Best Glazing Putty for Plastic: 5 Picks for Bumpers and Trim

A plastic bumper picks up a shallow scrape in a parking lot, and the ding sits right at eye level every time the car is washed. Filler alone can look lumpy on a flexible panel, and a skim coat that cracks or peels makes the repair worse than the dent. The best glazing putty for plastic fills pinholes and low spots, sands smooth and stays put on bumpers and trim, and this guide compares five listings by flexibility, sanding, hardener and finish.

GarageToolHQ earns a commission when you buy through links on this page, at no extra cost to you. Read our affiliate disclosure.

Picks for the garage

#	Product	Shop Score	Buy
1	Evercoat Body Shop 105021 Pro-Grade Glazing Putty	9.6/10	Buy on Amazon
2	Evercoat Poly-Flex Flexible Polyester Glazing	9.6/10	Buy on Amazon
3	KMK K-Glaze G-10440 Finishing Putty - 440ml	9.6/10	Buy on Amazon
4	USC 26006 Icing 24 oz tube	9.5/10	Buy on Amazon
5	Frienda 6 Pcs Body Filler Spreaders Plastic Auto	9.4/10	Buy on Amazon

1

Evercoat Body Shop 105021 Pro-Grade Glazing Putty

EVERCOAT Body Shop·9.6/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A pro-grade glazing putty in a 3 Fl Oz tube with cream hardener included, stated for minor imperfections and low spots on metals, plastics and wood, with sanding up to 50% faster than traditional products.

Check price on Amazon

Pros

• Stated for plastics as well as metals and wood
• Sands up to 50% faster than traditional products
• Stain-resistant and tack-free finish
• Cream hardener included in the package

Cons

• Small 3 Fl Oz size for wide skim-coating jobs
• Only 1 item per package
• No spreader is listed in the package
• No weight or dimensions stated in the listing

2

Evercoat Poly-Flex Flexible Polyester Glazing

Evercoat·9.6/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A flexible polyester glazing putty in a 30 Fl Oz size for spot filling and skim coating on flexible bumpers and plastic parts, with easy sanding using 180 grit sandpaper.

Check price on Amazon

Pros

• Made for flexible bumpers and plastic parts
• 30 Fl Oz size for skim coating
• Easy sanding with 180 grit sandpaper
• Stated for steel, aluminum and fiberglass as well

Cons

• No hardener is listed with the putty
• No warranty term stated
• Large 30 Fl Oz size takes more shelf space
• Only one size listed

3

KMK K-Glaze G-10440 Finishing Putty - 440ml

KMK·9.6/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A light green finishing putty in a 440ml size, listed as 15 fl oz, that self-levels to eliminate pinholes with minimal sanding and includes the hardener for a 2% paste hardener mix.

Check price on Amazon

Pros

• Self-leveling flow eliminates pinholes
• Minimal sanding required
• Tack-free surface with strong adhesion
• Hardener included for the 2% mix

Cons

• No plastic bumper listed among approved substrates
• No warranty term stated
• Preparation must follow the KMK Technical Data Sheet
• Only 1 item per package

4

USC 26006 Icing 24 oz tube

USC·9.5/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A glazing and finishing filler putty in a 24 oz tube, made in the US, sized for icing and finishing work on body panels.

Check price on Amazon

Pros

• 24 oz tube for finishing work
• Made in US
• Tube format for controlled application
• Larger than the 3 Fl Oz Evercoat tube

Cons

• Only one bullet in the listing: Made in US
• No hardener mentioned
• No sanding guidance stated
• No warranty term stated

5

Frienda 6 Pcs Body Filler Spreaders Plastic Auto

Frienda·9.4/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A set of 6 plastic body filler spreaders in 3 sizes, about 4 inches, 5 inches and 6 inches, with flexible edges for applying fillers, glazes, caulks and paint.

Check price on Amazon

Pros

• 6 pieces in 3 sizes for different areas
• Flexible edge suits curved body parts
• Maker lists quality plastic that resists deforming and breaking
• 2 sets of 3 pieces, enough to share

Cons

• Spreaders only, no putty included
• Spec table dimensions differ from the bullet sizes
• No warranty term stated
• Applicator only, no sanding role

Compared on paper

*Specs such as CFM, PSI and torque are the manufacturer’s ratings as listed, collected 12 November 2026.

How the picks are scored

Each putty is scored on performance, build, value, safety and warranty, with the weights published on the How We Pick page. No listing here states a safety certification or a warranty term, so safety and warranty score zero across the picks and the ranking turns on performance, build and value.

Shop Scores range from a low of 9.2 to a high of 9.8, with each tool positioned by its weighted points proportionally, and more points always yields a higher score. Where a tool neither runs on power nor lists a safety feature, safety shows n/a and the other 90 points decide.

What the listings tell you

Five glazing putty listings were read for this guide. Two include a hardener, one states sanding up to 50% faster than traditional products, and one gives a sanding grit of 180. One listing is a set of spreaders rather than a putty, and one listing gives a single bullet, so the detail on offer varies a lot from pick to pick.

Buying guide: the best glazing putty for plastic

Flexibility for plastic parts

Plastic bumpers and trim flex, so a rigid skim coat can crack. The Poly-Flex putty is made for flexible bumpers and plastic parts, and the Evercoat pro-grade putty lists plastics among its surfaces. A finishing putty that self-levels, like the KMK pick, also helps on curved trim.

Sanding and finishing

Glazing putty is a finishing step, so easy sanding matters. The Evercoat pro-grade putty states sanding up to 50% faster than traditional products, and the Poly-Flex putty states easy sanding with 180 grit sandpaper. The KMK pick states a self-leveling flow with minimal sanding, which suits pinholes and small surface imperfections.

Hardener and mixing

Two picks include a hardener: the Evercoat pro-grade putty includes a cream hardener, and the KMK pick includes the hardener for a 2% paste hardener mix. The other listings state no hardener, so check the listing before the first job if a hardener is needed.

Spreaders and application

A flexible edge helps lay a thin, even coat. The Frienda set includes 6 spreaders in 3 sizes, about 4 inches, 5 inches and 6 inches, with a flexible edge for fillers, glazes and caulks. Two sets of 3 pieces come in the package, so a spare stays clean while one is in use.

Pinholes before paint

Pinholes show through paint, so a putty that targets them saves a second coat. The KMK pick is made to eliminate pinholes and cover small surface imperfections before refinishing, and the Evercoat pro-grade putty fills minor imperfections and low spots.

After the repair, an air die grinder for auto body helps with shaping work around the repair.

Garage Fit Check

• Tube and tub sizes run from 3 Fl Oz to 30 Fl Oz, so pick a size that matches the job and the shelf space.
• The Poly-Flex putty weighs 2.59 pounds and the USC tube weighs 1.8 pounds, so both sit steady on a bench shelf.
• Two picks include a hardener, and the KMK pick calls for a 2% paste hardener mix, so keep the hardener with the putty.
• The Frienda spreaders come in 3 sizes, about 4 inches, 5 inches and 6 inches, so a size is at hand for small trim and wide panels.

FAQ: garage tools

Can glazing putty be used on plastic bumpers?

Yes, when the listing states plastics as a surface. The Evercoat pro-grade putty lists plastics among metals and wood, and the Poly-Flex putty is made for flexible bumpers and plastic parts.

What grit sandpaper should I use on glazing putty?

The Poly-Flex listing states easy sanding with 180 grit sandpaper. Other listings here state no grit, so follow the grit the listing for the pick in use states.

Does glazing putty need a hardener?

Two picks here include one: the Evercoat pro-grade putty includes a cream hardener, and the KMK pick includes the hardener for a 2% paste hardener mix. Listings that state no hardener should be checked before the first job.

How do I fix pinholes before paint?

Use a finishing putty made for pinholes. The KMK pick is designed to eliminate pinholes and cover small surface imperfections before refinishing, with a self-leveling flow and minimal sanding.

Can I apply glazing putty with a plastic spreader?

Yes. The Frienda set is made for applying fillers, glazes and caulks, with a flexible edge in 3 sizes, about 4 inches, 5 inches and 6 inches, for spreading and forming filler on car body parts.

Related: the best air die grinder for auto body and the best sanding discs for auto body.