Flux Paste

Alumatec™ B Tube Flux Paste

Custom-formulated flux paste for B-tube and folded tube automotive heat exchanger manufacturing. Delivers consistent flux distribution and clean burn-off in controlled atmosphere furnace brazing.

558–572°C
Active Range
1,000–75,000
Viscosity (cP)
15–45%
Flux Content
4
Variants

Product Overview

Alumatec™ B Tube Flux Paste is used in the manufacture of folded tubes, where an internal line of flux facilitates the flow of brazing material on clad surfaces. Each formulation is custom-engineered to customer specifications for the precise viscosity and flux loading required by automated tube forming lines.

The paste is applied via auto-dispense systems during the tube folding process, ensuring reproducible coverage with minimal waste. Both standard and cesium-enhanced formulations are available to address magnesium-bearing alloy challenges.

Key Features

  • Custom formulated to customer specifications — viscosity and flux content adjustable
  • Consistent flux distribution throughout tube length
  • Clean burn-off — binder decomposes below 200°C
  • Low settling characteristics — stable shelf life
  • pH neutral — compatible with standard aluminum alloy tooling
  • Potassium Aluminum Fluoride (KAlF₄) chemistry
  • Optional Cesium Fluoride for Mg-bearing alloys
  • Application rate: 0.1–0.5 g/m

Technical Specifications

Property Value
Active Temperature Range558°C – 572°C
AppearanceWhite paste
pHNeutral
Specific Gravity @ 25°C0.89 – 0.92
Density1.1 – 1.4 g/cm³
Viscosity Range1,000 – 75,000 cP
Typical Viscosity15,000 – 25,000 cP
Flux Content15–45% (typical range)
Binder DecompositionBelow 200°C
Application Rate0.1 – 0.5 g/m
Application MethodAuto-dispense (tube folding)
ProcessControlled atmosphere furnace brazing (CAB)

Chemical Composition

ComponentRoleNotes
Potassium Aluminum Fluoride (KAlF₄)Primary flux agentRemoves oxide layer during brazing
Cesium Fluoride (CsF)Optional additiveEnhances flux activity for Mg-bearing alloys
Carrier / BinderVehicle / binderDecomposes cleanly below 200°C

Available Variants

Standard
KAlF₄ flux paste. Standard formulation for most aluminum alloy combinations. Active range 564–572°C.
Standard Cesium
KAlF₄ + CsF. Enhanced flux activity for assemblies containing magnesium-bearing aluminum alloys. Active range 558–572°C.
Delta Flux
Modified KAlF₄ formulation. Improved flow characteristics for tighter tube geometries.
Delta Flux Cesium
Delta Flux with CsF additive for Mg-bearing alloys. Best performance in challenging clad alloy combinations.

Packaging

10 kg 20 kg 25 kg 20 lb 40 lb 50 lb

Supplied in plastic containers. Custom volumes available on request.

Request Technical Data Sheet

Full TDS, SDS, and application guidelines available on request.

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