Herculiner vs Rust-Oleum: Best DIY Spray-In Bed Liner Kit

For you if: you want a permanent textured coating bonded to the bed paint (or properly cleaned and scuffed metal), you will do the prep yourself — clean, scuff, solvent wipe, mask — and you will follow the kit’s mix and cure windows. You are fine with a black textured finish that stays put.

Skip this page if: you want a removable soft drop-in, Guardian Comfort, TechLiner, or bed mat — that is the drop-in / soft-liner page, not this one. Skip if a hard plastic drop-in is already in the bed and you refuse to pull it; these coatings need the bed surface, not the underside of a shell. Skip Herculiner if you cannot hold 65–90°F for application — the Professional Grade FAQ says temperatures outside that window affect cure time greatly. Skip if you wanted a LINE-X or other booth-spray franchise install; that is a shop service, not either of these DIY kits. Skip if you only needed a gallon of single-component roll-on without a kit hardener — different product class.

A DIY spray-in / roll-on bed liner kit is a coating. You prep the paint, mix a two-part formula, and leave a permanent textured film on the floor, walls, and usually the tailgate. That is the job on this page.

A soft drop-in or TechLiner-style liner hooks or sticks into the bed and comes back out. A hard plastic drop-in is a shell over the rails. A LINE-X booth spray is a shop service with professional equipment — not either DIY kit.

Herculiner Professional Grade sprays or rolls without changing viscosity. The gun is in the box; you still need an air compressor (Herculiner’s FAQ flags PSI and hose leaks as common gun troubles). Mix per bottle: shake resin, measure 6.5 fl oz hardener, shake 1–2 minutes. About 20 sq ft per bottle × four bottles covers an 8-foot bed in one coat on the maker page. Dry 4 hours, full cure 24 hours. Prep still owns the job: clean, scuff, solvent wipe, mask. Primer is not required on bare metal if cleaned and scuffed.

Rust-Oleum 323529 is epoxy amine with a burst pouch — mix 2–3 minutes, wait 15 minutes induction, then about 3–4 hours pot life. Roller, brush, sponge, and gloves ship in the kit; a spray gun does not. Finish two coats on the sidewalls before the floor. At about 70°F / 50% RH: touch ~11 hours, light duty 24–48 hours, full cure 4 days. Do not drag sharp cargo until full cure. Kit TDS: do not apply if temperature is expected below 50°F; keep the film above 50°F for the first 24 hours; keep rain off for 24 hours.

Want something removable for a trade-in? Soft-liner page. Want a franchise booth spray with a shop warranty card? Call that shop. HCL2K8 and 323529 are weekend DIY coatings with maker cure clocks you own.

Prep decides whether either kit sticks. Both makers assume a clean, scuffed, solvent-wiped bed. Skip the scuff and you are coating wax and gloss — adhesion fails.

Herculiner HCL2K8. Clean and wipe oils. Mask edges and drains. Scuff to kill gloss (sandpaper no higher than 100 grit per instructions). Solvent wipe and dry. Mix one bottle at a time (6.5 fl oz hardener), shake 1–2 minutes. Spray with the included gun on a compressor in the maker’s PSI range, or roll. Stay inside 65–90°F. Maker page: dry 4 hours, full cure 24 hours (cooler weather slows light/heavy use toward 12 / 24–48 hours). Ventilate. The kit gun is not a LINE-X booth gun.

Rust-Oleum 323529. Wash, dry, remove loose paint and rust. Abrade with the supplied sanding sponge — wax must go. Solvent wipe (mineral spirits, xylene, or IPA per TDS). Mask drains. Burst-mix 2–3 minutes, wait 15 minutes, apply within ~4 hours pot life. Dab corners, then roll sidewalls — two coats on walls before the floor. Recoat at tack (15–30 minutes; longer at 50–60°F). Light duty 24–48 hours; full cure 4 days. Keep ambient and film above 50°F the first day; no rain for 24 hours.

Both. Ventilate; gloves and eye protection. Pull masking while edges are workable. Plan edge lines before you open the kit.