[WWI] Modeling 101 doubt - Micro Sol and Future

[Matt Bittner]

I think the answer is a little simpler than that.  I think it's because
Micro-sol has a little bit of ammonia in the mix.


Matt Bittner


On Wed, 4 Jun 2008 19:40:33 -0500, Mark Shannon wrote:

> It really isn't a problem.  If you see the whitening appear, just do not
> touch anything.  The whitish fogginess will go away as everything dries.  A
> later coating to seal the decals will help, too.
> 
> Ways to avoid it in the first place are:
> 
> Let the Future coat dry at least 12, preferably 24 hours,
> Use the minimum amounts of MicroSol in any one application, and
> Use the thinnest coats of Future necessary to get a gloss coat.
> 
> What happens is that all acrylic and enamel paints and coatings have two
> drying times.  I'm not sure if it is a general term, but in the automotive
> paint industry the first is called the "tack-free time," and you often hear
> 'touch dry'.  This is the point at which you could place a cotton wool ball
> on the painted surface and pull it back off without leaving any strands
> behind (the test is to actually do this on a painted test sheet every five
> minutes until you leave no lint behind)  However, if you were to put some
> solvent on it it would dissolve and get mushy, or if you press on the paint
> at this stage, you would leave a fingerprint.
> 
> There is a final drying time, which is really a 'curing' time.  What is
> happening is that the shorter chains of the film producing chemical
> (acrylics, linseed, alkyd, or whatever) are fusing together into a polymer
> that will form the final coat.  With many hobby paints, there is an
> intermediate time when you can safely mask over the paint, even though it
> is not fully cured.  Future is like this -- since it was designed as a
> floor 'finish' it has a relatively short time before it won't lift up or
> take a fingerprint, but it really takes longer to cure -- sort of fully
> cured in about 48-60 hours, like the PollyScale paints.  In floor use, you
> can walk on it in thirty minutes, but it is designed to only slowly
> polymerize so that it is easy to strip for re-'finishing'.  If you check,
> you will see that Future gets glossier over about the first week.
> 
> So, letting it have a longer 'drying' time makes it more durable.  Shorter
> times mean that it is still not cured and will dissolve or soften with a
> mild solvent like MicroSol, but as the Sol evaporates out of the film it
> will leave not residue and no permanent damage -- unless you touch it or
> press or scrape during the time it was soft.
> 
> Lacquer paints have a different drying chemistry, but they still have a
> 'tack-free time' and a fully cured.
> 
> Mark Shannon
> shingend at ix.netcom.com
> 
> 
> 
> > [Original Message]
> > From: Marcio Antonio Campos <marcio.antonio.campos at gmail.com>
> > To: World War I Modeling Mailing List <wwi at wwi-models.org>
> > Date: 6/4/2008 6:35:57 PM
> > Subject: Re: [WWI] Modeling 101 doubt - Micro Sol and Future
> >
> > 2008/6/4 Rob Stewart <rob at rob-stewart.to>:
> > >
> > > Hi,
> > > I have had no problems with that.
> > > What happens?
> >
> > It gets whitish around the decal. The best comparison I can imagine is
> > a glass after a long time in the freezer.
> >
> > All the best from Brazil
> >
> > Marcio
> 
>