Veneering Notes By Richard Nice

Veneering dates back to the Egyptians, although refined over the years the principal is the same:- that of putting a thin layer of wood over the top of another. This is can be done for a number of reasons which are as follows:-
1. The decorative effect of a veneered pattern. E.g. Marquetry is a picture in woods whereas parquetry is a geometric pattern in woods.
2. The economic use of an expensive wood. Ebony, Rosewood. The wood may be of a small size, therefore cutting it into veneer makes it go further.
3. The structural use of veneers for strengthening an item. E.g. Chair backs, grand pianos. In the case of grand pianos it was less wasteful to laminate the rim.
4. To cover up a cheaper groundwork. E.g. Chipboard, Ply, MDF. Any one or combination of reasons may be used to veneer an object. Marquetry is a picture in woods whereas parquetry is a geometric pattern in woods. Veneer comes in two basic types:-
1. Decorative veneers are 0.5mm to 0.7mm thick Knife cut.

2. Constructional veneers are 1.5mm to 3mm thick usually knife cut and used for laminating. Most veneers nowadays are knife cut where either the wood moves or the knife moves. Saw cut veneers are generally thicker and more expensive, as you must pay for the saw kerf, usually this waste at least doubles the thickness of the veneer being cut, thus halving the amount a log can produce.
Groundwork is the base wood the veneer is going to be laid upon, this can be:-
1. Ply it is strongest, but has the disadvantage of having hidden defects in the under-lying layers of laminates. Ply is made up of a central core veneer with veneer- near laminates built up on either side at 90 degrees to the last, thus ply always has an odd number of laminations, By veneering one side only the ply will warp, ply must always be veneered on both sides. This is called balancing. This is also true with plastic laminates and a cheaper laminate called a balancer is often sold for this purpose. Veneer use as a balancer should be of the same thickness as the showwood veneer otherwise the sides will not balance each other. The edge of ply must be treated in some way to disguise the laminations either by a solid wooden edge or by a coat of ”mud”. This is a thick coat of polish with pigment added. When laying a veneer onto ply remember to place it at 90 degrees to the proceeding layer
2. Chipboard has the advantage that there are no hidden faults under the surface as with ply, but it is a lot weaker and the strength of veneer is often underestimated. The result is a badly bowed panel at best. The edge must also must be treated with a solid wood lipping
3.M.D.F. has no hidden defects, but will swell readily if it comes into contact with hot water, such as a coffee mug placed on the surface, and this must be flattened before the veneer is laid otherwise it will telegraph through. The disadvantage is that it is heavy The edge can be lipped with solid wood or it can be machined directly, this is usually done with a high speed router and cleaned up with a profiled polishing head.