🏅 Surface Prep Masterplan for Badges & Crafts (QLQ System)
Substrates: Zinc Alloy (Die-cast) or Iron/Brass (Stamped).
Goal: A "Tooth-like" surface for paint to grip, without destroying fine details.
Phase I: Vibratory Deburring & Polishing (The "Detail Safe" Method)
For badges, we avoid aggressive Rotary Barrels (which nick edges). We use Vibratory Bowls.
1. Media Selection (The Critical Choice)
The Problem: Badges have tiny holes (for pins) and deep recesses (logos). Media getting stuck (Lodging) is the #1 nightmare.
The Solution:
For Zinc: Use Plastic/Resin Media (Cones or Pyramids). It cuts gently and doesn't "peen" (close up) the pores.
For Iron: Use Ceramic Media (Angle Cut Triangles).
Anti-Lodging Rule: The media size must be either 70% smaller than the smallest hole OR 150% larger than the largest hole. Never the same size!
2. The Process Steps
Step A: Deburring (Removing Flash):
Media: Green/Blue Plastic Media (Medium cut).
Chemical: [QLQ Product] Deburring Compound.
Time: 2–3 Hours.
Note: Use a lower vibration amplitude to prevent badges from hitting each other (nicking).
Step B: Surface Smoothing (Leveling):
Media: Porcelain balls or High-Density Plastic.
Chemical: [QLQ Product] Bright Polishing Liquid.
Time: 1–2 Hours.
Goal: Remove the "scratch pattern" from Step A, but do not mirror polish. Paint needs a slight matte texture to stick. Too shiny = Poor adhesion.
3. Common Mechanical Problems & Fixes
Issue: "Flat-on-Flat" Sticking. Flat badges stick together like wet coins.
Fix: Use [QLQ Product] Anti-Sticking Compound. Increase the ratio of Media-to-Parts to 4:1.
Issue: Rolled Edges. The sharp corners of the logo look rounded/blurry.
Fix: Shorten the time. Use smaller, faster-cutting media.
Phase II: Phosphating & Chemical Conversion (The "Invisible Glue")
Note: "Phosphating" is strictly for Steel/Iron. For Zinc Alloy, we use "Chromating" or "Zirconium Silane."
Scenario A: For Iron/Steel Badges (Zinc Phosphate)
Process: Degrease $\rightarrow$ Rinse $\rightarrow$ Surface Conditioning $\rightarrow$ Phosphating $\rightarrow$ Rinse $\rightarrow$ Dry.
The Chemical Bath:
[QLQ Product] Zinc Phosphate Salt: 50 g/L.
[QLQ Product] Accelerator: As needed.
Temp: 60°C – 80°C.
Time: 5 – 10 mins.
The Result: A grey, crystalline coating. The paint soaks into these crystals and locks on.
Scenario B: For Zinc Alloy Badges (Chromate / ZAP)
Process: Degrease $\rightarrow$ Activation (Weak Acid) $\rightarrow$ Conversion Coating $\rightarrow$ Rinse $\rightarrow$ Oven Dry.
The Chemical Bath:
Option 1 (Traditional): Yellow/Clear Chromate (Hexavalent is banned; Trivalent is OK).
Option 2 (Advanced QLQ): [QLQ Product] Nano-Ceramic Adhesion Promoter (ZAP).
Advantage: Eco-friendly, no heavy metals, creates a nano-scale coating that bonds paint chemically.
Temp: Room Temp.
Time: 1 – 2 mins.
Phase III: Master's Experience Share (Real World SOP)
1. The "Water Break" Warning
Observation: Before the badges enter the Phosphating/ZAP tank, lift one up.
Test: Does water cover the whole badge smoothly?
Reality: If you see water beading up on the logo, the polishing wax is still there. Phosphating will fail.
Action: Strengthen the Ultrasonic Degreasing step immediately.
2. The Drying Temperature Trap
Observation: Drying the parts after Phosphating.
Rule: Do not bake Iron Phosphate > 140°C.
Why? High heat breaks down the phosphate crystal water (dehydration), turning the coating into powder. The paint will peel off with the powder.
SOP: Dry at 100°C – 120°C max. Paint curing comes after painting.
3. Racking Marks (Shadows)
Issue: Badges are often painted on flat trays. The contact point doesn't get painted.
Solution: Use "Pin Racks" (Needle points) that hold the badge by the back pin or the screw hole. Never lay a high-end badge flat on a mesh belt if you want 360° coverage.
4. The "Dust" Defect
Issue: Phosphating leaves a loose "sludge" or white dust on the badge.
Cause: The solution has too much sediment/sludge.
Fix: Phosphate tanks need a "Settling Zone" or filtration.
Quick Fix: A "Passive Rinse" (Hot water + weak sealer) helps wash away loose dust before drying.
Phase IV: Troubleshooting Guide (Q&A)
| Problem | Likely Cause | Solution |
| Paint Peeling (Tape Test Fail) | Surface too smooth (Over-polished). | Reduce polishing time. Ensure Phosphating coating is present. |
| Blistering after Paint Curing | Moisture trapped in the metal. | Pre-bake the badges at 150°C for 30 mins before painting to drive out gas. |
| Rough Paint Surface | Phosphate crystals too coarse/large. | Add [QLQ] Surface Conditioner (Titanium salt) before phosphating to refine grain size. |
| Yellow Spots (Iron) | Flash Rusting during drying. | Add [QLQ] Anti-Rust Agent to the final rinse water. Dry faster. |
Description for the Blog/Guide Album:
🏅 The "Badge Perfection" Album: Preparing High-Value Crafts for Paint
A Nameplate is the "Face" of a product. If the paint falls off the logo, the brand looks cheap. This album bridges the gap between Dirty Polishing and Pristine Painting.
What's Inside:
🛑 Stop the "Lodging": A definitive chart on selecting the right Media Size vs. Badge Hole Size. Never pick media out of a hole with a needle again!
⚗️ Iron vs. Zinc: Why treating Zinc Alloy like Steel is the biggest mistake in phosphating. We explain the [QLQ Nano-ZAP] technology that replaces old-school sludge baths.
🔍 The "Crystal Size" Secret: Why big phosphate crystals ruin your gloss paint, and how to get the "Micro-Crystalline" finish for that luxury look.
🔥 The Pre-Bake Protocol: How to prevent die-cast zinc from "spitting" gas bubbles into your wet paint during the curing cycle.
👉 Ensure your badges survive the test of time. Read the Craft Preparation Album now!