Metal Pickling: Acid Chemistry, Inhibitors and Bath Control

Pickling removes oxides, mill scale and rust before phosphating, galvanizing, painting or welding. Industrias Trevigo supplies formulated pickling acids with inhibitors, defines your process parameters, and keeps your baths under control — with continuous chemical supply from Monterrey to plants across Mexico.

The right acid for each substrate

Acid selection and concentration depend on the metal:

Carbon steel: hydrochloric (15-25%) or hot sulfuric (10-15%) systems depending on volume and geometry.
Galvanized steel: specially inhibited formulations that strip oxide without consuming the zinc layer.
Stainless steel: nitric-hydrofluoric or nitric-phosphoric blends to remove free iron and heat tint.
Aluminum: caustic etch followed by nitric desmut.

Inhibitors: the difference between cheap and expensive pickling

A pickling inhibitor stops the acid from attacking clean base metal while it keeps dissolving oxide. The result: 20-40% longer bath life, less metal loss, less hydrogen absorption (critical on high-strength steels) and lower cost per part. Our acid blends come pre-inhibited, or we dose inhibitor into your existing bath after a process diagnosis.

Supply and waste guidance

We deliver in 50 kg carboys, 200 kg drums and 1,000 kg totes across Mexico, with scheduled weekly deliveries in the Monterrey area. We also advise on neutralization and connect you with authorized hazardous-waste handlers for spent baths, in compliance with Mexican regulation (NOM-052-SEMARNAT).

Frequently asked questions

Can you define the pickling process for a new line?

Yes. We run a no-cost diagnosis with your actual parts, define acid type, concentration, temperature and immersion time, and deliver a process sheet with projected chemical consumption and cost per kilogram of oxide removed.

How do we know when to dump the bath?

When dissolved iron exceeds roughly 30-50 g/L (depending on the acid), pickling speed drops to 20-30% of optimum. We monitor your bath weekly and tell you when to regenerate or replace — before quality or cycle time suffers.

Do you ship outside the Monterrey area?

Yes. We ship pallets and totes across Mexico. Nearshoring plants in Saltillo, the Bajío corridor and the border region are within routine delivery range.

Setting up or relocating a line in Mexico?

Get a no-cost process diagnosis from our bilingual technical team — we answer in English within one business day.