Painted on 'Oil-Canning' Effect, and some other Tricks

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12200

    Painted on 'Oil-Canning' Effect, and some other Tricks

    Oil-Canning is the dishing in of metal plate between frames and stringers -- this deformation of a ships sides and superstructure is almost always the result of prolonged wave action. Most metals are not terribly elastic and over time, when subjected to a repeated force in one direction will eventually distort in a direction along the path of the force applied. The only time you will see dishing, other than that caused by wave action, is in the case of air or foam filled spaces subject to underwater shock (explosions) or sever hull torsional stress (check out the under wing fuselage sections on old B-36's and B-52's to see torsion caused dishing).

    OK, now that I've laid out what oil-canning is and what causes it, lets look at one way to represent it on small scale models:

    Since a portion of hull/superstructure plate, boarded by stringers and frames, is pushed inward and adopts a concave complex curve, that surface, when subject to bright overhead light will cast a shadow on the upper portions of the plate, and a bright area low where the light source (Mr. Sun) can get to it. Careful masking and painting of a darker hull color up high and in the corners of each dished in area is an effective way to simulate this bright/shady disparity over the face of the plate.

    And that's just how I represented the dished in plating on the sail of the SKIPJACK. How do I know this? Simple: by researching the subject; by studying pictures I have of actual units of the class. The air filled spaces of the sail (on the surface) -- in heavy seas, over a few years of pounding, leaving and coming back to port -- dish in.

    You won't see this dishing on GUPPY-3 sails or portions of other GUPPY converted boats superstructures -- as those portions were built up from plates of GRP -- a material with a much better elastic memory than Iron alloy. Nor will you see this dishing on the German Type-212 and Type-214 boats (no matter how old they get, and how long they may wallow in the North Atlantic in winter); their sails and superstructures all almost entirely GRP.

    So, when representing oil-canning on your boat, know your subject, and study your research photos before simulating such dishing. And Don't overdo it -- less is more. In the shots you'll note that the initial oil-canning is way over-stated. Later, as I finish off the work, I'll give the entire sail a mist coat of the base 'black' color to tone down the oil-canning effect, making it more believable to the discerning eyeballs out there.

    You see my old reliable hull test article in some of the shots -- a discarded upper hull half from a Trumpeter 1/144 SEAWOLF kit. Note all the different effects I've tried out on this test article. Even today, employing now familiar techniques and mediums, I still make my first few passes of the day on the test article, just to get my head on straight before committing myself to the work at hand.

    You following all this, Albion?!

    The 1/96 SKIPJACK makes use of several cast white-metal pieces: the antennas, scope heads, sail induction screen, and zincs. These were all removed from the sprue, cleaned up, pickled in acid to make them receptive to primer, and then integrated with the other model pieces and painted as required.

    Sometimes I use water soluble paints for the vertical streaking effects -- simulating running water, which always follows the gravity line -- and sometimes, like today, I'll use oil paints. Each medium has its virtues and liabilities for this job: The water soluble paint goes down as stark, well defined streaks, but is unforgiving once dry; the oil paint tends to blend too readily, but is easier to wipe down and feather. If for whatever reason one of the two mediums won't work for me that day on the test article, I'll switch to the other... depends on my mood at the moment, not just my abundant talent.
    ________
    FORD XK FALCON HISTORY
    Attached Files
    Last edited by He Who Shall Not Be Named; 02-19-2011, 02:29 AM.
    Who is John Galt?
  • roedj
    Captain
    • Sep 2008
    • 559

    #2
    David,

    Two questions please,

    1) Where did you get the metal masks as shown in picture 12 of 12?

    2) This is probably clutter but this picture posting thing is driving me bats. Did you determine the order the pictures were posted as an attachment or did the machine do it for you and you took whatever you were given?

    Dan
    ________
    Bmw N52 History
    Last edited by He Who Shall Not Be Named; 02-19-2011, 02:29 AM.
    Born in Detroit - where the weak are killed and eaten.

    Comment

    • He Who Shall Not Be Named
      Moderator
      • Aug 2008
      • 12200

      #3
      Originally posted by roedj
      David,

      Two questions please,

      1) Where did you get the metal masks as shown in picture 12 of 12?

      2) This is probably clutter but this picture posting thing is driving me bats. Did you determine the order the pictures were posted as an attachment or did the machine do it for you and you took whatever you were given?

      Dan
      Those are acid-etch stainless steel scribing stencils produced by the Verlinden company, http://www.verlindenonline.com/store/ I got the one pictured about 15 years ago. In my application, I use them as painting masks.

      As to picture order: Man, I have no idea how to get those damn pictures in any coherent order for you. Also, I have not been able to figure out how to wrap the pictures within my text, something I really would appreciated being able to do. Mike has tried to walk me through the process, but I've not been able to master this aspect of posting here. Sorry.

      David,
      ________
      Continental
      Last edited by He Who Shall Not Be Named; 02-19-2011, 02:29 AM.
      Who is John Galt?

      Comment

      Working...