Veneer over Fiberglass Column

Question:

I applied wood backed veneer over a fiberglas colunm. The veneer is a three layer product consisting of the surface veneer which is about 11 thousands of an inch thick, a paper layer, and a wood layer. The column is 15′ 6″ tall and about 30″ in diameter.

I was sent 6 pieces of book matched veneer. Each 8′ x 3′. The application failed at one point. I am trying to determine the contributing factors to this failure. The application required six vertical seams and three horizontal seams due to the size of the column and size of the sheets of veneer. The point of failure was where the horizontal and vertical seams met at the center of the column height, approximately eight feet up or down its height, depending upon your perspective.

At this precise point at the column, was a “patch” of drywall and joint compound. This patch was an attempt to mate the lower column with the upper column to achieve the desired height of the column. I suspect this patch area was the contributing factor in the delamination failure, although, I am also wondering about:

• surface prep
• adhesive choice
• method of applying the adhesive
• environment issues
• proper grain direction of the wood backer in relationship to the face of the veneer.

I am looking for anyone that has expierence with wrapping columns with veneer in hopes of establishing a cause or causes of this failure. Any feedback would be very helpful.

Answer:

Based on your description of the whole assembly, the one thing that stands out is the drywall patch.

Applying flexible veneer, or any veneer for that matter, over drywall isn’t reccomended. We always suggest the use of Bondo or fiberglass body filler for patching or filling substrates. We fully agree with your assessment that this is the cause for the failure.

Oakwood Veneer Tech Support