Structural Adhesives for Vehicle Conversions
Vehicle converters and specialist vehicle producers use structural adhesives for challenging applications, often bonding dissimilar materials in high stress environments where there could be vibration and peel stresses on the joint, broad temperature ranges, impact, and heavy wear and tear.
Uses for structural adhesives
Ambulance fit-outs and conversions
Structural applications include bonding composite materials for cabinetry, overhead lockers, bump strips, rails, wiring harnesses, plastic interior walling, aluminium chequer plate, shelves, etc. Adhesives help avoid the need to drill holes and use mechanical fasteners, providing a number of benefits:
- Less vibration and rattling when going over bumpy roads and rough ground in an emergency.
- No vibration loosening.
- Better stress distribution – drilling holes weakens the substrate and mechanical fasteners can concentrate stress in one place, causing cracks to appear around the hole.
- Easier to clean and disinfect – this is vital in an ambulance. Another benefit is there is no potential leak hole as you would encounter with a drilled panel. Helps keep it lightweight.
- Mechanical fasteners can catch peoples’ skin, clothing etc.
- Bonding panels and brackets to metal skin saves drilling holes which could rust or cause moisture ingress. Low-shrinkage adhesive structural adhesives help minimise witness marks or show through on thin vehicle skins.
Bonding metal skins requires a structural adhesive – generally pre-mixed products with application via a mixing nozzle are preferred. It is important that there is no show through. Vehicles with bonded skins look aesthetically more pleasing than riveted vehicles. Another application is pipe sealing for manifolds, pumps, and valves. Tambour roller door construction and track installation may also require an adhesive – bonding tracks instead of screwing them in place helps ensure no sticking points (oh the irony!).
Police Brawlers or “Paddy Wagons” and inmate transportation trucks
Criminals and troublemakers require secure transportation to ensure they do not escape or harm themselves in transit. Mechanical fasteners are not practical in this environment, so most interiors are moulded from high performance composite and plastic materials. Aluminium profile stiffeners are often used to strengthen door and wall panels. If any bolts are used, they have to be permanently locked, sealed, and capped to prevent tampering, to help with clean-up operations, and to prevent injury.
Disability / Mobility vehicle conversions
Driving adaptions include hand mounted controls, pedals, and steering aids. These modifications may require adhesives such as retainers, threadlockers, and cyanoacrylates for bonding rubber grips and cushioning. Structural adhesives may be used for bonding wiring harnesses and bracketry.
Access adaptions include hoists, swivel seats, transfer plates, and pneumatic lifts for tailgates / side door entry. Changes to the vehicle can range from fairly minor to extensive, such as a completely new rear end. Adhesive applications include threadlocking joints on transfer plates, structural bonding of supporting structure for transfer plates and hoists, and pneumatic and hydraulic sealing for tailgate lifts.
Extensive vehicle alterations may require structural bonding of panels and interior fittings. Again, structural adhesives must offer high strength performance, impact and vibration resistance, and good aesthetic appearance. EPDM seals on altered doors, windows, and tailgates may also require adhesive bonding.
RV Vehicles, Campers and Caravans
High-performance structural acrylic adhesives can be used to bond bracketry and fixings for interior composite panels. Adhesives need to be impact and vibration resistant and able to bond dissimilar materials (such as metal to composite). Contact adhesives are often used for bonding upholstery materials, roof liners, etc. Other applications include sealing water tank components and pipework. Clear, plastic-bonding, structural adhesives are ideal for Plexiglas-type window applications and can offers some degree of flexing as well as good environmental durability and resistance to sunlight yellowing.
Permabond has assisted with multiple vehicle / truck conversion type projects. Some of the more exciting and challenging projects have included trucks for transporting nuclear waste – helping to support and protect nuclear waste canisters and also bonding and sealing truck sides / bed for transporting waste chemicals. Sealing and bonding panels provides a 100% seal against leakage, whereas traditional welding doesn’t provide a proper seal.
For help and support with your technical projects, please contact Permabond.