Is it safe to use water based dyes and finishes on veneers bonded to MDF?
by Alan Noel
Professional Wood Finisher
MDF stands for Medium Density Fibreboard which is broken down wood fibres combined with wax and
resin as a binder and formed into panels using high temperatures and pressure. MDF is a great
substrate for veneering, and I have sometimes worked with pieces made of MDF. Most were veneered with
wood, and sometimes with photographed wood-grained vinyl, which can easily fool the untrained eye. The
number one reason for the work was related to water damage of some type that would usually cause
swelling of the substrate due to moisture absorption, typically around the edges of tops and along the
lower edges of case goods. So obviously, water based anything is tricky to use on veneered pieces
made from MDF.
In my shop we have refinished pieces made of MDF and various combinations of wood edging and wood
veneers. Stripping and refinishing these types of pieces requires a lot of concentration, along with speed
and accuracy. Typically the chemical strippers don't have much effect on the substrate. After stripping
and sanding of any exposed edges, we will rub in waterproof glue to halt any type of moisture
absorption during the finishing processes that follow. I have used both water and oil based dyes during
the refinishing process and haven't had any trouble at all with the substrates. However, allowing any
water based dye to stand for long on any veneer would not be a good idea. As for water based finishes, I
can't really comment on this since we never use water based finishes in restoration.
I called a few of my friends who use MDF for veneering substrates, and the advice most often given
was to be sure to apply a thin layer of waterproof glue to the MDF first, and then let dry. This will
prevent the next layer of glue from being absorbed, cutting way down on adhesion problems from glue
starvation.
Visiting Atlanta? Attend one of Alan's upcoming highly informative Highland Woodworking wood finishing seminars:
French Polish Workshop
, April 14, 2010
Finishing the Finish
, May 5, 2010
Antique Restoration
, May 22 & 23, 2010
Gilding and Gold Leafing
, June 9, 2010
Antiques Show and Tell
, June 12, 2010
Visit Highland Woodworking's Online
Wood Finishing Supplies Department
Alan can be reached directly via email c/o Alan Noel Furniture Refinishing at
anoelfurniturere@bellsouth.net
.
