I HATE PUMP-JETS!!!!!!!!!!!!

All of the basic elements that will make up the masters for the 1/48 SEAWOLF propulsor are seen here: to the extreme left is the Renshape 40 blank that will be turned on the lathe to form the two-piece shroud. The three stacked items to the right are, from the bottom: the large conical hull piece, the rotor (in primer gray), and atop that the dunce-cap. At this point the eight stator blades are about to be joined to each section that sandwiches the rotor. The drawing on the table is a sequential presentation, in sketch form, the methodology to be employed as I cut the shroud to shape on my wood lathe (out in the cold shed in the backyard ... man, I'm dreading that!).

This is the after set of stator blades being mounted to their hub; the post-swirl stator assembly master -- the eventual parts job is to redirect the swirl flow from the rotor to a more rational axial flow, increasing propulsor efficiency.

The stator blade assembly jig in use here as I mount the stator blades to their hub. The jig insures correct spacing, rake, and pitch of the blades as they are CA'ed onto the dunce cap/hub. The cast white metal blades have already been band-sawed to length and given an initial sanding with #100 to knock off slag and to ready them for the later pickling process.

The blue item on the jig is the blade holding/alignment crutch. It's job is to secure each new blade in correct orientation -- the root of each blade fitting into a slot cut into the hub -- as I sprinkle on baking soda grout and then apply the CA adhesive to bond a blade to the hub.

Once the eight stator blades were on the post-swirl stator assembly, I built up fillets at the root of the blades using Evercoat Glazing Putty (a two-part polyester, heavily filled, filler), using my index finger as a fillet radius tool. After filing and sanding the putty, the assembly was dunked in acid, swirled around a bit, then rinsed in fresh water doped with a little baking soda to kill the acid. The work was then wiped down with cloth, dried thoroughly, then hit with 131S automotive lacquer primer. To the right is the primed rotor assembly.

The pickling induces a rough surface to the metal, greatly increasing the adhesive quality of the primer. Normally, un-pickled white metal presents a poor boning surface to most non-epoxy primers and paints.

The same stator blade assembly jig was used to mount the blades onto the pre-swirl master of the pump-jet. The jig was modified with a different sort of blade crutch -- a much easier to fabricate item, as the trailing edges of the stator blades for this master actually made contact with the surface of the assembly jig. Note that I incorporated a hold-down strongback to keep the hub unit firmly in place during blade attachment.

The two outer concentric circles penned onto the surface of the stator blade assembly jig denote the correct tip diameters of the stator blades trailing and leading edges. Note that I've already installed Oilite bearings into the inboard and outboard face of the propeller shaft foundations of the hub master -- a section of shaft was glued in the center of the jig to become the indexing point for the hub. As a blade is secured in place with CA, the strongback is loosened, the hub lifted a half-inch, rotated to the next position, the strongback tightened back down, and another blade glued in place. Work went very quickly.

Just like the post-swirl stator master, this pre-swirl stator master got a buildup of Evercoat filler to form the fillets between blades and hub. Note the tools I used here to further work the hardened filler -- specialized round-files are specific shaping tools I wish to draw your attention to.

This is some work I did in support of a new 1/100 pump-jet master I built to upgrade the OTW VANGUARD kit. I present it here to show off the modified round-file (rattail file) I bent to permit me to shape the very tightly packed fillets on this rotor master. A high-carbon tool like a file can be reshaped simply by bringing the tool up to a red-heat, bending to the desired shape, then quenching it in water quickly to get the temper back into the tool. All this is done without affecting the cutting ability of the tools serrated surface. Bending the rattail file as you see here permitted me to negotiate the tight areas between each blade of the rotor master.

The Completed 1/100 pump-jet masters. This British design only has a pre-swirl stator set. Interesting.

The pickled pre-swirl stator master, dried out, and ready for the first shot of primer.