Scalecoat I, thinners, and temperature

[nscaleSPF2]

I love the smell of solvent based paints in the air.  It smells like... victory.

Max,

Please, please, be careful when you use these chemicals.  If you can smell them, then they are concentrated enough to cause brain damage.  Don't ask me how I know this.

Kind regards.

[mmagliaro]

I was joking... honest.

I have been spraying solvent based paints for years, always outdoors or in the garage with the door open,
and I spray one model, and leave the room.

[mmagliaro]

The results are in.

Yep, both lacquer thinner and xylene do a great job.  The thinner hits the paint in a small sample cup and the paint
mixes perfectly.  It can be made watery thin and drips and brushes flawlessly without the slightest bit of gel
or goo forming in it.

I brushed some on styrene and there was no crazing or melting from either chemical.  But definitely, the xylene
yields a much glossier finish, much like what we're used to from Scalecoat I, so part of that gloss secret is
in the thinner.   The lacquer thinner left a sheen, but not as glossy.  (the thinner I used last night left the finish
quite flat, like Floquil.

I'd have to give the nod to xylene.   It seemed to be a much more powerful thinner that dispersed watered-down the
paint more quickly.   But hoo boy... the fumes are horrendous.  Much worse than ordinary paint thinners.
Definitely - fans, open windows, or work outdoors (unless you have a spray booth or a respirator mask).

The lacquer thinner was less noxious.

-------------
Well, so now we know. 

-------
Meanwhile... back to the boxcar and some decal work!

[nkalanaga]

From the MSDS that came with my last Scalecoat shipment, here are the solvents, and percent of the total volume/weight (it doesn't say which):

SC I:    VMP Naptha 17%, Xylene 41%
SC II:   VMP Naptha 88%, Xylene 3%

Both say 58% volatile by volume, so the different percentage total doesn't look right.  If SC II had 55% VMP Naptha, instead of 88%, they would both equal 58%, and that would be a natural typo on most numeric keypads.

In any case, they use the same solvents, but in different proportions, so either thinner should work in either paint.  If you want to use SC I on plastics thinning it with SC II thinner might make it less aggressive.

[peteski]

Ah, VMP Naphtha (aka. Ronsonol Lighter Fluid for old-fashioned Zippo lighters) - another easily obtainable solvent I often use in my hobbies.  Ronsonol is rather pricey, so I get VMP Naphtha in a hardware store in quart and gallon size cans.  Works great for degreasing model loco mechanisms.

BTW, VMP stands for Varnish Maker's & Painter's.

[nkalanaga]

Peteski:  Thank you.  Naphtha I recognized, and misspelled, but the VMP didn't mean anything to me.

[peteski]

Peteski:  Thank you.  Naphtha I recognized, and misspelled, but the VMP didn't mean anything to me.

I think it is simply a trade name (not an indication of some specific chemical composition).  But I could be wrong . . . 

[C855B]

https://en.wikipedia.org/wiki/Petroleum_naphtha

The best I can figure from the gobbledygook is that "VM&P" must denote a distillate blend with a higher flash point than fuel or process blends. I'll let you guys parse the MSDSs if you want to verify that's the case. 

[TiVoPrince]

Personally
my greatest challenge has been humidity over 80%. High humidity practically guarantees orange peel even with all best practices in place. Painting in an Atlanta garage is an adventure to begin with but drawing the line about painting with humdity over 80% has served me well, even if it eliminates a hundred painting days a year.

Never once have I tried other thinners so I cannot comment there. While expensive compared to big box gallons of thinner they have proved their worth to me because it would be complete madness to put all that effort into a model and 'cheap out' right at the finish line. Temped as I have been to get painting the urge has been resisted to use whatever was available at the hardware store...

[peteski]

While expensive compared to big box gallons of thinner they have proved their worth to me because it would be complete madness to put all that effort into a model and 'cheap out' right at the finish line.

Exactly!  Well put!

[mmagliaro]

I agree that for the amount I would use, the Scalecoat "genine" thinner is not a big deal, even though
it's expensive.  I bought a quart when I first started using Scalecoat in the 90s, and it lasted for years and years.
This all came about because I hadn't gotten around to ordering any more, and had been having
good results with Floquil and paint thinner.

[TiVoPrince]

On
the whole model railroaders are more thrifty than Scrooge McDuck.

There are a number of places to save a coin or two in most hobbies. Paint is the one thing that will make or break your project. Unless you are a master weathering god  the main paint colours are going to be the first thing seen. Even if you are the only one to see the model, it will irk you until the end of time.

There are a few failed attempts from 30 years ago lingering in my junk box for no other reason that they are  reminders to do good work and never rush anything or it will be joining the overflowing disaster zone of shameful items that we hope to never see the light of day...

[mmagliaro]

I wasn't cheap!

I was lazy and impatient!   

That's the truth.  It was just easier to go over to the hardware store and pick up a can of thinner than it was
to order the real stuff from Weaver (or another hobby dealer) and wait, so one day, I just bought
thinner and it worked well for Floquil so I never looked back.

Until now.

[TiVoPrince]

Perhaps
it is my own tightwad and miserly tendencies showing through.

Apologies to one and all who were offended by my crass comments painting model railroaders as overly thrifty...

[Doug G.]

Yeah, watch it! It's just a coincidence I still have switches from the sixties on my current layout.



Doug