Paint Wear on Corners & Edges of N Scale Models After Handling

[tehachapifan]

Even though I can achieve pretty decent airbrushed paint results, I always seem to end up with a paint finish that tends to wear-off of the sharper corners and edges at the model's common grasp spots (top of an exhaust stack on a switcher loco, for example, or fuel caps or the corners on fuel tanks....things like that). By the time I finally get a model assembled after painting, with all the (literal) bells and whistles added, decoder installed, etc., I'll typically have all the paint completely missing in some of these spots or clearly worn with maybe the dull finish gone. Keep in mind, I typically handle the model A LOT, usually without gloves, after painting it and getting it where it's finally track-ready. I've experienced this with both enamels and now water-based acrylics and I know it's the oils in our hands that soften the paint that can lead to this, but I haven't really noticed a problem with factory-painted models (granted, I haven't really pawed a factory loco near as much as a custom model, so perhaps it might happen if I did?). Now, before dissecting my painting process...BTW, I do meticulously wash the model with soap and water, let air-dry prior to painting and only handle with rubber gloves prior to painting (but I'm not currently using a surface primer)....is anyone achieving a finish where this is not happening at all? If someone is, please share your methods!

...also, I tried to do a forum search on the subject but got an error message, so sorry if this has all been covered. Also, I believe this is N scale appropriate because the paint methods discussed here need to render a finish that looks good over the surface of an N scale model without hiding the 1:160 relief details....how's that?

[Santa Fe Guy]

Russ I would highly recommend a surface primer, heck even Tamiya recommend it LOL. Their surface primer grey is excellent and will give tooth to the top coat.
By the way your SP Locos look cool.
Rod.

[coosvalley]

I wash my models after decaling and detail construction, then shoot them with polypropylene clear primer, the stuff used for painting flexible handrails, then apply a flat finish, followed by weathering. ..I was experiencing what you described until I tried this approach...

[tehachapifan]

Russ I would highly recommend a surface primer, heck even Tamiya recommend it LOL. Their surface primer grey is excellent and will give tooth to the top coat.
By the way your SP Locos look cool.
Rod.

Thanks, Rod! Are you using an airbrush version of the Tamiya primer?

I wash my models after decaling and detail construction, then shoot them with polypropylene clear primer, the stuff used for painting flexible handrails, then apply a flat finish, followed by weathering. ..I was experiencing what you described until I tried this approach...

Thanks, coosvalley! Good info.

[tehachapifan]

...one thought on using a surface primer....

I'm curious if what is happening has to do with lack of adherence, presumably what a primer would potentially help with. The paint seems to stick to the model OK...I typically don't pull underlying paint off when removing masking tape, for example....but it more or less seems to just sort of soften with handling and I guess smudges away. If using a surface primer, I'm curious if the finish colors would just wear down to the primer instead of the bare plastic and not really solve anything.

[peteski]

What are the specific brands of paints you are using (and what do you thin them with)?

[tehachapifan]

I'm currently using Modelflex (I'm a Pollyscale acrylics refugee) and I currently thin with distilled water. I use an external-mix Badger airbrush, which probably causes me to have to thin more than if I used an internal-mix (from what I've sort of gathered doing some research, having to do with acrylics tending to clog the external-mix perhaps a little more?). But, I've experienced the same issue all the way back to my enamel days using 3 different brands of paint now. I'm (almost) completely convinced that this is just the bane of the custom painter....unless someone can convince me they've completely solved the issue....as in, they can handle the model ALL DAY LONG and not experience any paint wear on the sharper corners and edges.

[peteski]

I'm currently using Modelflex (I'm a Pollyscale acrylics refugee) and I currently thin with distilled water. I use an external-mix Badger airbrush, which probably causes me to have to thin more than if I used an internal-mix (from what I've sort of gathered doing some research, having to do with acrylics tending to clog the external-mix perhaps a little more?). But, I've experienced the same issue all the way back to my enamel days using 3 different brands of paint now. I'm (almost) completely convinced that this is just the bane of the custom painter....unless someone can convince me they've completely solved the issue....as in, they can handle the model ALL DAY LONG and not experience any paint wear on the sharper corners and edges.

I still use the smelly paints (Accu-Paint, Tru-Color, Floquil, etc.) so I can't offer much advice on your current problem. But when I expect to do some excessive handling of a custom-painted model I wear cotton gloves (like they use  while handling museum artifacts.  Rubber gloves should work too.

[tehachapifan]

Thanks, peteski. Yeah, I'm trying to stay away from smelly paints these days. I'm also trying to put on gloves more these days for when I plan something that might take a few minutes and it does help, but it's a step I really wish I didn't have to take and I do wish for a more durable finish like the manufacturers seem to be able to somehow attain. The gloves also introduce their own issues, I've noticed, such as a tendency to snag on edges, tiny parts, handrails, etc.

Anyway, thanks for the tips thus far! I may put an internal-mix airbrush on my X-mas wish-list this year, to see if it makes a difference by letting me thin a little less. In the meantime, more comments and suggestions welcome!

[OldEastRR]

Plain old friction between your fingers  and the hard surface of the model will wear away anything, if done enough times. (even with gloves -- if there was no friction between the car and the latex the car would slip out of your hands every time). There's no "friction proof" coating of any kind to stop that. Factory models resist it but have quite a few coats of paint on them and I don't know, do they hot-air blow dry them? The only way to prevent wear is to put on as many coats as you can to stand up to the finger friction. But that doesn't mean over the entire car -- putting a series of extra coats on the upper corners and lower edges of the equipment where the wear usually occurs is all you need. Then you don't pile extra paint over details on the rest of the body. Quick light shots repeated many times will add more durability.  This is with an airbrush, of course, so you can feather in the new coats over the old.

[tehachapifan]

Plain old friction between your fingers  and the hard surface of the model will wear away anything, if done enough times. (even with gloves -- if there was no friction between the car and the latex the car would slip out of your hands every time). There's no "friction proof" coating of any kind to stop that. Factory models resist it but have quite a few coats of paint on them and I don't know, do they hot-air blow dry them? The only way to prevent wear is to put on as many coats as you can to stand up to the finger friction. But that doesn't mean over the entire car -- putting a series of extra coats on the upper corners and lower edges of the equipment where the wear usually occurs is all you need. Then you don't pile extra paint over details on the rest of the body. Quick light shots repeated many times will add more durability.  This is with an airbrush, of course, so you can feather in the new coats over the old.

These are good suggestions! However, it almost seems like what I'm experiencing is more like a reaction between I'm guessing the oils in my skin and the paint versus standard friction. I'm pretty sure I could gently lay a finger completely motionless over one of these areas, lets say a grab iron, for several minutes and some paint would likely be gone when I lifted it. But, I haven't actually specifically tried this, so I could be off-base.

[thomasjmdavis]

What follows may be more random thoughts than actual advise, but I have been using acrylics for a long time.  And yes, my advice would be to consider an internal mix airbrush whenever you get to buying a new one.

I have had the same issue with Modelflex.  For a long time, they told us we did not need to prime, but primer helps with adhesion- and now they have their own primer. I usually use Model Master acrylic primer instead, but mostly because it is readily available from the closest Hobby Lobby, so I don't need to mail order as with Modelflex. Room temp is also important- maybe its just me, but acrylics sprayed at temps over 70F seem to stick much better (as well as better flow through the airbrush).

For some reason, I can't spray Modelflex dark blues- too much like inks- they get under masking tape no matter what I do, and its like they stick well where I don't want them and don't adhere where I do want them. Which is why I took to doing the following-

When using Modelflex I do the first coat (after primer) with Model Master acrylics- I choose the closest color I can find to what the final coat will be.  I am willing to bet that neither company would recommend that, so use at your own risk.  But I have found that Model Master sticks better to most surfaces. Also, let the final coat dry 24-48 hours before decaling or masking (for any brand acrylic).  I know, virtually all acrylics will say at most a few hours, but I have had much better results letting it dry a good long time.

Get a clearcoat on after decalling, and do NOT handle until it is thoroughly dry- again I would recommend letting it sit for quite a lot longer than the nominal drying time.  Once that finish has hardened, you should be able to handle it as you would a "factory" finish.

The other recommendation I would have is that it is worthwhile to check out Rapido's new Proto Paint.  I've done geeps in CN green and some boxcars in Boxcar Red #4, and I really like the way the paints cover and the final gloss finish.

Hope that is of some help. 

[peteski]

I believe that manufacturers use "smelly"paints like True Color paint when decorating the models. That type of paint is probably more scuff resistant than the water-based paints.  I also agree with OldEastRR that if you handle even a factory-painted model a lot you will see the pain wear off on the corners/raised surfaces.

[tehachapifan]

Excellent tips, Tom D and all good points, peteski.

[C62-2]

I had a lot of problems with paint coming off on the corners/edges in the past. I mostly used modelflex, but have a strong suspicion that the problem was due to spraying dullcote (from spray cans) on top. Since moving to Japan (and having to deal with the completely different set of paints available locally), I've been using tamiya paints (both the spray cans, which are "smelly", and the jars, which are more or less water-based) as the paint, and Mr Topcoat (flat, semi-gloss, gloss) as a top coat after applying decals. This seems to result in a much more stable paint job (no problems so far with anything I've done in the last several years). Mr Topcoat is water base, while dullcote is not. This makes me think that the solvent in the dullcote was destabilizing the paint that it was sprayed over.