Chemical etching (or chemical milling) at Iron Forge Creations (IFC) in Mahim, Mumbai, is used to execute high-precision surface engraving, recessed patterning, and delicate motifs across sheet metals without causing thermal stress or mechanical distortion.
Unlike CNC laser cutting or mechanical engraving, chemical etching relies on controlled chemical reactions to dissolve exposed areas of metal, leaving smooth, highly detailed recessed textures or complete cut-outs.
Technical Etching Process at IFC
The workflow uses vector graphics and photo-resist masking to ensure exact transfer from digital design to metal substrate:
- Vector Artwork Prep ➔ 2. Surface Cleaning ➔ 3. Photo-Resist Masking ➔ 4. Chemical Bath ➔ 5. Neutralization & Polishing
- Digital Layout & Vector Prep: Patterns, typography, or architectural graphics are vectorized in layout software (such as CorelDRAW) to create precise high-contrast film masks.
- Surface Cleaning & Degreasing: Metal sheets (brass, copper, stainless steel, mild steel, or aluminum) are mechanically abraded and chemically cleaned to ensure complete adhesion of the resist layer.
- Photo-Resist Application & Exposure: A light-sensitive photo-resist film or acid-resistant masking material is applied to the metal sheet. The masked design is UV-exposed and developed, leaving the target pattern areas bare while protecting the rest of the sheet.
- Controlled Chemical Bathing:
- Ferric Chloride / Acid Etch Solutions: The sheet is treated in controlled chemical spray tanks or baths. The chemical selectively eats away the unprotected metal to the required depth.
- Depth & Relief Control: Etch depth is strictly monitored—ranging from shallow decorative engraving (0.1 mm to 0.5 mm) to deep relief or complete chemical perforation.
- Mask Removal & Neutralization: The etched sheet is thoroughly rinsed, neutralized to halt chemical reaction, and stripped of the protective resist layer.
- Post-Etch Finishing & Infilling: The recessed regions are often infilled with contrasting paints, resins, or patinating agents (e.g., blackened steel or aged brass patina) followed by mirror or satin buffing on the raised surfaces.
Suitable Metal Alloys
Metal Alloy | Typical Etchant | Common Surface Finish & Infill |
Brass & Bronze | Ferric Chloride / Ammonium Persulfate | Antique distressing, black oxide infill, satin polish |
Stainless Steel (304 / 316) | Ferric Chloride / Acid blends | High-contrast black enamel, brushed or mirror polish |
Copper | Ferric Chloride | Natural verdigris patina or clear lacquered contrast |
Mild Steel | Acid bath solutions | Blackened oxide rust-inhibited finish |
Key Applications at IFC
- Architectural Wall Cladding & Jali Screens: Intricate geometric panels, latticework, and room dividers where mechanical tools might distort thin sheet metal.
- Decorative Metal Inlays & Trims: Custom accents integrated into wooden daybeds, table tops, cabinetry, and door frames.
- Signage, Nameplates & Brand Plaques: High-durability corporate logos, tactile signage, and luxury metal nameplates.
- Textured Furniture Surfaces: Patterned metal drawer fronts, tabletop panels, and sculptural feature walls.
