# ASTM A780/A780M

Source: https://coatmentor.com/standards/astm-a780/ · Updated 2026-10-14

Touch-up and repair of bare or damaged spots on hot-dip galvanized steel.

**Publisher**: ASTM International

**Area**: Metallic coatings and cathodic protection

ASTM A780/A780M gives the ways to repair galvanizing damaged by welding, cutting or handling, and areas the zinc did not cover. The current edition is A780/A780M-20.

## Three repair methods

- **Zinc-based solder:** a low-melting zinc alloy rod or powder, worked onto the preheated area.
- **Zinc-rich paint:** a paint with a high zinc content in the dry film, organic or inorganic.
- **Sprayed zinc:** thermal spraying of zinc wire or powder (metallizing).

## What the inspector checks

The repair must reach the specified thickness and should protect the steel as zinc does. A zinc-rich paint repair is applied thicker than the galvanizing around it. The galvanizing specification, such as ASTM A123, sets how large an area may be repaired.

**2** practice items in the members area mention ASTM A780/A780M (CIP 2: 2).

## Related

- **Concepts:** [Zinc-rich primers](https://coatmentor.com/learn/zinc-rich-primers/) · [Galvanic corrosion](https://coatmentor.com/learn/galvanic-corrosion/)
- **Standards:** [ASTM A123/A123M](https://coatmentor.com/standards/astm-a123/) · [ISO 1461](https://coatmentor.com/standards/iso-1461/) · [ISO 2063](https://coatmentor.com/standards/iso-2063/)

## About this page

This page describes the subject of ASTM A780/A780M in our own words; it does not reproduce the standard. For the full text, buy the current edition from ASTM International. Checked on 2026-10-14; errors go in the [corrections log](https://coatmentor.com/method/). CoatMentor is an independent study aid. It is not affiliated with ISO, AMPP, SSPC, NACE International, ASTM or FROSIO.