Choose epoxy measuring tools from the manufacturer-specified ratio basis, smallest component amount, batch size, and process risk. Graduated cups fit approved volume batching. A suitable scale fits an approved weight ratio. Calibrated pumps fit only their documented resin/hardener and container system.

There is no universal “best epoxy scale.” A high-capacity 1 g platform can be useful for a large batch and incapable of resolving a small hardener dose. A 0.001 g laboratory balance can resolve a tiny amount but may have too little capacity, too small a platform, or unnecessary complexity for field production.

This is a research-based guide. Epoxy Science did not purchase or test the named products. Examples illustrate documented selection criteria and are not scored or ranked.

Start with the product instruction—not the tool catalog

Record these facts before selecting equipment:

  1. exact Component A and Component B identities;
  2. ratio by volume, weight, or complete units;
  3. smallest and largest planned batch;
  4. whether partial kits are permitted;
  5. minimum or maximum batch limits;
  6. mix vessel, time, method, and transfer instructions;
  7. working time and heat-management requirements;
  8. component SDS controls and disposal instructions.

Use the epoxy mix-ratio explanation to calculate component amounts and the mix-ratio calculator to scale an approved A:B ratio.

Tool-selection matrix

Task Suitable class when documented Key selection question Common limitation
Volume proportioning Graduated straight-sided cup or calibrated dispensing system Are graduations appropriate for the smallest component volume? Printed marks and sloped vessels can introduce error
Weight proportioning Digital balance/scale Can it resolve the smallest dose while supporting total load? Display readability is not the same as accuracy
Repeat production Manufacturer-matched ratio pump Is it approved and verified for this exact component pair? Generic or mismatched pumps can deliver the wrong ratio
Mixing Clean compatible vessel and specified stirrer/paddle Does geometry let the tool reach walls, bottom, and corners? A measuring vessel may be a poor mixing vessel
Batch control Timer, labels, batch log Can the crew trace identity, amounts, and time? Records do not correct a bad batch
Condition check Product-required temperature/environment instrument Which exact conditions does the TDS require? Generic readings do not establish cure or approval

Volume measurement

Graduated cups and containers

Use clean vessels with legible graduations in the required unit. Straight sides make level changes easier to interpret. Check that the planned resin and hardener volumes fall comfortably within the marked range; a large pail with coarse graduations is a poor tool for a small hardener amount.

Inspect disposable cups before use. System Three notes that printed graduations can be misplaced and that a marked-stick method only works in a vertical-sided container. Manufacturer-supplied ratio scales on a cup are useful only when read correctly and when that ratio is actually approved for the product.

Practical criteria include:

  • graduation interval and legibility;
  • straight-sided geometry and stable base;
  • sufficient headspace for mixing without splash;
  • compatibility with the component and cleaning method;
  • ability to scrape walls and bottom;
  • whether a lid or transfer vessel is needed;
  • batch traceability and disposability.

Do not reuse a vessel with cured ridges, uncertain residue, moisture, solvent, or contamination that could affect measurement or mixing.

Manufacturer-approved dispensing pumps

Ratio pumps can reduce repeated manual measurement, but their value comes from being calibrated for a defined system. WEST SYSTEM’s pump families are matched to particular resin/hardener ratios and package groups; one complete stroke of each paired pump delivers the intended proportion.

Evaluate:

  • exact resin and hardener compatibility;
  • package or group size;
  • ratio and output per cycle;
  • full-stroke versus permitted partial-stroke operation;
  • priming and air-removal procedure;
  • verification frequency and method;
  • seals, rebuild parts, cleaning, and storage;
  • viscosity and temperature limits.

Two ordinary pumps delivering equal strokes do not become a ratio system. Pumps can drift, clog, draw air, crystallize, or be installed on the wrong containers; verify output as instructed.

Weight measurement

What scale specifications matter

Choose a scale or balance using the full measurement problem:

  • Capacity: container plus all components must stay below maximum load.
  • Readability: the smallest displayed increment.
  • Repeatability: how closely repeated measurements agree under stated conditions.
  • Linearity: how measurement error can vary across the range.
  • Minimum practical dose: the smallest component amount the process can measure credibly.
  • Tare range: whether the container can be zeroed without consuming needed capacity.
  • Platform: stable and large enough that the vessel does not bridge or tip.
  • Calibration and verification: documented method, weights, frequency, and records.
  • Environment: drafts, vibration, temperature, leveling, contamination, and power.

Readability alone is not an accuracy claim. A displayed extra decimal can create false confidence if the balance is unlevel, unverified, overloaded, drifting, or used below a defensible minimum quantity.

Documented equipment examples

Example Manufacturer-documented characteristics Where it may fit Important limitation
OHAUS Navigator family Multiple models span different capacities and readability; manufacturer publishes model-specific repeatability, linearity, stabilization, platform, and calibration features Controlled small-to-medium batch weighing after selecting the exact model “Navigator” is a family; specifications cannot be transferred between models
OHAUS NV123 120 g capacity and 0.001 g readability with a small 93 mm pan Very small controlled measurements where its capacity and full accuracy specification are suitable Too little capacity and platform area for many resin containers; readability is not a blanket process tolerance
My Weigh KD-8000 Manual lists 8,000 g capacity, 1 g increments, tare, percent mode, and a 165 mm square tray Larger batches whose smallest component amount is comfortably above its resolution One-gram increments may be inadequate for small hardener doses; percent mode does not validate an epoxy ratio

These are class examples, not winners. An industrial production process may require a verified bench or floor scale, while a tiny formulation batch may require a suitable precision balance and controlled environment.

Do not substitute weight for volume without approval

If the TDS specifies only a volume ratio, buying a precise scale does not create a weight ratio. Densities can differ between components and may vary with temperature or formulation revision. Use a manufacturer-published weight ratio or obtain written technical guidance.

Batch-handling tools

Secondary mixing containers

Some instructions call for transfer or “double-cup” mixing: mix in one clean container, transfer while scraping into a second, then mix again. This can reduce unmixed wall and bottom zones. Use it only where appropriate to the product and do not scrape residue from the first cup directly onto the work afterward.

Stir sticks and paddles

Tool shape must reach the container corners and move the stated viscosity without excessive air or heat. Small batches may require a flat stir stick; larger batches may require a product-approved powered paddle and speed. The wrong tool can create an apparently uniform center while leaving unmixed material on the perimeter.

Timers and labels

Use a dedicated timer for mixing, induction, and application milestones. Label vessels with product, component, batch or lot, ratio basis, quantity, and time. A phone timer may work operationally, but chemical contamination and glove use should be planned; a cleanable dedicated timer can reduce cross-contamination.

Quality-control instruments

Temperature can affect viscosity, measurement behavior, working time, and cure. Use the exact product instructions to decide whether to record component, air, substrate, or mixed-material temperature and what instrument accuracy is needed.

An infrared thermometer measures a surface and can be affected by emissivity, reflective surfaces, distance, and spot size. A probe measures its contact location. An ambient temperature/humidity meter does not substitute for component or substrate temperature. These tools document conditions; they do not change the ratio or prove cure.

A scale workflow that reduces avoidable errors

When weight batching is explicitly permitted:

  1. place the scale on a stable, level, clean surface;
  2. verify calibration or check performance according to its instructions;
  3. choose a vessel that fits without contacting nearby objects;
  4. tare the empty vessel and confirm a stable zero;
  5. add the first component slowly to its target;
  6. use a fresh delivery path for the second component to prevent cross-contamination;
  7. approach the second target slowly—do not remove uncertain mixed material to correct an overshoot;
  8. record actual readings, then mix by the product instructions;
  9. protect the scale from drips without bridging or loading the platform;
  10. clean or dispose of contaminated items under the SDS and site procedure.

If a target is overshot beyond the approved process tolerance, do not improvise. Adding more of the other component may exceed the permitted batch size, tool capacity, or working-time plan.

Commercial selection method

Future product modules should filter tools by:

  1. approved measurement basis;
  2. smallest component dose and complete loaded capacity;
  3. published accuracy-related specifications, not decimal count alone;
  4. platform and vessel fit;
  5. calibration/verification workflow;
  6. chemical and cleaning compatibility;
  7. system-specific pump approval;
  8. documentation and replacement-part availability;
  9. field versus controlled-environment use;
  10. stated limitations.

No affiliate destination is included at publication. Future retailer links can support a chosen device class only after the technical fit is established. Review the site’s affiliate disclosure for the governing policy.

Safety and housekeeping

Measuring creates opportunities for skin and eye contact, drips, mislabeled containers, and cross-contamination. NIOSH recommends using the exact safety instructions and appropriate exposure controls; glove selection must fit the chemical, and odor is not proof of safety.

Keep clean controls, labels, and records outside the contaminated zone where practical. Never return dispensed material to the original container. Do not use food containers or return a contaminated scale to food use.

Bottom line

Select the measuring method from the documented ratio. For volume, use appropriate graduations or a verified manufacturer-approved pump. For weight, select enough capacity and credible performance at the smallest component amount. Then control vessel geometry, mixing, time, temperature, labeling, and contamination as one process.

Future visual opportunity

A selection chart could map ratio basis and batch size to cup, balance, or matched pump classes, with a separate scale graphic showing why capacity, readability, repeatability, and minimum practical dose are different concepts.

Sources and technical references

Accessed September 2026. Product documents can change; verify the current revision before specifying or installing a system.

  1. Dispensing and Mixing — WEST SYSTEM Epoxy
  2. Metering Pumps — WEST SYSTEM Epoxy
  3. Measuring and Mixing — System Three Resins
  4. Navigator Portable Balances — OHAUS Corporation
  5. KD-8000 Digital Scale Manual — My Weigh
  6. About Epoxies and Resins and Reproductive Health — National Institute for Occupational Safety and Health