How to Properly Install USDOT Decals (and Fix Common Issues)
Installing USDOT numbers and other vehicle decals seems simple—until bubbles, peeling corners, or poor placement cost you time, money, or even a compliance fine. In this guide, we walk you through expert-backed installation tips and how to troubleshoot the most common issues.
🧰 What You’ll Need
- Clean microfiber cloths
- Rubbing alcohol or mild soap & water
- Squeegee or credit card
- Masking tape
- Tape measure or level (optional but helpful)
Pro Tip: Never apply vinyl to a dirty or waxed surface. Residue can prevent full adhesion.
🧼 Step 1: Prep the Surface
- Wash the area with soap and water.
- Wipe down with rubbing alcohol to remove any remaining grease or residue.
- Let the surface dry completely.
Avoid: Glass cleaner or silicone-based products. These leave behind residue that interferes with adhesion.
📐 Step 2: Measure and Position
- Use a tape measure or level to center your decal where required (usually on both sides of the cab).
- Mark your placement lightly with masking tape.
- Use the “hinge method” by taping along the top edge to hold the decal in place before peeling.
🖐️ Step 3: Apply the Decal
For Vinyl Stickers:
- Peel the backing off slowly from one side.
- Press the decal down from top to bottom or side to side using a squeegee.
- Smooth out air bubbles as you go.
- Once fully applied, slowly remove the transfer tape (if applicable).
For Magnetic Signs:
- Let the magnet come to room temperature before applying.
- Stick it to a flat, clean metal surface (not plastic or curved panels).
- Remove weekly to clean behind it and prevent rust.
🚨 Troubleshooting Common Issues
| Issue | Cause | Fix |
|---|---|---|
| Air bubbles | Applied too quickly or to a dusty surface | Use a pin to gently pop the bubble and smooth it out |
| Peeling corners | Incomplete adhesion or waxy surface | Re-clean surface and reapply or replace decal |
| Crooked placement | No guide used during install | Use masking tape or a level before applying |
| Won’t stick in cold temps | Vinyl becomes brittle | Apply in temps above 50°F or use a heat gun |
| Magnet won’t stay on | Curved panel or dirty surface | Only apply to clean, flat steel and remove weekly |
📦 When to Replace Your Decals
- Cracked, peeling, or curling edges
- Faded or unreadable numbers
- Loss of adhesion due to exposure or wear
- Updated DOT, MC, or GVW numbers
👨🔧 Need Replacements or Custom Help?
We offer high-quality vinyl and magnetic decals that meet USDOT requirements and are designed for long-term durability.
- ✅ Custom sizes
- ✅ Easy-to-read fonts
- ✅ Fast turnaround
🛒 Shop Now or contact us for a quote on fleet orders.