didn’t want painted. I had read this wasn’t always reliable but wanted to give it a shot. The main tips I read for doing this was to ensure that once you’ve applied the tape, give it another spray in the same base colour (in my case, white) as this will create a seal between the tap and the actual base layer. Then you’re free to apply your next layer. Honestly, this worked reasonably well in most places but there were a couple of locations where the masking tape has come away leaving small (but noticeable) blasts of green on the white base. For these, I painted over by hand using white enamel paint.

4. Decals

There are two main parts of this step. The first is to create and print the decals and then the second is to apply them. The first step can be done in parallel to the painting while you’re waiting for those multiple layers to dry.

Creating Decals

I created the decals myself. For Goose Rocks and Home Farm as neither had high resolution images I could use of their logos I created my own interpretations of them. Starbucks, fortunately, I had many options available online. An important thing to remember here is you cannot print white. Any white in an image will be blank when printed.

I arranged the collection of images on a page (you can use Microsoft Word). Ensure they’re approximately the correct size each. From here, you’re ready to print.

Screenshot of the app I used to create the decals

Printing Decals

It is possibly to print your own decals at home using an inkjet or laser jet printer. You do, however, need a special paper which is easily found on Amazon by searching “waterslide paper”.

Before printing on the (not so cheap) waterslide paper, I recommend using normal paper first. This helps you ensure everything is readable and approximately the correct size.

There are some difference between using an inkjet or laser jet printer. If you’re printing using an inkjet printer you will need to seal the ink following the manufacturers instructions before applying the decals. For laser jets, I found the ink has a tendency to smudge while printing (especially in large blocks of colour) and can leave residue for the second sheet you print. For this reason, I recommend printing a blank page in between the sheets you print.

For both, printers, the ink can take a few minutes to dry so be extremely careful handling it.

Applying Decals

I remain convinced this is a dark art and, candidly, was the hardest part for me. There are a number of great youtube videos online but I will outline here.

  1. Cut the decal to the side – try to keep the share as close to the outline of the decal as possible and avoid regular sharp turns as it will make it much harder to apply
  2. Add a thin later of water to a plate and add the decal. It will curl – this is fine – and use a clean paint brush to push the sides into the water ever 30seconds or so
  3. In parallel, use a Decal Fix (I used one from Humbrol) to clean and prepare the area. This helps the decal adhere to the surface
  4. Lift the decal from the water still one the paper using tweezers or similar (I used my fingers but it definitely made it harder) and position approximately in place.
  5. Use the clean paintbrush to draw the decal off the paper and move the paper slowly along the surface of the target – you want to the decal to be a close as possible as it moves onto the tanker
  6. Use the paintbrush to position and remove bubbles from the decal.
  7. Apply a layer of decal solution over the top to finish
  8. Leave to dry.

5. Varnishing

Before varnishing, find an area and a spare decal to test. I used the underside of the tanker first and was thankful I did. the original varnish I used caused the paint to splinter and the decal to fade. Turns out, I had ordered the wrong varnish.

In the end, I used Humbrol No. 35 Acrylic Varnish Gloss. It is applied in the same way as the spray paint – approximately 20-30cms away from the target in smooth, long motions. Apply thinly and leave to dry. In total, I applied 3 coats.

The Finished Product

With all that – reassemble the wagon. I decided to leave some parts off. The panels that listed the contents and destination. This was intentional as I liked the simpler style of the tankers. If you want to keep them but don’t want to use them as fuel tankers, I’d recommend scratching off the lettering as in Stage 2 and instead spraying them black.

Special thank you to the community as G Scale Forum for their advice, tips and support!

Appendix – Used Supplies

  • Fibreglass Pencil
  • Fingrit Sandpaper (240+)
  • Plastic Primer
  • Humbrol 35 Acrylic Gloss Varnish
  • Humbrol Decal Fix
  • Acrylic Spray Paint in colour(s) of choice
  • Waterslide Decal Paper for Inkjet/Laserjet printers
  • Plastic/Cardboard for spraypainting

Appendix – Useful Links