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  1. Member Since
    Aug 2012
    Messages
    394
    Sep 21, 2016, 12:12 PM - Model Kits with micro grain surface texture? #1

    Back when I built the old AMT Star Trek kits, most of the time the plastic was so smooth you could see a pretty good reflection in it. I've noticed some starship models from R2 and Revell have some micro grainy surfaces. I didn't think this would be a problem, but I lay down my coats so thin that I can see the grain through the primer! On something like a 1:1000 starship, this just can't be. The surface must be 100% perfectly smooth. Any tips on how to polish the plastic to get a nice smooth surface? Any primers that will fill in this micro texture without sacrificing kit details? Why are kit manufacturers using this type of plastic instead of the glossy smooth kind? You can see the micro graininess I'm talking about here...




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  2. Axlotl's Avatar
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    Sep 21, 2016, 12:34 PM - Re: Model Kits with micro grain surface texture? #2

    Maybe they're using a new kind of mold-release agent.
    In the old days they used a kind of oil, hence why we got in the habit of cleaning our parts with dishwashing liquid.
    Maybe they use some kind of silicone agent now, that somehow textures the plastic.
    Just guessing - I really have no idea.

    As for eliminating the texture, I don't think there's any way to sand that. Not efficiently, anyway.
    What if you coated it with Future before painting? Think that might smooth it out?
    Last edited by Axlotl; Sep 21, 2016 at 12:41 PM.
  3. star-art's Avatar
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    Cascade Mountains USA
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    Sep 21, 2016, 1:21 PM - Re: Model Kits with micro grain surface texture? #3

    I suspect that's not the plastic but rather the mold. It's probably been sandblasted as part of the finishing process. This is also commonly done to older steel molds when they rust. It results in softening of detail that used to be crisp and sharp. This is why older pressings of model kits tend to have sharper detail than newer "re-pops."
  4. Richard Baker's Avatar
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    Nov 2015
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    Sep 21, 2016, 1:58 PM - Re: Model Kits with micro grain surface texture? #4

    star-art said: View Post
    I suspect that's not the plastic but rather the mold. It's probably been sandblasted as part of the finishing process. This is also commonly done to older steel molds when they rust. It results in softening of detail that used to be crisp and sharp. This is why older pressings of model kits tend to have sharper detail than newer "re-pops."
    Except this appears to one of the new TFA kits which should be a pretty fresh mold.
    Weird thing is that the Sprue is glossy, it looks like that special micro-texture was intentional.
  5. newmagrathea's Avatar
    Member Since
    Jan 2014
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    Kansas City MO
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    Sep 21, 2016, 3:55 PM - Re: Model Kits with micro grain surface texture? #5

    Maybe they used a 3d printed piece to cast the mold. I would just use a very fine sand paper on the surface. Or use a thicker primer first like Mr. Surfacer 500 and then lightly sand it.
  6. TazMan2000's Avatar
    Member Since
    Nov 2009
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    Sherwood Park, Alberta, Canada
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    Sep 21, 2016, 4:37 PM - Re: Model Kits with micro grain surface texture? #6

    Unfortunately anything you do to smooth out the textured plastic will have some effect on the detail. I would use a good primer with scratch filling properties to try and reduce that texture. I don't have any recommendations of products, but perhaps others will chime in.

    TazMan2000
  7. Member Since
    Jan 2016
    From
    Toronto
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    Sep 22, 2016, 12:25 PM - Re: Model Kits with micro grain surface texture? #7

    Try using a Dremel with a Nylon bristle wheel.
    If that doesn't do the job, switch to a Steel bristle wheel.... I suggest trying this on a piece that you don't mind destroying.
    I used a steel bristle wheel to strip the rubber coating off my computer mouse. I thought it would destroy the mouse, but it actually did practically nothing to hard plastic. The rubber stripped easily. Wear a face mask though. Gets very messy with powder bits everywhere.

    I've never tried it on a model kit before. The plastic may be too soft though. Could be a disaster... Try the Nylon bristle wheel first.
  8. Member Since
    Nov 2001
    From
    Langhorne, PA - just outside of Philadelphia
    Messages
    2,149
    Sep 22, 2016, 1:09 PM - Re: Model Kits with micro grain surface texture? #8

    It was likely done on purpose to get a Matte effect on unpainted plastic for children just building the things straight from the box... at least on the Kylo Ren Shuttle. When PL did it on the 1/350 E I thin it was just to **** us off... I've not see it on their other kits - although I admit I don't have all of them.

    I removed it on the PL E with light sanding and several light coats of primer. but that was a essentially flat surface... on the detailed surface of the shuttle - Not sure - sorry that's not helpful...

    Jedi Dade
  9. Richard Baker's Avatar
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    Nov 2015
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    Sep 22, 2016, 1:16 PM - Re: Model Kits with micro grain surface texture? #9

    I have seen this done selectively- some parts on a military or auto kit getting this 'special' finish...

    I will be watching this thread (and the others started on the different forums) to learn more and find out if there is a way around this issue...

    Best of luck!
  10. Member Since
    Aug 2012
    Messages
    394
    Sep 22, 2016, 3:01 PM - Re: Model Kits with micro grain surface texture? #10

    Richard Baker said: View Post
    I have seen this done selectively- some parts on a military or auto kit getting this 'special' finish...

    I will be watching this thread (and the others started on the different forums) to learn more and find out if there is a way around this issue...

    Best of luck!

    Although I haven't finished yet, last night I knocked down the surface texture with 600 grit sandpaper. This got rid of the texture and "potholes". I hope to now spray these pieces sometime this weekend with Alclad gray primer & microfiller. This...in theory....should even out the surface to be smooth. We'll see. Tamiya Fine Primer also has microfiller.
  11. rbeach84's Avatar
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    Sep 24, 2016, 7:57 PM - Re: Model Kits with micro grain surface texture? #11

    Probably the finish was introduced on the molds using spark erosion machining techniques. I think the previously mentioned idea of keeping the unpolished mold was to give a consistent matte finish to the unpainted plastic, which might be appropriate for the ship in the movie. I just can't recall if it was shiny or not... looking into the archive for that hi-def render, it appears in the movie it was shiny, giving a metallic sheen.

    So, got a lot of polishing ahead... using a bit of Scotchbrite sanding/scouring pad might help.

    R. Robert

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