---
title: "Cast Iron & Sand Casting Cleaning"
url: "https://www.kolene.com/application/cast-iron-sand/"
description: "Kastech® Electrolytic molten salt removes burned-in sand, scale, and graphite from iron castings and internal passages. We also process castings in Detroit."
site: "Kolene Corporation"
updated: "2026-09-25T04:30:43+00:00"
breadcrumbs: "Home > Applications > Cast Iron & Sand Casting Cleaning"
---

# Cast Iron & Sand Casting Cleaning

## Electrolytic Removal of Sand, Scale & Graphite

![Cast Iron & Sand Casting Cleaning](https://www.kolene.com/wp-content/uploads/2024/02/castiron_sand.webp)

Kolene® Kastech® Electrolytic removes burned-in sand, scale, and surface graphite from iron sand castings.

Kastech Electrolytic is chemically neutral without applied direct current. When current is applied, the workpiece is oxidized during anodic cycles and reduced during cathodic cycles. Appropriate polarity and processing time remove graphite, scale, and burned-in sand from external surfaces and internal passages.

The process is also effective in preparing iron surfaces for brazing or babbitting.

Castings are racked or fixtured so the salt reaches every internal passage (no air pockets) for complete cleaning, and so all molten salt drains freely out of the castings after processing.

### Sand removal

After mechanical shake-out, residual sand may remain in internal passages. Critical components such as hydraulic or pneumatic valves and cylinders can fail when remaining sand breaks free. Scoring of seals and spindles can quickly destroy the components. As-cast scale and oxide can impede good thermal transfer, especially important in engine heads and blocks.

Both sand and scale can be removed with a simple reducing cycle in the Kastech Electrolytic process. Surface scale is chemically reduced, helping to expose burned-in sand. The electrolysis helps dissolve any exposed sand. Treatment time depends on the amount of scale, sand, and graphite to be removed.

![Diagram: original cast iron surface with surface oxide, burned-in sand and exposed graphite](https://www.kolene.com/wp-content/uploads/2024/05/CastingDiagram1-1024x789.webp)

![Diagram: after the first reduction cycle, oxide and sand are removed and graphite is still intact](https://www.kolene.com/wp-content/uploads/2024/05/CastingDiagram2-1024x789.webp)

### Brazing or babbitting

If you are brazing or babbitting iron sand castings, Kastech Electrolytic can improve bond strength. The bath electrochemically oxidizes exposed surface graphite to produce carbon dioxide. At the same time, any casting oxides are gently converted to a uniform ferric oxide.

Once the graphite has been removed, the polarity of the charge is reversed. This reduces the ferric oxide and leaves an oxide-free surface. Any exposed sand is removed simultaneously during both oxidation and reduction cycles.

If you will braze or babbitt to a *machined* iron surface, we recommend machining before the Kastech Electrolytic process. Machining after salt bath cleaning re-exposes fresh graphite and cancels the bonding benefit.

![Diagram: after the oxidation cycle, exposed sand and graphite are removed under a uniform bath oxide](https://www.kolene.com/wp-content/uploads/2024/05/CastingDiagram3-1024x789.webp)

![Diagram: after the final reduction cycle, the surface is free of scale, sand and graphite](https://www.kolene.com/wp-content/uploads/2024/05/CastingDiagram4-1024x789.webp)

![Diagram: after brazing or babbitting, the alloy fills the voids to form a stronger bond](https://www.kolene.com/wp-content/uploads/2024/05/CastingDiagram5-1024x789.webp)

We also remove sand and graphite from cast iron castings with the Kastech Electrolytic process at our Detroit plant. See [Commercial Processing](https://www.kolene.com/service/commercial-processing/).

Equipment

[Electrolytic](https://www.kolene.com/equipment/cleaning-systems/#electrolytic-salt-baths)

Literature

[Kastech® Electrolytic](https://www.kolene.com/wp-content/uploads/2024/05/9_Kastech__Electrolytic.pdf)

[Molten Salt Cleaning of Cast Irons](https://www.kolene.com/wp-content/uploads/2024/03/10_Molten_Salt_Cleaning_of_Cast_Irons.pdf)

[Corporate Overview](https://www.kolene.com/wp-content/uploads/2024/03/1_Corporate_overview-1.pdf)

[Process and Environmental Overview](https://www.kolene.com/wp-content/uploads/2024/05/2_Process_and_Environmental_Overview.pdf)

Products

[Kastech® Electrolytic](https://www.kolene.com/product/cleaning-chemicals/#chemical-kastech-electrolytic)

[KGC™](https://www.kolene.com/product/cleaning-chemicals/#chemical-kgc)

[KLC™](https://www.kolene.com/product/cleaning-chemicals/#chemical-klc)

[Play video for Cast Iron & Sand Casting Cleaning](https://www.youtube.com/watch?v=zW-2Gvv-Ebk)

Have parts like these? Tell us the alloy, the coating or residue, and your volume, and we will recommend a salt, a system, or processing at our Detroit plant.

[Contact us](https://www.kolene.com/contact/?interest=Unsure) [Request a processing quote](https://www.kolene.com/contact/?interest=Commercial%20Processing)

KOLENE® and KASTECH® are registered trademarks/service marks of Kolene Corporation. KGC™ and KLC™ are also trademarks/service marks of Kolene Corporation.