Bondo, a two-part (resin with hardener added) mix of talc and plastic, was introduced in 1955. It was developed by WWII veteran and automotive repair shop owner Robert Merton Spink of Miami, Florida.

Is Bondo the same as fiberglass resin?

Part of a brand that is well-known for auto repair, this fiberglass resin works with fiberglass, wood, concrete and more. … Bondo® All-Purpose Fiberglass Bondo® Fiberglass Resin Liquid Hardener is included with the resin.

What is Bondo hardener made of?

This hardener is mixed with polyester fiberglass resins to create extremely strong, durable and waterproof repairs. Once mixed, the fiberglass resin will cure in approximately 2 hours.

What is the difference between Bondo and fiberglass?

The diffrence between the fillers is what’s in them. Regular filler is basically resin with talc, Bondo glass and fiberglass jelly have strands of fiber glass, short or long depending on the strenght needed, and metel-2-metal has aluminum in it. Most fillers go over metal, fiberglass, or SMC with no problem.

Is Bondo toxic?

Bondo is very toxic, especially the dust fibers. Don’t get it on your skin or breathe it directly without a mask. Fumes are very flammable too; not something you want to use around a home heater. fire may build pressure and explode.

Can you use fiberglass cloth with Bondo?

When properly used with Bondo® Fiberglass Resin, Bondo® Fiberglass Cloth reinforces repair areas and allows for repainting so that the repair looks like the original surface once the job is complete. … To complete the repair, you’ll add layers of fiberglass cloth along with fiberglass resin to fill the hole.

Does Bondo harden without hardener?

Without it the bondo won’t get hard. Put a small piece of bondo on a board and run a line of hardener from end to end. It will take about five minutes to mix it up and apply it.

Can you mix fiberglass resin with Bondo?

Mix the Bondo® All Purpose Fiberglass Resin in a paper cup with the Bondo® Fiberglass Resin Hardener. … For larger applications, use half of the fiberglass resin hardener supplied, to half of the resin container. Using large amounts at one time will cut the working time in half of the mixed resin.

Is Bondo resin polyester?

As a brand of 3M, Bondo® is well known among boat manufacturers and collision repair professionals. This polyester resin is another way that 3M applies science to life, and helps you restore and maintain the beauty and value of your cars, boats and other possessions in and around the home or shop.

Why is Bondo bad?

Unfortunately, filling compounds such as Bondo also present some drawbacks. Fillers like Bondo can crack if they are mixed too thickly, harming rather than improving the look of the car. Additionally, there’s a risk of discoloration and poor long-term wear when you use a dent repair filler like Bondo.

Article first time published on

What can I use instead of Bondo?

You can use plastic/metal 2-part epoxies. Repair epoxy is also a good alternative.

Does Bondo come with hardener?

(Bondo comes with a tube of hardener.) If you add too much hardener, the mixture will gel too quickly. … If you add 1 line of hardener across the top of the dollop of Bondo, it takes about 15 minutes to dry after applying.

What is fiberglass hardener made of?

The majority of all fiberglass parts are constructed using polyester resins, it’s the most widely used type of resin in the composites industry. Polyester resins require a catalyst to cure or harden, typically methyl ethyl ketone peroxide (MEKP).

What is Bondo plastic metal used for?

Bondo Plastic Metal is a product commonly used for filling dents and cracks in metal surfaces, usually on automobiles. It’s built up gradually in thin layers until the dent or hole is filled and level with the surface of the metal, but it should only be used with dents no more than 4 inches in diameter.

Are car fillers toxic?

Most body fillers contain a solvent called styrene. As the filler dries, styrene is released to the air and you can breathe it. … Exposure to styrene can cause respiratory irritation. It may also damage your liver and possibly cause cancer at very high levels of exposures – not usually found in autobody shops.

Should you wear a mask when using Bondo?

Dry sanding or bondo/filler work—It’s best to wear a half mask with organic vapor cartridges and paint pre-filters because fresh primer often has isocyanates in it and bondo/filler dust contains styrene, which is a carcinogenic solvent. … Otherwise, use a half mask cartridge respirator with HEPA filters (pink color).

Is it safe to sand Bondo?

Once the Bondo cures, it’s time to sand. Power sanders are OK to break the surface and knock down any high spots, but hand sanding with the body contour is the best way forward. … The lightweight Bondo Gold is far easier to sand than the heavier type, so consider using the good stuff on the way out.

Is Bondo better than wood filler?

The biggest advantage of using Bondo over a regular wood filler is the short dry time. Wood filler can take hours to dry and require more than one coat. Bondo dries in less than 30 minutes and only requires one coat! This means more projects in less time.

Will filler go off without hardener?

Wood fillers can be used to reinforce softwoods or rotten woods structurally. However, this is usually only a stopgap without using a hardener as well. You can use both in conjunction to save ancient, fragile woods.

How long does it take Bondo to fully cure?

Allow the putty to dry 15 minutes at 77 degrees F (25 degrees C). In cooler climates, putty may take 20-30 minutes to dry. 7. Using 3M™ Sandpaper 80 grit, sand and shape the filled area to the contour of the surface.

Can you use liquid hardener with Bondo?

Bondo Fiberglass Resin Liquid Hardener is designed specifically for use with Bondo Fiberglass Resin and Bondo Metal Reinforced Filler. This hardener is easily mixed with resin or filler; a chemical reaction creates an extremely strong, waterproof repair material.

Can you use Bondo on fiberglass tub?

The Bondo Shower & Tub Kit from 3M was designed to permanently repair small chips, scratches, cracks gouges and holes in fiberglass, porcelain and acrylic tubs, showers, sinks, hot tubs, pools and boats. … Bondo Shower & Tub Kit should be used on white or almond surfaces only if a perfect match is desired.

What weight is Bondo fiberglass cloth?

Manufacturer‎3M – AADBrand‎BondoModel‎Bondo 20128 Fiberglass Cloth – 8 sq. ft.Item Weight‎5.6 ouncesPackage Dimensions‎7.52 x 5.08 x 1.34 inches

What kind of hardener do you use for fiberglass resin?

Bondo fiberglass resin liquid hardener is designed specifically for use with Bondo fiberglass resin and Bondo metal reinforced filler. This hardener is easily mixed with resin or filler; a chemical reaction creates an extremely strong, waterproof repair material.

Can epoxy be used on fiberglass?

One reason that an epoxy product such as WEST SYSTEM® Epoxy is so useful for fibreglass boat repairs is that it’s an incredibly effective adhesive. It creates a resilient bond to fibreglass, cured polyester laminates, wood and metals – even when you only use a thin film.

How long before you can sand fiberglass?

Before sanding, let the fiberglass sit out in the sun for 2 to 7 days to cure the gelcoat. This process releases any air pockets from the gelcoat that would cause problems when sanding and painting.

Can you put Bondo on top of fiberglass?

Bondo Body Filler cures fast, shapes in minutes and is formulated to be a non-shrinking and permanently durable material. In addition to its uses on vehicle exteriors and other metal surfaces it is also a suitable repair option for wood, fiberglass and concrete.

Is there a Bondo for plastic?

Like most plastic body fillers, Bondo is a lightweight polyester-based plastic body filler that was originally developed as an alternative to lead body solder. …

What is stronger epoxy or Bondo?

The epoxy product that I have used (Abatron) is worth the extra if for no other reason that it sands more like the wood, whereas Bondo is much harder than the wood and will tend to stand proud of the surrounding areas if you’re not careful when sanding.

Do auto body shops still use Bondo?

Yes auto body shops still use Bondo and other fillers. It is a great product and if used properly, thin applications, it works great. Most Bondo problems are due to excessive thickness and improper application.

Is Bondo epoxy or polyester?

Bondo is a trade name for a common automotive filler that is polyester resin and typically talc. The Bondo name is used like Kleenex to refer to any mix of polyester filler. Epoxy is not polyester.