is a slightly edited version (mostly for pagination and spelling
:) of an excellent article by Keith A. Lahteine of Audio
Box Design, followed by some personal thoughts and comments.
Wood and Plastic Laminates
Keith A. Lahteine
materials are available in any number of formats. The least
expensive is probably rotary cut pieces about 1/32" thick.
The next is face cut, followed by quarter sawn of the same
thickness. Paper backed sheets, 1/32'' and less in thickness,
will cost from $50.00 to $100.00 a sheet (4'x8') depending
on species and cut. The last, and most expensive of all, is
mica backed wood veneer "Formica Ligna" which sells
for $120.00 a sheet and up. Straight mica veneers which carry
a photographic type face meant to simulate various wood types,
sells from $35 to $75 a sheet. The image face on these laminates
is very thin and care must be exercised to avoid harming the
to handle these materials are, for the most part, simple and
not too expensive. Tools for cutting mica backed wood veneers
and plastic laminates are a little more specialized than those
needed for straight wood and paper backed veneers. For mica
and mica backed plastics, a pair of laminate shears is handy.
They come in models for cutting straight lines or curves and
cost about $35 each. Some well stocked home supply stores
as well as cabinet and laminate supply stores should have
them. If you have a table saw you can cut straight lines.
When ripping thin laminates and veneers on the table saw it
helps to raise the laminate above the table surface with a
thin piece of material for the veneer or laminate to ride
on. This prevents the material your cutting from slipping
under the fence and thus jamming. Cut pieces large enough
to allow for about a 1/2" overlap. This will be trimmed
off in the final stages of finishing.
you are or are not going to use a grill cloth will decide
some of the next steps. If you cover the baffle board completely
then the decision is moot. The instructions are for a normal
rectangular prism (6 sides). The first surface to be covered
is the front (baffle board). Even is you have decided to use
a grill cloth to cover the front of the enclosure, having
the baffle covered allows the grill to be removed or to remain
in place depending on your whims. At least a frame of 1''
or wider can be used to start the veneering process. Next
is the bottom of the cabinet which will overlap the front
piece. Each piece of veneer or laminate must be flushed before
the next piece is applied.
I have received
queries as to whether or not the pieces meeting at right angles
(90 degrees) should be mitered. Apparently some of the tool
manufacturers have responded to this same request. In the
past five or six years a miter laminate trimmer has become
available to effect this kind of treatment. It is used to
45 the edges of the pieces being joined. Given this specialized
tool, the joint is still very hard to produce. The reason
for producing this effect is still very much a puzzle to me.
It is almost always a requirement to relieve 90 degree corners
with the use of a file and/or sandpaper. When this is done,
flush overlapping or mitering appear pretty much the same
without the use of a magnifying glass. Flush overlapping is
easier and much more painless to achieve.
In any event
you will need (if working with mica backed laminates) a laminate
trimmer with a flush (carbide) bit. The type with a roller
bearing on the bottom is the easiest to use. Laminate trimmers
are manufactured by a number of different companies which
I'll list to the best of my recollections : Makita, Ryobi,
Bosch and Porter Cable.
These are the best and most accepted of them. Porter cable
and Bosch make both the regular as well as miter types. A
small router can be substituted for the laminate trimmer but
the dedicated trimmer is easier to control. Trimmers can also
be purchased in kits which include a number of different bases
for varying offset and angle. These usually sell for about
$200 and up. A standard trimmer will cost about $80 to $150
and a miter trimmer will sell for about $170 to $200. Next
is a standard "Mill bastard" file. About 8'' to
12'' in length is ideal. There are files dedicated for use
with laminates but are not necessary.
cements are the next concern you'll have. Most petroleum based
adhesives are very volatile and should only be used in areas
with adequate ventilation. There are formulas which use non
volatile, water based mixes but their performance is less
than the petroleum based adhesives. Tack time is from 15 to
25 minutes, depending on temperature and humidity. Waiting
a little to long rather than not long enough is preferred.
A solvent for cleaning the seams and joints is necessary.
Acetone is the best and most effective but can soften and
remove too much glue if not used with care. Lacquer thinner
will not work as well but is safer to use.
If you are
going to use paper backed veneer or straight wood veneer you
really don't need a laminate trimmer. What you will need instead
is a small veneer saw. This is a small hand tool that costs
about $10 . You can't use a laminate trimmer on non mica backed
veneers; it will tear them up to easily. When you use the
veneer saw to flush the edges always saw in a direction which
will be pulling the veneer down. If the veneer starts to separate
you're sawing 180 degrees in the wrong direction. Finish up
with a sanding block with 150 or 180 aluminum oxide paper.
You shouldn't have more than about 1/32'' to remove.
Why I think
mitering is such a waste of time and effort has to do with
the material thickness you're dealing with. The overlap is
only about 1/32'' (thickness of the veneer). Unless you want
the corners as sharp as a knife they will have to be relieved
with sanding. The radius for each corner can only be the veneer
thickness (about 1/32''). That is, potentially, the largest
end grain you have to worry about. Even if you were to miter
the corners together, you would still have to relieve the
corners. That's why I think mitering is a waste of time. If
you do a proper job you'll see no difference in the end result.
that I've gotten that off my chest we can get back to the
task at hand. Even though you probably won't see the difference,
I maintain an order to the sequence of applying the sheets
of laminate or veneer. After the front (baffle) is applied,
the edges are flushed, the bottom piece is the next to deal
with. The sides follow. Remember, each piece has to be flushed
to accept the next piece. Don't do any relieving of corners
until the entire piece is covered. The last surface, to be
applied, is the top. This overlaps both sides as well as the
front. If you have any areas that need fill, this is the time
to do it. There is an excellent product for filling gaps,
scratches and gouges. It is like plastic wood but is available
in a number of wood colors as well as natural. It is called
"Famowood" and I have found nothing superior. This,
or any filler, should be applied before any stain or oil based
finish. It accepts stains very well and you would be hard
pressed to notice it's use if applied carefully. It also sands
easily and this should be done just prior to staining. When
you are applying contact cement to the surfaces to be joined
only apply to two joining surfaces at a time. Don't forget
the edge has to be flushed before the next piece can be joined.
When coating the mating surfaces with adhesive, determine
which of the surfaces is the more porous and coat this piece
second. This way each should reach the same state of dryness
at, approximately, the same time. One tool, I have not mentioned,
that comes in handy is a J-Roller for applying pressure to
the glued surfaces. It makes the job that much easier. A small
wood block struck with a hammer all over the glued pieces
will work as well. Pre-cut all of your veneer or laminate
pieces about 1'' larger than the finish dimension. This allows
about 1/2'' overlap all around. After the veneer is applied
sand with 220 and stain and finish with good varnish or polyurethane.
Very light sanding with 220 between coats. It takes a minimum
of four coats (six is even better) to achieve a good finish.
A few tips
follow : In order to position the veneer pieces before the
glue makes contact, use 1/2'' to 3/4'' dowels to separate
the surfaces. (Wax paper will work with smaller pieces) .
When you are satisfied with the position slide the dowels
or wax paper out and let the glue do it's job. Get it right
before making contact; the cement won't give you a second
chance. Once contact is made picking it up and re-applying
is impossible. When you're using a veneer saw use a
couple layers of masking tape on the surface that the saw
will be riding on. This prevents damage to the veneer and
the small overlap can be flushed with a sanding block and
180 or 220 paper. The choice depends on caution and courage.
Don't hesitate to ask questions or disagree with me about
my system. It works for me but then criticism never hurt anybody.
A. Lahteine "Audio Box Design"
personal thoughts and comments
- One very
important consideration for non-pre-processed veneers (such
as raw wood stock) is that the veneer must be perfectly
flat. Veneer conditioners exist for doing this. Pre-processed
veneers should be flat already, but check first.
- I find
it easier and more accurate to flush the edges with a hand
plane. I find saws to be too rough and more prone to tearing.
- I'm not
a fan of sanding veneers. Many are too thin to begin with
and run the risk of sanding through if not done with care.
But more important is that I like the beauty of the wood
to show through. I prefer to use a cabinet scraper, which
never leaves the surface dull looking as sanding does. The
result is a surface with more depth, and just as smooth
if not smoother than sanding alone.
- Not all
woods will glue correctly with all glues due to their properties.
When in doubt, experiment with scrap pieces before commiting
your veneer to the glue.
glues have different properties that may affect their choice
for use. For example, the traditional veneering glue of
choice - hide glue - allows repairs to be made more easily
but is more difficult to use and to apply by today's standards.
Contact cement is quick but much less forgiving of mistakes.
- For those
doing this for the first time, invest in extra materials
and practice, practice, practice.