What is Spray Sealant?

J. Airman

A spray sealant is a liquid or foam barrier applied to surfaces to protect them from external elements. Spray sealants are made by combining plastic polymers that adhere to a surface and each other to create a solid layer of defense. Custom spray sealant formulations are manufactured for specific surfaces in both small, commercial, and large-scale industrial applications. Sealing a surface with sealant prevents much of the moisture and chemical seepage that can cause damage. Painted and unpainted surfaces have microscopic gaps and cracks that can be filled in by applying one or more layers of the correct variety of spray sealant.

Spray sealant often comes in the form of foam insulation, which holds in heat very well.
Spray sealant often comes in the form of foam insulation, which holds in heat very well.

Sealant sprays are available in many sizes and types to meet the specific needs of the project. Sealing smaller areas is commonly done with small hand-held aerosol canisters. Larger areas require a large volume of sealant packaged inside pressurized refillable cylinders. Carefully reading the label of a spray sealant prior to application is an important step to ensure that it is safe for use on the intended surface. Some foaming sealant sprays have two liquid components that react to generate a dense foam when they are combined in the spray nozzle at the very last moment before application.

A respirator mask should be worn when working with spray sealant.
A respirator mask should be worn when working with spray sealant.

The layer of protection provided by a spray sealant generally becomes clear or slightly opaque once it has been allowed to dry completely. Clear sealants applied to the paint of a vehicle allow the color of the paint to show through while extending the longevity of the original shade. The extra cost of using a sealant is an investment in the future condition and appearance of the protected surface. Some spray sealant varieties have an ultra-violet additive that blocks almost all of the damaging rays from the sun. Permanent pigments can be added to a liquid sealant to turn it into a colorful glaze.

Spray sealants can be applied using a small, hand-held aerosol canister.
Spray sealants can be applied using a small, hand-held aerosol canister.

Many graphic artists and printers use spray sealant to protect applied inks, paints, and pigments from smearing and water damage. Sealing sprays are sometimes applied to high-quality prints to keep the ink from seeping into the paper and spreading out in the surrounding area. Spraying the front and back of a sheet of paper created a laminate layer that keeps the print sealed. Sealant must be applied from the manufacturer's suggested distance to avoid over-saturation and streaking. Gloss and matte spray sealant options are available to leave the sealed page looking shiny or dull depending on the needs of the project.

Spray sealants are made out of plastic polymers.
Spray sealants are made out of plastic polymers.

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Discussion Comments


@Perdido – I also spray on a paint sealant when I'm finished with a charcoal or pastel chalk drawing. It's probably easier than sealing a mailbox, because I only have one surface to cover.

My art teacher taught me a neat trick. She said that instead of buying a regular paint sealant, which could be expensive, I could use cheap hairspray instead. I had already bought the paint sealant, since it was on the class supply list, but after I ran out, I started using the hairspray.

It worked great! I sprayed just a light coat on, and it sealed in the drawing. I could not smudge it if I tried, and I did just to test things out.

You can spray on a coat when you're halfway done and then spray it again when you're finished. If you have completed an area that you don't want to smudge into another area or another layer you are going to draw on top, then you can spray it before you start the next part.


My brother used waterproof sealant spray on his deck. He said it was much more convenient than having to paint sealant over the whole thing.

He wore a mask while using the spray. It is easy to accidentally inhale the fumes, and that could do anything from giving you a headache to making you pass out.


I didn't know you could seal graphics with coats of spray! It seems to me that the paper would wrinkle from the moisture. I suppose they must use special paper for this, though.

The only time I ever used sealant spray was when I painted my mailbox with acrylic paint. I did a beach scene all over it, and I knew that the weather would soon destroy it if I didn't seal it.

I put down some newspaper in the carport and sprayed the sealant all over the mailbox. I let it dry for several hours and applied another coat.

I had to do this outside, because the fumes would be dangerous in an enclosed room. Luckily, no birds or squirrels bothered the mailbox while the sealant was drying, so it dried to a smooth finish.


Every spray on sealant I've ever known has had a terrible odor. Sealant spray smells like a combination between nail polish remover and caulk, so it is very powerful and hard to breathe around.

I have to leave the area if spray sealant is being used. I have a sensitive nose anyway, so I just can't tolerate the odor.

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