Shellac hardening times
Robert
Well, I just finished my first project with shellac. While it didnt turn
out great, I will blame the finisher and not the finish.
I built a table out of solid core doors stained with a cherry stain,
trimmed with ebonized poplar (I had the extra poplar on hand.) It looks
fairly decent. The problem came in when I attempted to shellac it.
First couple coats were very thin 1# coats. I was hoping to fill in the
pores in the luaun to get a very smooth finish. I followed these coats
with a 2-3# coat and that is where my troubles started.
The heavier coat left ridges and dimples in the finish. I tried to
remove the ridges via 600 grit sandpaper but stopped when I got concerned
about sanding through the shellac and the stain. I switched to 00-0000
steel wool and was still unable to remove the ridges satisfactorily. I
then decided to use several 1/2 - 1# coats of shellac on top to see if
the added coats would help to eliminate the ridges by disolving them into
the top coats. That didnt work very well either.
At this point I got some rubbing then polishing compound and tried my
random orbit polisher. I was very suprised that even with the polishing
compound I was unable to get a sheen anywhere close to that of the
unsanded, brushed on shellac.
I decided to cut my losses at this point and very carefully brushed on
two more thin coats of shellac. It is very shiny now, but of course the
ridges are quite visible. I was surprised to discover that 24 hours
after the last coat was applied, I can still leave fingerprints in the
finish. I was under the impression that shellac hardens much faster than
that.
Also, folks here have talked about wiping shellac on with a rag. How in
the world do you manage to do that? Do you pour some on the surface then
spread it with your rag or do you pour some into your rag and wipe it on
the surface? I tried the latter and was frustrated that the rag was
would dry out too quickly and would stick to the the previous coat after
moving about 2 inches across the surface.
Thanks for helping to set me straight. I have one more table to do and
want to do it right this time.
Bob
By the way, I am still a believer in shellac. Just not the shellacer at
this point.
Taig
If you are using Zinser's shellac check the bottom of the can for
the date that it was created on. Shellac only has a shelf life of 6 to 12
months.
Robert
>
> Now I'm not going to swear to it, but your still sticky shellac may be the
> result of having used the polishing compound. If it is an automotive
> compound there was a fair amount of wax in it along with some petroleum
> products so ............ But that's just a guess.
>
Actually, the rubbing and polishing compound were the last thing I tried
before just brushing on the last two coats. After the polishing compound
I rubbed it down with steel wool just to remove any buildup that may have
formed.
Bob
Sy Kaplan
it into small cubes about 1"x1"x2", dip it, squeeze out excess and apply in
nice even strokes from one end of a panel to the other. As it dries, I
re-dip and continue.
I would also recommend you use the 1# cut until you have improved your
application methods.
Sy
Michael Glennon
Shellac is an evaporative finish. That is it is cured when the
carrier/solvent evaporates. Since, in this case, that carrier/solvent is
alcohol, it should and usually does cure pretty damn fast.
Now I'm not going to swear to it, but your still sticky shellac may be the
result of having used the polishing compound. If it is an automotive
compound there was a fair amount of wax in it along with some petroleum
products so ............ But that's just a guess.
When wiping on shellac I like the quasi French polish approach. A rubber,
NO, not that kind, but cotton waste packed and wrapped nicely in a clean
soft cotton cloth, that is dipped into the shellac with a tad of boiled
linseed oil added to the cloth to keep things slippery.
--
Hope it helps
Mike G.
Weymouth Ma.
http://home.att.net/~mjag/
mj...@worldnet.att.net
"Robert" <Roberthp@mindspring(REMOVE FOR SPAM).com> wrote in message
news:MPG.1307efb1b...@news.mindspring.com...
Joseph Meehan
have to have fresh stuff. If you try and use old stuff it will never
harden. It sounds like you have old shellac. The only fix is to clean it
all off and start over.
I might add that humidity temp etc. also effects drying time.
--
Joseph Meehan
Mike Meier
shellac? If you just mixed it yourself with good alcohol, then this
is suprising.
I use a piece of old teeshirt wrapped into a ball, which I soak with
shellac. Then I wrap that with cheesecloth, and wipe. This has been
quite effective for me. So far, the shellac is dry to the touch in 20
minutes or less, (1-2# cuts), and dry to sand in a few hours.
Try wiping the ridges with a cloth soaked in your alcohol. That
should melt the ridges and either pick up the excess or spread it
thin. From what I have read, the real high gloss comes with many,
many coats, of a thin mix.
Keep trying, as this is one of the nicest finishes I have used. I
like it better than oils, varnishes, and WAY more than poly.
Keep trying, and good luck.
Mike
ElJoya
<< If you are using Zinser's shellac check the bottom of the can for the date
that it was created on. Shellac only has a shelf life of 6 to 12 months.>>
If I may be so bold as to interject: depending upon storage conditions, freshly
made shellac (usually amber) can have a useful shelf life of up to 18 and even
24 months. Bleached shellac has a much shorter shelf life than that. The "6 to
12 month" rule appears to have developed as a rule of thumb among finishers who
use shellac.
It should be noted that Zinsser shellac is formulated to stay fresh much longer
than any other pre-mixed shellac and is guaranteed to have a shelf life of 3
years from the date of manufacture stamped on the bottom of the container.
Best regards,
Gene Hoyas
Wm. Zinsser & Co., Inc.
deryee
I was just wondering if shellac is a good finish for a table?
Is it tought enought?
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Hoff Stuart
and it works great (I even put my feet up). It will handle reasonable
assaults like a wet glass or even a little beer. You would need to avoid
ammonia cleaners, any real hot coffee cups without a coaster or letting
any strong alcohol linger.
I'm not using it on a dining room table I am building, however. I'm
planning on using Behlen's rock hard varnish.
Hoff Stuart
Mike & Donna McCombs
Robert wrote ...
> Evening folks.
>I followed these coats
What brand or source is the shellac? Premixed or flakes?
Mike McCombs
Gerry Glauser
that additional coats were put on a base that wasn't fully cured, except
on the surface. The solvent eventually worked its way to the surface.
Search back a bit and you'll find a more detailed explanation of this by
jim mcnamara, with an indication of how long it might actually take to
cure. Yes, the shellac could have been bad, but I think this is more
likely.
--Gerry Glauser
Hoff Stuart
Nielsen would do a good job. I wasn't confident enough of my scraper
tuning to do this (afraid of scratching through the shellac and the oil
finish) and I just took some straight alcohol and rubbed the ridges out.
I then finished it off with many coats of a 1 pound cut from a rag. This
worked fine. After this dried, I used 600 grit and then 1200 grit wet
dry paper and water to rub it out to get the nubbins and dust particles.
Came out real smooth.
Hoff Stuart
Joe Blow wrote:
>
> On Sun, 6 Feb 2000 20:53:42 -0800, Robert <Roberthp@mindspring(REMOVE
> FOR SPAM).com> wrote:
>
> snip snip
>
> >The heavier coat left ridges and dimples in the finish.
> snip snip
>
> >Bob
> >
> I watched a finisher working with shellac once. He was probably
> applying about a 2-3# cut. It formed ridges, just as you described.
> After it had dried he came along with a cabinet scraper and leveled
> out the ridges and ended up with a damned fine surface.
>
> This was years ago. I tried it later myself and it didn't work for
> me. I've since developed other techniques but have often thought that
> now that I am a lot better at tuning a scraper that I might just give
> this method a try. It would be interesting to know if anyone else has
> seen or tried or heard of this scraping technique for leveling shellac
> surfaces..
>
> Joe
Taig
appreciate the date printed on the can. I have only used shellac for the
first time in the last year. I picked up the 6 to 12 month rule from other
users as a rule of thumb. If I have any left from the batch that I currently
have in 2 years I will apply some to some scrap and report back.
Sy Kaplan
Sy
"Mike & Donna McCombs" <NOSPAMflw...@earthlink.net> wrote in message
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Joe Blow
Paul T. Radovanic
>"Taig" wrote:
>
><< If you are using Zinser's shellac check the bottom of the can for the date
>that it was created on. Shellac only has a shelf life of 6 to 12 months.>>
>
>If I may be so bold as to interject: depending upon storage conditions, freshly
>made shellac (usually amber) can have a useful shelf life of up to 18 and even
>24 months. Bleached shellac has a much shorter shelf life than that. The "6 to
>12 month" rule appears to have developed as a rule of thumb among finishers who
>use shellac.
Maybe it *can* have a useful life for that period of time, but that
doesn't mean it *will*.
I usually figure on fresh-made shellac being okay for a year, but I
prefer to mix it in smaller quantities and use it up within a few
months so that I am *sure*.
Just because shellac will still dry quickly after 12 months does not
mean that the quality of the film is the same as when it is fresh. It
most definitely is not the same.
The esterification process begins immediately upon mixing -- the
longer you wait, the more the process will progress, and the poorer
your final film will be. That's the nature of shellac.
>
>It should be noted that Zinsser shellac is formulated to stay fresh much longer
>than any other pre-mixed shellac and is guaranteed to have a shelf life of 3
>years from the date of manufacture stamped on the bottom of the container.
With all due respect, Gene -- that guarantee only covers the cost of
the can. It doesn't pay for the labor and time involved to strip and
recoat, not to mention the aggravation. And it doesn't specify what
happens if the film dries quickly, but orange-peels immediately after
application, or worse, fails in six months because of poor film
quality.
Paul Rad
>
>
Robert
NOSPAMflw...@earthlink.net says...
>
> Robert wrote ...
> > Evening folks.
> >I followed these coats
>
> What brand or source is the shellac? Premixed or flakes?
>
> Mike McCombs
>
>
>
>
It was freshly made from flakes. Only about 4 days old.
Bob
Mike & Donna McCombs
Robert wrote ...
>
> > Robert wrote ...
> > > Evening folks.
> > >I followed these coats
> >
> > What brand or source is the shellac? Premixed or flakes?
> >
> > Mike McCombs
> >
> >
> >
> >
>
> It was freshly made from flakes. Only about 4 days old.
I have had the same problem in the past. In my case, it was not
the flakes, it was my impatience to get the build up that I
wanted. I was filling the grain with shellac and not filler.
Although shellac dries fairly quickly, you still have to allow
enough time for it to cure. Mine did finally cure hard after a
few days, even though I had globbed on too much too quickly.
I only mix 1 1/2 LB cuts now. Most of my shellac is sprayed on,
and with the thinner cut, I can apply more often and get a
quicker build than when using the thicker cuts. For me, it seems
that three 1 1/2 LB cut coats sprayed will dry faster than one
coat of 2 or 3 LB cut brushed.
With the problems filling the grain that you described, it is
instinctive to just keep on applying more shellac. That only
gives you more prominent grain appearance. You have to sand down
the shellac on top of the wood, as the grain gradually fills.
Eventually you will have a flat even surface. With grainy wood,
it takes awhile.
Mike McCombs
brians...@gmail.com
> Hello Robert,
> the date that it was created on. Shellac only has a shelf life of 6 to 12
> months.
Leon
Jack
in chunks, chop it up and dissolve it in some pure booze. I see no
reason a can of Zinser's would go bad, or have a shelf life at all. I
have used cans several years old and works just like new cans. Perhaps
that's why no date on your can? If you have a 20 year old can that
dry's up, chop it up in your wife's coffee grinder and soak it in
alcohol for a while.
--
Jack
Tolerance is the virtue of the man without convictions.
http://jbstein.com
Markem
opened the can the lid flew hit the ceiling when it blew off. The can
had been used in the winter and sealed, open at 90 f in the summer.
nailsh...@aol.com
> If you have a 20 year old can that
> dry's up, chop it up in your wife's coffee grinder and soak it in
> alcohol for a while.
Michael
Jack
Never had a can "noticeably" evaporate on me that I recall. I try to
keep a can of Zinser's on hand at all times, and about the longest I've
stored it is a few years, never had a problem with evaporation or
application though.
Sonny
https://woodworkersedge.wordpress.com/2012/07/15/decode-your-shellac/
As to shellac in flakes or chunks, as Jack mentions, store the flakes/chunks in a cool place, like in the frig.
Sonny