Photo Etched

Discussion in 'Questions on Kits, Decals, Tools and Pilots' started by KevinK., Nov 4, 2010.

  1. KevinK.

    KevinK. Member

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    I've seen them, and people here use them alot. What do they actually do? Are they just overlays?
     
  2. JohnAnthony

    JohnAnthony Member

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    They are basically small pieces that are used to augment the detail of a model. They are made by the precision cutting of a very thin sheet of brass called a fret. Here is an example of an extensive PE detail set...

    [​IMG]

    Depending on the set, the pieces can range from cockpit and other internal components to all kinds of externals: cowl flaps, engine wiring, antennas etc. They are intended to add a level of complexity and sophistication to a build.
     
  3. Wurger

    Wurger Siggy Master
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    Unfortunately the plastic injection technique for making parts for models has a few kinds of limitation to a couple of areas. One of these areas is accuracy of details.. Therefore the photo etched parts appeared. The way of their making allows to get a much better precision of details. However the techique of making details has limitations as well. The photo etched parts are made of brassy plate. And it isn't possible to make objects that are of circle-shape in cross-section, for instance wires, thin pipes.But other parts are really of nice accuracy.In other words, you can replace all these crude plastic details with PE parts making a great looking cockpit interior for example. The photo etched sets let you add more details to plastic engines, wheel bays, landing gear legs etc....as well.
     
  4. JohnAnthony

    JohnAnthony Member

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    Frequently the pieces have to be bent in specific ways to get them into the right shape, and they are generally very small, so you are working on a microcosmic level - a good magnifier is crucial. Also, ordinary model glue does not work on PE - you need to use a CA adhesive like superglue or an epoxy resin.
     
  5. Wurger

    Wurger Siggy Master
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    And a few shots of PE using... pics via the Internet
     

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  6. Airframes

    Airframes Benevolens Magister

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    Good explanations, and great pics too, Wojtek.
    I'll add to what Wojtek said; the main reason for photo-etched parts is to be able to produce small, thin, and delicate items, which would not only be beyond the capabilities of plastic injection moulding, but, even if they were able to be produced in plastic, would melt or deform when they came into contact with most adhesives, such as polystyrene cement, due to being so delicate and of 'soft' material.
    The process, an off-shoot of the PCB industry, is quite simple. A drawing of the parts is transferred to a film negative, which in turn is then exposed, in contact, to a brass, or steel sheet, coated with a metal-etch resist, which is photo sensitive. The exposed metal is then immersed in an etch bath, which etches away the unwanted areas, leaving the same design, in '3D', as the original drawing. End result - a photo-etched fret of parts, ready to cut and bend.
     
  7. KevinK.

    KevinK. Member

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    Ok, my 2nd question would be. Resin parts. They are just add more detail but in larger pieces. So photo etched parts are added to the model, and the resin peices would replace whole parts? ie.. There wouldn't be etched parts for a cockpit seat, but a resin seat could be used in the original's place. Correct?

    Ok, just thought of a 3rd question. Paint and painting techniques would not differ using photo etched or resin parts correct?
     
  8. Matt308

    Matt308 Glock Perfection
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    Clean and prime first. Always.
     
  9. Airframes

    Airframes Benevolens Magister

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    I agree with Matt re photo-etch and resin parts - both must be cleaned, and then primed, and then can be painted as normal.
    Resin parts are normally, but not always, conversion parts. For instance, a different shape of wing or engine cowling, to change the Mark of an aircraft, example Ju88A-4 to Ju88A-1.
    However, they can also be, for instance, cockpit side walls, with more detail than that provided in a particular kit, and possibly to correct errors. Others can be better detailed individual items, which will also be more accurate, such as wheels, exhausts etc. This is due to the limitations of the plastic injection moulding process again, but in this instance, due to cost restraints versus the intended retail price of a kit. For example, plastic injection moulded exhausts can be made with hollow outlets, but this one item could double the cost of the moulding tool which might contain 50 other parts which don't require this part of the process.
    Yes, some seats can be and are made from resin parts, but they can also be made in photo-etch, depending on the shape of the original, for even better finesse, but these will require bending and assembly.
     
  10. Night Fighter Nut

    Night Fighter Nut Well-Known Member

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    For a good example of use go to the group build section and watch what some people do with resin and PE parts. It's very educational. :)
     
  11. KevinK.

    KevinK. Member

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    I have been watching the groups with interest. Thanks for all of your help guys!
     
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