Bonding timbers treated with preservative is notoriously difficult because the preservative, by its very nature, hinders the adhesive from curing. These preservative deposits and water repellents (which are retained near the surface), together with the problem of the moisture content of the timber being very high, resist the adhesive from wetting out on the substrate thereby interfering with the curing process. High moisture contents will also interfere with the adhesive curing, and in addition, may set up high stress concentrations due to subsequent shrinkage of the glued structures. On the plus side, kiln-drying of timber treated with a water-borne preservative should present no significant bonding problems.
HINTS AND TIPS TO MAKE A SUCCESSFUL BOND
- Kiln-dry to a suitable moisture content for the chosen adhesive. We would recommend Prefere 4050 Phenol Resorcinol Resin or Prefere 4535 Melamine Urea Resin
- Sand the surfaces to be bonded. Heavy sanding may be necessary where salt deposits are high. Note: After sanding, the surfaces must be flat enough to ensure a close- fitting joint.
- Glue the joint not more than 24 hours after sanding.
Joints made with Prefere 4050 and 4535 adhesives are fully resistant to moisture and, to long term weathering. These adhesives are ideally suited to the gluing of timber structures or plywood designed for use where dampness is likely to occur.
For more information on the exhibition, please contact us on 0117 971 1364 or email us on firstname.lastname@example.org.