Re: Painting HO Scale Brass


Paul Hillman
 

Googled the following for all list chemists:
 
 Vinegar consists of acetic acid (CH3COOH), water and trace amounts of other chemicals, which may include flavorings. The concentration of the acetic acid is variable. Distilled vinegar contains 5-8% acetic acid. Spirit of vinegar is a stronger form of vinegar that contains 5-20% acetic acid.
 
"Table salt - ( 'Morton's Salt' ) " = sodium chloride = NaCl
 
Hydrochloric acid = HCl
 
So,.........mixing NaCl + CH3COOH = HCl ( ? )
 
Paul Hillman
 
 

----- Original Message -----
Sent: Tuesday, May 27, 2014 8:42 PM
Subject: RE: [STMFC] Painting HO Scale Brass

 

I may amuse (or exasperate) the chemists on the list, but IIRC, vinegar and salt make weak hydrochloric acid.  I don't know as it >replaces< grit blasting, as that can reduce or eliminate some surface imperfections (solder buildup, epoxy smears, things like that, I think) but once the model is physically what you want it to be, it really does CLEAN the surface.

You might want to take into account that I do not own a grit blasting setup.  And since I don't own one or have ready access to one . . .

I use distilled white vinegar (not derived from foods) and yup, plain ol' Morton's.  I keep it back in the glass bottle, appropriately marked and stored with my paint stuff, with some plastic wrap under that steel cap.  I probably should buy a new bottle with a plastic cap!  Same bottle's done  . . . I dunno, 15-18 models?  A lot.  Lasts quite a while.

Schuyler

From: STMFC@... [mailto:STMFC@...]
Sent: Tuesday, May 27, 2014 9:28 PM
To: STMFC@...
Subject: Re: [STMFC] Painting HO Scale Brass

 

Schuyler, thanks for the response. Found it new & interesting about etching with vinegar & salt. What kind of vinegar? (Type of salt = sodium chloride / "table salt"?)

Sounds like this replaces having to sand-blast.

Thanks, Paul Hillman

----- Original Message -----

To: STMFC@...

Sent: Tuesday, May 27, 2014 6:48 PM

Subject: RE: [STMFC] Painting HO Scale Brass

 

How many members are there on this list? That's about how many methods
there are, I suspect.

But, for me, once I'm sure there's no clearcoat on the model and I'm really
dealing with brass as my surface to paint . . .

I wash it vigorously, soap and water, then rinse until I'm really bored with
that, hot water will get any soap off. Then etch the surface in vinegar
with salt added to a saturated solution. Doesn't take long, maybe 15-20
minutes. Rubber gloves from here on.

I prime it with Scalecoat 1, first, and bake it per the directions. Maybe
140-150 degrees for a half hour plus. This will give you a rock-hard glossy
surface. Then the finish coat, or coats as the case may be, and bake those
too.

For masking, I use Scotch 3M 218 Fine Line tape, cut to fit around any
protuberances. Cover any gaps in the taping with rubber cement, or
MicroScale's Micro-.Mask There's been a ton printed about how to remove the
tape, pulling it back so it's coming off the model at a 178 degree angle (as
near to 180 as you can manage) so you're minimizing the perpendicular pull
on the paint.

Decal.

Flat coat.*

Weather.

Done.

*There's been a bit of whining about the demise of Dullcoat. Not from me.
I say "Finally." I have for years used a flat photo lacquer, which is DEAD
flat. If you remember Kar-Line models, which came with paint approximating
the finish on your new car, photo flat lacquer would turn Kar-Line cars into
presentable, weatherable layout scenery in one coat. They were usually
Athearn Blue Box models, hence "scenery" models. I bought a gallon of
McDonald's Photo Flat Lacquer around 1985. Thinned to a ratio of about 5:1
thinner/lacquer, it sprays very nicely and really works far better than
Dullcoat. And I still have a LOT left.

Schuyler

From: STMFC@... [mailto:STMFC@...]
Sent: Tuesday, May 27, 2014 6:25 PM
To: STMFC@...
Subject: [STMFC] Painting HO Scale Brass

I have an unpainted brass car that I've had for a few years and I'm getting
around to painting it.

It's been quite a while since I painted a brass car. Wondering what are the
best current methods?

In the past I have baked on a primer, then sparyed the final colors. There's
always problems with paint adherence to handrails and corners / edges of
parts.

I've tried "Blacken-It" on brass parts but it doesn't adhere
"super-strongly". Of course blasting & cleaning are first required.

Thanks, Paul Hillman

[Non-text portions of this message have been removed]

Join main@RealSTMFC.groups.io to automatically receive all group messages.