The Art Of Thinning Bondo For A Perfect Skim Coat

Bondo is a type of body filler used in auto-body repair. It can be challenging to work with due to its fast-setting nature, requiring skill and quick action. While it is possible to thin Bondo with acetone or polyester resin, this can be tricky and may result in incomplete curing or increased shrinkage. Instead, some recommend using a product like 3M Flowable spot putty, which doesn't leave a tacky top skin like Bondo, or Evercoat's Plastik Honey, which can be used to thin Bondo without affecting cure time. However, for those determined to thin Bondo themselves, small test batches are recommended to perfect the technique and ratio of hardener to filler.

Use acetone to thin Bondo before adding hardener

When preparing Bondo for a skim coat, it is essential to understand the properties of the product and the role of the hardener. Bondo, a body filler, has a fast setting time, and thinning it with acetone requires careful consideration.

Firstly, it is important to note that Bondo should not be thinned with acetone after the hardener has been added. The hardener initiates the curing process, and altering the mixture with acetone at this stage may disrupt the chemical reaction and lead to an incomplete cure. Therefore, if acetone is to be used, it should only be mixed with the Bondo before the hardener is introduced.

The role of acetone in thinning Bondo is to reduce its viscosity, making it easier to apply a skim coat. Acetone is a solvent that can dissolve some of the resins in Bondo, creating a more fluid consistency. However, it is crucial to use acetone sparingly and gradually add it to the Bondo, mixing thoroughly, until the desired consistency is achieved.

It is also essential to work in a well-ventilated area when using acetone, as it can produce strong fumes. Additionally, as acetone is flammable, ensure there are no open flames or sparks nearby.

Finally, before proceeding with a skim coat application, it is advisable to perform a small test patch to ensure the thinned Bondo performs as expected. This includes checking the cure time, adhesion, and workability of the mixture.

Polyester resin can be used to thin Bondo

Bondo is a popular brand of polyester resin used for a variety of applications, including auto, boat, and home repairs. It is often used to seal cracks, repair breaks, and recreate or join surfaces. Bondo can also be used as a sealer on damaged and rotted wood. One of the key advantages of Bondo is its high strength, which makes it suitable for building and repairing boats.

When it comes to thinning Bondo for a skim coat, one option is to use polyester resin. Polyester resin is a common thinner for Bondo and can be used to achieve the desired consistency for skim coating. It's important to note that Bondo is already a type of polyester resin, so using the same material to thin it can be effective.

There are different types of polyester resins available, and the specific one chosen may depend on the project requirements and personal preference. For example, the Bondo brand offers a clear liquid polyester resin that can be used for various applications, including auto, boat, and home repairs. This particular resin is mixed with a hardener and can be sanded within a few hours of application.

When thinning Bondo with polyester resin, it's important to follow the manufacturer's instructions and safety guidelines. The mixing ratio of resin to hardener is crucial to ensure the desired results and curing time. Additionally, proper ventilation and protective gear are important when working with these materials.

In summary, polyester resin can be used to thin Bondo for a skim coat. The Bondo brand offers a range of products, including polyester resins, that can be used for various applications. By following the manufacturer's instructions and safety guidelines, individuals can effectively thin Bondo to suit their specific needs.

Don't thin Bondo, buy 3M Flowable spot putty instead

If you're looking to skim coat, don't thin Bondo—instead, opt for 3M Flowable Spot Putty. Here's why:

Thinning Bondo for a skim coat can be tricky and time-consuming. Bondo, also known as body filler, is a type of putty used to fill imperfections in surfaces, such as dents, scratches, and gouges. While it can be thinned with a suitable reducer or solvent, this process can be challenging and may not always yield the best results.

That's where 3M Flowable Spot Putty comes in. This product is specifically designed as a self-leveling, flowable, brushable putty that can be easily applied as a skim coat. It fills pinholes, minor dents, scratches, and other imperfections in a variety of surfaces, including body filler, steel, galvanized steel, aluminum, SMC, fiberglass, and OEM paint.

One of the biggest advantages of 3M Flowable Spot Putty is its ease of use. It comes in a convenient squeeze tube, making application simple and mess-free. Additionally, it cures tack-free in 20 to 25 minutes, or 30 minutes depending on the source, which is significantly faster than traditional body filler. This means you can quickly and efficiently complete your repair or restoration project without the hassle of thinning Bondo.

Another benefit of 3M Flowable Spot Putty is its versatility. It is compatible with a wide range of substrates, including galvanized steel, sanded paint, aluminum, steel, SMC, and fiberglass. This makes it suitable for use on various surfaces and projects. Additionally, its stain-resistant formula works well with basecoat and clearcoat systems, minimizing the staining that can occur with traditional body filler.

In conclusion, if you're considering thinning Bondo for a skim coat, don't waste your time and effort. Instead, opt for 3M Flowable Spot Putty, which offers a convenient, effective, and versatile solution for your surface repair and restoration needs. With its easy application, fast curing time, and broad compatibility, it is a superior choice for achieving a smooth and flawless finish.

Evercoat's Plastik Honey can be used to thin Bondo

Evercoat Plastik Honey is an auto body filler thinner that can be used to thin Bondo. It is specifically designed to thin and enhance traditional polyester body fillers and polyester glazing putties. The product is blended with a premium, clog-free and stain-free resin, which improves the spreading properties of fillers and reduces pin holes.

To use Plastik Honey to thin Bondo, simply add a small amount of the product to the Bondo filler before adding the hardener. You can then continue to add Plastik Honey in small increments until you achieve your desired consistency and smoothness. This process will also increase the amount of time you have to work with the Bondo before it hardens.

Plastik Honey is a versatile product that can be used with a wide range of fillers and putties, including those from competing brands. It is a popular choice for automotive body repair due to its effectiveness in improving the spreadability of fillers and reducing the number of air bubbles.

It is important to note that Plastik Honey has a sharp, aromatic odour and contains chemicals that may be harmful. Therefore, it is recommended to use this product in a well-ventilated area and follow appropriate safety precautions.

Bondo can be cut with fibreglass resin

The Bondo Liquid Resin for Fibreglass Filler comes with a Bondo® CLEAR LIQUID Hardener included. The two-part formula creates an extremely strong chemical bond with surfaces. The resin is mixed with the hardener and applied to the repair area. The mixture will be workable for 8-12 minutes once combined, and it will cure in approximately 2 hours at 75°F.

When using Bondo Liquid Resin for Fibreglass, it is important to follow the correct preparation and application steps. The repair area should be cleaned and sanded to remove any paint, primer, or debris. The resin and hardener should be mixed in small amounts, as per the instructions, and applied to the repair area using a paintbrush. For larger repairs, Bondo® Fiberglass Cloth or Mat can be used in conjunction with the resin for added strength.

Bondo also offers an All-Purpose Fibreglass Resin that can be used for sealing cracks, repairing breaks, or filling holes in a variety of materials including fibreglass, wood, concrete, or metal. This resin is also 100% waterproof and includes a liquid hardener.

Frequently asked questions