hardener

[hahr-dn-er]

noun

1. a person or thing that hardens.

2. a substance mixed with paint or other protective covering to make the finish harder or more durable.

3. Photography.,  a chemical used to raise the melting point of an emulsion.

ˈhardener

/ ˈhɑːdənə /

noun

1. a person or thing that hardens

2. a substance added to paint or varnish to increase durability

3. an ingredient of certain adhesives and synthetic resins that accelerates or promotes setting

Word History and Origins

Origin of hardener¹

First recorded in 1605–15; harden + -er ¹

Example Sentences

Research specialist Alex Baer painted the greenhouse’s exterior with several coats of whitewash mixed with a hardener to block the sun’s rays and help the coating withstand winter rainstorms.

Read more on Los Angeles Times

Mix the resin and hardener and press the mixture into the screw holes with a putty knife.

Read more on Washington Post

The hardener, sold separately, is $6.99 for a .37-ounce tube.

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You’d have to mix its two thick components — a polyamide hardener and an epoxy resin — and then carefully try to get it into the crack without making a mess.

Read more on Seattle Times

A kit with four ounces of resin and four ounces of hardener costs $17.99 at rockler.com.

Read more on Washington Post