How to Clean Wettable Selective Soldering Nozzles: Maintenance Guide

Proper cleaning and maintenance of wettable selective soldering nozzles is essential for maintaining consistent solder quality, extending nozzle life, and reducing production downtime. This guide covers the tools, techniques, and best practices for nozzle cleaning.

Key Takeaways

**Daily wipe-down prevents oxide buildup** — quick maintenance keeps nozzles performing consistently

**IF930 cleaning paste is the standard** — for removing oxide layers and restoring wettable surfaces

**Match brush size to nozzle ID** — 2.5mm brush for small IDs, 6mm for larger IDs

**Weekly deep cleaning recommended** — with paste and brushes for thorough oxide removal

**Replace when cleaning cannot restore flow** — worn IDs and cracks require new nozzles

Why Nozzle Cleaning Matters

Over time, selective soldering nozzles accumulate:

**Solder oxide and dross** — Reduces solder flow consistency

**Flux residue** — Can block the nozzle inner channel

**Tin buildup** — Alters the nozzle ID/AD dimensions and affects solder contact area

A dirty or partially blocked nozzle produces inconsistent solder waves, leading to defects such as insufficient solder fill, bridging, or cold joints. Regular cleaning prevents these issues and extends nozzle service life significantly.

Impact of Poor Maintenance

ConditionSymptomRoot Cause

|---|---|---|

Oxide buildupInconsistent wave heightLack of daily wipe-down Inner channel blockageReduced solder flowFlux residue accumulation ID enlargementWider solder contact than expectedWear from abrasive cleaning Surface de-wettingSolder does not wet nozzle tipOxide layer too thick

Essential Cleaning Tools

Cleaning Paste (IF930)

Part NumberDescriptionSizeUse

|---|---|---|---|

179904Cleaning paste IF93010 ccmSmall package, trial use 179905Cleaning paste IF93030 ccmStandard package, regular use

Apply cleaning paste to the nozzle surface while the solder pot is at operating temperature. The paste chemically removes oxide layers and restores the wettable surface.

Cleaning Brushes

Part NumberDescriptionDiameterBest For

|---|---|---|---|

258787Nozzle brush2.5 mmSmall ID nozzles (1.8-3.0mm) 247811Nozzle brush6 mmMedium ID nozzles (4.0-8.0mm) 47700Tube brush3 mmInner channel cleaning 47701Tube brush5 mmInner channel cleaning 47702Tube brush8 mmInner channel cleaning 47703Tube brush10 mmInner channel cleaning 213024Stainless steel brush—Heavy-duty oxide removal

Nozzle Removal and Maintenance Tools

Part NumberDescriptionUse

|---|---|---|

6ISK47957091Nozzle removal toolSafe hot nozzle extraction 6ISK47957090ACombi toolRemoval + maintenance 106249Complete cleaning tool setAll-in-one maintenance kit

Step-by-Step Cleaning Procedure

Step 1: Remove the Nozzle from the Solder Pot

Use the appropriate nozzle removal tool (6ISK47957091 or 6ISK47957090A) to safely extract the nozzle from the hot solder pot. Always wear heat-resistant gloves and eye protection.

Step 2: Apply Cleaning Paste

While the nozzle is still warm, apply IF930 cleaning paste to the outer surface and inner channel. Allow the paste to react with oxide deposits for 30-60 seconds. The paste will turn dark as it absorbs oxides.

Step 3: Brush the Nozzle

Select the appropriate diameter brush:

For ID ≤ 3.0mm: Use 2.5mm brush (258787)

For ID 4.0-8.0mm: Use 6mm brush (247811)

For inner channel: Use tube brush matching the ID size (47700-47703)

Brush the inner channel and outer surface until the oxide layer is removed and the wettable surface is restored.

Step 4: Rinse and Inspect

Wipe the nozzle clean with a dry cloth and inspect:

Inner channel for remaining residue or blockage

ID/AD dimensions for wear (compare with specification)

Surface condition for cracks or deformation

Wettable surface quality (should be smooth and shiny)

Step 5: Reinstall and Test

Reinstall the nozzle in the solder pot and run a test solder cycle to verify:

Consistent wave height

Smooth solder flow

Proper wetting of the nozzle tip

No spattering or irregular wave patterns

Maintenance Schedule

FrequencyActionTime Required

|---|---|---|

DailyVisual inspection + wipe-down2-3 minutes per nozzle WeeklyFull cleaning with paste + brushes5-10 minutes per nozzle MonthlyDimension inspection + replacement planning15-20 minutes per nozzle

When to Replace a Nozzle

Replace your nozzle when:

The inner diameter has worn beyond specification (ID enlarged by more than 0.5mm)

The nozzle body shows cracks or deformation

Cleaning does not restore consistent solder flow

The wettable surface no longer activates properly even after paste treatment

The nozzle has been in service for more than the recommended lifetime

See our [Maintenance Guide](/technical-guides/selective-wave-solder-nozzle-maintenance-guide) for complete solder bath and nozzle lifecycle management.

Related Products

[Nozzle Maintenance Guide](/technical-guides/how-to-clean-wettable-selective-soldering-nozzles) — Cleaning and inspection guidance

[Nozzle Catalog](/selective-soldering-nozzle-catalog) — Browse compatible nozzles by part number

[B14.1/B22 Nozzles](/products/b14-1-b22-nozzles) — Replacement nozzle catalog

[Custom Nozzles](/technical-guides/custom-selective-soldering-nozzles-by-drawing-or-sample) — When standard replacements don't fit

Need Cleaning Supplies?

[Request a Quote](/contact) for cleaning paste, brushes, and maintenance tool sets, or [WhatsApp us](https://wa.me/8615706606161) for quick ordering.