CAIG No Clean Soldering Flux RSF-R39-2
Best flux for electronics hobbyists and professionals performing PCB repair.
This CAIG Laboratories DeoxIT Brand No Clean RMA Soldering Flux is designed for efficient and reliable soldering applications. It comes in a convenient 2 oz. jar and is a single-pack quantity. The flux can be safely left on the circuit board after reflow, eliminating the need for post-soldering cleaning. Its formulation is excellent for Printed Circuit Boards (PCBs), ensuring a clean and effective soldering process. The product dimensions are 1.5" x 4.75" x 6.37". This is the CAIG No Clean Soldering Flux RSF-R39-2, packaged in a 56g jar. It is a mildly activated rosin flux, offering more activity than standard water-white rosin. It's highly recommended for various electrical and electronic soldering tasks, especially for P.C.B repair and rework. A great feature is that it is a 'No Clean' flux, meaning it can be safely left on the circuit board after reflow without the need for cleaning. It presents as a smooth and tacky amber paste and does not require refrigeration for storage, boasting a nominal shelf life of 12 months for unopened containers. The formulation consists of 50-60% WW Gum Rosin and 40-50% proprietary ingredients. It is RoHS Compliant and VOC Compliant. While it is designed to be no-clean, residues can be removed if necessary using an aqueous saponifier cleaning process or by wiping with a cloth or cleaning solvent. Please note that typical soldering processes will generate fumes that must be adequately exhausted for operator safety.
$9.95
Owner Satisfaction
4.7
/ 5
Category Rank
27
/ 775
#27 in Circuit Board Accessories
Price vs Category Average
-63%
Below average
Tool Type
Flux
/ Flux
Who it's for
- Technicians seeking a faster, cleaner assembly workflow
- DIY hobbyists needing reliable bonds on oxidized components
- Repair professionals working with diverse solder alloy types
Who should skip it
- Users lacking proper ventilation or fume extraction setups
- Engineers building sensitive, high-impedance electronic circuits
- Makers requiring precise, mess-free application control
Performance breakdown
Post-Soldering Convenience
No-clean formula eliminates the need for tedious board scrubbing.
Application Consistency
Smooth, tacky paste ensures precise placement during delicate rework tasks.
Regulatory Compliance
Fully RoHS and VOC compliant for modern environmental safety standards.
Storage Stability
Twelve-month shelf life without the hassle of refrigeration requirements.
Electrical Reliability
Passes rigorous SIR testing to ensure long-term circuit board integrity.
Flux Activity
Mildly activated rosin strikes the perfect balance for effective soldering.
Key Specs
Tool Type
Flux
Size
2 oz.
Quantity
Single pack
Dimensions / Design
1.5" x 4.75" x 6.37"
Material
Rosin/Paste Flux
Appearance
Smooth and tacky amber paste
Viscosity (Malcom)
Typically 200 – 280 at 5 rpm @ 25 C
Tack strength (per IPC J-STD-004)
Initial TBD 6 hr @ 50%RH TBD 24 hr @ 50%RH TBD
Features
- No-clean formula
- Safe to leave on circuit boards after reflow
- Excellent for PCBs
- Convenient jar packaging
- Mildly activated rosin flux
- Recommended for electrical and electronic soldering applications
- Excellent for P.C.B repair and rework
- No refrigeration necessary
What customers say
The CAIG No Clean Soldering Flux RSF-R39-2 enjoys overwhelmingly positive customer sentiment, positioning it as a premium, high-performance option favored by both hobbyists and professional technicians working on sensitive electronics. The primary driver of this satisfaction is its exceptional 'no clean' formulation. Users consistently praise the minimal, non-tacky residue left behind, which genuinely eliminates the tedious post-soldering cleanup process required by traditional fluxes. This feature significantly speeds up workflow, especially for intricate surface-mount device (SMD) work or delicate repairs where residue removal could potentially damage surrounding components. Analytically, the flux excels in its core function: promoting excellent solder flow and wetting action. Reviewers frequently note that the flux dramatically improves the consistency and quality of solder joints, making difficult tasks, such as dragging solder bridges or reworking fine-pitch components, much more manageable and reliable. The flux’s viscosity is often cited as ideal, allowing for precise application without excessive spreading. While the performance is top-tier, the few minor critiques generally revolve around the cost, which is perceived as slightly higher than bulk alternatives, though the consensus is that the quality and time savings easily justify the premium price point. Furthermore, a small subset of users occasionally mentions minor issues with the dispensing mechanism (particularly in the pen format), citing occasional clogging or inconsistent flow near the end of the product life. Overall, the sentiment reflects a highly reliable, effective product that delivers consistently on its promise of superior soldering performance with minimal cleanup hassle, making it a staple in many electronics repair kits.
Know before you buy
No, this is a 'no-clean' formula. You can safely leave the residue on your circuit board after the reflow process without affecting performance.
Yes, while it is designed to be left on, you can remove the residue if necessary. It can be cleaned using an aqueous saponifier process or by wiping the area with a cloth and appropriate cleaning solvent.
Yes, it is specifically recommended for PCB repair and rework. Its mildly activated rosin formulation provides the necessary activity for effective soldering while remaining safe for sensitive electronic components.
You do not need to refrigerate this flux. It should be stored in a cool, dry place, and it has a nominal shelf life of 12 months when kept in an unopened container.
Yes, the flux is both RoHS and VOC compliant. It is also halide-free and passes IPC SIR testing, making it a reliable choice for modern electrical and electronic soldering tasks.
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