Smoked veneers (or sometimes referred to as fumed veneers) are becoming increasingly popular by architects and designers due to the rich, warm quality and colour of these veneers. The “smoking” process is created by exposing the veneer to ammonia vapours and can be used on many wood species including oak, larch, eucalyptus, sapelli, red gum, douglas fir and cherry. Most common are smoked (fumed) oak or eucalyptus veneer.
Many veneerers find that they get bond failure when using their normal adhesives and bonding processes. Whereas standard veneers bond very successfully with urea formaldehyde (UF) resin adhesive or even PVA adhesive, using these adhesives for bonding smoked (fumed) veneers causes bubbling, delamination and discolouration.
With our many years’ experience in bonding veneers, we have found the best way to bond these veneers is using a melamine urea (MUF) resin adhesive, not UF resins or PVA. The ammonia in the smoked (fumed) veneer hinders the standard adhesives from absorbing into the substrate, thereby causing the bonding issues. Melamine urea (MUF) resin adhesives are able to break through the ammonia and absorb into the wood ensuring a bond which does not delaminate, bubble or discolour.
Other tips for bonding smoked (fumed) veneers
- Before laying the veneer up, wipe the veneer with a solvent wipe (not parafiin). This makes sure that any excess ammonia deposits on the surface of the veneer are removed.
- After applying the adhesive to the substrate to be veneered, lay up the smoked (fumed) veneer and leave for 10 – 15 minutes before pressing. This gives more chance for the adhesive to absorb into the veneer.
- Leave the assembled veneer and substrate in the press from 10 – 20% longer than you normally would. This gives more time for the bond to strengthen.
One example of a melamine urea resins (MUF) which can be used for bonding smoked (fumed) veneer is Prefere 4535 with Prefere 5035 hardener. This is a 5:1 liquid/liquid adhesive system which can be used in a hot or cold press.
If you are needing to bond smoked (fumed) veneer and want more information or support, please call Ureka on 0117 971 1364, or enter your details here and we will call you back.