CSS Hunley by Renova

Discussion in 'Ship & Watercraft Models' started by cdavenport, May 5, 2008.

  1. cdavenport

    cdavenport Member

    Renova CSS Hunley

    When I learned this model was released I just had to have one (actually two). I have a couple of other resin kits but they are somewhat inaccurate. Renova’s kit seems to be based on the latest information available. I live about about 5 hours from Charleston, SC and have seen the Hunley under restoration. So, it was with great anticipation that I began this project.

    You will find my text keyed to numbered photos as if you were reading a zine article. Also, I will share some equipment choices and techniques with you. Though I cannot design like some of our more prolific forum members, I have a varied base of experience in materials, techniques, and processes to share. Though I have started this as a naval thread, you will see I used techniques applicable to other subject areas, too.

    Photo #1 Eschewing the shot of the packaging and parts, I’ll start straight with the build. First, I have seen reported a number of problems with 1mm cardstock warping. The simple answer is to stop using the 1mm cardstock we routinely associate with paper modeling and switch to mechanical board, sometimes called “illustration board.” Go to dickblick.com and search for “LetraMax 2000 mechanical board.” It will cost about $7.00 plus shipping for a sheet 30” x 36” that will last many models. Save shipping and go to your local art supply house. The product does not warp. In fact, I have a supply that I have been carrying around the world since the middle 80’s that suffered a bit of water damage recently. The area not affected is perfectly fine; in fact, I used it for this project. It measures a tad over 1mm thick and can be delaminated. However, under regular use, it does not delaminate, fray or exhibit any of the undesirable qualities normally associated with cardstock. I assembled the bulkheads with Tacky Glue. Notice that the edges of the bulkheads are colored. You’ll learn why shortly.

    Photo #2 In a departure from normal building procedure and taking a cue from the RC guys, I am cutting sections of closed-cell Styrofoam to size to fit the spaces between the bulkheads. I use the foam in which computers are packed. It is light, dense, and very strong. I am using the “Hot Wire Foam Factory” kit which includes a number of useful accessories to cut the foam. The heated nichrome wire cuts through foam like, well, a hot knife through warm butter.

    Precision is the watchword here. I want the foam to fit exactly. If I cut too small, I have to backfill the gaps (acrylic spackle); too large and I force the bulkheads out of square. Fortunately, the hot wire technique is so precise that I can shave off pieces that are a few thousandths of an inch thick if the need arises.

    Photo #3 This close-up shows that I have ensured the wire is square with the table. Additionally, I use a draftsman ruler as a fence to ensure precise and constant cuts. Any straight-edge will do. You can make your own hot wire cutter with some wood, a motorcycle battery and 30AWG nichrome wire purchased over the Internet.

    Photo #4 Using Elmer’s White glue (PVA glue) to adhere Styrofoam, this is what the hull looks like. It took a few hours to do this, working continuously, but you are going to see that this extra effort up front is going to pay off in spades later!

    Photo #5 Using one of the accessories in the Hot Wire kit, I am roughly removing the excess Styrofoam using the bulkheads as a guide.

    Photo #6 With an aluminum T-bar and 50 grit sandpaper, I roughed the Styrofoam down and finish sanded with 180 grit. This is where the colored bulkheads come in handy. The second I touch and edge, the color comes away indicating the limit of my sanding. Once complete, the hull is rigid.

    Photo #7 The reason for the Styrofoam is three-fold; first, it gives me a solid surface onto which I can glue the hull plates WITHOUT backing strips. Second, the foam undersurface prevents sagging of the paper between bulkheads. Real ships do show evidence of this but usually only after sea duty. Nevertheless, in the scales we build, that sagging is really over stated. Finally, having a solid hull allowed me to really muscle the paper into place minimizing any seams. I used some simple tools, mainly a wooden ruler, to make sure adjacent seams were perfectly flush with each other. The foam carried the load!

    More importantly, the Hunley was flush riveted and quite smooth. I didn’t want to see bulkhead bulges and sagging plates.

    Photo #8 The proof is in the pudding. There are several seams here. Judge for yourself. This technique actually saved time and effort. I completely covered the hull in about 5 hours, taking my time and carefully aligning hull plates.

    General notes:

    1. The Renova CSS Hunley is excellent value for the money!
    2. The parts fit is superb, in particular the hull plates.
    3. There are three main plates in addition to bow and stern plates. Each plate is designed as one wrap-around piece. I recommend cutting each main plate into an upper and lower plate. It is easier to adhere and align them this way. The bow and stern plates are best assembled as is. Their fit is almost perfect requiring just a little filler material.
    4. Speaking of filler material, the kit includes extra black and copper color sections for any eventuality that might arise. I used a bit of the black to fill in areas not completely covered by the bow and stern plates.
    5. God willing and the creek don’t rise, I’ll have her complete in a couple of weeks for your perusal.


    Attached Files:

  2. cdavenport

    cdavenport Member

    CSSHunley part 2

    Here are the last two photos

    Attached Files:

  3. cgutzmer

    cgutzmer Guest

    Nice work! I merged the threads for you :)
  4. cdavenport

    cdavenport Member

    Thank you for doing that. I'll remember the six photo limit next time.
  5. cjwalas

    cjwalas Member

    This looks like it's coming together beautifully. I almost strated this one last month, but real life said no.
    I love the raised rivets on the cover photos on this one, but as you point out, they aren't very realistic. I look forward to the rest of your build on this one. Please post plenty of photos along the way. I suspect this model is on a lot of people's "to do" list!
  6. B-Manic

    B-Manic Peripheral Visionary

    This one is definitely on my build list. Interesting technique with the foam. The build looks very nice. Putting on x million rivets should be fun ;). Do you plan to paint it ?
  7. redhorse

    redhorse Member

    Thank you very much for the tips. I do like this foam technique, the hull looks great!
  8. lriera

    lriera Member

    WOW, I also have this one in my ToDo pile. I will follow your thread with a lot of interest.

    Thank you for the tips and the advices.
  9. cdavenport

    cdavenport Member

    I have been pondering what to do about the rivets; Renova rendered them in a slight grey tone to contrast with the black iron of the hull. Whether the hull plates were cold or hot riveted, the conservators have not yet indicated. Nevertheless, the rivets would not have differed much in color from the surrounding hull plates.

    There is also no indication that the hull was painted to prevent rust, but it stands to reason that they did. History indicates the builders intended the Hunley to be used to break the blockade, not act as a one-time weapon of suicide. Paint seems logical. It also seems logical that the paint would have further obscured any flush rivet detail.

    However, if I paint the rivets out, then I am left with a featureless blob. I have some time to consider how to deal with them. If any of you have ideas, please share them with me.

    As for the hull itself, I will clear coat it and do some shading and detailing to give it a little extra "life." More on that later.
  10. B-Manic

    B-Manic Peripheral Visionary

    When I build it it plan to paint it with Testors model master 1949 flat black spray paint (FS37038). A nice light coat with any missed spots providing the shading/texture. Maybe two coats on the top half as it would logically be the easiest to maintain. Have to wait and see. That and a bit of rust applied with a sponge tip brush ought to do it for me. Lots of time before I get to it though.
  11. cdavenport

    cdavenport Member

    There is an excellent website run by Michael Crisafulli, The Hunley where he reconstructs the Hunley in interactive 3D using the latest available information.

    I checked with him to learn that the hatch coaming flanges show evidence of raised rivets. He also indicates that the hull was still black once the sediment was removed. Obviously, paint was not used. However, the original flush rivet detail was barely discernible, which means that a scale model should show none at all.

    I may wind up painting mine. I'll decide in a bit.

    For Nautilus fans, Crisafulli's website is a visual and informative feast!
  12. cdavenport

    cdavenport Member

    I like the idea of mist coats, but curiously there wasn't much in the way of rust at least in areas you would expect. The speculation is that Hunley was built with used boiler plates which would have been readily available in Mobile from a nearby boiler manufactory. Since metal preservation techniques were well known at the time, I am wondering if the plates had some rust-preventive treatment.

    I think I will build my model in prisitine condition with some shading to bring out highlights.
  13. Millenniumfalsehood

    Millenniumfalsehood Active Member

    For the rivets, may I suggest spraying the entire hull in gloss and then painting the rivets flat black or satin black? This would make the entire hull black and the rivets would be descernable as a subtle yet pronounced way to break up the hull. Its your call, but that's how I would handle it.
  14. B-Manic

    B-Manic Peripheral Visionary

    You might want to check ou the "Friends of the Hunley" site Friends of the Hunley they have great pictures of the excavation and other information. It is the official site of the Hunley Commission that was created by the State of South Carolina to acquire, recover, and preserve the H.L. Hunley submarine for public display. You will see in the pictures that no miracle metal preservation was used. The amount of corrosion might explain the low profile of the rivets as the rivet's surface structure would be changed by the installation process.

    btw - I like your idea fo a pristine, just drove it off the lot look and await more pix of your great build. :thumb:

  15. cdavenport

    cdavenport Member

    I have been using the Friends of the Hunley site extensively. Thanks for that.

    I like that idea about highlighting the rivets with different finish coats. That's a good one. I think I have figured out how to do it easily by creating a punch mask and laying it over the hull and spraying the rivets last. In fact, that's what I am going to do.

    Since I have two kits, I have all the original rivet patterns that I can copy and punch. Great idea!
  16. cdavenport

    cdavenport Member

    Hatches and other details

    I am working on all the various subassemblies. In this photo, I am using the Reheat Models Precision Punch and Die set to punch out the viewports on the fore and aft hatches. Mike Crisafullis' site indicates that Renova got the viewport placement for the captain's hatch right on money. My intent is to allow light to bleed through the viewports for that extra touch of realism.

    The subsequent photo comes courtesy of Mike and clearly shows the raised rivet detail on the coaming flange. Notice the thickness of the flange? Renova got this wrong. The two flanges need to be thicker than the supplied printed parts. No worry, I'll just do a bit of laminating to get it right. I'll shoot a photo and show you how I did this.

    Attached Files:

  17. cdavenport

    cdavenport Member

    CSS Hunley by Renova, Pt 2

    1. In this next installment, I am preparing to construct and add the two hatches. Because the real coaming flange is a thick object, notwithstanding the concretization that has yet to be removed, the Renova part is too thin. In order to prevent any cupping or creasing of the part I laminated it to a new part that I formed by laminating two pieces of card together on top of the completed hull form. Notice that I stretched Saran Wrap around the hull to prevent any damage to the hull. Notice also the registration line that allows me to align the printed part to my laminated part. Once I glued the Renova part to the preformed part, I simply glued the whole shebang into place.

    2. The next photo shows a close-up of the coaming flange with the hatch and conning tower in place along with the other fitments. Notice the light coming through the view ports. I glued the flange to the hull first, then added the conning tower after ensuring all mating edges were flush. Renova included one bulkhead at the top to shape the tower. I added another at the bottom, which made for a rigid part, easily aligned and mated to the flange.

    3. The next shot is an extreme close-up showing the compound curves of the hatch cover. This is a scratch built piece that eliminates the use of the Renova part and, therefore, the appearance of any cutlines. I am working with cgutzmer to try to upload an mpeg video to demonstrate the basic process of rolling paper to achieve compound curves.

    4. The final shot shows the hull with both hatches and the keel ballast installed.

    Comments: All of the parts fit perfectly with only minor trimming needed. To fit the conning towers to the coaming flange required a swipe of sandpaper to ensure the surfaces mated perfectly. Secondly, I added cardboard reinforcement to the keel ballast even though Renova did not make any mention of doing so. Adding the card made the structure rigid which aided in attachment to the hull. It also gives me a solid base for subsequent mounting.

    Attached Files:

  18. B-Manic

    B-Manic Peripheral Visionary

    Great build - your attention to detail is impressive
  19. cgutzmer

    cgutzmer Guest

    Merged your threads together! Looking really good :)
  20. lriera

    lriera Member

    You are doing a great job. It really inspires me. When I begins the build of my model, I will follow your build as my guide.

    Thank you.

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