Finishing the Finish

Finishing the Finish

Post by dcook0 » Thu, 01 Feb 2001 11:32:32



Flexner mentions, in his book "Understanding Wood Finishing", that the
biggest mistake made in finsihing the finish is not giving the finish
sufficient time to cure.  He says to wait a month.  Now, I'm not questioning
the man's intelligence, if he says a month then I'll wait a month, but why?
Shellac and lacquer will dry in minutes whereas varnish and urethanes will
take hours, many hours, to even get to tack dry.  Why does the
shellac/lacquer take as long to cure (with their short tack time) as the
varnixh/urethanes (with their excessively long tack times)?  And just out of
curiosity, do any of you live on the edge and spit in the face of conformity
by finishing the finish when you think it's darn good and ready to finish!
And if you do, how long do you wait?

Dan Cook, Saint Louise, MO
Lip Ripper, the angler who.....b wishin' 2b fishin'.
-------------------------~  <*}}}}}}}}><{

 
 
 

Finishing the Finish

Post by Nova » Thu, 01 Feb 2001 12:39:02


Hi Dan,

    My guess would be that with the wide variety of finishes available,
different application methods, various climatic conditions, etc. one month
should safely cover all variables.

Jack Novak
Buffalo, NY - USA

Quote:

> Flexner mentions, in his book "Understanding Wood Finishing", that the
> biggest mistake made in finsihing the finish is not giving the finish
> sufficient time to cure.  He says to wait a month.  Now, I'm not questioning
> the man's intelligence, if he says a month then I'll wait a month, but why?

<snip>

 
 
 

Finishing the Finish

Post by Grusser » Thu, 01 Feb 2001 13:11:52


There is a big difference between being the surface being dry to the touch. and
being fully cured. The first can be overnight, the is much longer. For most
finishes, overnight can be dented with a fingernail, fully cured cannot.

Varnishes and oils do not develop full hardness for several weeks. Shellac
continues to cure for several years.

Russ Fairfield
Silverdale, WA

 
 
 

Finishing the Finish

Post by jerr » Thu, 01 Feb 2001 22:42:46


It takes concrete 500 years to fully cure.....
but we start using it much sooner....
Cure time and use time are different....

jerry


Quote:
> There is a big difference between being the surface being dry to the
touch. and
> being fully cured. The first can be overnight, the is much longer. For
most
> finishes, overnight can be dented with a fingernail, fully cured cannot.

> Varnishes and oils do not develop full hardness for several weeks. Shellac
> continues to cure for several years.

> Russ Fairfield
> Silverdale, WA

 
 
 

Finishing the Finish

Post by Steve Tiedma » Fri, 02 Feb 2001 10:24:01


He especially wants you to wait if you plan to rub out the finish with buffing
compounds, like rottenstone, etc., or other very fine abrasive material or
products.  For this to be truely effective, the finish must be cured as hard as
it is ever likely to get.  The longer a varnish, for example, has cured, the
slower the curing process is happening.  The evaporating solvents are having to
escape from resins that are bonding into a cured film, and the more curing, the
harder it is for all the solvent to fully evaporate out.  That is why he
suggests the one month wait.  If not going to this step, don't worry too much,
just don't handle the finish roughly for that first month.

Another way to see if the solvents are about done doing their thing is to smell
the finish.  If you no longer smell the odor of solvents, the finish is probably
close to being done.  Again, this is going to take a few weeks.

Steve.
--
Steve Tiedman

St. Paul, MN, USA
REMOVE "NOSPAM" TO REPLY
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Quote:

> Flexner mentions, in his book "Understanding Wood Finishing", that the
> biggest mistake made in finsihing the finish is not giving the finish
> sufficient time to cure.  He says to wait a month.  Now, I'm not questioning
> the man's intelligence, if he says a month then I'll wait a month, but why?
> Shellac and lacquer will dry in minutes whereas varnish and urethanes will
> take hours, many hours, to even get to tack dry.  Why does the
> shellac/lacquer take as long to cure (with their short tack time) as the
> varnixh/urethanes (with their excessively long tack times)?  And just out of
> curiosity, do any of you live on the edge and spit in the face of conformity
> by finishing the finish when you think it's darn good and ready to finish!
> And if you do, how long do you wait?

> Dan Cook, Saint Louise, MO
> Lip Ripper, the angler who.....b wishin' 2b fishin'.
> -------------------------~  <*}}}}}}}}><{