Making Thin Stock

Making Thin Stock, Woodworking Tips, Guides, Articles, Magazines, Texts, etc

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Making Thin Stock
Woodworking project plans often call
for stock that is thinner than the
thicknesses of lumber available in
hardwood stores. Surfaced 1x lumber
comes out to 3/4" thick or perhaps a
little more, and this is the thinnest
commonly available. There are mail
order companies that sell thicknesses
down to 1/4" and less, but this tends to
be expensive. So what can you do to get
thin stock? There are numerous things
you can do; find a local cabinet shop that is willing to occasionally plane down some
stock for you and perhaps do some resaw, use your table saw to rip thin pieces, use
your table saw and band saw in tandem, or use a jointer, band saw, and planer to do
the work.
The last solution is the one of choice, if you have the machines. But many people
don't and that is why one alternative is to find a shop that will help you out. If you can
find such a shop it may turn out to be very easy for you to show up now and then with
a few boards and quickly have them planed down, so it's worth the effort to
investigate by calling around. But keep the following in mind. These shops will be
busy and it is not worth their while to disturb their normal flow of materials for the
sake of a small job like this. But, if you find a convenient time for them, say right at
closing time or on the weekend when someone is puttering around, they may be more
than willing to help. Secondly don't debate the price they ask for the work, any way
you look at it they aren't going to profit from planing a few small sticks for you. If it
costs too much don't come back.
One other thing you can do to make it easier for them is to prepare the stock as much
as you can before you bring it in so that they have a minimum number of steps to
perform on the lumber. If all they have to do is plane 5 pieces from 3/4" to 3/8", it is a
lot easier for them than if you ask them to joint, rip, resaw, then plane. If your stock is
thick you may need to ask them to do all those steps because it is senseless to plane
thick stock way down. But the easier you make it for them the more likely they will
be willing to help, so maybe you should go buy 3/4" stock and ask them only to plane
it just to make the process simpler.
Whatever process you choose for getting thin stock, consider taking your result to a
cabinet shop with a wide belt sander for the final thicknessing process. Wide belt
sanders are industrial grade machines, technically referred to as abrasive planers.
They work very fast and effectively to bring stock to a consistent thickness with an
excellent surface finish. They only cost from $5-10,000 though, which is good for you
in one critical respect. Cabinet shops that buy these machines must rent out time on
them to other woodworkers to pay for the machine, so they welcome your business.
They’ll charge about $1/minute, but in 30 minutes you can surface a lot of stock far
faster and better than you will ever achieve in your shop with a hand belt sander.
RESAW ON THE TABLE SAW
Photo 1- Resaw thick stock into
thinner pieces at the table saw by
making a progression of cuts. First
make cuts at about an inch high as
shown.
Thin stock is made on the table saw by double ripping the stock on edge, as in photos
1 and 2. The maximum width of stock you can achieve equals twice the maximum
height of your blade above the table, which on most 10" saws is about 2-3/4", so 5-
1/2" is about the most. This kind of ripping is very demanding of your saw blade if
you try to cut the full 2-3/4" in one pass, which I don't recommend. First set the blade
at 1" high and double rip the stock as in photo 1, always putting the same face against
the fence, of course. Then raise the blade to 2"; rip again, and then set it at full height
for the final pass (photo 2). Be sure your fingers are out of the way on all these passes
and use a push stick as shown.
Photo 2- Raise the blade and make
more cuts without moving the fence.
When the thin part will be cut free,
push it through with a push stick as
shown.
The first thing you'll notice when doing this kind of cut is that if your stock is not flat,
and does not ride flush against the table saw fence, the blade will tend to burn inside
the cut. This is because the wood is being turned slightly against the side of the blade
during the cut. You want to minimize this kind of action because it is bad for the
blade to heat it this way, it is bad for the wood to burn it, but mostly because if this
action is severe enough the blade can bind or worse it could grab and throw the stock.
Doing the cut in three passes will help, but this is treating the symptom and not the
cause, which is twisted stock. Try to pick the straightest stock you can. Cut longer
pieces into shorter sections, but don't work with pieces less than 18" long. Using a
jointer to flatten the face of the stock is the best solution to twisted wood. If you don't
have a jointer you could flatten the stock the traditional way with hand planes- an
arduous but venerable task. A belt sander with very coarse grit could be used to do
this, but this will only work well to remove severe high spots, it won’t work well to
make boards accurately flat.
Once you have stock that is straight to your satisfaction, look at it carefully and if the
piece is still not perfectly straight place the outside of the curve against the fence, as
in drawing 1A. If you place the inside against the fence, as in drawing 1B, you can
cause severe binding as the tail end of the piece comes in contact with the fence. This
is potentially very dangerous and should be guarded against.
Drawing 1- This
drawing is
greatly
exaggerated for
the sake of
clarity, you
should not cut
pieces on the
table saw that
are as badly
distorted as
those shown.
See text. 'A'
shows how you
should run
slightly bowed
stock in the
table saw, with
the outside of
the curve
against the
fence. 'B' shows
what not to do,
because if the
inside of the
curve is to the
fence severe
binding agains
the blad
t
e can
result.
How far should you set the fence from the blade? If your stock is very straight and the
ripping cuts go easily, you can place it very close to the thickness you want to ach
with only a little bit extra for sanding or planing. But if the stock is not perfectly
straight there will be some variation in thickness, so it is best to
ieve
rip it over thickness
by about 1/16" or so, and then sand or plane to thickness later.
A word of caution. We are talking here about running stock that is not perfectly
straight through the table saw with a deep cut, and as I've said this is potentially
dangerous. The amount of danger is a matter of degree- slightly twisted stock will not
present much problem but severely twisted stock will. If your stock is out of flat more
than 1/8" over two feet of length, either find a way to flatten it or don't use it.
Using a thin kerf blade will be a big help on a job like this, for two reasons. First,
because it moves less wood it is easier to push the piece through the cut, and secondly
because the kerf is less wide, less wood is wasted in the cut and you can get more
pieces from your stock. One disadvantage to thin kerf blades is that they can wobble a
bit in the cut, making a rougher cut than with a regular blade, but the pieces will need
to be sanded anyway so this is not a serious problem. It is more important with a thin
blade to take the cuts in multiple passes as described above, because if you try to take
a full 2-3/4" cut the blade could seriously distort under the great load. Thin blades are
more likely to distort with heat build-up than thicker blades. Thin kerf blades come in
many different diameters like other blades; remember that you want the largest
diameter that will fit on your saw in order to get the maximum height of cut.
Whether or not you use a thin blade, it is still possible to get several thin pieces from
one thick piece, depending on the dimensions. And so you may be merrily cutting
along on a thick piece, gradually moving the blade up and down as you progressively
peel off thin pieces, and then you find that as you start to cut the third or fourth piece
that now the blade is binding where it wasn't before- and sure enough looking at the
now thinner piece you see that it is no longer straight. Why is this? As wood is
removed from the original piece, tensions in the wood are released causing the wood
to move. On some pieces you won't see this at all, others a fair amount and on some it
will be extreme. Keep an eye on the stock as you work it and straighten or eliminate
those that move a lot.
Once you have your thin pieces roughed out, they need to be brought to their final
thickness, and the obvious choice for this is to use a planer, if you have one, or visit
your local cabinet shop and use their planer or wide belt sander. Or you can belt sand
the pieces with a hand belt sander to approximate thickness, though this is not a
reliable means of getting a consistent thickness. Using hand planes to thickness the
stock gives you more control, as well as sore muscles, but all kidding aside if you
have a penchant for planes this is where you can really make use of your skill.
Photo 3- Winding sticks on a board
that is almost flat. Note that the sticks
are very close to being parallel to each
other.
Here is a trick the old timers used to check for flatness when planing the face of a
board. Take two straight sticks (called ‘winding sticks’), each about two feet long, and
place one on each end of the board you are planing, as in photos 3+4. Then sight
down the board such that both the sticks are close to your line of sight, and you will
quickly see whether or not the two sticks are parallel to each other, and if not which
corners to joint, plane or belt sand down. The key with a procedure like this is to
check frequently and remove only a little at a time, so you don't go beyond your
intended goal.
Photo 4- Winding sticks on a board
that is quite twisted. This exaggerated
example shows how the long winding
sticks make it easy to detect twisted
stock.
USING A BAND SAW AND PLANER
Making thin stock with a band saw, planer, and hopefully a jointer is easier and more
precise than using the table saw procedure described above, and it allows you to work
with widths that are greater than twice the height of your table saw blade. If you are
lucky enough to have these machines, here is where you can really put to use the
machining capabilities they have- and make you feel that the investment was
worthwhile.
Note that many smaller band saws are only capable of cutting a maximum height of
6". This is not much more than twice the height of a 10" table saw blade. Many small
band saws can be increased in cutting height capacity by purchasing an extension kit,
which bolts on between the lower base and upper arm. Many band saws cannot be
extended this way however, because the machine base is one big casting rather than
an upper and lower casting bolted together. Keep this in mind when you buy a band
saw.
Though the resaw process can be easy and a delight when the machines are well
adjusted and your stock has consistent grain, it can be a nightmare when either aren't.
Resaw on the band saw requires that the guides be adjusted carefully. If you have only
cut thinner stock on your band saw (up to 2" or so) you may have never had the need
to carefully adjust the guides. Here it is critical so that the blade is guided in the same
direction both below the table and above the work on the descending arm.
Better quality replacement band saw guides are available to fit most saws. If you plan
to do a lot of resaw with a band saw consider getting some of these.
When you are planing any stock, there is less chance of tear out if the stock has
consistent grain direction and you plane with the grain, but this is even more critical
with thin stock, and the thinner the more critical. If you plane against the grain on
pieces less than 3/8" thick or so, there is a good chance that the stock will not only
tear out but tear apart in the planer. This can send wooden shrapnel out the dust shoot,
as well as back at you by the in feed roller. Using consistent, even grained stock is
really the only way to go. As well, a general safety rule with planers is that you never
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