Priced as of May 25, 2026
4.6(431 ratings)Buy on AmazonSaved to your guest loadout. Sign up to also save to your Cabinet (consumables) or Kit (tools you own).
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Prices may varyAbout this product's hazards. This product's Safety Data Sheet uses signal word danger. Read the manufacturer's SDS and follow all safety instructions before use. CarCareTruth ratings translate the manufacturer's safety sheet. They do not replace the SDS or substitute for a hazard assessment specific to your task.
Health score is for adult use as intended, per the manufacturer's SDS. It does not model child ingestion, accidental spill cleanup, or off-label use. See the safety panel below for full hazard classification, and /disclaimer for the full editorial scope.
No Safety Data Sheet on file.
CarCareTruth has not received a Safety Data Sheet from the manufacturer for this product. Hazard classification and PPE cannot be cited. Request an SDS from the manufacturer before use.
The Podium · Top 3 in Undercoating
See the full ranking →This product ranks #5 of 6 in Undercoating.Three above it ↓
CarCareTruth's Analysis
Last reviewed May 25, 2026
TL;DR Rubberized topcoat for the POR-15 3-step corrosion system — Amazon verified-purchase reviewers (4.6★, 431 ratings) confirm solid underbody coverage over the Rust Preventive base. The DANGER signal word and label statement "VAPOR HARMFUL. SKIN AND RESPIRATORY IRRITANT" indicate a half-face respirator with organic vapor cartridges for overhead aerosol application. Prop 65 warning for Toluene and Carbon Black.
What it is and how it performs
POR-15 Rubberized Undercoating cures to a hard, impact-resistant rubberized film over the POR-15 Rust Preventive base. Amazon verified-purchase reviewers (4.6★, 431 ratings) describe it as the final step of the three-step sequence — degreaser, metal prep, rust preventive, then undercoating. Coverage is multi-can: reviewers report 7–8 cans for an 8-foot truck bed plus cab corners and rockers, spraying at 12–16 inches with one minute of shaking per directions. The product is formulated for clean or POR-15-coated metal; surface prep determines long-term adhesion.
Who should buy this — and who should skip it
Right for owners running the POR-15 system who need a rubberized topcoat over the corrosion-inhibiting base. Skip it over active rust perforation — a rust converter or encapsulator comes first. Also skip aerosol use in a sealed garage: the label states "Use only with adequate ventilation" and petroleum solvent vapors accumulate in enclosed spaces.
Safety and environmental impact
The DANGER signal word reflects a petroleum-solvent aerosol formula — Toluene, t-Butyl Acetate, Acetone, and VM&P Naphtha with LPG propellant. No GHS SDS is publicly available from POR-15 as of 2026-05-25. A Prop 65 warning for Toluene (reproductive harm) and Carbon Black (cancer) appears on the POR-15 product page. Overhead aerosol application in a closed garage is the primary inhalation exposure scenario. Estimated VOC places this in the high-VOC bracket; the stay-on-car cured film limits direct aquatic exposure.
Frequently asked questions
Is POR-15 Rubberized Undercoating meant to be used alone or as part of a system?▾
Amazon verified-purchase reviewers (4.6★, 431 ratings) consistently describe using it as the final step in the POR-15 3-step system — Marine Clean (degreaser), Metal Prep (phosphoric acid surface conditioner), then POR-15 Rust Preventive Coating, topped with the Rubberized Undercoating. The undercoating provides the impact-resistant rubberized cap over the rust-inhibiting base layer. The manufacturer positions it as a protective topcoat, not a standalone rust treatment.
How many cans are needed for a full truck undercarriage?▾
Amazon verified-purchase reviewers (4.6★, 431 ratings) report 7–8 cans for an 8-foot truck bed plus extended cab corners and rockers. Coverage varies by application thickness and surface area — budget generously and spray in consistent overlapping passes at 12–16 inches.
Does POR-15 Rubberized Undercoating have a Safety Data Sheet?▾
POR-15 does not publicly host a GHS-format SDS for this aerosol product as of 2026-05-25 (por15.com/pages/sds returns 404). The official directions PDF discloses the full ingredient list and hazard label language. The DANGER signal word is confirmed from Amazon product page safety information. A Prop 65 warning for Toluene and Carbon Black is listed on the POR-15 product page.
What respiratory protection does POR-15 Rubberized Undercoating require?▾
The product label carries a DANGER signal word and states 'VAPOR HARMFUL. SKIN AND RESPIRATORY IRRITANT.' The aerosol format applied overhead beneath a vehicle — a semi-enclosed space — concentrates petroleum solvent vapors. The label designation and aerosol exposure scenario indicate a half-face respirator with organic vapor cartridges for this application. 'Use only with adequate ventilation' is stated on the label.
From the manufacturer
Marketing copy from POR-15, via Amazon. Not editorial.
- •✅ WHY CHOOSE POR-15 RUBBERIZED UNDER COATING – Protective undercoating is essential in protecting your car’s undercarriage from the elements. Using our trusted POR-15 Rust Preventive technology your vehicle’s chassis and undercarriage will be protected against moisture, salt, chemicals, dust, heat, and cold inhibiting rust and corrosion.
- •✅ PROTECT AGAINST RUST AND CORROSION - Be sure to prep the area before application by removing all loose rust, dirt, grease, and wax. Once the area is clean and dry, shake well for at least one minute before spraying from 12-16 inches from the surface. Allow coating to dry for 1 hour before touch or applying recoat. POR-15 Rubberized Undercoating can be applied to cleaned bare metal but is best when applied over POR-15 Rust preventive Coating.
- •✅ LASTING PROTECTION & PEACE OF MIND – In addition, our Rubberized Undercoating creates an effective sound barrier that reduces vibration, & deadens sound in wheel wells, quarter panels, fenders and under carriages. May also be used to insulate against engine and muffler noise, and exhaust fumes.
- •✅ WHEN DO I NEED THIS – The first line of defense - Whether you are restoring a classic car or your newer vehicle’s undercoating has failed, our Rubberized Undercoating is essential to inhibiting corrosion and rust. Undercoating is a smart way to extend the lifespan of your vehicle and keep your investment protected.
- •✅ OUR SATISFACTION COMMITMENT – At POR-15 we strive to bring the ultimate in rust prevention. Known for the unbeatable 3-step stop rust system, POR-15 is trusted by DIY & Professionals. We are committed to innovation, quality control, and excellent customer service.
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Manufacturer images
Manufacturer specifications
- Brand
- POR-15
- Color
- Black
- Finish Type
- Satin
- Size
- 22 Ounce (Pack of 1)
- Item Volume
- 22 Fluid Ounces
- Special Feature
- Chip Resistant
- Unit Count
- 22.0 Ounce
- Paint Type
- Spray
- Specific Uses For Product
- Interior/Exterior
- Surface Recommendation
- Metal
- Brand Name
- POR-15
- Indoor Outdoor Usage
- Outdoor
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Top Amazon review
↗External — Amazon's most-helpful review for context.
Great product highly recommend
7 to 8 cans to cover my 8ft bed and ext cab .Still had extra and was able coat the inside of my new rockers and cab corners. Great product easy to use. All cans were great no issues shake well beforehand. Spray with some distance. Great coverage end results is spot on. Cheaper to do it yourself then taking it to the shop. Will update my review in an year or so.