Suitable Substrate Surfaces
Common Substrate Surfaces and the Suitability for Adhesive Bonding
A critical factor in the success of any adhesive bond is the condition of the substrate surfaces being joined. Every assembly surface has unique characteristics, either inherent in its material make up, such as aluminium oxidation; or added to it during manufacturing, such as rust inhibitors. This guide provides an overview of several common substrates and their suitability for adhesive bonding. Consult a Permabond representative for a complete assessment of your assembly surfaces and determination of the best Permabond adhesive for your specific application.
Aluminium and its Alloys
The surface appears clean but has a thin oxide film that weakens the bond between the true aluminium surface and the adhesive. Some oxide films may be stable enough to provide a strong bond without any surface preparation. Aluminium is the exception. Permabond can help you evaluate your aluminium and advise which method of pre-treatment would be most appropriate to optimize bond performance. Oxide films form immediately, even after surface treatment. Surface bonding must take place as soon as possible to achieve maximum adhesion strength. See How To Bond Aluminum.
Conventional Steel Alloys
Mild steel alloys typically present surfaces readily able to be bonded. There are several adhesive technologies to choose from. See How to Bond Mild Steel.
Presents an oxide film that may weaken the bond between the true steel and the adhesive. Zinc plating may separate from the steel surface as a result of the adhesive. May require chemical treatment to eliminate the zinc separation from the steel sheet.
Treated Zinc-plated Steel
The treated surface is both unsuitable and unreliable for adhesive bonding. Certain chemical treatment methods can present workable bonding surfaces. Consult with a Permabond representative to evaluate treated zinc-plated steel surface bonding applications.
Structural joints cannot be formed on PVC clad surfaces of mild steel. Cyanoacrylate adhesives will provide good adhesion to the PVC surface.
Painted Steel Panels
Structural joints cannot be formed on the painted surfaces of steel panels. Several Permabond adhesives will provide good adhesion to painted steel panels. Maximum adhesion will be achieved by those Permabond adhesives that will flex with the bending of thin sheet panels.
Stainless Steel Alloys
Depending on the application, chemical surface treatment may be necessary. Surface preparation with abrasion and a solvent wipe is suitable in most cases. However, it can depend on the finish – see How to Bond Stainless Steel.
Permabond cyanoacrylate adhesives bond well to these surfaces. Surface activated toughed acrylics may not provide suitable gap filling ability for large structural applications.
Acrylic-faced Thermoset GRPs
Structural joints cannot be formed on the acrylic face of these surfaces. Permabond cyanoacrylate adhesives will provide the maximum adhesion to the acrylic faced surface. The cyanoacrylate adhesive, in its liquid form, will cause stress cracking on the acrylic face after prolonged exposure. Use a Permabond cyanoacrylate activator to accelerate cure and minimize exposure to uncured adhesive.
Wood-faced Thermoset GRPs
Wood-faced Thermoset GRPs typically present surfaces readily able to be bonded. Several Permabond adhesives will provide good adhesion to these surfaces. Consult with a Permabond representative to evaluate wood-faced thermoset GRP surface bonding adhesives.
These structural composites, typically epoxy-based, bond well with a variety of Permabond adhesives.
Permabond cyanoacrylate adhesive will provide good adhesion to these surfaces. The adhesive, in its liquid form, will cause stress cracking on the surface after prolonged exposure so be certain to contain the adhesive between two surfaces, so it cures quickly. Another option is UV cure adhesive. Learn more about bonding ABS
Extensive surface treatment may be necessary to achieve suitable bonding. Consult with a Permabond representative to evaluate nylon-faced surface bonding applications.
Permabond POP primer can be used to treat polyolefins before bonding with cyanoacrylate adhesive.
Permabond TA4610 and TA4605 are designed to bond polyolefin substrate with no surface treatment. Both products create bonds strong enough to have the plastic stretch and fail before the bond. See the image here.
Depending upon the type of polyurethane several adhesive technologies can be used. See surface preparation techniques and how to bond polyurethane.
Several adhesive technologies can be considered. Adhesive selection to bond PVC is based on whether the PVC substrate is rigid, flexible, or green PVC. See options to Bond PVC here.