Sodium bicarbonate blasting media
Supplier-specific bicarbonate blast grades, formulations, size data, chemical-property conditions, and limits on cleaning, residue, and waste claims.
Tags: abrasives, blasting, sodium-bicarbonate, reference
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Identity and formulation
ARMEX Maintenance XL and Flow XL both list 270 µm and approximately CAMI-relative grit 70. Their flow aids differ, MoistureGuard 2 for Maintenance XL and Advanced Moisture Resistance for Flow XL. Natrium reports 0% flow aid for its named blast grades. Maintenance XL TDS Flow XL TDS Natrium grades The abrasive is sodium bicarbonate, NaHCO₃, CAS 144-55-8. Natrium media reference
ARMEX Maintenance also uses MoistureGuard 2. The sheets leave additive chemistry, loading and coating form unresolved. Maintenance TDS Maintenance XL TDS Flow XL TDS Natrium grade table
Soda ash is sodium carbonate, a different compound identified among bicarbonate's thermal decomposition products. Natrium SDS, sections 5 and 10 Dry ice is solid carbon dioxide and sublimates to gas. Bicarbonate's dissolution in water is a different process. ARMEX comparison
Synthesis. Food-grade or USP pharmaceutical terminology for bicarbonate does not establish a blast formulation's suitability for a particular cleaning process. The ARMEX sheets describe NSF A1 registration as Nonfood Compounds for general cleaning. This is not blanket authorization for direct food contact or proof that a blasted surface is ready for food use. Maintenance, Maintenance XL, Flow XL
Exact-grade size comparison
These are supplier entries, not equivalent grades across brands. One micrometre, µm, equals 0.001 mm.
| Supplier and grade | Published size label | Formulation distinction |
|---|---|---|
| ARMEX Maintenance, SKU 20511312 | 170 µm; approximate CAMI-relative grit 100 | MoistureGuard 2. Product page, TDS |
| ARMEX Maintenance XL, SKU 20511313 | 270 µm; approximate CAMI-relative grit 70 | MoistureGuard 2. Product page, TDS |
| ARMEX Flow XL, SKU 20511309 | 270 µm; approximate CAMI-relative grit 70 | Advanced Moisture Resistance. Product page, TDS |
| Natrium 150 | Average 160 µm; mesh 100 | Flow aid 0%. Manufacturer table |
| Natrium 260 | Average 300 µm; mesh 50 | Flow aid 0%. Manufacturer table |
| Natrium 300 | Average 350 µm; mesh 45 | Flow aid 0%. Manufacturer table |
The ARMEX product-page footnotes call grit an approximate relative size according to CAMI. Their flow-aid numbers describe claimed resistance to moisture relative to regular baking soda, not additive percentages. No humidity, exposure duration, or test method accompanies that comparison. Maintenance page, Maintenance XL page, Flow XL page
The complete size entries in the three ARMEX technical sheets are below. Each percentage retains the sheet's retained on wording.
| Sieve opening printed in TDS | Maintenance | Maintenance XL | Flow XL |
|---|---|---|---|
| 40 mesh, 425 µm | Not listed | 8% maximum | 8% maximum |
| 60 mesh, 250 µm | 8% maximum | 60% minimum | 60% minimum |
| 100 mesh, 150 µm | 55% minimum | 70% minimum | 70% minimum |
| 170 mesh, 90 µm | 93% minimum | Not listed | Not listed |
| 200 mesh, 75 µm | Not listed | 80% minimum | 80% minimum |
| 325 mesh, 45 µm | Not listed | 90% minimum | 90% minimum |
Sources are the full one-page Maintenance, Maintenance XL, and Flow XL sheets. They do not identify percentage mass versus count basis, cumulative versus individual-screen retention, sieve standard, or test procedure. The increasing minima at smaller openings must not be added as independent size fractions. No D10, D50, or D90 values are supplied. Natrium's grade page gives averages without an averaging method or distribution limits. Natrium
Synthesis. A product number is not necessarily its average diameter. Natrium 260's published average is 300 µm, for example. Matching approximate grit labels does not establish matching distributions, flow behavior, or finish.
Shape, hardness, and density
The ARMEX technical sheets describe white crystalline powder. Natrium's grade-named SDS describes powder or granules. Neither supplies a numerical angularity, roundness, or aspect-ratio criterion. Maintenance, Maintenance XL, Flow XL, Natrium SDS, section 9
ARMEX's process article gives Mohs hardness 2.5 without a test procedure. This scratch-hardness value is not a measured fracture strength, workpiece-damage threshold, or reuse count. How blasting works
ARMEX's July 2025 SDS lists density approximately 62 lb/ft³ and 0.99 g/cm³, but does not label it bulk, tapped, or particle density. The general Huber/Natrium April 2024 SDS lists 2.2 g/cm³ under density, also without a measurement method. Bulk density includes spaces between particles, while particle-material density excludes those spaces. The sources do not establish that their entries share either basis. They do not establish a hopper-volume conversion for an actual lot. ARMEX SDS, section 9, Huber/Natrium SDS, section 9
Chemical values and their conditions
| Source | Reported value | Basis or missing condition |
|---|---|---|
| ARMEX July 2025 SDS, section 3 | Sodium bicarbonate 99.5–100% | Explicitly weight by weight; not evidence that all formulations lack additives. SDS |
| ARMEX July 2025 SDS, section 9 | pH approximately 8.3, 1% solution at 25 °C | Percentage concentration basis unstated. SDS |
| ARMEX three TDS | pH approximately 8.2, 1% solution | Temperature and percentage basis unstated. Maintenance, Maintenance XL, Flow XL |
| Natrium grade-named January 2022 SDS, sections 3 and 9 | Bicarbonate 100% by weight; pH 8.3 at 25 °C for 0.1 M solution, also labeled 0.84% w/v | Concentration conditions belong to this measurement. SDS |
| ARMEX July 2025 SDS, section 9 | Water solubility approximately 9.5% at 20 °C | Percentage denominator unstated. SDS |
| Natrium January 2022 SDS, section 9 | Water solubility 86 g/L at 20 °C | Does not specify litres of solvent versus final solution or measurement method. SDS |
The ARMEX pH entries differ and have different stated conditions. Neither is silently substituted for the other. Its process article also calls ARMEX pH neutral despite describing it as mildly alkaline. The conditioned solution measurements above are more specific evidence. ARMEX process article
The general Huber/Natrium April 2024 SDS reports decomposition beginning above 50 °C without a heating-rate or dwell-time method. Its melting-point entry instead notes decomposition on heating. This is not a process-temperature allowance. ARMEX's SDS supplies no decomposition temperature and states that the product contains hygroscopic material. Huber/Natrium SDS, sections 9–10, ARMEX SDS, sections 9–10
Synthesis. These solubility entries cannot be converted into one equivalent percentage without their denominators. They describe neither dissolution time nor complete residue removal from a cavity. Dissolution is not biodegradation. Natrium's 2022 SDS calls biodegradation not applicable, while ARMEX's SDS says persistence and degradability are not established. Natrium SDS, section 12, ARMEX SDS, section 12
Cleaning results, residue, and reuse
ARMEX describes crystals fracturing on impact and treats its media as one-pass rather than recyclable. That supplier statement does not establish a cycle life for every bicarbonate grade. ARMEX FAQs
The manufacturer describes removal of grease, coatings, and other contamination through relatively soft, friable crystals. Its broad no-damage and contaminant-free claims are not accompanied by matched substrate-loss, roughness, retained-salt, or next-coating adhesion measurements in the inspected article. How blasting works
Synthesis. Selective coating removal depends on the coating, underlying material, protected features, equipment, and operating conditions. A soft-abrasive designation alone cannot establish preservation of a particular dimension, coating layer, seal, or finish. Fresh-media solubility does not prove absence of trapped powder, additives, dissolved salts, or removed contamination after blasting. The inspected sources establish no universal pressure, nozzle distance, exposure time, rinsing quantity, washing method, or subsequent-coating compatibility.
Dust, waste, and scope limits
ARMEX's SDS classifies the supplied product as not classified under its stated US and Canadian hazard systems, while retaining dust precautions. It directs prevention of release to sewers and public waters. These statements do not classify dust generated from removed coatings. ARMEX SDS, sections 2, 6, and 8
ARMEX's disposal article makes contaminants and local requirements material to spent-media handling and conditions sewer disposal on treatment-plant approval. Dissolving abrasive does not classify the resulting solids or liquid. ARMEX disposal reference The general Huber/Natrium April 2024 SDS likewise assigns waste codes according to the application and cautions against runoff into waterways and sewers. SDS, sections 6 and 13
Synthesis. Neither a fresh-product SDS, food-related label, nor water solubility establishes harmless discharge, zero environmental effect, a spent-waste classification, or compliance of a blasting process.
Source versions and coverage
Reviewed 29 October 2026 PDT. The three complete ARMEX technical sheets were inspected, including size entries, ingredient lists, registration wording, and footers. Maintenance and Maintenance XL carry review date 10/01/25; Flow XL carries 10/14/25. The seven-page ARMEX NA GHS 2024 SDS is version 3.0, revised 8 July 2025. Its density and solubility bases remain unresolved. Maintenance, Maintenance XL, Flow XL, SDS
The complete Natrium grade table and linked three-page, grade-named SDS were inspected. That SDS is issued 28 January 2022 and names grades 30, 70, 150, 220, 260, and 300. The product page lists only 150, 260, and 300. Natrium's resources page separately links a ten-page general sodium bicarbonate SDS dated 17 April 2024, revision 1.1, which does not name those blast grades. Its existence does not silently replace the older grade-specific identity. Grade page, 2022 SDS, 2024 SDS
Undated manufacturer web pages are retrieval snapshots. Coverage does not establish lot certificates, additive chemistry, analytical detection limits, qualified removal selectivity, technical cleanliness, or operating settings. Related references cover glass blasting beads and Finishing process references.