# decaling



## jark (Jan 4, 2015)

If I'm going to repaint a piece, should the old decals be remove. If so, how do I do that? Your help is appreciated. Any additional recommendations are welcome.


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## Mr. SP (Jan 7, 2015)

*Decals*

If you are going to completely repaint a model strip the old paint and decals. There are some paint removing products available . Scalecoat makes a stripping product. 
Test first but cheap automotive brake fluid will take paint off. Remove all clear lenses and "Glass" before soaking the model. A stiff bristle toothbrush works to remove paint. As mentioned test the brake fluid inside the model to be sure the brake fluid won't attac the plastic


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## DonR (Oct 18, 2012)

The brake fluid does a good job and takes off
the decals too. Leave it soak overnight. You may
need to do a second soak if it all doesn't come off
smoothly. You'll likely need a fine point tool to
get old paint out of some fine details.

When brushing off the old paint be mindful of any
glued in details such as horns, stacks, bells,
and such. 

Don


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## jark (Jan 4, 2015)

*Decals*

Thanks, I'll move forward


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## traction fan (Oct 5, 2014)

*Removing paint*

The absolute, most effective,:appl: method for removing paint from models is with alcohol in an ultrasonic cleaner.
Most of the original factory paint jobs on our models are alcohol based paint. The ultrasonic cleaner doesn't have to be anything big or expensive. Harbor freight has a small one that will hold most N-scale items and a larger one that should hold smaller H.O.
The cleaner I use was made to clean dentures. Unfortunately, it is no longer made. Using 70%-99% alcohol, I have stripped loco shells down to bare plastic in a few minutes. Unlike brake fluid, you can't over do it, and ruin small details. Shells come out perfect.

Traction fan


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## kevinh (Jan 26, 2015)

A note of caution: most ultrasonic cleaning baths are *not* designed or rated to be used with flammable solvents (including isopropyl alcohol). Flammable vapours can collect above the bath, in the case of the instrument, in a confined space around it, or in a poorly-ventilated workshop--where they can present a significant and surprising fire and explosion hazard. In operation, the liquid in the bath tends to warm over time, increasing the rate of evaporation and vapour formation.

(Baths which are designed for use with flammable solvents do exist, but are typically much more expensive. They include systems to contain and recover solvent vapours, and employ sealed electrical components to prevent solvent vapours from being exposed to sparks.)


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## traction fan (Oct 5, 2014)

*Ultrasonic cleaner*

I have used alcohol in my ultrasonic cleaner, successfully, for forty years. Never had so much as a whiff of smoke, let alone fire or explosion! The cleaner has a built in thermostat that shuts it off when it gets warm. It never gets hot enough to set itself, or the alcohol in it, on fire.

Traction fan


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## traction fan (Oct 5, 2014)

*Correction to my last post*

Sorry, I haven't really been using the ultrasonic for forty years, without fire,or any other problem. It's really only about thirty years!

Traction fan


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## kevinh (Jan 26, 2015)

The problem isn't that the bath gets hot enough to ignite the solvent; it's that solvent vapours can collect in and around its electronic components and be ignited by a spark. (The fact that the bath gets warmer when in operation just means that there's more vapour.)

I'm not saying that some people won't be able to use a flammable-solvent-filled bath for a long time without any trouble, but the problem with being lucky is that it works right up until the very surprising day that it doesn't. Some folks will get away with it for a lifetime; other folks will get away with it for...well, a much shorter lifetime.

In the lab if we need to sonicate something in flammable solvent - and we don't want to spring for an explosion-proof ultrasonicator - the usual dodge is to fill the bath most of the way with water, and then put the piece to be sonicated in a resealable container that can be immersed in the water. This contains the flammable vapours, and saves on solvent. (Win-win!) It may be difficult to find a suitable container (that still fits in the bath) when you're doing pieces the size of a locomotive shell, though.


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## traction fan (Oct 5, 2014)

*Compromise*

Kevinh;

Rather than continue a pointless debate over theoretical possibilities, vs. real world experience; lets leave it at this. Since you apparently are convinced that using alcohol in an ultrasonic cleaner is a potential fire hazard, by all means don't do so.
Since I really have done so, for many a successful paint stripping job, with no fire, I will continue as I wish. Let everyone else decide for themselves.

Traction fan


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## kevinh (Jan 26, 2015)

Traction fan - It's not my intention to tell you, personally, what you can or should do in your own workshop, nor is it my intent to express any doubt that you have experienced what you have experienced. 

My only intent is to make my fellow hobbyists aware of a potential danger before they are unpleasantly surprised by it. What has worked for you, in your workshop, with your ventilation arrangements, and your particular ultrasonic bath, may turn out differently for someone else working under different circumstances.


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