You need an airbrush.

I'm kinda partial to the Paasche VL Double Action Siphon Feed Airbrush myself.   It works great with acrylics which is a big plus for weathering track that is already secures to your layout.   I like the double action because it allows you to introduce the paint gradually allowing a greater amount of control and accuracy.  YMMV.

Chief Bob (Retired)

Badger makes a nice single action airbrush. I bought one a while back after using a double action for years.  Very user friendly and easy to clean. I still have some unweathered rails. I plan to use this along with Rail brown and grimy black from Micromark. I've used it on some jobs and am pleased with how it works. One thing about badger. If you ever need a part. They are readily available.

 If your going to paint the rails. If paint it gets on the ties or ballast I wouldn't worry to much about it. Ballast near the rails is seldom squeaky clean. If you aim pretty much at the rail. You will end up hitting the ties and ballast. Likely it will be more of a mist rather than a direct hit. The dirty ballast will just add to the effect. 

 You really need to paint only what is visible during normal viewing.

You could try Krylon camo spray paint, easy to use and looks great. Should be done before laying the track but if your careful and have good air circulation it can be done. 

Dave

If you just want to paint the rails and maybe some landscaping there's no need to spend a lot of money on Badger or Paasche air brushes.  Amazon has a nice little kit for $49.95 that will work just fine for simple things.  You should check it out.  BTW I have both Badger and Paasche but they are overkill for what you want.

Since the track is down, air brushing Will give the best result.  Even with an air brush you will probably get a slight amount of overspray, but this gives a mottled dirty look that is more realistic looking. Most better air brushes come with multiple needle sizes for smaller to larger spray patterns. The two brands listed above are good quality. You can get a decent air brush compressor at harbor freight. Wouldn't try doing it with an aerosol can. The paint volume and spray volume is too large.

 If your layout is anything like mine. Airbrushing already laid track isn't like spaying in a spray booth from a comfortable position. You will be standing on step stools and such trying to reach areas from awkward spaying positions. Most times you will be spraying from an uncomfortable position. The one area I still have to do. Has been in the works for a number of years. Not easy to get at.  I'm not getting any younger. It's on for this summer. When looking at airbrushes. Color cups built into the brush are nice for weathering and detailing. Not so great if your climbing onto the layout. You'll be surprised how quick the cup empties when spraying rails. You don't want to be constantly refilling while your on or near the layout. A bottom feed brush that accepts a bottle will let you carry about 3 times as much paint onto the layout. It goes much quicker if you can find a helper to clean up the rails as you move along. This way you are only focused on the painting.

 Laidoffsick had a great video showing this. I believe he used an inexpensive touch up gun. While not the most accurate. It will cover well and carry a lot of paint.

 The track below was in place for years with ballast. No masking. The ballast takes on a dirty look but it still looks somewhat gray.

Just get yourself the cheapest Badger external mix brush, under $10 on the bay.  Also buy yourself the larger jars.

Air brush

Mask off the ballasted area and blast away. Don't make yourself crazy with a fine spray pattern. Rail painting is just not that kind of task. If you want to tear out your hair in frustration, by all means, buy a fancy airbrush with a cup.

DON'T ballast anymore until you've painted. Then you can clean the paint and glue off at the same time.

Trust me, I've done over 2000 feet of this.

Big_Boy_4005 posted:

Just get yourself the cheapest Badger external mix brush, under $10 on the bay.  Also buy yourself the larger jars.

Air brush

 

This is essentially the same airbrush Harbor Freight sells. Always under ten bucks sometimes 5 bucks with the coupon. Its what I use on weathering projects save the high end airbrushes for modeling projects.

Pete

With a piece of cardboard in one hand, and an airbrush in the other hand, you can protect any foreground or background item you don't want overspray on.   

Harbour Freight also has this air brush kit for $88.00 and will handle most of your needs.

Good advice on this topic.

I have to admit I am a bit intimidated by spary/air guns...I just don't think my hand is steady enough to do a decent job.

Actually Paul, for this task, you don"t need to have a steady hand. Just be able to keep your finger on the trigger, and move from side to side. I've done so much of this, I've become proficient with both hands, so when one gets tired, I can switch.

The secret is to keep moving, and don"t let the wet paint build up too much, then you get runs. You can always go back and give it another coat when it's dry, if it didn't cover. Happens to me all the time.

BTW, you can save time, paint and energy by only painting the side of the rail you can see. About 75% of my track can only be seen from one side.

Honestly, I was intimidated by air brushing when I started too. My first brush was an internal mix. I found it terribly frustrating. It didn't help that I was in my teens when I got it. It was a real pain to clean that thing. This cheap external mix that I've recommended will eliminate all of that, and build your confidence.

Paul Kallus posted:

Good advice on this topic.

I have to admit I am a bit intimidated by spary/air guns...I just don't think my hand is steady enough to do a decent job.

Paul, you can always steady your hand on a spare truck and just roll along spraying.

 Paul one more tip I remember. Get the longest possible hose from the compressor to the brush. I know Badger offers a longer version than what comes with the brush. If your layout already has scenery in place. Drape the hose up your back and over your shoulder. This will keep it off the layout as you move along. Rather than dragging along the surface knocking over things. 

Just bought a set of two air brushes on eBay from a vendor in Florida, Artists Emporium. They're Chinese, but frankly, are nicely made and will do what I need. I have a 35 year old Badger XF-150 gun which they rebuilt for free five years ago. They have a life time warranty and stand by it. The Chinese guns won't have that, but they're a fraction of the price. Even though it would be more prototypical to spray the rails AFTER ballasting since the rust runs down into the ballast near the rails, doing so would blow loose ballast all over the place. (Experience talking). You also have to be careful around switch machines and would suggest masking any areas where paint intrusion would not be recommended. I'm currently in the market for a new compressor since my Badger is also well over 30 years old. They too ALL seem to be made in China. It doesn't matter which brand, Pasche, Iwata, Badger or no name, the compressors all seem to be made by the same Chinese company. You can get a 2 cylinder, quiet compressor with a reservoir for just over $100.00. So for less than $150 you can get two airbrushes (one detail top feed and a bottom feed, both double-acting). That's a good way to get started. BTW: My hands are not steady and I do some very specialized paint jobs.