What is a weathering wash?

A weathering wash is a very diluted paint (typically enamel or oil-based) applied over a sealed base coat. It flows into panel lines, rivets and recessed detail by capillary action, adding depth and realism. The excess is wiped away with thinner, leaving colour only in the recesses.

What dilution ratio should I use?

A typical wash uses a 5:1 to 8:1 thinner-to-paint ratio. More dilute washes are subtler and easier to control. For panel line washes, use 8:1. For general grime and weathering, 5:1 gives stronger effect. Always test on a spare piece first.

How many passes of wash do I need?

Light weathering needs 1 pass. Moderate weathering benefits from 2 passes with full drying between each. Heavy weathering on armour may need 3-4 passes with different wash colours for realistic grime buildup. Always allow complete drying between passes.

Do I need a clear coat before washing?

Yes, always apply a gloss or semi-gloss clear coat before weathering washes. The smooth surface helps the wash flow into recesses by capillary action. A matt surface absorbs the wash unevenly and creates staining that is difficult to control.

ModelCalcs

Weathering Wash Calculator — Wash & Weathering Product Quantities

Calculate wash volume, pigment amounts, enamel thinner and application passes for weathering model kits.

Model Scale

Select the model scale

Model Type

Select the type

Surface Area Estimate

Total surface to be weathered

Weathering Level

Select an option for weathering level

How We Calculate This

This calculator estimates weathering product quantities based on model surface area, weathering intensity and model type detail level.

The formula

Wash volume = (Surface area / 100) x Base rate x Weathering level x Detail factor

Pigment = Wash volume / Dilution ratio

Thinner = Wash volume - Pigment

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.