Paint Adhesion Issues
#1
Probably a very basic question, but...I’m ready to paint the track on my layout and have run into a problem. The paint doesn’t seem to stick too well and I’m not sure whether this is typical or not. I am also running into the same issue with freight car trucks. I can fairly easily scrap the paint off with my finger nail. Now I know that I will be handling my stock carefully and the track once ballasted probably won’t get scraped, but I want to know if I should be doing anything differently. :wall1: :wall1: :wall1:

I have the same problem with Polly Scale (water based) and Model Master (solvent based) Paint. I brush painting my test pieces, but will also be airbrushing with these paints.

I just checked a structure that I airbrushed with the Polly Scale paint a couple of years age and the paint is “bonded” perfectly. Is my issue with the "slippery" plastic that freight car trucks and Micro Engineering track is cast in?

Any help would be greatly appreciated.

Mark
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#2
Get a spray can of Rust-oleum or Krylon comouflage brown !!!!! cut some blue painters tape in small strips , place the strips on top of the rails & paint the sides & ties !!!!
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#3
You might also make sure there isn't any oil on the rails. Try a bit of detergent in water and use a small stiff brush to clean them before applying paint.
Don (ezdays) Day
Board administrator and
founder of the CANYON STATE RAILROAD
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#4
Track is one area where I have had the most luck brush painting a water based acrylic paint. Depending on the brand of track, I've had mixed results with it rubbing off the ties or rails, but luckily once it is in place it gets zero handling. Sometimes I have to do touch up after ballasting, but once the trackwork is done, the paint lasts for many years. Lately, I have been using craft paint for this.

Trucks usually get airbrushed at the same time I paint the model. And I almost exclusively use a petroleum based paint when airbrushing. Again, depending on the brand, it doesn't always adhere well to the plastic and it does not hold up well to handling. But if the paint is thick enough, and I seal with some kind of lacquer, it does okay, and I just try to not handle the trucks much after the model is completed.
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#5
I've always used Krylon spray paint .....I like the " camouflage series " colours . For track I vary red oxide , flat black , and grey . It sticks so well , it takes a little " elbow grease " to clean the top of the rail with a Bright Boy .

T
To err is human, to blame it on somebody else shows management potential.
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#6
I’m checking out the samples of the trucks that I have completed so far. The first one had no prep at all and was painted with Polly Scale and it has actually sticking pretty well, maybe the bond got stronger after a week? The second one I prepped by scrubbing with Bon Ami cleaner which was handy and it took the shine off the truck. I used Polly Scale and now that I check it again the bond is also better than last week. I can’t say one is better than the other, but they both seem much better to me. The last truck had no prep, Model Masters paint and it flakes off the easiest, actually real easy, but it was only painted 24 hours ago. I will prep another truck with the Bon Ami and paint it with the Model Masters to see how it sticks. I will also give it several more days to dry/cure to be fair.

The un-prepped, Model Master painted Micro Engineering track is a big fail as well. It flakes off very easily Nope . I’m cleaning a section now to see how it will react with new paint, both Polly Scale and Model Masters.

The sample I have of Polly Scale on rail is not going anywhere. I would probably need sandpaper to get it off :tada: . So my problems seem to be only on the soft plastic.

As for the spray cans, I only have a little track to do so it would probably be wasteful. I also need to practice on my air brush and I figure what better way than to force myself to use it whenever possible. Plus, I have lots of bottled paint already on hand. :lol:

Mark
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#7
When I do rail, the successful attempts usually involve a brush. I like the little ones that are a plastic stick with a cotton ball on the end (very small -- my dentist uses them to put glue in for fillings!)
I don'r usually paint ties.
Somebody makes a paint that's supposed to stick to plastic handrails. That might work, if they make colours other than safety yellow.

Had a friend who sprayed his track with car primer. Got a shock when the supplier switched from red oxide to grey primer.
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
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#8
Plastic trucks on rolling stock and Micro Engineering ties are both cast in hard engineering plastic (the same stuff as is used on diesel handrails nowadays and many other details which might be better done in metal :mistht: ). That's why paint won't stick to it, nor will ca or other common adhesives. Even solvent-type paints or cement have little grip, and it's certainly not a permanent one.
Scrubbing with an abrasive cleaner will improve adhesion, and when I remember to do it, sandblasting freight car trucks, using baking soda as a blasting medium, helps to make paint stick better.
I recall reading somewhere that soaking plastic trucks and other such smaller items in alcohol for about a week will remove the mould release agent which is supposedly the culprit causing the slipperiness, but have not tried it. Washing engineering plastic with dish detergent seems to have no noticeable effect, but it works very well on the softer styrene used for buildings and rolling stock.
As for paints, old Floquil (the lacquer-based one, not the latest mineral spirit-based version) will deal with the residual oil left on rail from the drawing process, but I opted to use PollyScale on my rails because of the lower odour. PollyScale paint dries very quickly, but it takes longer (24 hours, at least) to cure and it's very likely that it would be even tougher after a week or so. I brush-painted all of my track using PollyScale and a 1/2" brush with relatively stiff bristles. This eliminates the need for masking, creates no overspray (that paint which goes beyond what you're trying to paint and often beyond the masking tape, too). Much of that overspray is dry before it lands, and that is what's known as dust. You will have many opportunities in the future to revisit it. Wink :wall1: :mistht:
Brush-painting rail is a very simple operation, and requires almost no preparation and very little clean-up, so you can paint anytime you have five or ten minutes to spare. Turnouts, of course, take a little longer, but nowhere near as long as it would take to mask and spray. Using PollyScale, I generally paint 10' or 12' of track at a time (both sides of both rails - even on a shelf-type layout, there may be opportunities for photos taken from the "wrong" side of the tracks). Don't worry about paint on the ties, tie plates, or spikes, as the metal parts all rusted on the prototype and that rust also bleeds onto the ties and ballast - this is not fine art. After painting that length of track, I used a dry rag over my fingertips to wipe the dry but not hardened paint from the rail tops. You may be surprised, but this is enjoyable and relaxing work, and is probably the operation which will give you more "bang for your buck" than any other you will do on your layout. Closely following that is ballasting, but that's another topic. Goldth
As for PollyScale becoming tougher with time, I've found that to be true and no longer use Floquil even for painting brass steam locomotives. The original Floquil (square bottle) was a tough paint, but PollyScale is even better, in my opinion.
Painting ME ties presents the same problems, and while you could sandblast the track before laying it, I think that PollyScale applied just before ballasting may be the simplest option. Ties are not normally touched once the track is in place, and unless you have frequent derailments, the paint will likely remain in place.

Wayne
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#9
I meant to mention:
I tried using Sharpie markers on the rails. First problem is not getting close to the spikes -- the tip bounces off them.
The brown marker turned quite red. Brown paint markers had more adhesion problems and also left shiny spots around the fastenings.
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
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#10
Wayne,

Thanks for the detailed response. you confirmed a lot of what I am experiencing, so I know that I am not doing something wrong.

I painted some more samples last night and will let them cure several days before I check them, but so far the Polly Scale seems to be working better for this application.

Mark
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#11
David,

Thanks for the tip on the 'micro brushes'(?). I have seen them and would like to find a local source for them, otherwise I'll have get them off the internet.

Mark
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#12
Mark:
They're called Microbrush. My LHS carries them. Microbrush is at 1376 Cheyanne Ave, Grafton, Wi 53024. Also in Ireland.
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
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#13
All waterbased paints require about a week to harden (cure). Most enamel type paints (solvent based) take about two weeks to fully cure, Scalecoat can sometimes take even longer.

For a more wathered look I usually paint my track (ties and rails) with one brownish rusty color (i use waterbased and rattle cans, it doesn't really matter). Once the paint has cured (at least a month) I brush the ties with a wire brush. This lightens the paint on the ties a bit and lets some of the black plastic show through. giving the ties a less uniform look, I then seal everything with some Dullcote or Polyscale flat.
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