A single, integrated workshop-style guide for modelling coal‑tar creosote railway ties at 1:35 using Abteilung 502 oil colours (Bitume, Smoke, Industrial Earth, Cassel Earth, Starship Filth, Buff, etc.). Includes precise drop recipes, step‑by‑step application, airbrush variants, troubleshooting, and a printable cheatsheet/bench‑card-ready section.

---

Quick overview & intent

• Scale goal: make creosote look believable at 1:35 — mostly dark stain with tiny glossy pools and gritty dirt, not an all‑over glossy tarp. Small gleams and subtle tonal shifts sell the effect.
• Three core tasks in this article:
  1. Fine checks & cracks (hairline washes) that read at scale.
  2. Coal‑tar creosote surface washes for ties — thin body, runs, and localized pooling.
  3. Dust veil over the rail rust patina (Buff‑based) to mute and integrate bright rust.

---

Materials & tools

• Abteilung 502 oils: Bitume, Smoke, Industrial Earth, Cassel Earth, Starship Filth, Buff, Yellow Ochre, Raw Sienna, Lamp Black (optional), Titanium White (tiny speck).
• Solvent: OMS (odorless mineral spirits).
• Brushes: rigger/liner 000–1, small round 1–2, soft flat 2–4, soft fan or hake for dust, soft toothbrush (stipple/flick).
• Other: glass palette/tile, toothpicks, cotton buds, paper towels, dropper (optional for consistent drops), masking tape for railheads, nitrile gloves, ventilated area.
• Optional: linseed (tiny amounts for local gloss), alkyd medium (speeds drying — test first).

Drop note: “Drop” is a small, repeatable unit. Roughly 1 drop ≈ 0.03–0.06 mL depending on squeezing pressure/tube. If you prefer ml, multiply accordingly.

---

How to think about the colours

• Bitume: primary coal‑tar/bitumen black — backbone for creosote and soot.
• Smoke: cool neutral grey — tones down/neutralizes black for scale reading.
• Industrial Earth: warm, gritty brown — dirt & stain undertone.
• Cassel Earth: deeper warm brown — useful for warm pooling and stain around hardware.
• Starship Filth: greasy brown‑black — best for oily streaks and glossy pooling accents.
• Buff: base for pale dust veils — mixes well for brush or airbrush dust.

---

STEP 1 — Checks & Cracks (Fine hairline wash)

Objective: settle fine dark lines into hairline cracks, knot checks and bolt holes so they read as depth at 1:35 without appearing oversized.

Crack wash recipe (base)

• Bitume: 2 drops
• Cassel Earth: 0.5 drop (a toothpick dot) — warms the black slightly
• OMS: 20–25 drops (start with 20; add for thinner ink‑like flow)

Consistency: ink‑thin, flows easily into cracks but still deposits tone.

Application — step‑by‑step

1. Ensure the tie base coat is matte and dust‑free.
2. Load a 000 rigger sparingly; wipe the stem so flow is controlled.
3. Touch brush tip at crack entry; let capillary action draw the wash in — don’t push.
4. After 5–15 seconds, remove excess on flats with a barely‑damp OMS cotton bud or rigger, dragging with the grain. Leave deeper deposits in the checks.
5. If a crack looks too stark, lift with a clean OMS‑damp brush and feather edges outward.
6. For sootier hairlines, use a purer Bitume mix (Bitume 3 : OMS 25).

Pro tips:

• For ultra‑fine hairlines, dilute +5–10 drops OMS.
• Slight warming (tiny Cassel Earth) prevents a flat, artificial pure black.

---

STEP 2 — Coal‑tar Creosote Wash (Surface body, runs, pools)

Objective: create believable tarry staining — dark, slightly warm overall stain with localized oily/glossy pools and streaks.

Creosote — Base surface wash (first thin pass)

• Bitume: 4 drops
• Smoke: 2 drops
• Industrial Earth: 1 drop
• OMS: 25–35 drops

Consistency: thin, translucent — lets base wood grain read while darkening and toning the tie.

Application — step‑by‑step

1. Mask running rails/parts you don’t want darkened.
2. Apply the wash with a soft flat or wide round, working with the grain. Use a light stipple/drag motion on ends to suggest uneven application.
3. Within 10–30 seconds remove excess with an OMS‑damp paper/towel and drag with the runoff direction — this leaves darker pools in recesses and lighter streaks on flats.
4. Use a rigger to pull thin vertical streaks from bolt heads or tie‑plate edges; feather or lift edges while still wet for realistic runoff.
5. For heavier localized build (where creosote pools), make a second local pass with the heavier accent mix (see below).
6. Let cure (24–48 hrs for thin washes; longer if linseed used).

Localized pooling & oily streak accents

• Starship Filth: add 1 drop locally (mix with a little OMS on palette) — apply sparingly for glossy pool accents.
• Cassel Earth: add 0.5–1 drop in local mixes to warm pools where dirt has mixed with tar.
• Optional gloss: a single drop of linseed in a local mix will increase sheen — use very sparingly and only where you want a tiny bright gleam at scale.

Application tips for pools & streaks

• Apply Starship Filth with a rigger or small round only to the lowest areas (tie ends, around bolt holes).
• Feather edges with an OMS‑damp soft brush to avoid blobbery.
• Keep most of the tie surface matte — small glossy flecks or thin pools read far more realistically at 1:35 than broad glossy areas.

Variants

• Cooler, sootier ties: increase Smoke or Bitume ratio.
• Heavily soiled ties: increase Industrial Earth for dirt mixing, or apply a very thin speckled stipple of Industrial Earth after the main wash.

---

DUST WASH — Buff over rail rust patina

Objective: apply a thin veil of dust to mute bright rust and integrate the rail into the environment. Buff is the primary dust colour; mix options given for warmth or neutralization.

Buff dust wash (brush method)

• Buff: 3 drops
• Yellow Ochre or Industrial Earth: 0.5–1 drop (optional — warmer dust)
• Smoke: a pinch (optional to neutralize bright yellows)
• OMS: 18–25 drops

Consistency: translucent veil; not opaque.

Application — step‑by‑step

1. Ensure the rust patina is fully cured.
2. Load a soft fan or soft flat with a barely wet brush. Lightly sweep in long, even passes across the rail head.
3. Use 2–3 ultra‑light passes (let each dry 30–60 min). Rust should peek through.
4. For ballast/rail foot micro speckling, use a soft toothbrush flick or small round stipple.
5. If the dust dries too bright/chalky, tone back with a hairline glaze of Industrial Earth (1 drop Industrial Earth : 8–10 OMS) and feather over the dust to unify.

Airbrush variant (smoother veil)

• Add +8–12 drops OMS (total OMS ≈ 26–37) to the Buff dust wash and airbrush low pressure in micro‑sprays. This is the most scale‑correct method for railheads and long runs.

Dust intensity controls

• Paler dust: add a tiny speck of Titanium White (use very sparingly — kills transparency).
• Dirtier dust: add 1 drop Industrial Earth or 0.5 drop Smoke.

---

Application flow & timing suggestions (sample order)

1. Complete base painting of ties and rails; let cures where needed.
2. Crack wash (Step 1) — do first so checks read under later stains.
3. Creosote base wash (Step 2) — thin first pass across ties.
4. Remove excess, feather, and then add localized pools/Starship Filth accents.
5. Allow to cure.
6. Apply Buff dust veil over rails and tie tops where dust collects.
7. Final feathering and a very light matte varnish over ties (avoid sealing local glossy pools if you want shine on those spots). Mask rail running face if you want a shiny steel strip.

---

Troubleshooting & fixes

• Wash won’t wick into a crack: add a drop of OMS at the crack entry to help capillarity, or open the crack slightly with a toothpick.
• Too heavy in cracks/pools: lift immediately with an OMS‑damp brush or cotton bud, then retouch the surrounding wood with a thin glaze of base colour if needed.
• Excessive gloss: remove linseed from mixes on future passes; blot and feather with OMS; finish with a matte varnish over the surrounding area, leaving tiny pools alone.
• Chalky dust: tone back with a thin glaze of Industrial Earth.
• Slow drying: tiny amounts of alkyd medium speed drying — test first on scrap.

---

Cheatsheet — copyable recipes

• Crack wash: Bitume 2 : Cassel Earth 0.5 : OMS 20–25
• Creosote base wash: Bitume 4 : Smoke 2 : Industrial Earth 1 : OMS 25–35
• Pool accent: add Starship Filth 1 (locally) or Cassel Earth 0.5–1 for warmer pools; tiny drop linseed for gloss.
• Buff dust wash: Buff 3 : Yellow Ochre 0.5 : Smoke pinch : OMS 18–25 (add +8–12 OMS for airbrush)

---

Pro tips & finishing notes

• At 1:35, less is more with gloss — tiny bright flecks sell oil better than broad shine.
• Vary the undertone across ties by alternating small local additions of Cassel Earth or Industrial Earth to avoid visual monotony.
• Airbrushing the Buff dust mix at low pressure produces the most natural veil on long rail runs.
• Make a small bench card with these recipes (A5) and keep it at the bench for fast reference.

---