The following steps should be taken when spraying a new bed liner over an existing aged or damaged truck bed liner. This procedure was designed to spray over an existing 100% solids polyurethane or polyurea sprayed on coating with a similar or matching 100% solids polyurethane or polyurea spray-on coating. While we have focused on recoating truck beds, these steps may also be used to spray over aged or damaged coatings such as floors, decks, containment units, trailers, marine, commercial and industrial applications.
What you will need.
TSP (Tri-Sodium Phosphate)
TSP (Tri-Sodium Phosphate) has a pH of 12 meaning the chemical is an alkaline. Alkaline agents have a powerful capacity to penetrate greases and oils.
MEK (Methyl Ethyl Ketone)
MEK (Methyl Ethyl Ketone) is a strong solvent and degreaser. It is used as a final wipe before applying the Bonding Agent.
Bonding Agent is suitable for use as a tie coat when applied over elastomeric coatings prior to re-coating. Bonding Agent is also ideal for priming metal surfaces prior to a coating application. Learn More.
FLUIDS REQUIRED: Bonding Agent can be applied by brush, roller or a standard automotive paint gun. A thin coat of Bonding Agent is all that is needed. Apply the Bonding Agent at a rate of 400 – 500 square feet (37 – 46 square meters) per gallon.
SAFETY ALERT: This article cannot cover all safety concerns; each user should follow correct procedures outlined in the manufacturers equipment manual and understand the requirements for safe operation. Also be sure to read chemical manufacturer’s warnings and material MSDS to know specific hazards and precautions related to the chemicals.
01Thoroughly clean all surfaces of the spray on bed liner, removing all traces of contamination, i.e., oil, grease, dirt, etc. Clean the entire bed liner with TSP (Tri-Sodium Phosphate) in a hot a water solution. A stiff brush will help with stubborn areas. Immediately rinse washed areas with clean water. Do not allow cleaners to dry on the surface of the existing bed liner. Repeat the cleaning procedures as required to insure complete removal of all contaminates. Aged truck bed liners may require more than one cleaning to effectively remove all contaminants.
02Thoroughly dry the old sprayed bed liner. If any moisture is left in the cracks or seams you will run into foaming and blistering problems. Be sure to pay special attention to any damaged areas in the liner that may be lifting or peeling where moisture may hide (remove all areas of the liner that have lifted or peeled).
03Bevel all edges of the existing bed liner, this will help to hide the old bed liner and leave nice clean edges on the new bed liner. Mask all areas that don’t need to be sprayed. Be sure to mask a 1/8” to 1/4” inch past the edge of the old bed liner to hide the old spray on liner and insure a good bond at the edge of the new liner.
04The existing truck bed liner will need to be sanded or grit blasted to remove any oxidation and roughen the surface of the aged liner, this will provide good adhesion for the new liner to the old liner (Wear appropriate safety gear). Any damaged areas within the old spray on liner will need to be feathered out otherwise the edges of the damaged area will show in the new truck box liner.
05Use compressed air or a vacuum cleaner to remove the dust and debris from the surface of the entire truck box liner. To provide proper adhesion to the aged spray on truck bed liner, wipe the surface with MEK (Methyl Ethyl Ketone). The surface can then be coated with our Bonding Agent, this will provide a good bond between the old and new liners. Bonding Agent can be applied by brush, roller or a standard automotive paint gun. A thin coat of bonding agent is all that is needed. Please allow 30-45 minutes for the bonding agent to cure.
06You are now ready to spray a new truck bed liner over an existing old and/or damaged spray on truck bed liner.
This article is not intended to provide specific legal or technical advice, and is made without warranty, expressed or implied as to merchant-ability, fitness for particular purpose, or any other matter. Persons applying polyurethane/polyurea coatings and foam should consult with their own technical and legal advisors and other appropriate sources of safety and handling information, including information from product suppliers, product labels, technical bulletins, MSDSs, and other literature.