Slip Stream 24/7 – Global Supply and Distribution Company providing 3M Industrial, Commercial & Safety Solutions
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SKU 7100152666
Legacy SKU 60455056048
UPC 00076308009120
Catalog Number 912
Product Number 912

Liquid Hardener mixes with Fiberglass Resin and Bondo Metal Reinforced Filler to create high-quality, long-lasting repairs. When hardener is mixed with product, a chemical reaction occurs to create a mixture that will deliver a strong, lasting repair. This hardener is also easy to mix.

  • Liquid hardener designed to mix with Bondo® polyester fiberglass resin and Bondo® Metal Reinforced Filler requiring liquid hardener
  • Creates chemical reaction with resin for fast curing
  • Use with Bondo Fiberglass Resin for auto and home repairs including tubs, showers, sinks, pools, hot tubs, boats, and more.
  • Results in a 100% waterproof repair
  • Apply to fiberglass, metal, brick, wood, and concrete surfaces
  • Once mixed, the fiberglass resin will cure in approximately 2 hours
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On it's way to you May 28   


Minimum Order 6 Items
Order Increment 6 Items
Product Dimensions
Imperial Metric
Weight 0.0975 lbs
Width 2-3/4
Length 0.85
Height 6-1/2
Shipping Dimensions
Weight 0.585 lb
Length 9.25 in
Width 7.6248 in
Height 4.25 in
Color Transparent


  1. What is the main purpose of 3M's Bondo® Liquid Hardener, 00912, .37 oz.?

    The Bondo® Liquid Hardener is designed to be mixed with body filler or fiberglass resin to accelerate the curing process and create a stronger, more durable bond.

  2. How much Bondo® Liquid Hardener should I add per ounce of body filler?

    We recommend adding approximately 1% - 2% of hardener by weight to ensure proper curing.

  3. Can I use other brands of body filler with this liquid hardener?

    Yes, the Bondo® Liquid Hardener can be used with most types and brands of automotive body fillers for optimal results.

  4. Is it easy to mix and apply the Bondo® Liquid Hardener?

    Yes, simply follow the instructions on the packaging for accurate measurements and thoroughly mix before applying to achieve desired results.

  5. How long does it take for the Bondo® mixture to fully cure after adding this hardener?

    Depending on environmental conditions such as temperature and humidity, the cured bond can typically be sanded or painted within 20-30 minutes.

Chemically Activate the Hardening Process
Bondo® Liquid Hardener is a hardening agent specifically designed to accelerate the curing process of polyester fiberglass resins and Bondo® Metal Reinforced Filler. Its liquid consistency allows for easy and quick mixing. This hardener offers a perfect balance between user-friendliness and high-quality final results.

Lasting Repairs that Stand the Test of Time
When mixed with polyester fiberglass resins, this hardener creates repairs that are exceptionally strong, durable, and waterproof. The fiberglass resin will cure in approximately 2 hours after mixing. It is suitable for both interior and exterior automotive and home projects.

Formulated to Strict Purity Standards for Quality Results
Bondo® liquid hardener is formulated and packaged under temperature-controlled conditions to ensure freshness and optimal performance. Mixing the liquid hardener with Bondo® polyester fiberglass resin, other resins, and Bondo® Metal Reinforced Filler is a simple task that requires minimal time and effort.

Use During the Fill Stage of the 3M™ Body Repair System
Even a seemingly small repair can be complex. That's why 3M’s Body Repair System simplifies the entire automotive body repair process by dividing it into four stages:

  • Stage 1 - Prepare: This stage involves tasks such as dent pulling, paint and rust removal, and efficient masking of the repair area.
  • Stage 2 - Fill: Patching holes with reinforced filler and smoothing and shaping the filler before painting are the key steps in this stage.
  • Stage 3 - Paint: Painting the repaired area and blending and smoothing primer and paint are the main activities in this stage.
  • Stage 4 - Finish: This final stage focuses on achieving showroom-grade results by removing small defects, sealing, and polishing clear coats and other painted surfaces.

3M provides premium products, including abrasives, tapes, body fillers, and tools, for each stage of the body repair process. This comprehensive system enables you to work easily, efficiently, and successfully throughout the entire process.

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