Serious Education ... plus the most fun you can have in metal finishing.
Use of aluminum with pressure treated lumber(2006)
I would like to know if I hard coat 6061-T6 Aluminum angle will it protect it from the copper used in the pressure treatment. If not is there any finish I could apply to the angle to keep it from corroding. The use is in a salt water environment (dock) not immersed in the water.
Thank you very much for your time.
Briarpatch Engineering - Pocasset, Massachusetts
There is an epidemic nationwide of copper/aluminum corrosion since wood treatments changed to high copper for environmental reasons. I worked with our state department of transportation to solve the problem on the highway signs. We used one of two different materials one a wax coating with corrosion inhibitors. The other was an acrylic aerosol spray again with corrosion inhibitors. Both coatings work well in saltwater environments. The wax coating provides better UV protection.
- Colville, Washington, USA
I recently had a porch re-built and the contractor used 2 by 6 inch pressure treated wood to build the support beam. He covered it with aluminum flashing and may have used regular nails to attach the roof beams and ceiling joints to the beam.
Should I be concerned that the nails will corrode in a year and the aluminum flashing will corrode as well? All the info I have found indicates that my porch could fall down in a few years due to corrosion. CB
- Louisville, Kentucky, USA
October 10, 2013
A. You should be very cautious. Aluminum and pressure treated wood do not mix. Where aluminum comes in contact with the wood, the aluminum will eventually pit and holes will appear.Linda Julius
- Louisville Kentucky