1:72 Los Angeles

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  • spankey
    Lieutenant Commander
    • Aug 2010
    • 103

    1:72 Los Angeles

    I’m just starting my latest project… a 1:72 Los Angeles Class Fast attack boat. The boat is a whopping 60 inches long (without the screw), with a 5.5” beam. She’s going to get some real attention when she puts to sea in Lake Washington!
    I still haven’t decided which flight boat to make this thing. Having been to sea on the SSN 714, USS Norfolk, that boat is a prime candidate, but I’m debating the merits of the increased controllability of the flight 3 boats with the retractable bow planes. I welcome anyone’s thoughts on this.
    This hull is from Lee Upshaw at the Scale Shipyard. He didn’t have the 1:72 LA hull in full production, so the hull has the bottom scribed already but the top is not scribed. The Escape trunks are molded into the upper hull half, so that’s good.
    The fiberglass layup on this hull is excellent. After having seen some other fiberglass work on stuff like this, I’m quite pleased. The thickness is good, not too floppy.
    My camera is being borrowed, so I cant send any photo’s out yet, but they will be forthcoming.
    I’m getting all the scribing marks/detail from the top of the hull drawn up in Autocad, and then that’ll be printed on Mac-Tak type paper, and will be used to make a scribing template. I also welcome any advice on scribing.
    More to follow…
  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12254

    #2
    How the fit of the upper to lower hull?

    (Break out the Bondo)

    David,
    Who is John Galt?

    Comment

    • spankey
      Lieutenant Commander
      • Aug 2010
      • 103

      #3
      YES!! I will become intimately familiar with Bondo! I've been reading as much as I can about the best ways to do that (as cleanly as possible). I will use the standard 'Z' cut, I have just been debating where to make the cut... The most logical place in the Bow is at the seam between the Fiberglass/GRP sonar dome, and the Steel hull, but it might work further aft, where the fluid flow is not transitioning onto/around the nose cone. Thoughts?


      Daniel-
      Last edited by spankey; 07-29-2011, 09:40 AM.

      Comment

      • SSBN659
        Commander
        • Feb 2009
        • 405

        #4
        I'd go with the most logical place, i.e., the seam where the nose cone meets the parallel mid-body. With a good cut and a backing strip at the cut your Bondo will make the seem almost invisible. Don't over engineer it. As David said, your big problem right now is to get the upper and lower hull to fit. Good luck.

        SBN659

        Comment

        • spankey
          Lieutenant Commander
          • Aug 2010
          • 103

          #5
          Yeah, as I inspected things more carefully, If I tried to make the Z cut in the bow any further back than the sonar dome, I'd be cutting through the FWD MBT flood holes, which is possible, but a recipie for breaking them later...

          I scribed parts of the safety track in last night. Had a little trouble with my thick plastic templates....I had to shift over to my metal rulers/scales, as the plastic stuff began to shift. Filler here I come, then gobs of low grit sandpaper...

          Right now the two hull halves are taped together with the blue painters masking tape. This stuff is great for all sorts of stuff. The two hull halves dont have any interfacing trouble. As you get closer to the bow, the halves do begin to separate up to about 1/16". I honestly dont expect this to be too much trouble once I make the cut near the bow, and glass the lower sonar dome half to the upper hull half.

          Like David said, there will be bondo work to do, but I should be able to survive. Speaking of bondo, I wondered if that was the right stuff....or are either of these two products better? (Nitro-Stan or Evercoat)

          Dont fear...pictures are going to be coming soon! The camera accidentally went with my sister after she got married.

          Comment

          • ADDINGTON
            Lieutenant
            • Sep 2008
            • 80

            #6
            I built and later sold a 1/48 Scale Shipyard LA years ago. I split the hull at the painted waterline. The color change and any scum/weathering band really hide the break and no nasty midline seam to obsess over. Of course, you'll need to check and see if in 1/72 you have a wide enough opening for your SubDriver, and access to the rear cone and control linkages could get tight in that scale. I know this all sounds nuts but a big nuc hull with no midline seam is one nice sight.
            -Kerry
            Last edited by ADDINGTON; 07-14-2011, 08:21 AM. Reason: grammar

            Comment

            • He Who Shall Not Be Named
              Moderator
              • Aug 2008
              • 12254

              #7
              The word, Bondo is to fillers what the word, Kleenex is to nose-wipe.

              Yeah, The Evercoat brand of two-part fillers is the way to go. Use their Metal-Glaze -- great stuff and won't clog files and sandpaper like Bondo.

              Get filler and putty from Caswell or we will track you down.

              Sounds like you got one of the rare 1/72 hulls that is not warped -- count your blessings.

              Kerry's a crazy man!

              Go get 'em, Tiger!

              David,
              Who is John Galt?

              Comment

              • spankey
                Lieutenant Commander
                • Aug 2010
                • 103

                #8
                So I did some quick math in CAD, and found that with a waterline cut on that sub, I'd have 4.873" of space from 'gunwale' to gunwale' [if you will]. Round that down to about 4.5" after a joining lip, and I guess I'd still have enough room for one of david's 3.5 subdrivers. I suspect that I may need to get a longer section of Lexan cylinder, and stretch the ballast tank on that 3.5" SD. Anyone have thoughts on that? I'll have to figure out how much mass I'll have above the waterline, etc...

                Whats the best way to make a waterline cut, and have the two halves go together? That is very much new to me.

                David, I'm all the way out in Bremerton....I dont think I can wait that long for the Evercoat to come! I just got one of your Revell viic fittings kits, and will be getting a SD for it shortly, so dont worry, I havent forgotten where to send my money!

                Comment

                • He Who Shall Not Be Named
                  Moderator
                  • Aug 2008
                  • 12254

                  #9
                  Use the same cut-off saw arrangement I showed in the GATO presentation.

                  Don't worry, the 3.5 SD's now come as a 'kit' with nearly a 30" long length of tube that you cut to suite your specific ballast tank volume.

                  David,
                  Who is John Galt?

                  Comment

                  • spankey
                    Lieutenant Commander
                    • Aug 2010
                    • 103

                    #10
                    Thanks, that sounds like the ticket.

                    Does anyone out there have any pictures of a nuke boat that has been cut at the waterline? I was just skimming the Gato presentation of David's, and it might work, but pictures of a nuke boat that had a waterline cut might give me some courage!

                    Comment

                    • He Who Shall Not Be Named
                      Moderator
                      • Aug 2008
                      • 12254

                      #11
                      Originally posted by spankey
                      Thanks, that sounds like the ticket.

                      Does anyone out there have any pictures of a nuke boat that has been cut at the waterline? I was just skimming the Gato presentation of David's, and it might work, but pictures of a nuke boat that had a waterline cut might give me some courage!

                      OK, stop right there!...

                      ... You don't want to separate the LA hull at the waterline, and here's why: American submarines, since the SKATE class, have given up a great deal of their reserve buoyancy to go the 'single-hull' route (a very bad call in my opinion). The consequence is that the boats from SKIPJACK on up don't have the constant double-hull void space in which to put to use as ballast tanks. The Soviets still retain the double-hull feature and they have boats with at least a 35% reserve buoyancy. American submarines are now blessed with only a 10-15% reserve buoyancy. Put an LA up against a VICTOR-3. Now, punch a hole in the center of each boats engineering space. At the end of the day you'll find the VICTOR-3 at its pier. Bag-pipe time for the LA. That's how important reserve buoyancy is: can you flood a main space and still make the surface? They can. We can't.

                      What does that mean to you? It means that your very un-cork like LA has a waterline only ten or so feet from the top of the hull. In 1/72 model terms that puts a horizontal separation plain on that cylinder/hull of yours that is hardly wide enough to push and pull a SD in and out of its interior, nor at all willing to let fat fingers in there without biting!

                      Don't break this model at the designed waterline. No room! (Damn you, Kerry!). You don't need courage here. You need brains.

                      Break the upper and lower halves where they break now ... at the centerline. And that's already been done for you. OK, so you get a nasty looking separation break line; minimize it by good filler and sanding work. Suck it up! Man up and live with the seam!

                      Oh, by the way: If you paint this thing as an operational LA (not pre-deployment) the black-red demarcation line is at the centerline, hiding the break. Take THAT Kerry Addington! HA! ... in your face!

                      I have spoken, so let it be written!

                      David,
                      Who is John Galt?

                      Comment

                      • spankey
                        Lieutenant Commander
                        • Aug 2010
                        • 103

                        #12
                        That loud noise we just heard was the sound of David's close air support potentially keeping me from getting overrun in the jungle!

                        Fair enough on the dimensional issue of the hull being too small to work inside of. I still curse the times that I have to work on the tailfeathers of your 1:96 Skipjack! Thats tough back there!

                        You pointed out another point that I was trying to rectify....the paint line. The 688 boat's i've seen have had no red anti-fouling paint at the waterline...It was at the centerline, so I wondered what the story was there. I've seen pics of the Greenville in Drydock, and she had the anti-fouling at the centerline.

                        Either way, I'm on a learning curve for this boat, so thanks all for the input!
                        Last edited by spankey; 07-29-2011, 09:42 AM.

                        Comment

                        • He Who Shall Not Be Named
                          Moderator
                          • Aug 2008
                          • 12254

                          #13
                          Anyone who can get their pinkies (or tools) into the ass-end of a 1/96 SKIPJACK has my respect.

                          Up till the Navy went with all-black hulls, the anti-foul red went up to the waterline when built, working up, commissioning, and pre-patrol house-keeping. Dry docked around the time of acceptance, the red anti-foul-black demarcation went from waterline down to the centerline and stayed there -- this to make the boat less observable from air and space.

                          Most glamor photos of a boat (the ones likely to grace the pages of a magazine article or book) are when it's fresh from the Yard; at a time when it still has the protective coating applied to all below waterline portions of the hull and appendages.

                          David,
                          Who is John Galt?

                          Comment

                          • spankey
                            Lieutenant Commander
                            • Aug 2010
                            • 103

                            #14
                            Update

                            So here are some pictures. Had a little trouble getting some of the detail to show up.

                            The scribing...Dont beat me up on it too bad, I'm correcting a number of problems right now with the Evercoat Metal Glaze.

                            I've never done scribing on a model like this, so its a big learning curve. Being the engineer I am, I'm running into the trouble with wanting perfection...

                            Hopefully these pictures come through ok.Click image for larger version

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                            • He Who Shall Not Be Named
                              Moderator
                              • Aug 2008
                              • 12254

                              #15
                              Originally posted by spankey
                              So here are some pictures. Had a little trouble getting some of the detail to show up.

                              The scribing...Dont beat me up on it too bad, I'm correcting a number of problems right now with the Evercoat Metal Glaze.

                              I've never done scribing on a model like this, so its a big learning curve. Being the engineer I am, I'm running into the trouble with wanting perfection...

                              Hopefully these pictures come through ok.[ATTACH=CONFIG]8697[/ATTACH][ATTACH=CONFIG]8698[/ATTACH][ATTACH=CONFIG]8699[/ATTACH][ATTACH=CONFIG]8700[/ATTACH][ATTACH=CONFIG]8701[/ATTACH][ATTACH=CONFIG]8702[/ATTACH]
                              Pictures came out fine. Awful application of the filler. Next time use a putty knife so you won't have so much over-fill to knock down with file and sanding block. Oh, and when you fill engraved lines: you need to cut into the bad engraving with a scratch-awl or you won't reach the still residing mold-release agents. Failure to do so risks future masking tape application and removal pulling out your fill from the bad engraving work. Also, the fill of choice is CA adhesive, not a two-part filler.

                              I don't remember that class having five ballast tanks in the forward group. Tell you what, send me your address and I'll send you a set of proper drawings for the Flight-1 and Flight-2 and 3. How about that? Then you can enlarge them to scale and do a proper scribing job!

                              David,
                              Who is John Galt?

                              Comment

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