Working up Joel's Excellent 1/72 PERMIT

[He Who Shall Not Be Named]

This shot of one of the early THRESHER class boats, likely the PERMIT. It illustrates just how grungy the topside areas of hull can get. Most of it the result of rain-water -- mixing with dirt, oil, ash, and other crap -- running down the sail, upper rudder and hull. The result is the streaking you see here. Also, another source of such streaking is the occasional dumb-ass who spills milk, paint-thinner, hydraulic oil and the like as he trips over a mooring line.

So, don't get your nuts in a bunch when you examine my work and assume I've 'overstated' the weathering. Trust me, American and even Japanese (true fanatics when it comes to post WW-2 ships husbandry) submarines get dirty.

The radial streaking is represented by the dry-brushing I described previously and by the air-brush you see being used here. Stark and soft forms of streaking that together render a very credible weathered look to the round hull.

Most of the radial streaking on the hull done I masked off the area on the deck and sail planes where Sailor's walk, this area -- on the real boats -- is coated with non-skid, a very rough textured substrate that affords plenty of traction. Though the same color (black) as the rest of the hull, the rough surface bounces light a bit differently and appears as a very dark gray to the observer. Using Greg Sharpe's excellent THRESHER/PERMIT drawings, I laid out the non-skid demarcation lines onto the model. Greg's drawings you can see just below the model.

I first lay down a mask over the area where non-skid will be represented with a dark gray -- this to guide me on where to put the outboard elements of masking tape. Trust me, it's easier to get things symmetrical this way.

I then applied the actual masks following the edge of the inboard pieces of masking tape. Note that the upper faces of the two sail planes (fairwater planes to some of you) also had patches of non-skid.

You likely wonder how I achieve the circular mask elements. I either use a modified compass -- one leg of which has been ground to a knife edge, or brass tube punch-cutters. Masking consists of either long strips of masking tape, sections of circles, or full circles. Easy.

I took the pre-mixed very, very dark gray hull black (not a true black for a model, there is this thing called 'scale-effect' you have to account for) and doped it with some white to achieve the contrast between non-skid and rest of the hull. I've started to peel back the masking tape, revealing the slight contrast between non-skid and hull.

[He Who Shall Not Be Named]

Once I had painted the slightly lighter shade of 'dark, dark gray' onto the hull and atop the two sail planes -- which represented non-skid -- I painted the two escape buoy fairings international orange.

When it comes to mixing paint colors I prefer to make my own -- all you need are the primary colors (Red, Yellow, Blue), black, white, and the metalics (silver and gold), along with a clear-coat. And you want a flatenning agent you can use with you paint and clear-coat systems. To work out the color you need you employ a 'color-wheel'. To identify a specific color to a military (US) specification, you need the appropriate paint-chip index.

Nothing to it.

The thing about the water soluble acrylic paints is that over time they will clump up and get gooey, even after you mix the hell out of the bottle. So, you shake the crap up as best you can, do you color matching in a little disposable cup, thin it with water till it looks like it will shoot out of the gun without too much trouble, then run it through a nylon stocking seive at least five times. For each bottle of paint, you want to put a drop of detergent dish-soap -- this but reduce the paints surface tension. This goes a long way in reducing the dreaded fish-eye once the sprayed paint hits the models surface. Do all this right and the paint is ready to shoot. You can't filter the mix too much ... look at all the gunk Ellies stocking stopped from getting into my little double-action air-brush!

This shot should make you appreciate why I made the escape hatch hold-down padeyes and down-haul cable sections removable -- it's much easier to mask and paint around those areas if such projects are not there to get in the way. Only after all the painting is done will I permanetly install those little do-dadd's, then touch-up paint them to blend in the glue smears with the rest of the work.

I'm an exhibit-maker from way back -- detail and exactness is everything to me. My customers were museums, defense contractors and private collectors. However, that's what made me so useless in the effects miniature making game -- my first love. I was too damn good at the craft to be much use to Hollywood! A place where good=time and time=money; a place where the uncritical camera lens, and slow film emulsions dictate what surface finish and detail can be captured; the work does not have to stand up to eye-ball scrutiny, not after after being distorted by the optical capture and projection machines of the day. My moment of clarity came after Ellie and I traveled West to find a job. A good man gave me the brutal facts of life during a job search in LA as I applied at Roger Corman's New World Pictures. The effects supervisor, Bob Skotak -- who had just finished Escape From New York -- told me: "Can't hire you, you take too long to finish things". I never looked back.

[greenman407]

Yep, thats what they tell me....Im too slow at everything. They want you to blow and go, Rip and Run

[He Who Shall Not Be Named]

Yep, thats what they tell me....Im too slow at everything. They want you to blow and go, Rip and Run

Yeup!

All you can do is ask them:

"You want it done fast, or do you want it done right? Pick ONE!!!!"

M

[JSSN700]

The effects supervisor, Bob Skotak -- who had just finished Escape From New York -- told me: "Can't hire you, you take too long to finish things". I never looked back.

Bob Who? His loss.

Jason

[He Who Shall Not Be Named]

Bob Who? His loss.

Jason

After he showed us the door, Mr. Skotak continued to correspond with me for several years -- he saw to it I got the job of restoring the 'return-pilot ship' portion of the Spaceship-1 miniature from Pal's The Conquest of Space. Though we eventually fell out of touch, Bob was always gracious with his time and thoughts. I learned so much from this man.

What he told us at New World were the hard facts of life in the effects miniature industry at that time -- he could have blown me off with some feel-good pap. But, no, he looked me and Ellie in the eyes and gave it to us straight. So, after that and similar interviews with those in the game over there, I terminated my leave from the Navy, went back to the East Coast and finished my career as a Diver. After retirement we formed D&E Miniatures and developed a line of static and r/c kits.

Yes, I eventually did some significant effects work, but it was pick-up work for Greg Jein, some consultation, and in one case, we helmed the entire miniatures job on an independent film.

... but, that's another story.

Bob Skotak is one of the good ones in my book.

David

[He Who Shall Not Be Named]

These are the items kept off-hull as I finished the detailing and applied the dry-transfers -- the draft markings, hull number, and ships 'name'.

Final weathering tricks included dry-brushing white oil paint to pick out sharp edges; radial streaking with ground chalk and oil-paint; and applying water-soluble acrylic paint to get the draft numbers to the same 'mung-green' as the surrounding areas of hull just below the waterline. All the work to detail the forward and after escape trunk areas with buoy down-haul cable and hold-down padeyes paid off -- turning an otherwise boring subject into something more representative of the 'real thing'.

I've learned over the years to leave considerable clearance between moving parts -- this to account for the inevitable build-up of paint, weathering mediums, and clear-coat. If you don't do this, things won't work! That round thing to the left is the mushroom anchor that fits aft, just under the starboard stabilizer.

When I made the anchor I put a 4-40 stud through its inboard center. This, and a 4-40 nut were used to hold the anchor up tight against the hull -- I like to keep as many appendages removable as possible ... you never know!

The anchor is another effort to make the display 'interesting'. Modern submarine models look like stupid black pickles unless you make every effort to replicate, on the model, the weathering the prototype displays as well as all the little details you can identify. Failing to do this, and the damned model winds up looking like a toy. Don't think so: Go to any regatta where I'm playing, and look at my models an the models of other, less gifted craftsmen.

Prosecution rests, your Honor!

I should have done more with the rows of zincs: stippled and dry-brushed white onto and around the zincs -- not that stupid primer-gray I have here. Damn!

Attaching the propeller, anchor, and two rudders took all of five-minutes -- good planning, careful design, and a rational assembly methodology go a long way in making an otherwise tedious exercise (model building) bearable!

The stern plane bell-cranks and rudder yoke came from my 1/72 SKIPJACK fittings kit -- that saved a lot of time.

I had the boat trimmed out and running well while it was in primer gray. So, while it's in paint and ready to go, the owner now has a ready-to-run r/c submarine to add to his fleet. Maybe a fine tuning of the foam and weight. Other than that, he's good to go.

This model employs a stock 3.5", single-shaft Sub-driver. I'm currently running my 1/72 SKIPJACK, and a 1/72 ALFA on identical type SD's.

http://www.sub-driver.com/sub-drivers/sas-sub-drivers-5/sas-1-72-moebius-skipjack-sub-driver.html

[greenman407]

Not just Beautiful Dave.....OUTSTANDING. I saved the 2nd picture into my files as one of the most perfect pictures Ive ever seen . I cant find a flaw in it, almost computer generated.

[He Who Shall Not Be Named]

Thanks, Mark. Yes, I'm damned good at this. Almost God-like, I would say.

[trout]

David,
The photo of the forward portion of the sub is excellent. I really like it for several reasons, the subject matter is (of course) superbly done, but also the well taken photo. It has a very nice diffused light, composition is appealing, and excellent exposure. It shows the details well too!
i keep going back to look at it.
When you cut the foam for the boxes, how do you get the correct profile. Is it simply a circular cut matching the diameter, or are you using a profile device? I am looking at my Gato and would like to do something like that.

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

Well, this thread is about a year-and-a-half stale. But, there’s new stuff to report:

Over the years I had the good fortune to contribute some work in support of Joel Stadnick’s line of 1/72 GRP and resin r/c submarine kits. Specifically, his incredible SEAWOLF and PERMIT.

I’m breathing new life into this thread – that dealt with an early version of Joel’s 1/72 PERMIT kit – to show off, in better detail, the propeller, appendages, and sail work. I’ve already assembled one of these kits for a friend. Now, it’s time for me to stick one together for my fleet.

As a reminder, here are some shots of the initial THRESHER I assembled from Joel’s first incarnation of the kit.

(Why do I depict the THRESHER instead of the PERMIT? Because THRESHER was the first of the class, and should always be regarded as such; to me, the series should always be referred to as, the THRESHER class, not the PERMIT class. THRESHER, and those aboard that boat, paid the check!)



The kit was an enjoyable assembly job. Unfortunately, other than a few trim runs while it was still in primer gray, I only had a few minutes of fun-time with the finished model before I had to hand it off to its new owner. That occasion was one of the fun-runs at the Groton sub-base North Lake.

But, those few minutes were a blast. This thing is FAST! And, maneuverable. The standard 3.5 SubDriver (SD ), originally designed for the 1/72 Moebius SKIPJACK model, provided more than enough ballast tank volume to get the beast up to designed waterline. It was hard turning this one over to a new owner.



Though a big model, the 1/72 THRESHER turns tight and depth control is assured and requires little attention to the fair water planes once trimmed out properly for submerged running.

The new work – for the upgrade to the kit – from my end involved creation of masters, tools, and parts for a new propeller based on source material (more on that later); a detailed sail with removable masts; and control surfaces and stabilizers.



My propeller and stern appendage work on display here. Joel’s kit parts were serviceable, but I felt a new set of parts would be easier to fabricate and integrate than trying to correct the small flaws in the original kit parts. The tooling for these parts as well as the sail tooling will be sent to Joel for integration in his new version of the 1/72 PERMIT kit.



The new control surfaces are well integrated with their operating shafts, yokes, and mechanical extensions -- the geared gizmo that links the fair-water planes to its pushrod, for example. A bit of a cheat here, most of those linkage items scrounged from my 1/72 SKIPJACK fittings kit … what worked for one works for the other. Why keep re-inventing the wheel, anyway?

THE PROPELLER

A recently started thread by Tom Chalfant questioned how model submarine propellers are made. His post reminding me that I had just completed such a task for Joel’s 1/72 PERMITS kit. So, killing two birds with one stone, I’m taking some of that discussion and photos to this thread.

Backing up even further in this story I should mention that the genesis of this particular model submarine propeller is the work of fellow modeler, Adam Carlson, who identified and shared with me an illustrated article describing the very propeller used by the THRESHER class and so many cold-war era American submarines. This once highly classified -- oft talked about, but until recently, little seen -- seven blade, large diameter, skewed back propeller IS what it’s all about!

That article can be studied here:

http://americanhistory.si.edu/subs/anglesdangles/taming6.html

The three big things I gleaned from this material are a definitive look at this wheel (a scale model) from the back with little if any offset of the picture plane; a dead-on side-view showing propeller rake; and notations as to the diameter of the propeller hub and diameter from the tips of the blades. Solid gold!



The pictures in that article were of a study model of the propeller, and one can assume subtle changes of pitch and profile as this thing went through the many iterations dictated by test results before brass was poured for the real things. Examination of photos tells me that this information is close to what the real wheels look like. It all became source material as I set about making propeller masters to the scales of 1/96 and 1/72.

Why the two sizes? I’m working up wheels for Kevin Rimrod’s 1/96 kit as well.

(So, when you read on about propeller and sail fabrication and you think your eyes are playing tricks on you, don’t worry. I’ve mixed in shots of both 1/96 and 1/72 S5W propeller master and sail assembly for you – the process is identical for each size).

And once I have cast white metal propellers in hand, they will likely find use aboard every 1/72 and 1/96 model submarine of an American combatant from SKIPJACK up to (but not including) the LOS ANGELES class. That’s a lot of submarines!



And here’s one of those screws hanging off the ass-end of either a 616 or 640 class boomer. Note that dried up marine-growth on both hull and screw make the two surfaces appear as one -- something to think about when weathering the model.

OK, enough background about the prototype. Let’s get on to model propeller manufacture:



Analyses of the graphic presentation of radius cord, from the blade chart, permitted creation of an accurate developed blade template, which was used to cut out the blade profile on the RenShape blank that would later be cut to shape.

The propeller blade chart – a graphic method of working out a propeller blades true developed profile and twist-angle at each radius point along the span of the blade – was used to define how I hacked out a single blade master of dense RenShape pattern making medium. As the blade master was worked it was periodically checked for correct helical twist with this cardboard gauge.

After it was finished, a rubber tool was made off it, and from that tool I cast the required number of blades, from white metal, to make the propeller master proper.



Working out the slot to cut into the side of the hub for the first blade is a bit tricky, but once done permits about 1/8” of blade root to project into the hub. This foundation insures a strong union between metal propeller and plastic hub.

[He Who Shall Not Be Named]

The completed blade master was used to make a BJB, TC-5050 silicon rubber mold – a material that can tolerate the 600-degree heat of molten white-metal (an alloy of 95% Tin, 5% Antimony).The alloy is sold in America as ‘leadless solder’. Ten or so blades were case. One used as hub root marking templates, the others as spares.

A hub was turned from RenShape and outfitted with a 3/16” shaft that permitted mounting of the hub onto the face of the blade assembly jig. Here I’m using an enlarged copy of the dead-on-from–the-rear photo Adam sent me of the museum model propeller. This guided me (along with a side-view of the propeller) as I installed a single blade to the hub, as I set rake and skew angle.

Note the use of a wedge to jack the blade up. Once in position it was glued permanently to the hub. Under this blade would be built up the blade alignment crutch, formed from two-part automotive filler. Succeeding blades would fit perfectly onto the crutch.



The blade alignment crutch insures that each blade goes to the hub at the identical rake, skew, and pitch as the first. I took one of the spare blades and trimmed away material from its root till the root was a flush fit to the hub. This blade becoming a template used to pencil mark the hub. Within each pencil mark on the hub I ground out a hole to receive the root of a blade. Baking soda grout filled any gaps between hub and blade.



Before casting the blade tool, I indexed the tip of the blade master with a notch. You can see it on some of the cast white-metal blades above. This indexing notch, aligned with a radial line on the jigs face, assured correct blade spacing.

A blade is placed upon the blade support crutch with its root projecting into the hole in the side of the hub. Baking soda (acting as a grout) is packed into the spaces between hole and blade and CA is applied, instantly bonding the metal blade to the hardened grout and hub. The propeller master rotated atop the blade assembly jig 51.5-degrees, and the process continued till all seven blades are attached to the hub.



And here’s what the still-in-the-rough propeller master looks like installed at the ass-end of Joel’s upgraded 1/72 PERMIT kit hull.



Note the indexing notches at the tips of the metal blades. These will go away during the finishing process. Enough play time! The propeller master was worked with filler, putty, files, knife, pickling, and primer till it was near perfect to the eye.



Pickling corrodes the metal. In polite circles the process is described as, ‘chemical milling’. The active chemical is an acid; I use Ferric Chloride (often used for circuit board etching). The acid oxidizes the metals surface producing a porous surface receptive to primer and paint. The nice thing is that the this acid only attacks the metal, not the polyurethane RenShape, CA adhesive, or putties and primer used to fabricate the propeller master. However, know this: the acid will do a number on your pinkies if you don’t use rubber gloves.

The dark areas on the blades are oxides of Tin and Antimony, indicating ware raw metal was revealed as putty and primer was abraded away as dings were filled, and bumps removed. The metal should be so treated before priming.



Nearing the end of the finishing phase, the propeller master gets one final coat of primer, readying the master for creation of the propeller production tool.



And, of course, I could not resist seeing how the nearly completed propeller master looked plugged into the stern of the hull. The sail and sail top masters are in foreground. More on them soon.



Tool making is its own very special area of discussion. For brevities sake let’s just say I employ the propeller master to make the production tool. Here is the first step, blanking off half of the master in modeling clay. Over this is poured the first of a three-part tool. From that tool will be made all the propellers I could ever want. I’ve got metal production tools that have been through hundreds of shots and they are as serviceable as the day they were created. Wish I could say the same thing about tools used in resin work!

[He Who Shall Not Be Named]

This is a 1/96 S5W propeller tool and cast metal parts. Though not the right size for this project the photo does fill you in on how the 1/72 tools and parts came out.

Metal casting is dirt simple: you take some store-bought ‘leadless solder’ (Tin-Antimony) melt it in a bullet casting ladle, available from gun-shops and big sports box-stores, and pour the molten metal into a silicon rubber tool. When the metal freezes, you pop out the part, cut off most of the sprue stem, machine the sprue stem remaining into a tapered dunce-cap, drill a transverse set-screw hole, tape it with a 4-40 thread, inset a set-screw, and you’re good to go.

Don’t forget the eye protection (I did once, much to my discomfort!), keep water well away from the work, chase the cat out of the shop, and give the work your undivided attention. Working molten metal is serious stuff!

Note that the tool is a three-piece affair. The long cylinder portion keys to the top of the upper tool half and has the sprue channel running down its center. The height of the sprue produces the pressure-head required to insure a complete fill of the tool when the molten metal is poured in.



The only clamping pressure is a flat plat outfitted with some lead weights to compress the upper and lower tool halves together. That’s all it takes to insure a tight, near flash-free casting. The key to successful gravity pouring is the provision of a tall sprue channel, well illustrated here -- in this case the casting of 1/96 BLUEBACK propellers.

The bottom half of the tool receives a 3/16” stainless steel mandrel that is coated in grease to keep it from sticking to the white-metal when the alloy freezes. After the cast propeller is removed from its tool the mandrel is pulled, leaving a perfect bore to accept the 3/16” propeller shaft.

The silicon tool cavities are liberally powdered with talc, and the excess then banged out onto the floor before assembly of the tool parts. The talc is hydroscopic, meaning it absorbs water. Even the moisture in the air will gather on the tool cavity surfaces, and if not treated with the talc that moisture would produce a blemished surface onto the surface of the cast metal part. The talc pulls the water off the tool cavity surfaces -- a task done just before the pour.



As the single pouring sprue in the propeller production tool runs down the propellers shaft axis, the proper tapered shape of the dunce-cap has to be restored on the lathe. But, first, the propeller is plugged into a holding fixture and the transverse hole for the set-screw is drilled out and then.

The 3/16” bore of the propeller hub was formed by a short length of stainless steel rod set into the bottom of the production tool, projecting into the hub cavity, producing a ¾” long bore within the hub. This mandrel was greased so it would not bond with the white-metal during the casting operation.



On the lathe a cast propeller is secured to the chuck (equipped with a short length of 3/16” rod) and the set-screw tightened. I then use a tapper tool-holder to restore the shape of the dunce-cap.

Off the lathe, a bit of filing and sanding to remove flash and the propeller is ready for finishing. Then an overall sanding of the blades with #240 sanding sticks; a soaking in acid to mill the surface down a bit and producing the surface texture for good adhesion of the primer. The propeller is rinsed in fresh water, dried, and primed. When the primer dries the observed flaws are attacked with files, sandpaper and air-dry putty; then another wash in acid and the cycle repeated till the propeller part is all pretty.



Two cast metal propellers ready for sanding-pickling-priming, and so on and so on. This is my typical propeller shaft-coupler-propeller type running gear. This is the arrangement I favor for r/c submarines employing a single, centrally running shaft. With this configuration the universal coupler sits well aft of the stern plane and rudder yokes so it will not interfere with their travel. Two Oilite bearings set into the hull absorb the thrust and transverse loads. I just don’t understand why guys go for long, protruding propeller shafts!

In background is a 1/72 PERMIT sail master I’m working up as another enhancement to Joel’s ‘new’ PERMIT kit.

THE SAIL



To avoid confusion I once again remind the reader that I worked up not only the 1/72 PERMIT sail master, presented here, but concurrent with that work did the same for a 1/96 sail for another job. So, you’ll see the occasional pictures with two different sized items of the same subject being worked on. Don’t let it spook you.

The excellent Deep Sea Designs drawings, authored by Greg Sharpe, were my primary reference as I lofted dimensions and shapes from paper to master blanks.

All appendage master blanks (control surfaces, horizontal stabilizers, and sail) started as 40 lbs. RenShape halves. The union between each half forming that particular items longitudinally running datum plane. Once the two halves were bonded together, no matter how much material is lost to the forming process, the central datum plane is present on the surface of the master. The glue used was CA and the face of each glued surface was first darkened with a broad Sharpie pen.

Maintenance of a visual line girdling the master is the datum which assures symmetry as the master is cut to shape.



Here you see the 1/72 and 1/96 sail masters which have already been shaped to profile and plan. Note the clearly visible longitudinally running datum plane on each master.

[He Who Shall Not Be Named]

As most of the engraved lines that will be dug into the masters run horizontally and vertically, each master was mounted on a block that permitted orientation of the master either right-side-up or on its leading or trailing edge. This made lofting from drawing to master a quick, easy, and exacting operation. The tool employed to do the marking was a Machinist’s surface-gauge equipped with a sharp pencil lead.



A separate master blank for the top of the sail was made. This master would be used to make an intermediate tool from which intermediate parts would be cast and a series of production master sail tops, with different arrangement of mast openings, would be produced. The end-game is to provide Joel’s customer with three sail top options: One with all penetrations open, one with only a few penetrations open, and one with just the engraved lines.

Note how the centrally running datum plane remains visible, no matter that the blank has already been cut to profile. It’s at this stage that the preliminary scribing is done.



The blank was first cut to profile, then plan. You can see the initial profile cut on the 1/96 sail top to the left, and the profile and plan cut to the 1/72 sail top to the right. Note that immediately after the profile cut, the blank was scribed to indicate mast penetrations and bridge clam-shell doors. It’s much easier to mark-off, handle and engrave the piece while it’s still squared off than to do so after it has been cut to plan.
Commercially available stencils were used to guide the engraving tool, except for the aluminum sheet template I formed to guide the scratch-awl as I engraved the three mast fairing lines.



Though the initial scribing near the sides are lost as the master is cut to section, it’s an easy matter to connect-the-dots later and restore those lost engraved lines using the surviving engraved areas near the center of the work as guides.

Most of the rough work getting the master to correct shape was done with this course rotary sanding drum. The work was completed with files and sanding sticks.



The nearly completed sail and sail top masters. The earlier work I did on the Moebius kit of the 1/72 SKIPJACK came in useful, as I employed some of the mast fairings from that job to serve as masters for the 1/72 PERMIT mast fairings. In foreground are the templates I used to cut out the control surface and horizontal stabilizer master blanks.

THE CONTROL SURFACES AND STABILIZERS



Showing the 1/72 PERMIT control surfaces and horizontal stabilizer masters at an advanced stage of construction. Illustrated to good effect are the templates pulled off the plans and used to transfer geometry from paper to blank. Note that the plan template to the left deals with the horizontal stabilizer and stern plane as a single piece, which will be split only after being contoured. Note also that all plan templates not only define shape, but also orientation of the control surface operating shafts.

Unsightly at this stage the bores for the operating shafts, previously dug out on the milling machine, extended well past the outboard portions of control surface. No big deal, all it took was a little Bondo and elbow grease and those openings in the masters were made to go away.



As each control surface and horizontal stabilizer master blank would be made of two halves I took advantage of that by milling an appropriately sized trough along the line where the operating shaft would go. Here you see that operation performed on the sail plane blanks halves.

This chore done, the block of RenShape is pull off the milling machine bed, and the sail plane blank halves band sawed out. The faces of the two blank halves were darkened with Sharpie pen, smeared with CA adhesive, and slapped together.



The next three steps were to mark out root and tip foil shape, tapper, and finally to sand to section to proper foil section.