WD-40 Specialist Contact Cleaner: Cleaning Circuit Boards Before Soldering

John C
Mar 17
2 min read

Updated: Mar 22

I'm JC, a passionate DIYer and electronics enthusiast with years of hands-on experience repairing and maintaining circuit boards. Here's how I keep circuit boards clean to ensure solder joints stick reliably.

Why Clean Before Soldering?

Dirt, oxidation, oils, dust, and flux residues can prevent solder from bonding correctly, causing issues like cold solder joints and short circuits. A thoroughly cleaned board ensures optimal electrical contact, better solder flow, and longer-lasting repairs.

Why Use WD-40 Specialist Contact Cleaner?

Fast-drying – evaporates in seconds.
No residue – leaves surfaces perfectly clean.
Safe for electronics – specially formulated to protect plastics and metals.
Powerful spray – blasts grime away effectively.

WD-40 Specialist Contact Cleaner uses rapidly evaporating solvents specifically formulated for electronic applications. It's non-conductive, safe on sensitive components, and highly effective for electronics maintenance.

How to Clean a Circuit Board Before Soldering:

Step 1: Disconnect all power sources completely (remove batteries, unplug devices).

Step 2: Perform a visual inspection for dirt, corrosion, flux residue, or oils.

Step 3: Spray WD-40 Contact Cleaner from 10-15 cm away. For stubborn grime, immediately use cotton buds or a microfiber cloth to wipe away debris before the cleaner evaporates (within 10-30 seconds).

Step 4: Allow the board to fully dry (typically 10-30 seconds).

Step 5: Begin soldering on your clean and fully dried board.

💡 JC’s Pro Tip:

For older electronics, spray the contacts, switches, and connectors too—they often have hidden dirt and oxidation that affect performance.

🔧 What You'll Need (on Amazon):

WD-40 Contact Cleaner

Fast-drying, leaves no residue

Cotton Buds

Good for stuck on grime

Anti Static Brushes

Brush out bits of residue

Anti Static Clothes

Lint-free anti static for sensitive electronics

(Note: As an Amazon Associate, JCintheShed earns from qualifying purchases at no extra cost to you. Thanks for your support!)

🗒️ Quick Recap:

✅ Disconnect all power sources first.✅ Spray and immediately wipe away grime.✅ Allow complete drying before soldering.✅ Enjoy clean, reliable solder joints.

❓ Frequently Asked Questions:

Q: Can I use regular WD-40 instead?

A: No. Regular WD-40 leaves residues that can damage electronics. Always use WD-40 Specialist Contact Cleaner.

Q: How long should I wait after spraying?

A: Typically, 10-30 seconds is sufficient. Ensure the surface is fully dry before soldering.