Making good Masking

[Green_Elite_Cab]

First up

I would add that the window trim on the PATCO car could be brush painted with a brush like this:

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Andrew

I LOVE MICRO BRUSHES. I got a few packs when I was 15, and I've been using them for ages. I actually have a hard time finding them at hobby shops, but i've got enough laying around that I haven't run out of the super-fine tips yet. The best part is, unlike a regular brush that gets frayed, these stay "tips", and never puff out.

It hadn't occured to me to try and use these to do the black rubber gaskets around the windows. This is a detail I've left out of many of my commuter cars because i'm so nervous the black paint will get on the metallic paint (and once it does, the metal paint is ruined). I'm thinking though, a microbrush, a steady hand and some masking tape may help.

There are several good strategies, and sometimes a mix is best.

First, masking tape: I've found Scotch Magic Tape (i.e. #119) is by far the best. It's thin and sticks well, but not too well. Don't use any sort of paper type masking tape like what's used for auto painting. Practice helps, and certainly it's best for straight lines.

I tend to use 3m blue painters tape, though the sort in question has a different texture than the usual stuff. unfortunately, it will not seal in around the edges of EMD engine doors on the hoods. I didn't think scotch magic tape would work, it seems like "regular" tape to me, though we have plenty of it here. I'll have to try it.

A second issue is airbrush technique: you've got to learn to spray so the paint is almost dry when it hits the model. The less fluid the paint, the less likely it is to bleed under the masking.

THis has always been frustrating to me. When i first started airbrushing, I was able to do this pretty much immeadiately. For a little while, I wasn't even worried about painting anymore. However, it seems like i've been regressing in this area, and i suspect it has to do with the thinning of the paint.

For example, the Alclad metal paints are prethinned, so i can shoot them right through the airbrush and expect reasonable results from the get go.

However, I cannot get Polly scale, floquil, or similar paints to cooperate. I use 1 ml scientific droppers, and i count the drops, and do the math so to create a mixture within the parameters on the bottle. I use Floquil airbrush thinner and deionized water for solvent and acyrlics respectively. No matter what I do, the paint seems to come out runny.

Now that I think about it, suspect something is up with my airbrush as well, but i can't see anymore paint clogs. I clean it thoroughly in acetone after every use, yet still paint flow seems restricted sometimes. In fact, I haven't painted anything for so long that I forgot part of the reason i put those projects on hold!

A third technique, which I use only when I'm pretty worried, is to spray color A on the model, the base color that most of the model will be. Then mask for the next color. However, before spraying color B, spray another coat of color A over the original color A coat and the masking as well. Any bleed through will be the same color as the base color. However, in most situations, good masking and airbrush technique should help. (An example of where this might be helpful, though, is in elaborate bicentennial type schemes where the color separation is going across hood doors, latches, vents, etc.)

I've heard of this strategy, and I think I tried it once or twice, in particular on mind bending "Metro North" paint job I did for a friend. It still didn't work, but I wonder if the masking tape was really working. I burnished it as much as i could, but I ended up repainting the different stripes 4 or 5 times before I gave up and decided to try and touch up the sizable splotches with a paint brush.

Fourth, use Micro Scale trim film. That's how I would do the PATCO car in the photo: spray on the aluminum paint, then measure and cut the black decal trim film where the black will go.

I was tempted to do this early on. The only reason I hesitate is I'm not sure how easy it would be for me to cut the trim film perfectly to size. I was recently cutting trim film (though at much smaller sizes) to make the red warning stickers on my E44 electrics, and it took quite a bit of trimming to get them right.

If a decal could be made to fit around the front windows, it would be ideal, but i'm not clear how I would translate the exact sizes to the trim film itself. the very front face might not be to bad, but getting the angles to work out on the sides seems tricky. It seems like proper masking it the only good way to garauntee a accurate window band.

Fifth, and this would apply to the NJT cab units, look carefully for any commercial decals that might include all the striping already in the set. There are probably dozens of small vendors among whom you might find this stuff. Then you're home free.

Sixth, if that fails, look for a decal set that has similar striping. The NJT scheme looks like the striping pattern is similar to RF&P, GM&O, or maybe SP Daylight. Check those out with photos. If any are really close, buy a set of those (or borrow one maybe), photocopy it, and use the photocopy as a pattern to cut Scotch Magic Tape in the masking pattern that matches the stripes. Use Technique 3 if needed.

No dice on these two. So far as I can tell, only one company has made the NJ DOT decals, but they only do the stripes and logos for the Passenger cars and the U34CH locomotives. I've been looking for a similar set for a while, but very little reveals itself to me. While there are plenty of small decal places around, I haven't yet found an NJ DOT E unit decal or a good stand in. I'm going to have to synthesize this myself.

In all cases, use Micro Scale fine striping decals for the thin stripes over color separations.

Yup, thats the way to go with the thin stripes!

In addition to what jwb posted;
I have been using the blue painter's tape, since it first came out, and have had no problems with the tape ( the way I have applied it ? sometimes there's a problem there ) .

This is the tape I've been using.

I think the biggest problem is the hood details and doors. Paint seems to pull into the seems with caillary action. I suppose the overspay method would work to a point, but I tried that at least once on a Metro North paint job, and the paint still pulled through.

Any time I'm working with a curve, or on an irregular surface, or "the nose of a F unit", I will first mask off the area using 3/32" to 1/8" wide strips of tape ( apply tape to a small glass plate, and then with a straight edge, and a sharp #11 blade, pre-cut the tape strips ) which can be curved better that the full width. Then, the rest of the unpainted area can be masked off from those thin "edge strips".

I was even cutting notches into the tape to facilitate its bending, but it can be tricky to get consistent, symmetrical lines.

Yes. a bit of practice with this method is highly recommended, as well as a last minute burnishing of all the edges.
A clear spray could also be used to seal the tape edges, instead of the base, or body, color. In many cases this is absolutely necessary. You will eventually learn where and when you an get away with not sealing the edges.

I guess this must be the case. I've always dreaded painting things, its probably my weakest skill in the whole hobby. Perhaps i should just bite the bullet and paint some more until I get it right (though not on anything expensive yet)

The masking for the orange stripe/nose of these WP FTA+B - F7A was done with blue painter's tape:
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As was the orange "Flow-through" on the LIRR C-420 kitbash:
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Very Nice! The LIRR one concerns me though, how did you get the tape in around the hood door seams?