This
article focuses on dust collection for the wood turner, however,
any woodworker who
works with the woods listed below should take the same precautions
when handling or working with these woods.
I
often hear turners say that the only time that they feel they
really need dust collection is when they are sanding. I generally
agree, since turning involves the removal of wood with chisels
that cut or gouge the wood off in large shavings. However, the
other main reason for dust collection while turning is to reduce
contact with toxic or hazardous woods. The most common hazardous
wood is spalted maple (maple that has started to rot). This wood
is identified by the black line patterns running through its grain.
It contains corticalc mold. Mold is made up of spores, which thrive
in dark damp places, such as lungs where it causes "pneumonitis"
or "alveolotis", (hypersensitivity pneumonis). Virtually
any thing you do to spalted maple, can release the spores contained
in the
wood: so be especially careful when cutting, machining or sanding
this wood.
Rosewood is another wood that needs to be handled with caution;
it can be an irritant to your skin, your eyes, and your respiratory
system. Cocobolo, Obeche, Olivewood, and Beech also fall into this
category. The
dust from the following woods is known to cause cancer of the
nose: Beech, Hemlock, Oak, Quebracho, Redwood, and Sassafras.
Although some woods are more toxic than others, people can become
sensitized to any wood if they are overexposed to the wood and
especially to its dust.
Protect yourself by wearing a special mask and protective coatings
for skin. If you turn in your basement, remember to be responsible
toward other people who live in the house. Forced-air furnaces
in homes can easily transmit dust and spores throughout the home
if there is not proper dust collection to remove it as you work. The
recommended velocity for dust and shaving removal in industrial
applications is between 3500 and 4200 feet per minute and the volume
should be near 785 cubic feet per minute. To achieve this, the
home shop owner would need to have at least a 2hp dust collector
with a 6-inch line running to the lathe's dust collection hood.
It is easy to find the 2hp dust collector but 6" flex hose
is expensive and rather hard to find. So I developed a hood to
fit a four-inch
flex line.
A typical roughing out operation on a piece of green wood (photo
1), results in the long shavings being directed toward the operator.
These shavings are typically harmless except in the case of toxic
woods. When sanding a bowl there are a couple of important things
to note about proper dust collection (photo 2).
First, the dust hood is positioned and oriented toward the bowl
to maximize its
effect. Secondly, the operator is keeping his hands in the 6 -
9 o'clock quadrant of the fowl, which is the safest position.
Notice the operator's hand placement (photo
3) in this spindle
sanding operation, with the hood oriented for pick up. This is a manufactured lathe hood. The arrow indicates the universal
mounting bracket. The bracket is bendable and can be bent as
necessary and permanently fastened or clamped to the lathe (photo
4). The "end boot" is
an HVAC (heating, ventilating and air-conditioning) fitting
that can be adapted to dust collection. You can fashion
a bracket to hold it in place or you can permanently fasten this
to your lathe. Be sure to fold the exposed edges over to eliminate
the sharp edges indicated by the arrow (photo
5). Another
option is to wet sand your project, thus eliminating the need
for dust collection. This procedure is done using mineral
oil on the sand paper. However, note that the oil is not compatible
with all finishes.
  
 
CHESTER VAN NESS is a Dust Removal Consultant in Scotland, Ontario.
(519) 484-2284.
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