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A Dubya
 
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Default Demystifying Shellac

Here is a little info on shellac that may be helpful and or informative.


Prior to any finish the wood must be adequately prepared for finishing. This
means that we hand plane the surface until it is completely smooth. You can
go directly to finish if you like the effect of leaving some fine tool marks
on the surfaces of your work. If you want to have a perfectly flat, smooth
surface, sand the planed surface with 400-grit sandpaper. Remove the dust
with your bench brush, and then with a tack rag. You may wish to vacuum off
the wood, but remember to hold the vacuum nozzle off of the surface. Wipe
the surface with a clean cotton rag.

Shellac is a classic finish that can be applied with a minimum of
difficulty. We choose to mix our own shellac so that we can control the
"cut" or the amount of shellac in solvent. A good solvent to dissolve
shellac flakes is denatured alcohol (ethanol with methanol added). This is
readily available a hardware stores in USA, but not so in Canada. The use of
ethanol is a safe process, since this is the same non-toxic alcohol used in
liquor. Some manufacturers use isobutanol to retard the drying time of the
finish, which improves workability as the shellac mix is applied to the
wood. Behkol is a commercial product from the Behlen Company, which contains
95 % anhydrous ethanol, and 5 % isobutanol. Other products used to dissolve
shellac that are available in Canada are the Lee Valley Shellac solvent, or
methyl hydrate.

Shellac is actually a secretion of the "lac bug" know technically as
"Laccifer lacca". These insects live in trees in India and Thailand. They
feed off the sap in the twigs, and then secret a cocoon - type shell which
is the source of our shellac. Workers shake the tree branches to dislodge
the cocoon, thus harvesting raw shellac know as sticklac. In this form it is
unrefined, and will include pieces of twigs. The shellac is then refined to
remove the debris, and to reduce the natural wax in the lac. Excess wax
reduces clarity in the finish, and reduces moisture resistance in the
finish.

There are several grades of shellac. Orange shellac is a mid grade with
about 4 % wax content. This grade can be used on dark woods, where the
orange color does not change the color of the wood. Orange shellac is less
refined, and is therefore less expensive than blonde shellac. Blond and
Super Blond shellac is highly refined, such that the wax content is down to
1%. The flakes are light yellowish brown in color. The dewaxing and
bleaching is achieved by bubbling Chlorine gas through the shellac. This is
the desired shellac for most fine furniture applications.

Mix your blonde shellac in a small jar with ethanol. It will take several
hours to dissolve the flakes. Determining your desired cut is an empirical
process. You simply look at the color of the mixture using window light. We
typically use two cuts - one for thin wash coats that is thinner, and a
thicker cut for quickly building coats of shellac. The color may be
described as looking like "thin apple juice". If you have excess shellac in
your mix, you will notice that your pad begins to stick to the wood as you
attempt the padding process. If this occurs, simply add more solvent. Note
that shellacs have a shelf life of about 6 months, so mix the shellac when
you need it. Old shellac develops gummy substances during a process called
esterification where organic acids react with the alcohol. The net result is
that the mixture will not cure properly.

Application of the shellac is done as a simple padding process. Make a
"pillow" out of a clean white cotton rag that is about 12 inches square.
Continuously fold in the corners to make a rounded pillow. Apply your
shellac mix to the bottom of the pillow, and then gently wipe the pad across
the wood, with the direction of the grain. Use a technique of landing like a
plane - touch the wood going right to left at about 1/3 of the distance from
the right side of the board. Run the pad across and off the left side of the
board. On the next pass, start the padding coming from the left side,
landing on the wood 1/3 of the distance from the left side of the board, and
running right off the right side of the board. Work from the far side of the
panel towards yourself, indexing by ½ of the pillow width per pass. The
pillow should be moist, but not wet. Recharge the pillow periodically to
ensure that you continue to lay down shellac, and that the surface of the
pad in moist, but not dripping wet. Excess shellac mix in the pad will cause
the previously applied shellac layers to be re-dissolved, which defeats your
building process.

After the first coat, allow the panel to dry for 15 minutes. Shellac dries
quickly due to the high alcohol content. If the wood feels cool, the shellac
is not dry enough to proceed. Apply a second thin coat and allow this to dry
15 minutes to ½ hour. We will eventually build up 7 or more coats, and the
drying time will increase as the coats build. Apply a third coat and allow 1
hour for it to fully dry. Cut back the finish now with 0000 steel wool. Cut
about a foot of steel wool off of your roll, and fold it twice to make a
hand sized pad for burnishing your finish. This process will knock down any
raised grain, and flatten the surface. Use Liberon brand cabinetmakers steel
wool without petroleum based oil in it - these oils adversely affect your
finish. Apply a 4th coat, and allow it to dry 2 hours. Burnish the surface
lightly with 0000 steel wool. Wipe off the steel wool debris with your bench
brush, and then dust off the surface with a clean cotton rag before the next
layer of shellac. Add the 5th, 6th, and 7th layers with 6 hours of drying
time or more between them. Burnish the surface with steel wool between each
layer, and then again after the 7th and final layer. You will now have a
satin sheen that is extremely smooth. If during the steel wool process you
feel a gummy surface, you will have to extend your drying time between
layers to allow the shellac to fully cure.

A fine wax is sometimes applied on top of shellac. One such wax is Clapham's
bees wax. This is a natural bees wax mixed with Carnauba wax to improve
luster. Apply a thin coat of wax in a circular motion with a clean cotton
rag in the shape of a pillow. Brush out the wax by making linear strokes
with the grain - in the same fashion as the padding process for shellac.
Burnish the surface with steel wool immediately after applying the wax -
this puts a scratch pattern into the wax to achieve a satin finish. Brush
off the steel wool debris with your bench brush, and then with a clean
cotton rag. Buff the wax with a clean cotton rag. You will have achieved a
wonderfully smooth satin finish.

Maintenance

If the surface has minor damage, you may steel wool the surface, wax the
surface, burnish with steel wool, and then buff the surface with a clean
cotton rag.



Taken from Rosewood Studio


  #2   Report Post  
Bay Area Dave
 
Posts: n/a
Default Demystifying Shellac

I was with you right up to the "tack rag"...there's more con than pro
for using a tack rag, A.D.

dave

A Dubya wrote:

Here is a little info on shellac that may be helpful and or informative.


Prior to any finish the wood must be adequately prepared for finishing. This
means that we hand plane the surface until it is completely smooth. You can
go directly to finish if you like the effect of leaving some fine tool marks
on the surfaces of your work. If you want to have a perfectly flat, smooth
surface, sand the planed surface with 400-grit sandpaper. Remove the dust
with your bench brush, and then with a tack rag. You may wish to vacuum off
the wood, but remember to hold the vacuum nozzle off of the surface. Wipe
the surface with a clean cotton rag.

Shellac is a classic finish that can be applied with a minimum of
difficulty. We choose to mix our own shellac so that we can control the
"cut" or the amount of shellac in solvent. A good solvent to dissolve
shellac flakes is denatured alcohol (ethanol with methanol added). This is
readily available a hardware stores in USA, but not so in Canada. The use of
ethanol is a safe process, since this is the same non-toxic alcohol used in
liquor. Some manufacturers use isobutanol to retard the drying time of the
finish, which improves workability as the shellac mix is applied to the
wood. Behkol is a commercial product from the Behlen Company, which contains
95 % anhydrous ethanol, and 5 % isobutanol. Other products used to dissolve
shellac that are available in Canada are the Lee Valley Shellac solvent, or
methyl hydrate.

Shellac is actually a secretion of the "lac bug" know technically as
"Laccifer lacca". These insects live in trees in India and Thailand. They
feed off the sap in the twigs, and then secret a cocoon - type shell which
is the source of our shellac. Workers shake the tree branches to dislodge
the cocoon, thus harvesting raw shellac know as sticklac. In this form it is
unrefined, and will include pieces of twigs. The shellac is then refined to
remove the debris, and to reduce the natural wax in the lac. Excess wax
reduces clarity in the finish, and reduces moisture resistance in the
finish.

There are several grades of shellac. Orange shellac is a mid grade with
about 4 % wax content. This grade can be used on dark woods, where the
orange color does not change the color of the wood. Orange shellac is less
refined, and is therefore less expensive than blonde shellac. Blond and
Super Blond shellac is highly refined, such that the wax content is down to
1%. The flakes are light yellowish brown in color. The dewaxing and
bleaching is achieved by bubbling Chlorine gas through the shellac. This is
the desired shellac for most fine furniture applications.

Mix your blonde shellac in a small jar with ethanol. It will take several
hours to dissolve the flakes. Determining your desired cut is an empirical
process. You simply look at the color of the mixture using window light. We
typically use two cuts - one for thin wash coats that is thinner, and a
thicker cut for quickly building coats of shellac. The color may be
described as looking like "thin apple juice". If you have excess shellac in
your mix, you will notice that your pad begins to stick to the wood as you
attempt the padding process. If this occurs, simply add more solvent. Note
that shellacs have a shelf life of about 6 months, so mix the shellac when
you need it. Old shellac develops gummy substances during a process called
esterification where organic acids react with the alcohol. The net result is
that the mixture will not cure properly.

Application of the shellac is done as a simple padding process. Make a
"pillow" out of a clean white cotton rag that is about 12 inches square.
Continuously fold in the corners to make a rounded pillow. Apply your
shellac mix to the bottom of the pillow, and then gently wipe the pad across
the wood, with the direction of the grain. Use a technique of landing like a
plane - touch the wood going right to left at about 1/3 of the distance from
the right side of the board. Run the pad across and off the left side of the
board. On the next pass, start the padding coming from the left side,
landing on the wood 1/3 of the distance from the left side of the board, and
running right off the right side of the board. Work from the far side of the
panel towards yourself, indexing by ½ of the pillow width per pass. The
pillow should be moist, but not wet. Recharge the pillow periodically to
ensure that you continue to lay down shellac, and that the surface of the
pad in moist, but not dripping wet. Excess shellac mix in the pad will cause
the previously applied shellac layers to be re-dissolved, which defeats your
building process.

After the first coat, allow the panel to dry for 15 minutes. Shellac dries
quickly due to the high alcohol content. If the wood feels cool, the shellac
is not dry enough to proceed. Apply a second thin coat and allow this to dry
15 minutes to ½ hour. We will eventually build up 7 or more coats, and the
drying time will increase as the coats build. Apply a third coat and allow 1
hour for it to fully dry. Cut back the finish now with 0000 steel wool. Cut
about a foot of steel wool off of your roll, and fold it twice to make a
hand sized pad for burnishing your finish. This process will knock down any
raised grain, and flatten the surface. Use Liberon brand cabinetmakers steel
wool without petroleum based oil in it - these oils adversely affect your
finish. Apply a 4th coat, and allow it to dry 2 hours. Burnish the surface
lightly with 0000 steel wool. Wipe off the steel wool debris with your bench
brush, and then dust off the surface with a clean cotton rag before the next
layer of shellac. Add the 5th, 6th, and 7th layers with 6 hours of drying
time or more between them. Burnish the surface with steel wool between each
layer, and then again after the 7th and final layer. You will now have a
satin sheen that is extremely smooth. If during the steel wool process you
feel a gummy surface, you will have to extend your drying time between
layers to allow the shellac to fully cure.

A fine wax is sometimes applied on top of shellac. One such wax is Clapham's
bees wax. This is a natural bees wax mixed with Carnauba wax to improve
luster. Apply a thin coat of wax in a circular motion with a clean cotton
rag in the shape of a pillow. Brush out the wax by making linear strokes
with the grain - in the same fashion as the padding process for shellac.
Burnish the surface with steel wool immediately after applying the wax -
this puts a scratch pattern into the wax to achieve a satin finish. Brush
off the steel wool debris with your bench brush, and then with a clean
cotton rag. Buff the wax with a clean cotton rag. You will have achieved a
wonderfully smooth satin finish.

Maintenance

If the surface has minor damage, you may steel wool the surface, wax the
surface, burnish with steel wool, and then buff the surface with a clean
cotton rag.



Taken from Rosewood Studio



  #3   Report Post  
A Dubya
 
Posts: n/a
Default Demystifying Shellac

I agree, but all in all, it's not a bad shellac write up (as noted it was
taken from the Rosewood Studio website) to pass along to shellac newbie's.

Cheers

Andy

"Bay Area Dave" wrote in message
om...
I was with you right up to the "tack rag"...there's more con than pro
for using a tack rag, A.D.

dave

A Dubya wrote:

Here is a little info on shellac that may be helpful and or informative.


Prior to any finish the wood must be adequately prepared for finishing.

This
means that we hand plane the surface until it is completely smooth. You

can
go directly to finish if you like the effect of leaving some fine tool

marks
on the surfaces of your work. If you want to have a perfectly flat,

smooth
surface, sand the planed surface with 400-grit sandpaper. Remove the

dust
with your bench brush, and then with a tack rag. You may wish to vacuum

off
the wood, but remember to hold the vacuum nozzle off of the surface.

Wipe
the surface with a clean cotton rag.

Shellac is a classic finish that can be applied with a minimum of
difficulty. We choose to mix our own shellac so that we can control the
"cut" or the amount of shellac in solvent. A good solvent to dissolve
shellac flakes is denatured alcohol (ethanol with methanol added). This

is
readily available a hardware stores in USA, but not so in Canada. The

use of
ethanol is a safe process, since this is the same non-toxic alcohol used

in
liquor. Some manufacturers use isobutanol to retard the drying time of

the
finish, which improves workability as the shellac mix is applied to the
wood. Behkol is a commercial product from the Behlen Company, which

contains
95 % anhydrous ethanol, and 5 % isobutanol. Other products used to

dissolve
shellac that are available in Canada are the Lee Valley Shellac solvent,

or
methyl hydrate.

Shellac is actually a secretion of the "lac bug" know technically as
"Laccifer lacca". These insects live in trees in India and Thailand.

They
feed off the sap in the twigs, and then secret a cocoon - type shell

which
is the source of our shellac. Workers shake the tree branches to

dislodge
the cocoon, thus harvesting raw shellac know as sticklac. In this form

it is
unrefined, and will include pieces of twigs. The shellac is then refined

to
remove the debris, and to reduce the natural wax in the lac. Excess wax
reduces clarity in the finish, and reduces moisture resistance in the
finish.

There are several grades of shellac. Orange shellac is a mid grade with
about 4 % wax content. This grade can be used on dark woods, where the
orange color does not change the color of the wood. Orange shellac is

less
refined, and is therefore less expensive than blonde shellac. Blond and
Super Blond shellac is highly refined, such that the wax content is down

to
1%. The flakes are light yellowish brown in color. The dewaxing and
bleaching is achieved by bubbling Chlorine gas through the shellac. This

is
the desired shellac for most fine furniture applications.

Mix your blonde shellac in a small jar with ethanol. It will take

several
hours to dissolve the flakes. Determining your desired cut is an

empirical
process. You simply look at the color of the mixture using window light.

We
typically use two cuts - one for thin wash coats that is thinner, and a
thicker cut for quickly building coats of shellac. The color may be
described as looking like "thin apple juice". If you have excess shellac

in
your mix, you will notice that your pad begins to stick to the wood as

you
attempt the padding process. If this occurs, simply add more solvent.

Note
that shellacs have a shelf life of about 6 months, so mix the shellac

when
you need it. Old shellac develops gummy substances during a process

called
esterification where organic acids react with the alcohol. The net

result is
that the mixture will not cure properly.

Application of the shellac is done as a simple padding process. Make a
"pillow" out of a clean white cotton rag that is about 12 inches square.
Continuously fold in the corners to make a rounded pillow. Apply your
shellac mix to the bottom of the pillow, and then gently wipe the pad

across
the wood, with the direction of the grain. Use a technique of landing

like a
plane - touch the wood going right to left at about 1/3 of the distance

from
the right side of the board. Run the pad across and off the left side of

the
board. On the next pass, start the padding coming from the left side,
landing on the wood 1/3 of the distance from the left side of the board,

and
running right off the right side of the board. Work from the far side of

the
panel towards yourself, indexing by ½ of the pillow width per pass. The
pillow should be moist, but not wet. Recharge the pillow periodically to
ensure that you continue to lay down shellac, and that the surface of

the
pad in moist, but not dripping wet. Excess shellac mix in the pad will

cause
the previously applied shellac layers to be re-dissolved, which defeats

your
building process.

After the first coat, allow the panel to dry for 15 minutes. Shellac

dries
quickly due to the high alcohol content. If the wood feels cool, the

shellac
is not dry enough to proceed. Apply a second thin coat and allow this to

dry
15 minutes to ½ hour. We will eventually build up 7 or more coats, and

the
drying time will increase as the coats build. Apply a third coat and

allow 1
hour for it to fully dry. Cut back the finish now with 0000 steel wool.

Cut
about a foot of steel wool off of your roll, and fold it twice to make a
hand sized pad for burnishing your finish. This process will knock down

any
raised grain, and flatten the surface. Use Liberon brand cabinetmakers

steel
wool without petroleum based oil in it - these oils adversely affect

your
finish. Apply a 4th coat, and allow it to dry 2 hours. Burnish the

surface
lightly with 0000 steel wool. Wipe off the steel wool debris with your

bench
brush, and then dust off the surface with a clean cotton rag before the

next
layer of shellac. Add the 5th, 6th, and 7th layers with 6 hours of

drying
time or more between them. Burnish the surface with steel wool between

each
layer, and then again after the 7th and final layer. You will now have a
satin sheen that is extremely smooth. If during the steel wool process

you
feel a gummy surface, you will have to extend your drying time between
layers to allow the shellac to fully cure.

A fine wax is sometimes applied on top of shellac. One such wax is

Clapham's
bees wax. This is a natural bees wax mixed with Carnauba wax to improve
luster. Apply a thin coat of wax in a circular motion with a clean

cotton
rag in the shape of a pillow. Brush out the wax by making linear strokes
with the grain - in the same fashion as the padding process for shellac.
Burnish the surface with steel wool immediately after applying the wax -
this puts a scratch pattern into the wax to achieve a satin finish.

Brush
off the steel wool debris with your bench brush, and then with a clean
cotton rag. Buff the wax with a clean cotton rag. You will have achieved

a
wonderfully smooth satin finish.

Maintenance

If the surface has minor damage, you may steel wool the surface, wax the
surface, burnish with steel wool, and then buff the surface with a clean
cotton rag.



Taken from Rosewood Studio





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