[Product Insight] Understanding the Difference Between CHPO and BPO Body Fillers — Choosing the Right Type for Your Clim

A Practical Guide from Gate Materials for Auto Body Repair Professionals

Why Choosing the Right Filler Matters

When repairing vehicle surfaces, the choice between CHPO and BPO body fillers can directly affect sanding quality, adhesion strength, and drying performance.

Many refinishers in Southeast Asia, Africa, and the Middle East face issues such as poor curing, cracking, or paint detachment — often caused by using the wrong filler type for their local climate.

What Is CHPO Body Filler?

CHPO (Conventional Unsaturated Polyester) filler is a cost-effective, general-purpose putty widely used in moderate and dry regions.

It provides excellent spreadability, smooth finish, and fast sanding performance — ideal for use on steel, iron, and fiberglass surfaces.

Key Features of CHPO Fillers:

• Smooth and creamy texture for easy application
• Quick surface drying (20–30 min @ 25°C)
• Excellent sanding with dry or wet methods
• Perfect for tropical and dry climate regions
• Cost-efficient for high-volume repair shops

Limitations: Not suitable for aluminum, stainless steel, or plastic surfaces.

What Is BPO Body Filler?

BPO (Benzoyl Peroxide Accelerated System) fillers are high-performance types designed for areas with cooler or humid climates.

They cure faster, adhere strongly to smooth metals, and resist temperature fluctuation — making them the preferred choice for professional workshops and 4S centers.

Key Features of BPO Fillers:

• Strong adhesion to aluminum, stainless steel, and alloy surfaces
• Faster hardening under lower temperatures
• Excellent stability and long-term crack resistance
• Ideal for Europe, North China, or cold-region applications

Pro Tip: BPO fillers typically use a red hardener, while CHPO usually uses a yellow one — making them easy to distinguish during use.

Climate-Based Selection Guide

Gate Materials’ Dual-Factory Advantage

Guangzhou Gate Materials Co., Ltd. operates both CHPO and BPO putty factories:

• Dongguan: Specializes in CHPO body fillers (high consistency, economical type)
• Dongguan (2nd plant): BPO fillers (high adhesion, fast curing)
• Yingde: Production bases for Bossde and Zuotong automotive paints

This structure allows Gate to provide customized formulations according to the distributor’s country, temperature, and storage conditions.

OEM & Export Flexibility

Gate Materials offers:

• Private label & OEM production with custom tins and hardener colors
• Container consolidation (putty + paint + thinner in one shipment)
• Fast production lead time (15–25 days average)
• 24-month shelf life with international MSDS & TDS support

Expert Tips for Application

• Always mix thoroughly at a 100:2 ratio (putty:hardener) by weight
• Avoid overuse of hardener to prevent cracking
• Ensure surfaces are clean, dry, and degreased before application
• Store unopened tins at 5–25°C in ventilated conditions

About Gate Materials

As a leading Chinese manufacturer of automotive refinish materials, Gate Materials exports body fillers, primers, clear coats, and color toners to over 20 countries.

With strong R&D support and integrated OEM service, the company continues to help global distributors build reliable brands in the automotive coatings industry.