How to Wrap Car Hood with MOZX: Complete Step-by-Step Guide.

PET Color-Changing Film—Complete Installation Steps for the Hood

PET Color-Changing Film Characteristics: High rigidity, poor elasticity, and an extremely high risk of shrinkage after stretching; strong pulling in localized areas is strictly prohibited. Prioritize heat-induced shrinkage and minimize stretching as much as possible.

Environment: Dust-free workshop, room temperature 18–25°C; the hood must be at room temperature—do not apply the film to a hot engine; the hood must have undergone a thorough pre-installation wash and deep degreasing.

Tools: Heat gun, soft and hard squeegees, film application mat, utility knife, lint-free cloth, 75% isopropyl alcohol, masking tape, air blower.

 Hood Pre-Treatment (Of Utmost Importance)

1. After washing the car, degrease the hood’s paint surface, the flanges around the edges, and the inner trim areas twice with isopropyl alcohol to remove silicone oil, grease, and wax residues; Blow out dust particles from corners and crevices.
2. Inspect the paint surface: Pre-treat any particles, paint spatter, or imperfections; blow out all dust from crevices, as dust can cause dust spots.
3. Mask the hinges and rubber seals around the hood with painter’s tape to prevent the utility knife from scratching plastic parts.
4. Unroll the film and verify dimensions: The hood film must have a 4–6 cm overlap allowance on all four sides; if insufficient, installation cannot proceed.

 Applying the Film and Overall Positioning (Standard Two-Person Procedure)

• Leave the protective film on the surface of the PET film; do not remove the backing paper. Two people should lift the entire sheet of film and position it suspended over the hood, aligning it with the hood’s contour and ensuring even excess on all four sides.
• Observation: Direct all wrinkles toward the edges of the hood; do not leave wrinkles in the center of the main surface.
• Preliminary Positioning: Peel back the release liner approximately 20–30 cm on the side near the windshield (rear end of the hood). Secure only a small section along the center of the hood’s upper edge for temporary positioning; do not peel back the release liner over a large area.

Do not remove the entire release liner at once. PET has high adhesion and can easily become permanently bonded, making adjustments impossible.

Peel off the release liner and perform initial air removal on the large surface

1. Starting from the rear end of the hood (where it has already been positioned), peel off the release liner in sections toward the front, removing 30–40 cm at a time; do not peel it all off at once.
   Leave the PET’s built-in transparent protective film on the surface. Use a squeegee with a protective film pad to avoid directly scratching the glossy surface of the PET.
2. Squeegee technique: Push bubbles out radially from the center toward the edges. First, smooth out the large, flat areas. Once the flat areas are complete, do not temporarily address the curved areas at the front of the hood; leave any wrinkles in the unapplied front section.
3. PET Do’s and Don’ts: Never forcefully smooth out wrinkles; once wrinkles are permanently smoothed out, they cannot be repaired, and you’ll have to peel it off and start over.

Handling the Curvature of the Hood (Most Critical for PET; Do Not Stretch Violently)

PET Principle: Prioritize heating to soften the film, relieve tension across the entire surface, and disperse wrinkles in a “figure-eight” pattern; avoid applying strong force to a single point. Strong pulling at a single point will inevitably cause the film to shrink and curl at the edges, fade in color, or develop printing marks later on.

1. If wrinkles appear on the curved, raised section at the front of the hood: Completely peel off the film that has already been applied but still contains wrinkles.
2. Set the heat gun to approximately 280–320°C, hold it 12–15 cm away from the film surface, and move it back and forth to evenly soften the entire area—do not focus on a single spot. Stop
3. heating as soon as the film softens slightly; overheating will cause deformation.
4. Hold the film lightly with both hands suspended in the air and gently stretch it in a figure-eight pattern to break up large wrinkles into fine, small ones; do not pull forcefully at a single point.
   Lay the film flat without tension and allow it to cool naturally for a short time (to release tension) before lightly scraping it into place with a scraper; do not press it down immediately while it’s still hot after heating, as this will lock stretching stress inside the film, causing it to shrink and curl at the edges later.
5. Repeat this process in sections: peel back a section, heat to soften and release tension, break up the folds, cool, and lightly scrape into place, working step by step toward the front of the hood.

• Correct Approach for PET: Rely on heat to allow the film to expand on its own, rather than forcibly stretching it by hand.
• Incorrect Approach: Vigorously pulling in localized areas to force the film to conform to the hood’s curvature may look good initially, but the edges will spring back and curl within 1–2 days.

 Edge Ridges and Corner Treatment

1. Hood Ribs (Edge Lines) Location: Apply the film loosely along the edge lines. First, press lightly to position the film along the ribs, then release air from both sides; do not apply lateral tension at the edge lines.
2. Front Corners of the Hood: Do not pull at a single point on the corners. After softening the film with heat, distribute the stress to the surrounding larger surfaces, leaving only a small amount of overhang at the corners.

Trimming the Edges (Leaving Overlap Allowance)

1. After the entire surface is smoothly applied without bubbles, trim the film along the outer contour of the hood; leave a 7–10 mm overlap allowance—do not trim flush with the paint surface.
2. Utility knife: Set the blade angle to shallow, place the knife against the outer edge of the paint surface, and cut—do not let the tip pierce the original paint; leave a rounded allowance at corners; do not cut sharp corners.
3. Remove the excess film; do not peel off the protective film from the surface for now.

 Edge Wrapping and Sealing (PET: Post-heating is mandatory to prevent shrinkage)

1. Fold the reserved 7–10 mm of film into the inner side of the machine cover’s flange.
2. Low-temperature sealing: Use a heat gun to gently heat the edge-wrapped area from a distance, allowing the film to soften slightly. Then, using a finger sleeve or soft scraper, press the film firmly against the inner metal surface in sections. Work gradually; do not press the entire edge flat all at once.
3.  Post-heating Setting (Critical Step for PET): After all edges have been pressed, apply a low-temperature heat pass over the entire edge area to allow the film to complete its heat shrinkage and set, releasing internal stress and reducing the likelihood of edge curling later on.
4. Near the hood hinges, do not force the film too tightly; leave a slight amount of space for expansion and contraction.

Inspection, Bubble Removal, and Peeling Off the Protective Film

1. Overall inspection: Check large surfaces, edges, and corners for hidden creases, adhesive marks, or particles. Small air bubbles can be removed by peeling back the film and re-deflating them; permanent creases must be peeled off and redone.
2. Once everything is confirmed to be OK, peel off the outer transparent protective film.
3. Use a soft scraper and a lint-free cloth to gently smooth all edges one final time.

Post-Application Care

1. Let the film sit at room temperature in the workshop for 30–60 minutes to allow the adhesive layer to bond fully;
2. Do not wash the car within 24 hours, and do not direct a high-pressure water jet at the edge seams; avoid washing the car in direct sunlight or high temperatures for 7 days.

Summary of Common Pitfalls in High-Frequency PET Hood Color-Changing:

•  Excessive stretching in localized areas: Consequences—shrinkage, curling edges, color fading, and adhesive marks. This is the most common issue with PET.
•  Applying high heat to specific spots with a heat gun: Causes film deformation and rippling.
•  Leaving too little overlap and cutting flush with the edge: Will inevitably cause curling.
•  Skipping post-heating setting and finishing immediately after edge wrapping: Stress is not released, leading to edge separation later on.
•  Failing to thoroughly clean the gaps: Dust trapped along the hood edges causes dust spots.
•  Applying the film directly to a hot hood: Uneven heating causes abnormal shrinkage.