# Aluminum desmutters

Aluminum desmutter identities, supplied-product chemistry, property bases, and alloy-dependent limits of residual-smut removal.

Reviewed: 2026-10-29

Tags: chemicals, aluminum, pretreatment, finishing

## Identity and process role

Hubbard-Hall’s **Enerox F 108** bulletin describes an iron-based liquid containing nitric acid and fluoride. Caswell’s **ALDEOX** SDS lists sulfuric acid at 18% and sodium nitrate at 6%. Its acid ingredient name separately includes 90–98%, and the SDS leaves the percentage basis unstated. [F 108 bulletin](https://www.hubbardhall.com/document?id=2552007&type=TDS) [ALDEOX SDS](https://caswellplating.com/content/sds/Desmut.pdf) The formulations differ despite the shared desmutting role. Henkel identifies residual smut as potentially containing intermetallics, metals and metal oxides. [Henkel, printed pages 20–23](https://dm.henkel-dam.com/is/content/henkel/Aerospace_Surface-Treatment-Catalogue_2025-Spreads)

AUSCHEM describes desmutting after either caustic etching or acid bright dipping. Alloyed metal residue can remain after brightening. [AUSCHEM, De-smutting](https://auschem.com.au/news-post/de-smutting/)

**Synthesis.** Desmutting names the residue-removal function. Deoxidizing names oxide removal. A commercial product can perform both functions, but the combined name does not establish equal removal of every residue or suitability for every alloy. Henkel separately describes cleaners for dirt and grease, etchants that dissolve metallic aluminum, and conversion coatings that form a protective layer by chemical reaction. These are distinct purposes within surface finishing. [Henkel, printed pages 6–9, 16–17, and 24–25](https://dm.henkel-dam.com/is/content/henkel/Aerospace_Surface-Treatment-Catalogue_2025-Spreads)

## Named supplied products

These examples describe the identified product literature, not interchangeable formulations. The composition entries concern supplied products, not working baths.

| Exact identity and document | Supplied form and disclosed chemistry | Scope and evidence limit |
| --- | --- | --- |
| Hubbard-Hall **Enerox Aluminum Desmut F 108**, product code **2552007**; bulletin revised **May 20, 2025** | Concentrated, clear brown liquid described as iron-based and containing nitric acid and fluoride. The shipping description names ferric sulfate and nitric acid. The product-profile table excludes chromium, gluconate-type complexing agents, and EDTA/NTA-type chelates. | Combined desmutting and deoxidizing product. The bulletin does not disclose a complete ingredient assay or identify every possible complexant or inhibitor. [F 108 bulletin, pages 1–4](https://www.hubbardhall.com/document?id=2552007&type=TDS) |
| Caswell **Deoxidizer/Desmut**, product number **ALDEOX**; US supplier SDS **version 1.0, June 3, 2016** | Light brown liquid. Section 3 lists sulfuric acid at **18%**, sodium nitrate at **6%**, and a combined water-or-other-non-reportable-ingredients entry at **76%**. | The acid ingredient name separately carries **90–98%** in parentheses. Percentage basis and alloy-performance tests are absent. [ALDEOX SDS, sections 1, 3, and 9](https://caswellplating.com/content/sds/Desmut.pdf) |
| NuGeneration Technologies/NuGenTec **DeSmut NS3**, product number **ng-DSNS3**; US SDS issued and reviewed **August 8, 2016** | Liquid. Section 3 lists sulfuric acid and nitric acid, each at **15–35%**; exact percentages are proprietary. | Identified for aluminum desmutting after etching. The TDS also describes etching and excludes chelates. The SDS percentage basis is unstated. [NS3 SDS, sections 1 and 3](https://nugentec.com/content/sds/DeSmut_NS3_%28US%29_EN_sds.pdf), [NS3 TDS](https://nugentec.com/content/tds/DeSmut-NS3-TDS.pdf) |
| McGean **Cee-Bee A-601**; five-page product data sheet **06/2021, Rev. A2**, supplied through the Asia-Pacific manufacturer site | Red-to-orange acidic powder. The properties say non-fluorinated; the precautions explicitly identify chromic acid. | Desmutting and deoxidizing are both listed. Non-fluorinated does not mean chromium-free. This TDS does not give ingredient percentages. **A-601** and liquid **A-601L** are separate product identities. [A-601 data sheet, pages 1–5](https://www.ceebee.com.sg/wp-content/uploads/2021/06/Cee-Bee-A-601-22015-TDS-4-27-2021.pdf), [A-601L manufacturer page](https://www.cee-bee.com/product/cee-bee-a-601l/) |

An older F 108 SDS, prepared **October 31, 2014**, uses the same product code. It lists nitric acid **10–15%**, ferric sulfate **20–30%**, and sodium bifluoride **<3%**. Its percentage basis is unstated. These disclosures identify a fluoride source but do not prove the 2025 formulation is unchanged or supply the unlisted balance. [F 108 SDS, sections 1, 3, and 16](https://www.hubbardhall.com/application/files/2017/3168/4745/ENEROX-ALUMINUM-DESMUT-F-108.pdf)

## Property values and their bases

| Product and source | Reported supplied-product properties | Missing conditions or comparison limit |
| --- | --- | --- |
| F 108, 2014 SDS | pH **<1**; relative density **1.43–1.45**; dark brown liquid. [SDS, section 9](https://www.hubbardhall.com/application/files/2017/3168/4745/ENEROX-ALUMINUM-DESMUT-F-108.pdf) | Test conditions are unstated. The 2025 bulletin instead describes a clear brown liquid; the documents do not explain the wording difference. |
| Caswell ALDEOX | pH **1.0**; relative density **1.4269**. [SDS, section 9](https://caswellplating.com/content/sds/Desmut.pdf) | No pH test concentration, temperature, or method; no reference temperatures for relative density. Relative density is a ratio, not a value in g/cm³. |
| NuGenTec NS3 | SDS pH **<1 at 20°C**; density **1.266 g/cm³ at 20°C**, also reported as **10.565 lb/gal**. [SDS, section 9](https://nugentec.com/content/sds/DeSmut_NS3_%28US%29_EN_sds.pdf) | SDS does not identify a separate pH test dilution. Measurement temperature is not an operating recommendation. |
| NuGenTec NS3 | TDS bulk density **10.6 lb/gal**; concentrate pH **<1.0** and pH at a **5% test concentration <1.0**. [TDS, physical-properties table](https://nugentec.com/content/tds/DeSmut-NS3-TDS.pdf) | TDS leaves density temperature and gallon convention unstated. The pH test percentage has no mass-or-volume basis or stated measurement temperature. It is not a bath recommendation. |

**Synthesis.** pH, density, solids content, and acid content measure different things. A pH value does not specify total acid, free acid, or an acid mass fraction. A liquid's density is not a powder's bulk density, and product percentage by volume is distinct from ingredient percentage by mass. No cross-product strength ranking follows from these values.

The NS3 TDS density is numerically consistent with rounding its SDS value, but the documents leave different measurement conditions unstated. Its TDS uses non-fuming wording while the SDS describes a pungent odor and addresses vapor and mist exposure. Neither description establishes absence of airborne exposure. [NS3 TDS](https://nugentec.com/content/tds/DeSmut-NS3-TDS.pdf), [NS3 SDS, sections 4, 8, and 9](https://nugentec.com/content/sds/DeSmut_NS3_%28US%29_EN_sds.pdf)

## Chemistry and alloy applicability

F 108's bulletin names 1100 and 3003 wrought alloys, **most** 2000-, 5000-, and 6000-series alloys, and high-silicon castings such as the 380 series. It also says alloy or casting identity is critical and calls for evaluation of the full finishing cycle. These supplier scopes are not universal alloy-family acceptance. [F 108 bulletin, pages 2–3](https://www.hubbardhall.com/document?id=2552007&type=TDS)

**Synthesis.** Silicon-, copper-, or iron-associated smut terminology describes a possible residue problem. An alloy designation or a dark appearance alone cannot establish the residue's phases, their amounts, or complete removal. The cited product documents do not provide a common residual-phase measurement method, removal threshold, or comparative test across these products.

Acid identity alone does not describe the whole formulation. NS3 classifies its nitric-acid ingredient as an oxidizing liquid, separately from its mixture classification. ALDEOX lists sodium nitrate but leaves oxidizing properties unavailable in section 9. Neither SDS quantifies the formulation's desmutting mechanism or removal selectivity. No universal inhibitor package follows from the word desmutter. [NS3 SDS, sections 2–3](https://nugentec.com/content/sds/DeSmut_NS3_%28US%29_EN_sds.pdf), [ALDEOX SDS, sections 3 and 9](https://caswellplating.com/content/sds/Desmut.pdf)

## Interpretation limits

**Synthesis.** Chromium-free excludes a broader stated substance category than hexavalent-chromium-free. Fluoride-free, nitric-acid-free, and chelate-free describe different exclusions. Supplier wording does not establish elemental purity, a detection limit, or current regulatory compliance. An unlisted ingredient is not evidence of absence. F 108's explicitly limited complexant exclusions cannot be extended to all complexants. [F 108 product profile](https://www.hubbardhall.com/document?id=2552007&type=TDS)

NS3 also reports **60.5% water** in section 9, without resolving its proprietary acid bands. Likewise, ALDEOX's combined 76% entry cannot be relabeled as pure water. Neither document supports reconstructing a complete manufacturing formulation. [NS3 SDS, sections 3 and 9](https://nugentec.com/content/sds/DeSmut_NS3_%28US%29_EN_sds.pdf), [ALDEOX SDS, section 3](https://caswellplating.com/content/sds/Desmut.pdf)

**Synthesis.** A desmutter designation establishes intended function, not non-etching behavior, universal alloy safety, zero residue, coating adhesion, or acceptance of the subsequent finish. The sources provide no shared qualification basis for customer, aircraft, food, or medical use. Environmental and waste-treatment marketing claims are not adopted here. Bath preparation, operating settings, control procedures, and disposal instructions are outside this reference.

## Source versions and coverage

Sources reviewed **October 29, 2026 PDT**. Full available documents for the four products were reviewed, including ingredient/property tables, precautions, and disclaimers. NS3 has both a two-page TDS and a twelve-page US SDS; its TDS ends with code **160822** without an explicitly labeled revision date. ALDEOX's SDS is eight pages. The F 108 bulletin is four pages. These retrieved versions do not establish that each formulation remains unchanged in every region.

Henkel's linked selector-guide filename says **2025**, while its closing imprint says **©2024, DSGN0040480 (11/24)**. The relevant process and desmutter sections, including their product tables and notes, were reviewed; this article does not adopt their regional availability, approvals, or operating values. AUSCHEM and the A-601L page are undated. The five-page F 108 SDS predates its bulletin by more than ten years. An A-601 SDS was not available for this review; its composition coverage is limited to the cited TDS.

Related reference: [Surface-finishing processes](../../processes/finishing/index.md).