Kirsten Wittenberg Dr. Guido Hora Meeting „COATINGS SYSTEMS FOR WOOD“ 30 th MEETING CTBA Centre Technique Du Bois Et De l’Ameublement Bordeaux, March 15 – 16, 2004 March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora WET ADHESION Test with Pull-off Adhesion Tester of DeFelsko ® Optimisation of the test method in support of prEN (doc. N 343(d)) March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Prescribed Test Parameter DD rying under climatic conditions 20 °C / 65 % rel. humidity 23 °C / 50 % rel. humidity 30 °C / 80 % rel. humidity 10 °C / 80 % rel. humidity TT esting under time oriented conditions 7 days air conditioned 14 days air conditioned 21 days air conditioned 28 days air conditioned March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Test Substrate TT ype of sample: Pine sapwood Pine heartwood Soft beech Beech plywood NN umber and size of samples: Each 2 – 3 pcs. 350mm x 50mm x 15mm March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Preparation of the Test Body  Coating of the test bodies acc. to the instructions of the manufacturer  Depositing in a wet condition in the prescribed climate  Bonding of 7 test dollies of each test body before testing  After completion of drying a cut of approx. 0,3 mm is made around the dollies  Approx. 0,5 ml of deionised water is deposited into the ring groove  After a penetration of 2 hours the test is carried out March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Arrangement of the Dollies March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Test Substrate Beech MPA March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Test Substrate Pine March 15/16, 2004 MPA CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Test Substrate Beech Plywood MPA March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Influence of Water Depositing Time on Beech Plywood after sample conditioning 28 days 20°C / 65% MPA March 15/16, 2004 CEN/TC/139/WG2/N349

Kirsten Wittenberg Dr. Guido Hora Results  Beech Extremely good adhesion properties Relative homogeneous substrate After 2 hours exposure to liquid the sample centre has not been moisturised enough  Beech Plywood The adhesion properties are comparable to pine wood Relative homogeneous substrate The test can already be carried out after 1 hour  Pine Poor adhesion properties Inhomogeneous substrate and therefore low reproducibility March 15/16, 2004 CEN/TC/139/WG2/N349