Flux plays a major role in every soldering job. Whether you use flux core wire, no-clean solder wire, or other soldering materials, the right flux type helps you make clean, strong, and reliable joints. Many users get confused about which flux core to use. This guide clears all doubts and helps you choose confidently.
At Kothari Metsol, Pune, we make high-quality solder wire and flux solutions trusted by electronics, electrical, automotive, and engineering industries. Our experience since 1967 helps you get the right product for every project.
What Is Flux and Why Is It Important?
Flux is a cleaning agent present inside the solder wire (flux core). It removes oxide, improves wetting, and helps solder flow smoothly on metal surfaces.
When you choose the correct flux type, you get:
- Strong joints
- Clean finishing
- Better conductivity
- Fast soldering
- Low rework
This makes flux core wire the preferred choice for most soldering applications.
Types of Flux Core: Rosin, No-Clean, and Water-Soluble
Let’s understand all three flux core types in a simple way.
1. Rosin Flux Core
Rosin flux is made from natural resin. It is one of the oldest and most widely used flux types.
Why Use Rosin Flux Core Wire?
- Good wetting
- Strong bonding
- Works well for PCB and electrical soldering
- Safe for most components
- Leaves residue that you can clean with isopropyl alcohol
Rosin is a great option when you want dependable results and stability.
2. No-Clean Flux Core (Most Popular Today)
No-clean solder wire uses a special low-residue formula. It leaves very little residue after soldering, so you don’t need to clean the PCB. This saves time and reduces processing cost.
Why No-Clean Solder Wire Is a Good Choice
- No cleaning required
- Fast workflow
- Safe for modern PCBs and SMD components
- Very low residue
- Ideal for mass production
At Kothari Metsol, our no-clean solder wire is one of the best choices for electronics, automotive, and precision assemblies.
3. Water-Soluble Flux Core
Water-soluble flux is strong and very active. It removes heavy oxidation easily. You can wash the residue with water.
Best Uses of Water-Soluble Flux Core
- Heavy-duty soldering
- High oxidation metals
- Strong wetting action
- Faster flow
- Works well when you want quick and clean joints
This flux type needs complete cleaning after soldering to avoid corrosion.
Which Flux Core Type Should You Choose?
Here’s a simple selection guide:
| Soldering Need | Best Flux Type |
|---|---|
| PCB assembly | No-clean / Rosin |
| Automotive wiring | Rosin / No-clean |
| High oxidation metals | Water-soluble |
| Fast, low-maintenance production | No-clean |
| Clean finishing with minimal residue | No-clean |
| Strong bonding and repair jobs | Rosin |
If you still feel confused, Kothari Metsol can guide you based on your application.
How Flux Core Wire Helps You Work Better
Using the right flux core wire gives you:
- Smooth solder flow
- Strong mechanical bonding
- Perfect electrical connectivity
- Clean finishing
- Low oxidation
- Long-lasting joints
This improves the efficiency of every project.
Why Choose Kothari Metsol Solder Wire and Flux?
Kothari Metsol, Pune, is one of the trusted names in soldering materials. Here’s why industries prefer us:
50+ Years of Experience
We manufacture solder wire and flux since 1967.
Premium Flux Core Wire Options
Rosin, no-clean solder wire, water-soluble flux, aluminium flux, and more.
Best Quality Material
Made from virgin non-ferrous metal ingots.
Consistent Performance
Smooth flow, strong bonding, low residue.
Fast Delivery Across India
We supply solder wire quickly for urgent needs.
Expert Support
Our team helps you pick the right flux type for your application.
Practical Tips for Using Flux Core Wire
- Select the right flux for your job
- Keep the tip clean
- Maintain proper soldering temperature
- Avoid overheating the joint
- Choose no-clean solder wire for modern PCBs
- Use water-soluble flux only when you can clean properly
These simple steps improve soldering accuracy.