Hi -
I applied about three coats of shellac to a tea chest almost four weeks
ago. I imagine the shellac has cured (the box has been at 60-70 degrees F
the entire time). I had planned to rub out the finish but I need a few
more coats before I can do that. So I'm wondering, if the shellac already
on it has cured and if so, what happens when I apply fresh shellac over it
(or should I)? Will it fuse to the cured shellac or is shellac that's
cured no longer able to meld into another coat? Should I strip off what
shellac I can and start the coats over until it's built up to where I want
it?
Mike
--
mike.ballard--at--earthlink.net
"Roses are red, violets are blue,
I'm schizophrenic and so am I"
As others have noted, shellac is a "hot" finish - each new
layer dissolves the surface of the previous layer, as opposed
to poly where each new coat merely sits on top of the previous
layer. Sanding between layers of poly provides a mechanical
connection between the layers.
On my current project I'm shellacing parts prior to assembly,
being careful to avoid areas that will be glued or sanding
those areas to bare wood later.
Got carried away on a pull out shelf - probably applied 15+
brushed on coats of one pound cut shellac in 30 -45 minute
increments. The garnet shellac made the cherry ply shelf
appear golden without obscuring the grain. Liked that look
so did the same on the sides and top of a pull out box
that will hold Scary Sharp plates. The finish looked
glorious!
Let the box sit for a couple of days in a 60-75 degree shop
while doing other parts and dry fitting things. When
all the parts were ready and the whole thing had been dry
fit just to make sure I hadn't miscut something, I set up
the clamps, glued things together and clamped them snug
but not tight.
Four hours later I removed the clamps - mainly Bessy K-bodies.
Everywhere the clamp faces contacted the finish I got
jaw imprints - not deep but noticable on the nearly glass
smooth finish.
So the question is -
To get a nice hard shellac finish
- how long between coats with a 1 lb cut?
- how long after final coat before the finish is
hard enough to clamp without imprinting the clamp
jaws into the finish (assuming 60-75 degree shop
with 75-80% RH?
I really like the range of looks you can get with shellac
Thin coats are quick and easy to apply, it loses its
tack quickly so dust is less of a problem and the finish
builds fairly quickly.
.
I also like prefinishing parts so the finish can be
applied with the parts laying down flat.
But if I want a thick, deep prefinish and have to wait a
week or so before clamping ...
charlie b
Lawrence Wasserman wrote:
>
> I think you need to rely upon cauls, blocks or clamp pads of some kind
> to prevent the marks, not the finish.
> --
>
I did use rounded edged redwood "pads" on four of the clamps
and they left imprints. I also used the twin cam/one movable
"jaw" clamps for the face frame - no way to pad them. They're
rubber jawed. Still left imprints in the finish.
charlie b
Silvan wrote:
> Well, Charlie, I'm a shellac newbie. The only stuff I've used is the
> Bullseye stuff with all the shelf life extenders in it.
>
> I have no idea how hard it's supposed to get, or how hard real shellac gets,
> but this stuff in this can I have (had, actually) never cures hard at all.
> I've got a piece I finished in November, maybe 10 coats with a 1# cut, and
> if I rest an arm on it, the fabric of my shirt leaves an impression that
> won't buff out.
>
> I think in my case I very likely got some bad shellac, but still, based on
> what experience I do have, I sure wouldn't characterize this as a hard
> finish.
With "Bulls Eye" shellac I find the finish will remain soft unless the wax is
removed before application. Did you decant the wax from the shellac before using
it?
I mix it 50/50 with denatured alcohol, let it sit for 2-3 weeks and then pour
off the clear liquid for use and discard the rest. It yields an approx. 1.5
pound cut.
Another option would be to buy the "SealCoat" which is already dewaxed.
--
Jack Novak
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
Wipe it down with mineral spirits to get any interim nastiness off, and coat
away. As others indicate, it'll chemically bond.
"Mike Ballard" <dont_w@nt_spam.org> wrote in message
news:m21xpvb0yv.fsf@west_f1.net...
>
> Hi -
>
> I applied about three coats of shellac to a tea chest almost four weeks
> ago. I imagine the shellac has cured (the box has been at 60-70 degrees F
> the entire time). I had planned to rub out the finish but I need a few
> more coats before I can do that. So I'm wondering, if the shellac already
> on it has cured and if so, what happens when I apply fresh shellac over it
> (or should I)?
Jim wrote:
> I've been using the "Bulls Eye" shellac on my latest project and haven't
> had any problems at all with hardening. In fact I have been able to sand
> without it balling up or doing serious clogging after only a couple of
> hours of curing. I found it worked better if I let it set overnight on
> heavy coats however.
I suggest you try decanting the wax out of the Bulls Eye. The wax inclusion
softens the finish, degrades the moisture/heat resistance and may cause
adhesion problems when shellac is used as a base coat for other finishes.
> I have read that shellac won't harden properly if it is too old. I
> assume the "old" counter starts once you open the lid.
The esterification process begins as soon as the flakes are mixed with
alcohol.
> Just out of curiosity, how hard is it to make the shellac from flakes?
> It looked like more trouble than it was worth compared to a $4 can from
> Menards.
Mixing shellac is not hard at all. For me the hard part is obtaining the
flakes as I either have to order them or drive forty miles or more to get
them.
--
Jack Novak
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
I think you need to rely upon cauls, blocks or clamp pads of some kind
to prevent the marks, not the finish.
--
Larry Wasserman Baltimore, Maryland
[email protected]
Nova <[email protected]> wrote in
news:[email protected]:
> Silvan wrote:
>
>> Well, Charlie, I'm a shellac newbie. The only stuff I've used is the
>> Bullseye stuff with all the shelf life extenders in it.
>>
>> I have no idea how hard it's supposed to get, or how hard real
>> shellac gets, but this stuff in this can I have (had, actually) never
>> cures hard at all. I've got a piece I finished in November, maybe 10
>> coats with a 1# cut, and if I rest an arm on it, the fabric of my
>> shirt leaves an impression that won't buff out.
>>
>> I think in my case I very likely got some bad shellac, but still,
>> based on what experience I do have, I sure wouldn't characterize this
>> as a hard finish.
>
> With "Bulls Eye" shellac I find the finish will remain soft unless the
> wax is removed before application. Did you decant the wax from the
> shellac before using it?
>
> I mix it 50/50 with denatured alcohol, let it sit for 2-3 weeks and
> then pour off the clear liquid for use and discard the rest. It
> yields an approx. 1.5 pound cut.
>
> Another option would be to buy the "SealCoat" which is already
> dewaxed.
>
> --
> Jack Novak
> Buffalo, NY - USA
> (Remove "SPAM" from email address to reply)
I've been using the "Bulls Eye" shellac on my latest project and haven't
had any problems at all with hardening. In fact I have been able to sand
without it balling up or doing serious clogging after only a couple of
hours of curing. I found it worked better if I let it set overnight on
heavy coats however.
I have read that shellac won't harden properly if it is too old. I
assume the "old" counter starts once you open the lid.
Just out of curiosity, how hard is it to make the shellac from flakes?
It looked like more trouble than it was worth compared to a $4 can from
Menards.
Jim
Shellac never "cures" like varnish does. It is always dissolvable by
it's solvent (alcohol) or the next coat. Just clean it off & apply
more coats til you get the thickness you want. It will be fine.
--
Larry Wasserman Baltimore, Maryland
[email protected]
On Tue, 20 Jan 2004 06:17:11 GMT, Mike Ballard <dont_w@nt_spam.org>
wrote:
>
>Hi -
>
>I applied about three coats of shellac to a tea chest almost four weeks
>ago. I imagine the shellac has cured (the box has been at 60-70 degrees F
>the entire time). I had planned to rub out the finish but I need a few
>more coats before I can do that. So I'm wondering, if the shellac already
>on it has cured and if so, what happens when I apply fresh shellac over it
>(or should I)? Will it fuse to the cured shellac or is shellac that's
>cured no longer able to meld into another coat? Should I strip off what
>shellac I can and start the coats over until it's built up to where I want
>it?
>
>Mike
the next coat will melt into it- forever.
Yep, Shellac is pretty soft.
I like it though.
"Think I'll go plane a piece of scrap wood, cant build nothing right now. "
Tony D.
charlie b" <[email protected]> wrote in message
news:[email protected]...
> Lawrence Wasserman wrote:
> >
> > I think you need to rely upon cauls, blocks or clamp pads of some kind
> > to prevent the marks, not the finish.
> > --
> >
>
> I did use rounded edged redwood "pads" on four of the clamps
> and they left imprints. I also used the twin cam/one movable
> "jaw" clamps for the face frame - no way to pad them. They're
> rubber jawed. Still left imprints in the finish.
>
> charlie b
I think iT might be bad too.
Tony D.
"> I have no idea how hard it's supposed to get, or how hard real shellac
gets,
> but this stuff in this can I have (had, actually) never cures hard at all.
> I've got a piece I finished in November, maybe 10 coats with a 1# cut, and
> if I rest an arm on it, the fabric of my shirt leaves an impression that
> won't buff out.
>
> I think in my case I very likely got some bad shellac, but still, based on
> what experience I do have, I sure wouldn't characterize this as a hard
> finish.
>
> --
> Michael McIntyre ---- Silvan <[email protected]>
> Linux fanatic, and certified Geek; registered Linux user #243621
> http://www.geocities.com/Paris/Rue/5407/
>
Nova wrote:
> With "Bulls Eye" shellac I find the finish will remain soft unless the wax
> is removed before application. Did you decant the wax from the shellac
> before using it?
No, I didn't. I didn't read about that trick until it was all said and
done.
I think for my next batch, I'll go ahead and get some flakes though.
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
Jim <[email protected]> wrote in message news:<Qr%[email protected]>...
>
>
> I have read that shellac won't harden properly if it is too old. I
> assume the "old" counter starts once you open the lid.
>
Yes but actually the "old" counter starts as soon as the solids
contact alcohol.
--
FF
charlie b wrote:
> I did use rounded edged redwood "pads" on four of the clamps
> and they left imprints. I also used the twin cam/one movable
> "jaw" clamps for the face frame - no way to pad them. They're
> rubber jawed. Still left imprints in the finish.
Well, Charlie, I'm a shellac newbie. The only stuff I've used is the
Bullseye stuff with all the shelf life extenders in it.
I have no idea how hard it's supposed to get, or how hard real shellac gets,
but this stuff in this can I have (had, actually) never cures hard at all.
I've got a piece I finished in November, maybe 10 coats with a 1# cut, and
if I rest an arm on it, the fabric of my shirt leaves an impression that
won't buff out.
I think in my case I very likely got some bad shellac, but still, based on
what experience I do have, I sure wouldn't characterize this as a hard
finish.
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
On Wed Jan 21, Silvan disturbed my nap when he said:
> charlie b wrote:
>
> > I did use rounded edged redwood "pads" on four of the clamps
> > and they left imprints. I also used the twin cam/one movable
> > "jaw" clamps for the face frame - no way to pad them. They're
> > rubber jawed. Still left imprints in the finish.
>
> Well, Charlie, I'm a shellac newbie. The only stuff I've used is the
> Bullseye stuff with all the shelf life extenders in it.
>
> I have no idea how hard it's supposed to get, or how hard real shellac gets,
> but this stuff in this can I have (had, actually) never cures hard at all.
> I've got a piece I finished in November, maybe 10 coats with a 1# cut, and
> if I rest an arm on it, the fabric of my shirt leaves an impression that
> won't buff out.
>
> I think in my case I very likely got some bad shellac, but still, based on
> what experience I do have, I sure wouldn't characterize this as a hard
> finish.
>
Shellac gets good and hard. If it didn't you'd never be able to rub it
out. Maybe you should consider using flakes. Far more economical and
flakes have many, many years of shelf life (unlike canned). You only mix
up what you need, when you need it and put them back in the fridge...
Mike
--
mike.ballard--at--earthlink.net
"Roses are red, violets are blue,
I'm schizophrenic and so am I"
On Tue, 20 Jan 2004 06:17:11 GMT, Mike Ballard <dont_w@nt_spam.org>
Crawled out of the shop and said. . .:
>
>Hi -
>
>I applied about three coats of shellac to a tea chest almost four weeks
>ago. I imagine the shellac has cured (the box has been at 60-70 degrees F
>the entire time).
shellac is great in this regards because it never really cures when
DNA, or fresh shellac is applied to it... one of the reasons its an
almost foolproof finish...mar it up, rub it out with fresh alcohol and
shellac...
so in essence, shellac has 100% burn in at any time.