Paint

[Chris333]

Hello,
I recently bought a PMR model 3 steam engine and I have a question about painting parts of it.

What sort of process and paint are best for these metal parts so that oil won't effect it. And should I bake the parts when done.

Thank you
Chris

 

[ironman]

Chris333, I am building a 3BI PMR engine and I will watch this post so I will know about paint for it too. Ray

 

[Tin Falcon]

Hey guys:
I have done a little painting on objects that can be held in your hand to 40 foot long boat patterns. And stuff in between. I was a painter for a shop that made models and training equipment for industry and colleges.Also trained as an aircraft painter. Most of my models are not painted .

first off all what finish are you looking for ?
the finished product will only be as smooth as the base metal .
here are some basics
the surface needs to be completely clean no metal chips no oil no oxidation. no finger prints.
use a sand-able primer if you want a fine finish
light bright colors such as yellow and orange show up much nicer with a white primer undercoat.
follow manufacturers recommendations
get the spray cans that give you a fan spray
make sure masking tape is tight to the surface for a clean line.
keep the spray can moving across the part.
look at the part and spray from as many angles as possible light coats.
A turntable helps but a coffee can you can turn helps or hang the part with a piece of wire coat hanger.
use proper ventilation.
when done invert can and spray air to clean nozzle.
My suggestion is get a can of white or gray sandable primer and a couple cans of paint from the local auto parts store.
If you have never painted before you may want to practice on a piece of scrap of similar size shape and material.

This model was done in 2003 and has held up fine it has run at least a couple of shows for the last 6 years. basic industrial enamel.

Hope this helps
Tin

 

[GWRdriver]

Chris.
The first thing I do is completely "clean" the castings in preparation for machining. As Tin mentions above this means filing and/or grinding the mold parting lines, removing sprues, unwanted bumps, etc, filling holes (with filler) and I scrub the castings in deteregent to remove any loose casting sand, oils, etc. I actually wash mine in detergent and then dry them immediately and they're fine. I then spray them all over with a good coat of automotive primer. This will seal the surface and keep the iron from absorbing any oil or other unwanted goop during machining. Brass, bronze, and aluminum don't absorb like iron so can be left bare if you want. After machining start again with another coat of primer, and then your paint, whatever paint you choose.

I think "baking" is overrated, often over-done, and sometimes ill-advised. There's one guy on another board who claims to be a paint expert and advises baking at no less than 300degF. That's crazy, most common enamels change colors if not char at that temperature. Baking (at any temperature) does only one thing . . . it speeds up the going off (evaporation) of volatile paint vehicles, but sometimes speeding up evaporation is not a good thing. One thing baking doesn't do is make the paint harder, although it probably will make it as hard as it will ever be quicker. If you want to speed things up a bit I see nothing wrong with baking for a while at 150degF.

My 2p.

 

[MikeR C]

A couple of hard won observations on painting metal:
Get the correct primer for the metal you are painting, especially aluminum. It is worth the trouble.
Do not use "rusty metal" primer or paints on clean metal surfaces.
Paint will tend to "pull back" on sharp corners. By the time you get good coverage on the sharp edge the adjacent paint will be very thick, or you will have to sand and sand. Consider one of the Badger airbrush sized abrasive guns. The abrasive it uses is just a powder, very fine. The matte finish it leaves lets the paint flow over the sharp edges. it is however a pain to wash off the abrasive.
Thin coats, i know it seems like a thicker coat will cover blemishes better but it will cause problems, thin coats.
Let it dry long enough between coats, if you try to sand or wax it to soon you will have problems.
I know these things, I still have crappy paint jobs, but not as crappy as they use to be

Thx
MikeR C

 

[Chris333]

Thanks guys.

I paint a lot of train models, but just wondered if painting cast metal was any different. I will try Testors enamel.

 

[shred]

I did a couple simple powder-coated pieces the other day with the discount HF kit and was pretty impressed. Anybody messed much with that? Particularly around masking and multiple colors?

 

[GWRdriver]

I wouldn't bake the Testors. I tried Red Gloss Enamel (#1103) on some steam fittings a few years ago and baking turned them very dark.

 

[BigBore]

I did a couple simple powder-coated pieces the other day with the discount HF kit and was pretty impressed. Anybody messed much with that? Particularly around masking and multiple colors?

Hey Shred - I have the Eastwood beginner gun http://www.eastwood.com/hotcoat-powder-coating/powder-coat-guns/hotcoat-elite-powder-coat-kit.html?SID=lp65qu3uepl9pfo81fs0cu2u31that I bought to do some brass bullet casings. I haven't turned my first piece of metal yet but when I saw the cool paint jobs on some of the engines of this forum, the first thing I thought was how great a powder coat would look. Before powder coating the brass casing I tested everything on some cheapo wrenches I had. Some were that shiny chrome looking stuff and some were old rusted steel of some kind. They came out perfect, so I'm looking forward to trying it on some flywheel spokes or bases, etc. Masking is easy and precise with the hi temp tape that is used. http://www.eastwood.com/1-8-x-72-high-temp-masking-tape.html The holes are plugged with Hi-temp silicone plugs. http://www.eastwood.com/high-temp-silicone-plugs-1-4-7-16-10-pack.html Color changes work out as good as your tape job. They are a hassle in that you have to completely clean the gun in between colors (about 10 minutes) The color selection is awesome. http://www.eastwood.com/hotcoat-powder-coating/powders.html?p=1 Clear coated, polished brass looks perfect and should stay that way without any maintenance. Unlike a lacquer coat you never have to worry about chipping or peeling.