Hot-oil treatment study
An older study comparing air drying and hot-oil treatment of ACQ treated wood is still relevant.
The leaching of active ingredients is reduced due to high water repellency of the treated wood.
In some markets, environmental authorities demand risk mitigation measures to reduce the risks for the environment when using preservative treated wood.
In some situations, the application of a paint top coat may be viable, but if maintenance is not secured, hot-oil treatment may be a better alternative.
As shown in the IRG/WP paper 11-50278 a typical reduction in copper leaching is about tenfold when a cladding/siding scenario is tested in a semi-field study. Data was collected during six years of field exposure and showed significantly lower concentrations of copper leached from hot-oil ACQ-treated pine.
Hot-oil treatment moreover leads to increased dimensional stability and increased service life of the treated wood. A relevant efficacy study can be found in IRG/WP 13-30612.
If you do not have access to the IRG-papers feel free to contact us for further information.