How to Apply Minwax Polyurethane to MDF
Applying Minwax to MDF (medium-density fibreboard) will help the board last longer and also give it greater resistance to the elements. Minwax stain will seal any MDF surface imperfections and leave the board looking brand new. Often times MDF is used for speaker boxes and bookshelves. Having a great Minwax seal will make it look all that much better.
Sand the piece of MDF with 120-grit sandpaper. Smooth out any imperfections in the board and cover the entire area in circular motions.
Vacuum up the surface with a small hand vacuum to remove any dust and debris that is left over from the sanding.
Apply the first coat of polyurethane over the MDF. Coat it on with a paintbrush using smooth short strokes. Work over the entire board until everything has been covered. Allow eight hours for the first coat to properly dry.
Sand over the first coat with 320-grit sandpaper. Go over the entire area to smooth out any imperfections or dust that remain from the first coat. Vacuum up the debris left over from the sandpaper once again. Apply a second coat of polyurethane in the exact same manner as the first coat and wait eight more hours for it to properly dry.
Sand down the second coat with the same 320-grit sandpaper and vacuum up the leftover debris. Apply a third and final coat for a complete finish. Allow eight hours for the final coat to dry before using the piece of MDF.
Things You Will Need
- Minwax polyurethane
- Wait time can vary depending on the type of polyurethane that was applied and how it was put on. Eight hours will allow for sufficient time to dry and putting on a second coat before the eight hour time period is up can be done.
- Complete this task in a well lit area to ensure no spots are missed and to make sure clean even strokes of polyurethane are applied.
- Make sure there is adequate ventilation if working inside and always wear a respirator so the fumes are not inhaled.