Tips for Gluing Metal !
As Ireland’s most respected company for glue for metal, each & every week we receive questions from people all over Ireland, looking for tips and advice for gluing metal’s. First of all, metals are divided into two families, active metals & passive metals.
Active Metals include iron, mild steel, nickel, copper, bronze, manganese, aluminium & brass. Passive metals include stainless steel, anodised aluminium, titanium, galvanized steel, magnesium & zinc.
The first question’s our chemist’s ask a prospective customer, are what is the metal, and what is being manufactured from that metal? We specify metal glues for hundreds of applications, from craft and jewellery to structural cladding panels, to automotive panels!
In gluing metals, we offer the widest range of adhesives possible. These include polyurethane adhesives, epoxy adhesives, methacrylate adhesives and finally epoxy hybrid adhesives.
We must remember, in bonding any metal, correct surface preparation is very important to ensure an optimum bond with the required integrity. There are four main ways to treat metal before gluing:
Surface treatments on metal:
Depending on the type of metal and what is being manufactured from the metal, not all of the four processes will be required. At a minimum, a clean dry surface is vital for bond integrity. Degreasing is the removal of all traces of oil and grease (even relatively clean surfaces have oils from fingerprints). Do not use white spirit or cellulose thinners for this as these products always contain contaminants which remain on the surface after the solvent has evaporated. Wipe the surface clean. When using a cloth, use a lint free cloth and keep turning the cloth to expose a clean surface before the wiping action is commenced. Wipe the metal surface from a north/south or east/west direction. We recommend degreasing whenever possible, because surface oil or grease will get in the way of almost all adhesives and weaken adhesion. We offer Ireland’s largest range of solvents for degreasing all metals.
We recommend abrading if practical for the material you are bonding. Use fine grain (P400) sand paper, emery cloth or steel wool. Abrade enough just to clean and roughen the surface. After the abrasion treatment, remove all loose particles before applying any adhesive. Brush the surface or blow down with compressed air, and then, degrease the surface to clear away all loose particles and residual oils.
Abrading and degreasing is enough surface preparation for all but the most demanding industrial applications. Be very cautious in abrading galvanised steel as if is important not to remove the zinc coating, otherwise, local rusting may occur. Caution is also needed when gluing aluminium. Aluminium has a layer of aluminium oxide on its surface. It is important to remove this before gluing the aluminium and apply the adhesive immediately.
Remember, all surfaces need to be dry before gluing. Finally, bond the surfaces as soon as practical after cleaning and degreasing to avoid having a re-contaminated surface!
Contact the Glue Guru for advice.