How much Spectrum do I need for a full vehicle?

The amount of Spectrum needed for a full vehicle depends on the vehicle size and how many coats you apply. See the table below for gallons needed at 2 or 3 layers. If you only need to treat select areas rather than the full vehicle, use the vehicle square footage calculator above on this page instead. Vehicle TypeGallons Needed for 2 LayersGallons Needed for 3 LayersApprox Sq Ft2 Door Truck7101302 Door Car8121554 Door Compact Car / 4 Door Truck913170Mid Size Car1014180Full Size Car / Jeep1116210Compact SUV1217230Full Size SUV1320260Minivan1522290Cargo Van1725335Covers the floor, doors, trunk, roof, firewall, hood, wheel wells, and undercarriage.

How is Spectrum applied?

Spectrum can be applied by brush, roller, standard spray gun, or airless sprayer. Keep the area above 50°F throughout the install and for the full 24-hour cure that follows. See our Spectrum install guide for full surface prep and detailed steps for each application method. Do I need a primer?MetalPrimer Not RequiredHigh Gloss, Shiny, or Wax Finish MetalScuff Up or Use PrimerPlasticSelf-Etching PrimerFiberglassSelf-Etching PrimerWoodPrimer Not Required

How thick should Spectrum be applied?

Apply Spectrum in 1mm coats, about the thickness of a credit card, to a recommended 2 to 3mm total and 5mm maximum. Measure while the coat is wet as it shrinks as it dries, so a dry reading looks thinner than what you actually put down.

How do I prep the surface for Spectrum?

Clean down to bare metal with denatured alcohol to remove oil, grease, wax, and salts, and sand or prime any rust spots. Plain, non-glossy bare metal and wood are ready for Spectrum with no primer needed. If the metal is high gloss, shiny, or has a wax finish, scuff it up or use a primer first, since those surfaces don't give Spectrum enough grip on their own. Plastic and fiberglass always need a self-etching primer. Keep the ambient temperature above 50°F during the install and for 24 hours after so it bonds properly.

How do I clean up Spectrum?

Clean tools and overspray with water within 30 minutes of finishing, before Spectrum sets. Keep it off clothing.

How long does Spectrum keep in the container?

Unopened, Spectrum is rated for 1 year and typically keeps 2 to 3 years; do a test spot if you've had it on the shelf for a while. Once opened, use it within about 30 days. Never let it freeze.

Spectrum spray on sound deadener (1 gallon)

Spectrum rear seat application inside cab

Spectrum in 1974 International Scout II restoration

Spectrum™ Spray On Deadener

Name: Spectrum™ Spray On Deadener
Brand: Second Skin Audio
SKU: SPEC-20-1GAL
Availability: InStock

In stock. This product ships in 1 business day

$99.99

Choose Amount: 1 Gallon (20 Sq Ft)

1 Gallon 20 Sq Ft

5 Gallons 100 Sq Ft

Square Footage Calculator

Spectrum™ Liquid Sound Deadener

Spectrum™ is a durable and long-lasting vibration damper that's as good on a hot rod as it is on a metal roof. By reducing sheet metal resonance and structure borne noise, any vehicle can be quieter and more comfortable to drive. Originally formulated as undercoating sound deadening, Spectrum™ liquid deadener is an awesome substitute anywhere you'd use a sound deadening mat.

Features

Water based viscoelastic polymer for damping loud metal vibrations
Lighter than mats at equivalent thickness (recommended: 2-3mm total thickness)
Enhanced durability for use in extreme environments or outside the vehicle as an undercoating
Waterproof and rustproof
Chemical resistant, non-toxic, and odorless once cured
Self-extinguishing
Temperature rated up to 400°F
Apply with a brush, roller, or spray gun (see Spectrum™ Spray Kit for spray applications)
Proudly made in the USA

Free domestic shipping on all US orders

Specs

Size Options	1 gallon, 5 gallon, 55 gallon drum
Square Foot Coverage	20 sq ft per gallon at 2mm thickness
Total Thickness	Recommended 2-3mm, max 5mm
Layer Thickness	Apply in 1mm layers
Weight	11 lbs (cured), 14 lbs (wet)
Water Resistance	Waterproof and rustproof
Temperature Resistance	400°F
Application Temperature	Above 50°F for first 24 hour dry period
Primer Required?	Shiny/waxy surfaces will require a primer

Material Testing

Acoustic Loss Factor @ 200Hz

Temperature	23°F	50°F	77°F	104°F	131°F
Spectrum (2mm)	0.037	0.083	0.215	0.105	0.034
Spectrum (3mm)	0.066	0.119	0.363	0.258	0.068
Spectrum (5mm)	0.081	0.165	0.534	0.379	0.093

Tested Properties	Performance
Flammability	Self-Extinguishing, FMVSS 302 (Pass)
Viscosity	4000 centipoise
Specific Gravity	1.45
Max Temperature	400°F
Solubility	Soluble
Odor	None (when cured), Mild (as solvent)
Water Resistance	Waterproof
Shelf Life	1 year (unopened), 30 days (opened)

Product Usage Tips

Clean up with water within 30 minutes of application. Do not wait longer or Spectrum™ will dry. Always clean the spray gun between coats by running water through it.
If applying multiple layers of Spectrum™, wait 30-60 minutes for the product to cure and change color from blue to black.
The temperature must be above 50°F for the entire 24 hours cure period after applying Spectrum™. Dry times increase with low temperatures and high humidity.
Spectrum™ is designed to adhere to metal. Do not apply to plastic or fiberglass without the proper primer. If applying to a high gloss wax coat, you must sand down and apply a primer.
Do not freeze Spectrum! If it does freeze, do not mix, shake, or move until it has completely thawed.
Wait 24-36 hours (depending on humidity) before putting upholstery back in the vehicle. Wait 7 to 10 days before painting or applying a bed liner.
As Spectrum™ cures, its deadening properties will continue to increase. Vibration damping doubles from 4 hours → 48 hours, and continues improving for 7 days.
Spectrum™ contains rust inhibitors and dries with a seamless finish. It is water resistant and safe to use for boat soundproofing.
Spectrum™ is not a bed liner. Even after it has cured, it can be damaged by heavy impact.
Shelf life of 1 year when stored at room temperature.
Wheel well sound deadening applications require about 2 gallons for all 4 wheel wells. (all vehicles) and helps a good bit with soundproofing car road noise.
Use Spectrum™ anywhere you have vibrating metal to soundproof the structure, like a car or soundproof shed roof.

Installation Instructions

After upholstery or carpet is out, remove loose debris, rust, dirt, and waxy oils to insure a solid contact surface. Clean with denatured alcohol.
If spraying, mask off all interior and exterior areas of the car for overspray. Cover mechanical parts, wires, and wire harnesses.
Spectrum™ can be applied with a brush or with the Second Skin spray gun.
The recommended total thickness is 2 to 3 mm for a vehicle. Some commercial applications can do 1mm total thickness.
Apply in 1mm layers. If Spectrum runs, you are applying it too thick. Always clean the spray gun between layers by running water through it until there's no dark pigment.
After 60 to 90 minutes (depending on temperature and humidity), Spectrum™ will skin over and change colors from blue to black. Once Spectrum™ is black, it's safe to add another layer.
Most regular paint guns will not be able to spray Spectrum™ due to the extremely viscous consistency. We suggest using a HVLP undercoating gun or the Second Skin spray gun. The nozzle and stem must be 2mm.
Spectrum™ is easy to clean up with water if done within 30 minutes of applying the product.
Allow 24-36 hours before another product or upholstery is installed. Spectrum™ may be painted or covered with a bed liner after 10 days.

Download the Spectrum™ Install Guide for comprehensive spray on sound deadener and brush on application instructions.

Common Product Uses

Alternative to a peel and stick sound deadening mat. Also can be used in combination with Damplifier Pro for maxed out sound dampening (the mat goes on first, Spectrum™ on second).
Personal vehicles (interior, undercoating, wheel wells)
Commercial vehicle fleets
Transportation industry (buses, trains)
Van conversions
Metal roofs
Metal carts
Elevator shafts

Resources

Installation Guides

Spectrum™ Install Guide

Spec Sheets

Spectrum™ Product Sheet

Spectrum™ Spray On Deadener

$99.99

OEM Approved

Reduce Road Noise

Thermal Insulation

Vibration Damper

Vehicle Square Footage Calculator

How Much Spectrum™ Spray On Deadener Do I Need?

Step 1: Select your vehicle type

Step 2: Select the areas you want to cover

.section-template--22730809311332__faq_accordion_ssa01 .faq-accordion__panel { visibility: visible; grid-template-rows: 1fr; } .section-template--22730809311332__faq_accordion_ssa01 .faq-accordion__trigger .icon-plus-toggle { display: none; } .section-template--22730809311332__faq_accordion_ssa01 .faq-accordion__item[hidden] { display: block; } .section-template--22730809311332__faq_accordion_ssa01 .faq-accordion__more { display: none; }

Yes, Spectrum at 3mm performs about as well as Damplifier Pro at 2mm, and at equal thickness our testing shows it damps close to 3 times better than a comparable asphalt mat. Because it is brushed, rolled, or sprayed on, it also reaches curved panels, seams, and tight spots that a rigid mat cannot cover.

Yes, Spectrum has been used as an undercoating and wheel well liner for over 20 years, and it is waterproof and rustproof. It holds up in the sun too: in over 10 years of Arizona testing it kept damping without cracking or chipping.

Yes, you can paint over Spectrum or put a bedliner over it once it has fully cured, which takes 7 to 10 days. We recommend testing a small spot first.

Yes, Spectrum can be used with FireWall. Spectrum will go down first, in at least two 1mm coats. Then, FireWall goes on top of that. Both go on the same way, by brush or spray. Be sure to clean the gun in between applications.

Spectrum is built to quiet vibrating and resonating metal: vehicle floors, doors, roofs, wheel wells and undercarriages, plus sinks, ducts, machinery, and metal furniture. It also bonds to wood, plastic, and fiberglass. See the table below for which surfaces need a primer first.

Metal	Primer Not Required
High Gloss, Shiny, or Wax Finish Metal	Scuff Up or Use Primer
Plastic	Self-Etching Primer
Fiberglass	Self-Etching Primer
Wood	Primer Not Required

More FAQs

Best Sellers

Damplifier Pro™ Sound Deadening Mat

CelluZorbe™ Cellulose Acoustic Panels

Damplifier Pro™ Sound Deadening Mat

CelluZorbe™ Cellulose Acoustic Panels

Spectrum™ Spray On Deadener