Note: Descriptions are shown in the official language in which they were submitted.
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NON-COATABLE DRYWALL FINISHING SYSTEM
Field of the Invention
This invention relates generally to the field drywall construction and more
particularly to a system of exterior and interior drywall seams and corners
that
greatly reduce the amount of time and labour required to finish a modern
structure.
Description of the Related Art
The use of gypsum drywall board in modern construction is well known.
Manufactured drywall sheets are nailed to studs to form interior walls and
ceilings. Before these sheets can be painted or textured, the joints must be
taped and sealed with joint sealing compound (drywall mud).
Taping (known as stringing) is a tedious process since first tape and mud must
be dispensed with a tool known as a bazooka, then the worker rolls and glazes
the tape while the mud is wet. As the tape strings out, it has a tendency to
pull
in the direction of motion.
An alternative to taping, especially in seams that do not meet at 90 degrees
is
the use of a product generally called "flex bead." Flex bead consists of two
thin
strips of metal bonded to a two inch paper tape. To use "flex bead", a worker
first spreads all-purpose mud along the wallboard on both sides of the angle.
A
length of "flex bead" is folded by hand to create a crease. The bead is then
installed in the angle. This requires a good eye for straight lines since the
"flex
bead" will not make a straight line by itself. The worker must move the bead
around to the best of his abilities to set it as straight as possible. On many
occasions, the worker will end up with a line that is not straight; this
condition is
called "snaking."
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Once the "flex bead" is installed and dry, the first coat procedure is
s;arted.
Most journeymen only coat one side of the angle at a time. If one tries to
coat
both sides at the same time, the mud flops over to the other side, and the
knife
digs a line into the mud on the other side of the angle. Thdrefore, the
following
process is usually used: 1) Apply the first coat of mud to one side and v;ait
until
it is dry; 2) Apply the first coat of mud to the other side and wait until it
is dry; 3)
Sand both sides and clean at the crease; 4) Apply the second coat of mud to
one side and wait until it is dry; 5) Apply the second coat of mud to the
other
side and wait until it is dry; 6) Sand and touch up both sides. This process
is
tedious, and requires considerable time while the respective sides are drying.
In addition to "flex bead", other corner beads are in common use. These
include both straight and "bullnose" or rounded versions. These are used on
exterior corners at windows and other openings. To use a standard corner
bead, it first must be cut from a standard length of 8 feet or 10 feet. The
cead is
nailed into position using short nails approximately every foot. The worker
must: 1) keep the bead plumb or level, and 2) keep the bead at the pror.e--
angle
to prevent slipping too far to one side or the other. If this latter condition
Dccurs,
a "shiner", as it is called in the trade, results. This is where the bead is
too far
toward one side of the corner making the other side flange hard to coat.
Once the bead is installed, the worker must "first coat" the bead. This means
to
coat it with mud for the first time. This is very labour intensive, and i;
uses a
large amount of mud. After the first coat, the mud is allowed to dry Drying
takes about a day.
After the "first coat" is dry throughout the building, the worker has to sand
this
first coat of mud and clean all the metal edges. This is especially diffic-ult
with
bultnose bead. After the "first coat" is sanded, the worker proceeds to
"second
coat" the bead repeating the entire process again and waiting another day to
dry. The worker finally must again sand the bead carefully loo'Ning for
imperfections, and touching these up. At this point, the bead is ready fc-
texture
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or paint. The entire process users considerable mud, and is very labour
intensive, especially the sanding. In terms of total construction time, it
requires
two to three days to complete all the corners of a typical residence_
What is badly needed is a system for finishing drywall on the interior of
buildings that avoids the difficulties of taping, "flex bead", and other
corner
beads while retaining the perfect finished appearance that is required for
texturing or painting. The sanding steps should be totally eliminated. This
system should reduce the labour to less than one day for a typical residence
and significantly reduce the amount of mud used.
Summary of the Invention
The present invention relates to a drywall finishing system product that
includes
inside and outside, multi-angle, non-coatable trim, and non-coatable corner
bead that forms 1) normal corners, 2) stub wall or closet corners, 3) window
wrap corners, and 4) L-metal for window sills and areas where drywall ends
against some other surface like brick. In addition, the system includes
accessory products for each of the pieces mentioned.
The present invention eliminates most of the intense labour associated with
present methods since none of the parts need to be coated with mud or sanded.
In addition, the parts form straight, finished lines and angles as soon as
they are
installed.
The present invention relates to corner bead and trim pieces that are simply
placed on top of a coat of applied mud at the corner. The corner can be an
exterior or interior angle. No nails are required, since the invention pieces
stick
to the mud. The pieces are paper, plastic, or other suitable material for
texturing and painting. They can be tapered on their edges to blend into the
adjacent wall when the edges are "killed" with a wide blade knife and a small
amount of mud.
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To install one of the embodiments of the invention, it is selected from stock
and
cut to length if not exactly the right length. A flat coat of mud is applied
to both
sides of an exterior or interior angle, and the device is placed over the mud
and
smoothed into place. Since it is preformed, the piece makes a straight line at
the required angle. Once, the piece is in place, the edge is "kiiled" once
with a
small amount of mud and a wide blade. At that point the corner is complete
except for drying. It does not need to be sanded or touched up. When dry, it
can be directly textured or painted.
Brief Description of the Drawings
For a more complete understanding of this invention, reference should now be
made to the embodiments illustrated in greater detail in the accompanying
drawings and described below by way of examples of the invention, and in
which:
FIGURES 1A and 1B show a no-coat natural corner piece.
FIGURES 2A and 2B show an embodiment that forms a speciality piece for
the no-coat natural corner of Figure 1 A.
FIGURES 3A and 38 show a stub wall or closet opening no-coat trim.
FIGURE 4 shows a no-coat stub wall or closet speciality piece.
FIGURES 5A and 5B show an embodiment of no-coat window trim.
FIGURES 6 shows a speciality piece for no-coat window trim.
FIGURES 7A and 7B shown an embodiment of a no-coat L-metal or L-
member piece.
FIGURE 8 shows an ultra-flex corner trim piece.
FIGURE 9 shows a cross-section of the embodiment of Figure 8.
FIGURES 10 and 11 show cross-sections of a right-angled drywall corner
trim and a bullnose trim, respectively, constructed in accordance with
preferred embodiments of the present invention.
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It should be understood, of course, that the invention is not necessarily
limited
to the particular embodiments illustrated herein.
Description of Preferred Embodiments
Figures 1A and 1B depict an embodiment of a no-coat natural corner. The
piece consists of two long flanges I of suitable material, preferably paper or
other material that will adhere to mud, that form the corner angle. The width
of
each flange is approximately seven inches; however, this size is not critical,
and
other sizes can be used from less than 3 inches to wider than 14 inches. The
piece can be supplied in standard 8 or 10 foot lengths, or any other length
that
is convenient. The thickness of the flange can be from thinner than 0.015
inches to greater than 0.625 inches. The edge of the flange can be tapered to
better merge into the wall board when the edge is "killed". While tapering is
preferred, it is not necessary to the functioning of the invention.
A key feature of the invention is the ability to "kill" the edge with a small
amount
of mud and a wide blade knife. In this process the mud is spread into an
extremely thin layer over the edge to merge the edge into the surrounding
wallboard. This step is preformed only once right after the desired piece is
put
into place. After this step, the installation of the piece is complete. It is
important to note the no nails or other fastening means is used. The pieces
are
simply stuck on to the wet mud. Of course nails or other fastening means can
be used if desired, and a version of the present invention using nails could
be
made; however, nails are neither necessary nor desirable since they require
time and skill to use, and have the tendency to rust.
Inside the flanges 1, a strip of plastic, metal, or other material 2 is bonded
or
glued to the flange to give it rigidity and support. This support member 2 co-
operates with the flange and forms a perfect corner seam. The fact that the
corner piece is preformed prevents the corner from wandering away from true
even when the underlying construction is imperfect. The support member is
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generally narrower than the flange and can be made from about 2 inches to 15
inches, with 5 inches being preferred on a 7 inch flange.
At the top and bottom of the piece, the support member can be cut flush with
the
flanges, or it can extend in length beyond the flange at one end and be
shorter
than the flange at the other end. This allows mating more than one piece when
required for longer seams.
The angle 4 of the flanges relative to one-another is around 89 degrees. This
angle can vary, and different types of pieces can be manufactured for
different
wall angles. Any angle is possible; however, 89 degrees is the best angle to
use for a typical 90 degree corner. This causes the flanges to slightly grip
the
wall pieces and the wet mud.
An optional method of constructing the corner piece is to use a second
covering
made of paper or other material, inside the support member to form a sandwich
(not shown). This has the advantage of providing better adhesion to the wet
mud when the piece is first put up.
It should be noted that in all the embodiments of the present invention, the
outside seams can be straight or bullnose of any radius, or any other shape.
Bullnose corner beads of the conventional type are popular in residential
construction. Bullnose pieces are simply fitted with a bullnose strip on the
outside of the corner seam.
Figures 2A and 28 depict an embodiment that forms a speciality piece for
corners that can be used in conjunction with the natural corner shown in
Figure
1A. The piece of Figures 2A and 2B is shaped to be used where two right angle
walls join a ceiling at an opening. An outer flat flange 5 fits the higher
wall and
extends over the opening. A second flat piece 6 runs the vertical wall forming
the opening and also along the top of the inside of the opening. The angle
between the wall parts 10 and the angle between the top of the opening and the
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wall 11 should be around 89 degrees for a right angle system; however, parts
can be manufactured with any angles for special requirements or special
construction angles. The edges 7 and 8 can be tapered to make the "killing"
process easier and the final blend into the wall more perfect; however,
tapering
is optional. The speciality piece shown in Figure 2A and 2B is made from
plastic or other suitable material. It can be any length; however it is
preferably
around 7 inches along the short sides, and around 10 inches along the longer
sides. The exterior seams can be straight or bullnose or other shape.
Figures 3A and 3B depict a stub wall or closet opening no-coat trim
embodiment. Its length can be a standard 8 foot or 10 foot, or it can be any
length. It consists of two long, approximately parallel flanges 12 of similar
construction to other embodiments already described, with an inner support
member 14. These can be paper or other suitable material, and the support
member can be plastic or other material for rigidity. The plastic can be
moulded
or extruded. The flange thickness is similar to the flanges shown in Figure 1.
In
this embodiment, the flanges are coupled to a flat back piece 13. The back
piece can contain a spacer if necessary. This spacer is used to eliminate the
need to wrap the opening with drywall.
This embodiment of the invention is used for typical closet doors and stub
walls
(walls that end in a room). The invention caps the wall or door. The back
piece
13 can be different widths (distance between the flanges 12) depending on the
construction. In the case of a 3 1/2 inch stud and two 112 sheets of drywall,
the
back piece 13 would be around 4 1/2 inches wide. In the case ol' the same stud
with two 5/8 sheets of drywall, the width would be around 4 3/4 inches.
Different
versions of this piece can be made for typical construction situations;
specialised versions can be made for any situation.
The width of the flanges 12 can be between 3 inches and 15 inches, with about
6 inches being preferred. The thickness of the back piece 13 can be around 3/8
inch to form a finished wall. This thickness is not critical to the invention,
and
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many other thicknesses are possible. As with other embodiments of the present
invention, the piece is first attached with wet finishing mud, and then the
edges
are "killed" or made to merge into the surrounding drywall with a flat blade
tool.
The edges can be optionally tapered to merge better.
Figure 4 shows a speciality piece to accompany the wall piece of Figure 3.
This
is another embodiment of the present invention, and is used where the wall or
door previously described meets the ceiling. This piece simply continues the
previous piece through the wall ceiling transition. It can be seen from Figure
4,
that the flanges 15 continue the design around the transition. The back spacer
13 of Figure 3 is made to have two parts 16. Its dimensions are similar to
those
of the embodiment of Figure 3. This piece can be made entirely from plastic,
paper, cardboard or any other suitable material, or its construction can be
the
same as the piece of Figure 3. The back piece 16 should have thickness to
match that of the piece of Figure 3 which it transitions from. As with all
embodiments of the present invention, the outside seams can be straight or
bullnose or any other speciality shape. The outside corners of the piece 17 do
not have to be square as shown in Figure 3, but may be rounded to make them
easier to "kill". While the piece can have any dimensions, the preferred size
is
around 7 inches on the bases, around 3 inches in the corners, and around 10
inches on the long sides 15. The width 16 can vary as did the piece of Ficure
3
for different types of construction.
Figures 5A and 5B show a no-coat window trim embodiment of the present
invention. This piece is used to provide a transition from wall drywall to
v:indow.
This piece is similar to other embodiments with two substantially flat flances
18
forming an approximate 90 degree angle or other speciality angle e' any
number of degrees. The actual angle 21 is chosen around 89 degrees of a right
angle system for reasons previously explained. Again a support mernber 19 is
used inside the flanges 18 for rigidity. As in other embodiments, this piece
can
be plastic or other rigid material. It is used to give strength and shape to
the
piece. One of the flanges contains a spacer 20 of the type previously
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described. This spacer is used to eliminate the need to wrap the opening with
drywall. The window piece is constructed so that one flange 18 is from around
3 to around 7 inches, with around 7 inches being typical. The other flange may
be shorter to fit a window, with a typical width being from around 3 inches to
around 6 inches. The piece can be supplied with several different sized
flanges
to fit different construction situations. As in other embodiments, the
thickness of
the flange can be from thinner than 0.015 inches to much thicker. The edges of
the flanges 18 can be tapered for easy "killing" by the worker. The support
member can be from about 5 inches on a 7 inch flange and can take a similar
ratio on a different sized flange. The spacer 20 can be any durable material,
and can be around 3/8 inch thick. Other sizes are possible to match the needs
of the construction. The length of the piece can be a standard 8 or 10 foot,
or
any other length dictated by the construction.
Figure 6 shows a speciality piece which is an embodiment of the invention
similar to that shown in Figure 4 except that this embodiment is specially
shaped to continue the window trim piece of Figure 5. Here, there is only one
side 22 that fits the window corner. A right angle extension 24 follows the
shape of the window corner. The edges 23 can be optionally tapered to make
"killing" easier. The corner 25 can be rounded or any other shape as well as
pointed. The exterior angles for right angle construction are around 89
degrees
as in the previously described embodiments. Again all outside seams can be
straight, bulinose, or some other shape.
Figures 7A and 7B show a non-coatable L-metal or L-member embodiment of
the present invention. This piece is used under window sills, or wherever
drywall abruptly ends such as an interface with brick. It is constructed like
the
previously described embodiments. Even though the piece is being referred to
as an L-metal or L-trim, this does not imply that any actual metal is used in
its
construction. There is a wide flange 27 and a narrow flange. The narro:v
flange
can be from around 1/2 inch to around 5/8 inch or greater. The wide flange can
be from 3 inches to over 7 inches. Again the length of the piece can be the
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standard 8 or 10 foot, or any length dictated by the construction. The support
member 26 is very similar to the support members of the previously described
embodiments, With a 7 inch wide flange, it can be around 5 inches. The
flanges can be paper; however, the preferred method for this piece is to use
paper covered plastic for shape and strength. As before, the outside corner
can
be straight, bulinose or other shape.
Returning to Figure 1A, an alternate embodiment of the present invention can
be made by causing the support member 2 to be constructed as two separate
strips with only the flange material 3 along the seam. This embodiment forms a
non-coatable flex trim where the worker can adjust the piece for wall corners
of
any angle. Here the support member 2 strips should be brought very close
together with only a small open region between them. While the distance is not
critical, it is important that they not be too far apart since they must
support the
corner in the folded position. This embodiment can be of an exterior or
interior
form. For an interior piece, the construction can be entirely of paper or
other
flange material; an exterior piece must be stronger and may be made from
cardboard or plastic or other suitable material. This flex trim embodiment of
the
present invention ca be supplied as standard 8 foot or 12 foot lengths, or any
other length. The interior version can be supplied on a roll of 25 feet or 100
feet, or in any other length straight or rolled.
Referring to Figure 8, an embodiment of the present invention that will be
called
"Ultra-Flex" is seen. This embodiment can be used for interior or exterior
corners. Its construction is that of an elongated semi-rigid member with
exterior
layers of covering and finishing materials. The semi-rigid member can be
plastic, metal, or other flexible, but strong material, with high impact
plastic such
as that used to construct modern cola bottles being preferred. The member can
be supplied in 10 or 12 foot lengths, or any other convenient length, or it
can be
supplied on a roll of 100 feet or an other convenient length. Running the
length
of the member can be a groove 32. This groove allows the piece to form two
flanges that can be repeatedly bent to form any angle from 0 degrees to 360
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degrees. In this manner, the piece can be bent to match any interior or
exterior
corner. The elongated semi-rigid member has a first surface 29 that is split
into
a left part and a right part by the groove 32. It also has a second surface 30
that is continuous (the groove 32 does not penetrate all the way through). The
semi-rigid member can be of uniform cross section; however it is preferred to
taper it from a maximum thickness near the groove 32 to a minimum thickness
near the edges 31. Preferably, the maximum thickness is between 3 mi( and 80
mil near the groove or apex and betvreen 1 mil and 30 mil at the edges with
the
thickness at the edges always being less than the thickness near the centre.
The preferred maximum thickness is around 60 mil, and the preferred minimum
thickness is around 4-6 mil. The thickness, of course, can vary from these
figures.
Figure 9 shows a possible cross section of the "Ultra-flex" piece. In this
cross
section, the groove 32 is V-shaped, and the overall cross section (without the
groove) is triangular. Many other cross sections are possible with this
embodiment of the present invention. The semi-rigid rriember 33 gives the
piece strength and support. The groove 32 allows the piece to be repeatably
bent to any angle between 0 degrees and 360 degrees by forming a hinge. If
the material chosen for the semi-rigid member is high-impact plastic, bending
does not fatigue the hinge, and the member can be bent any number of times
without breaking. Also, the member in that manner is extremely strong and can
resist numerous direct blows to its surface and hinge without any damage
The groove 32 separates the first surface of the piece into a left half and a
right
half. These two halves do not have to be the same width. Iri fact, cne of the
halves can be considerably wider than the other to form an L-trim member or
similar type member if desired. The first surface of the semi-rigid member 33
can be covered by two strips of covering material 29 firmly bonded to the semi-
rigid member 33. This covering material can be paper similar to that used on
drywall, or joint tape paper, or other suitable material to be placed against
drywall wallboard. The second surface of the semi-rigid member can be
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covered by a strip of finishing material 30 also firmly bonded to the semi-
rigid
member 33. This material can be a finished surface such as cup stock paper
that can directly receive paint or texture. It can be any other material that
can
directly receive paint or texture without the need of sanding or mud. By
bonded,
what is meant is any process that firmly attaches the material to the member.
Glue could be used, but it is preferable to extrude the entire piece with the
semi-
rigid member being high impact plastic. Here, the plastic with the groove and
both paper layers are formed at once with the plastic being hot melted to the
paper layers for a permanent bond. The groove can be made with an extrusion
die.
The embodiment shown in figures 8 and 9 is only one way of making this type of
piece, The piece can be made with any number of grooves to form flexible
speciality pieces. In particular, it can be constructed with two grooves to
form a
stub wall piece. Also, the groove can be of other suitable cross sections as
required. One great advantage of this embodiment is that the groove allows the
piece to be bent to form perfect corners. There is no "snaking" of the corner
line, even on uneven walls or construction. Also, since this type,of piece can
be
used at any angle, it can be used anywhere in a modern building.
It is also possible to make the piece of figure 8 with the semi-rigid member
very
thin to be extra-flexible for use primarily in interior corners with angles
less than
or equal to 90 degrees. This embodiment would generally have a constant
cross section. Pieces for interior angles greater than 90 degrees must be much
stronger since I have discovered that if a flexible piece is used for such an
angle, the shrinkage of the mud coupled with building movement causes the
entire piece to deform and shift leading to unacceptable work.
A rigid piece used for exterior corners can be constructed using the
techniques
illustrated in Figure 9 without the groove. The piece is made with an extruded
fixed angle of near 90 degrees or any other desired angle. This piece is ready
to receive paint or texture and is installed by simply placing it on wet mud,
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aligning it correctly, and then killing or feathering the edges with a small
amount
of mud. Such a piece takes the place or current exterior drywall corner pieces
leading to a perfectly sculptured preformed corner without the extreme labour
associated with building up mud, sanding, and finishing convention corners.
Briefly turning to Figures 10 and 11 in which there is shown a shaped right-
angled drywall corner trim 40 and a bullnose trim 50. In relation to Figure
10, a
copolymer-based plastic support 42 is dimensioned such that it is thickest at
the
apex 43 of the right-angled drywall corner trim 40. The plastic support 42
then
tapers down to its thinnest point at the peripheral edge of the plastic
support 42.
A typical thickness is about 45 thousandths in the middle, tapering to about
18
thousandths. This arrangement of plastic membrane (i.e. the plastic support)
achieves many advantages. Tapering of the membrane mimics what happens in
traditional methods with joint compound being coated over existing products,
i.e.
corner-bends. This reduces by 75% the amount of mud needed in corner
finishing, lending to a drastic reduction of drying time as well as giving the
corners strength and straight lines. The plastic support 42 is covered with a
quality paper surface 45 that is pre-finished and ready for paint or texture.
The
fibres of the paper surface absorb paint or texture, eliminating chipping and
peeling which occurs when mud is applied on corners in traditional methods.
Also, a surface paper overhang 46-47 is provided. When laid into mud with a
corner drywall knife, the overhang 46-47 eliminates all cracking along the
edge.
The overhang 46-47 also eases feathering and increases bonding capabilities.
Finally, joint tape 48 (or the like) is applied to an interior surface of the
plastic
support 42 and lends to a complete bond to the wall surface. Each flange of
joint tape is typically two inches wide creating an improved bonding surface.
Indeed, when the flanges are installed and dry, they become an integral part
of
the wall.
With regard to Figure 11, the bullnose trim 50 again contains a preformed
plastic support 52, a quality paper surface 45 that is pre-finished and ready
for
paint or texture, a surface paper overhang 46-47 and joint tape 48 (all as
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described in relation to Figure 10). However, in relation to the bullnose, the
plastic support has a uniform cross-section 54 that extends around the radius
of
the bullnose and only begins to taper at a point approximately half an inch
after
the bulinose has straightened. Typically, the uniform cross-section has a
thickness of about 34 thousandths which is carried to a point beyond the curve
and hence into the straight section of the pre-formed trim. In other words,
tapering only begins to occur some time after the straight sections of the
trim 50
commence. This structural arrangement leads to smooth transitions, whereas
prior art systems have noticeable ridge lines where mud fill meets the trim.
As
such, the corner has a much cleaner look, while the application of mud is both
easier and labour saving. In fact, by adopting a uniform thickness of support
and then tapering, mud does not slop over and onto the trim and hence
provides a neater and cleaner finish in relation to the quality paper surface
45,
especially around a tip of the bullnose. Generally, the edge of the trim of
Figure
11 is easier to kill, while the radius is less likely to be exposed to mud.
The present invention also comprises a method of installing the various
embodiments of the non-coatable, preformed drywall corner pieces. The worker
first applies drywall mud to both flat sides of the corner to be finished. The
pre-
formed piece is cut to length and placed in the corner against the wet mud.
The
piece is positioned for final appearance and pressed into place; then the
edges
are "killed" by applying a small amount of finishing mud to the edges and
smoothing them with a wide blade knife so that they merge into the surrounding
drywall. There is no further finishing. When the mud dries, the corner is
ready
for painting or texturing. This represents a considerable savings in time and
money over existing methods.
The variable cross-section of the semi-rigid (support) member is applicable to
the numerous embodiments described herein. Specifically, an ability to kill
the
dry wall trim into the drywall board is significantly enhanced by using a
cross-
section that varies from a central apex of the drywall trim to the periphery
of the
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dry wall trim. Indeed, killing of the dry wall trim becomes much simpler and
is
achieved In a straight-forward one-step process.
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