Gluing Metal

Gluing Metal

Gluing metal using structural glues

Metals are divided into two families, active metals & passive metals.

Active Metals. Iron, mild steel, nickel, copper, bronz, manganese, aluminium & brass.

Passive Metals. Stainless steel, anodised aluminium, titanium, galvanized steel, magnesium & zinc.

In gluing  any of these  metals (and exotic metals) , we offer the widest range of adhesives possible.  In bonding any metal, correct surface preparation is very important to ensure an optimum bond with the required integrity.

Surface treatments on metal:

  1. Clean
  2. Degrease
  3. Abrade
  4. Surface Treatments

At a minimum, a clean dry surface is vital for bond integrity.

Remove as many surface contaminants as possible from the bond area, including any dirt, oil, grease or other contaminents.

 Passive metals may need surface treatment of the use of activators.

Degreasing is the removal of all traces of oil and grease (even relatively clean surfaces have oils from fingerprints). If possible, use a solvent such as T160 or T556. 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.

For the strongest and most durable bonds possible, we also recommend abrading.

Abrading a surface gets rid of surface films, mill scale, paint, and oxides and also gives a much better area for the adhesive to “grip.”

We recommend abrading if practical for the material you are bonding. Use fine grain (P120 or P150)   sand paper, emery cloth or steel wool. Abrade enough just to clean and roughen the surface. After an abrasion treatment, remove all loose particles before applying any adhesive. Brush the surface or blow with compressed air, and then degrease 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.

There is a simple test to determine the cleanliness or otherwise of a metal surface.

Drip a few drops of water on the cleaned area. If the water spreads to cover the area with a continuous film, the bond area is clean. If the water beads, this indicates that the surface needs to be degreased further.

Remember: all surfaces need to be dry before gluing. Also, bond the surfaces as soon as practical after cleaning and degreasing to avoid having a re-contaminated surface. Contact the Glue Gure for advice glueguru@wipolymers.ie


Chemistry Grading

  • Fair
  • Good
  • Excellent

Material Type

Surface Preparation Required

Adhesive Suggested  Chemistry

Aluminium Degrease with T556. Abrasion may be required with P100 or P150 paper. Degrease again, bond immediately.
  • Cyanoacrylate
  • Two component acrylic
Aluminium (Anodised) Degrease with T160. Abrade with a non metallic abrasive pad.
  • Cyanoacrylate
  • Two component acrylic
Brass Degrease with T160. Abrasion may be required with P100 or P150 paper. Degrease again.
  • Cyanoacrylate
  • Two component polyurethane
  • Two component acrylic
Cast Iron Degrease with T556. Abrasion may be required P150 paper. Degrease again.
  • Anaerobic
  • Two component acrylic
Copper Degrease with T160. Abrasion may be required with P100 or P150 paper. Degrease again, bond immediately.
  • Two component polyurethane
  • Two component acrylic
Chrome Steel Degrease with T160. Abrade with a non metallic abrasive pad.
  • Two component acrylic
Galvanised Steel Degrease with T556. Bond immediately
  • Two component acrylic
  • Anaerobic
Lead Degrease with T556. Bond immediately.
  • Two component acrylic
Mild Steel Degrease with T556. Abrasion may be required with P150 paper. Degrease again.
  • Cyanoacrylate
  • Anaerobic, two component acrylic
Precious Metals (Silver, Iridium, Platinum, Gold) Degrease with T160. Remove tarnish, degrease again.
  • Two component acrylic, polyurethane or epoxy
Stainless Steel Degrease with T556. Abrade with a non metallic abrasive pad
  • Anaerobic, cyanoacrylate
  • Anaerobic, two component acrylic, polyurethane or epoxy.
Zinc Degrease with T556. Abrade with emery cloth. Degrease again. Bond immediately.
  • Two component epoxy
  • Two component acrylic

For small metal nuts, bolts and splines, we have the widest range of anaerobic adhesives which will cover most requirements. These adhesives differ mainly in viscosity and how easy it is to open the fittings, either a permanent bond or a temporary bond.

For repairing cracks or seams in welded components, we suggest the use of our X95 which is a steel filled epoxy resin. Seams can be filled & sanded either before or after painying.

For bonding metal in semi-structural applications, such as aluminium stringers, mild steel frames and signage, adhesives with very high shear and peel strength are required. For these applications, there are a number of choices. Our X15 is a two component 1: 1 mixing ration product is the premium metal bonding adhesive used for horizontal bonding. It cures rapidly and if two postage stamp sized pieces of mild steel were bonded together with it, the joint would lift a 300 kg weight! For medium length glue lines, for example often seen in the bus & truck sector, Scigrip SG5000 is used. This is a non sag product perfectly suitable for both horizontal and vertical bonding. It is a fast sure adhesive with exceptional environmental resistance.

For bonding structural metals where a wide range of working times is required Scigrip SG300 is the bespoke solution. It is available in a range of 5, 15, and 40 minute working times. The adhesive is known for its excellent environmental, chemical & shear resistance.

For bonding metal in structural applications where a wide range of working times is required, Scigrip SG5000 is suggested. This adhesive is available in a range of working times from 4 minutes to 45 minutes and fixture times of 15 minutes to 90 minutes.

Super glue is also suitable for bonding very small metal parts. Both X60 & X65 are suggested for these applications. X85 accelerator can speed up cure time.

For bonding flat metal panels, the choice of adhesive is typically either polychloroprene based adhesive or polyurethane adhesive. The choice depends on application method the size of the pieces being bonded. For manufacturing wood/steel sandwich panels, either S248 or S1922 are possible. Both products are spray applied onto the surfaces being bonded. For bonding smaller areas, particularly in the shop-fitting sector, AF 176 or its high temperature resistant version AF178 is suggested. Finally for bonding large curtain wall panels, we suggest one of our polyurethane adhesives. Products such as AF145 are perfectly suitable for all flat panel bonding applications.

Contact the Glue Guru for immediate advice glueguru@wipolymers.ie

To achieve optimum metal bonding, it is important to degrease the the surface and remove dirt. Apply a uniform amount of adhesive and clamp uniformly along the bond line.