The Mark 13 torpedo was the U.S. Navy’s most common aerial torpedo of World War II. It was designed with unusually squat dimensions for its type: diameter was 22.4 inches (570 mm) and length 13 feet 5 inches (4.09 m). In the water, the Mark 13 could reach a speed of 33.5 knots (62.0 km/h; 38.6 mph) for up to 6,300 yards (5,800 m).  Eventually, 17,000 Mk.13 torpedos were produced during the war.
True Details 1/48th Scale Mk.13 resin torpedo set
Well, here is finally a torpedo to go along my Accurate Miniatures TBF/M Avenger. It was built some time ago and went straight to the shelf in my office without the feature that distinguished this aircraft so much. Here comes the 1/48 U.S. Navy Mk.13 Torpedo #48506 from True Details.
I came across this set during a routine stop at my local hobby shop. So basically for the same price on-line with no shipping to pay, I decided to pick two torpedo sets. One is cast in a light gray resin and the other one in the traditional ‘butter cream’ resin color.
The 1/48th Mk.13 torpedo is comprised of basically of 9 parts. The torpedo itself, the wooden case, 2 propellers and 5 separate fins. There is an extra fin available in case you loose one. -that’s exactly what happened to me when I was removing them from the casting block-.
The cast is very clean on the main torpedo. There is an ‘eyelet’ on the tip that need to be opened. This should be the job for a pin vise and a small drill bit. Try to clean the extra resin from the casting on the eyelet, and you might end up blowing it up. Remember, I warned you 😉
As you can see on the provided pictures below, my MK. 13 torpedoes got a coat of Alcald 2 Gloss Black Base (ALC-304) and left to dry overnight. The leaflet included calls for a dark metal or dark gray color. Judging from pictures of the Mk.13, the color seems to be an aluminum shade either polished or dull.
I did tried Alclad 2 Polished Aluminum in a small portion of 1 of them. But this color proved to be too shiny almost chromed almost like the parts in model kit cars. I quickly changed to Alclad 2 ‘White Aluminum’ (ALC-106).
Meanwhile I left them to dry and started to work on the propellers. This is the most challenging part. Whatever you do, use a fresh #11 blade. Separating the propellers from the cast block is a very delicate job. The prop blades are thin and VERY brittle. No matter how careful I was or method I used, I didn’t get a single propeller without ruining a blade.
This is where I believe that little fret of photo etched propellers wouldn’t raise the MSRP that much and *I* would be more than happy to pay a little extra. The blade mounts could be provided as resin ferrules. Just thinking out loud.
The front portion or warhead of the torpedo, was painted with a 50/50 mix of Model Master Acryl 4765 Light Gray and 4757 Acryl Medium Gray. After sealing just the gray area with Acryl Flat Clear, I gave both torpedoes a wash of AK Interactive Dark Brown (AK 045). One of them has the war head all scuffed while the other one was left clean as a museum piece. The stand was built with Evergreen plastic 5/32” I beam (# 215). The exhibit plaque was made in .30 styrene. The picture and info was done with Photoshop as a .50” x .45” document at 200 DPI and printed on glossy paper.
The propellers are encased in a square resin frame with a lot of flash and the frames are closely adjacent to each other on the pour block.
Removing the frame from around the props before cutting loose from the pour block is impossible without damaging the adjacent prop. Removing after leaves you very little surface area to use locking tweezers or a third hand vise to grab onto. As you cut away the frame, the propeller becomes more and more fragile as a carpet leaper.
The props incorporate a natural twist and so are very weak indeed.at their root attachments. Recommend rotary saw blade on a Dremel and/or Xuron cutters.. Any attempt to sand or carve away resin pour flash with files or an X-Acto will shear the propeller blades from the hubs.
The torpedo body itself varies in quality with both of mine having scabs and molding imperfections all over the body which, when sanded, led to onion peel of the surface levels of the resin. This is typically due to too rapid removal of the part from the mold or poor mix control on the hardener but sanding them back to round and smoothing out the onion peel with layers of liquid styrene ended up removing over half the panel breaks and all of the mounting blocks for the end fins.
These latter fins are just as bad as the propellers in that they are flush mounts to raised pedestals on the aft end of the torpedo and because they are ‘scale thin’ have very little surface mating area..
Such a ‘looks good over smartly engineered’ approach is showing up as a feature rather than a bug in a lot of aftermarket weapons these days, with the Brassin R-77, AIM-9L and Hellfire all coming to mind as genuine ‘what were you thinking?’ examples.
Since half the problems of modern ordnance are inherent to removing body seams around complex fin assemblies, it should be obvious that the way to go is to either cast them as a monolithic piece with slightly thicker than scale fins or to cut the munition, transversely, at easy to sand sectional (warhead/motor etc.) breaks. Or to AT LEAST provide slots in the munition to slide fins in as keyed monoblocks which you can then sand clean before mounting the next fin.
Unfortunately, the Squadron Mk.13’s take advantage of none of these options with the result that the control fins are all but impossible to cleanly attach with gel CA. Your best bet is canopy glue with a quick rub down of the excess.
Finally the Mk.13 Mod 10 and onwards had a wooden shield built around the fins and propellers to allow for high speed drops from up to 410 knots and 2,400ft. But to make use of these higher speeds and drop angles, before the advent of parachute drogues, they also had a shroud ring which circled the forebody and was held together by a weak aluminum rod which passed through the recovery lug on the nose. The shroud ring banana peeled away from the nose on impact as the rod snapped and the act of doing so slowed the weapon enough to let the gyro steer the torpedo up to it’s set run depth.
This shroud ring element is not included in the Mk.13 kit at all. And it should be, if the tail fin fairing is there.
All in all? Not a good accessory. Even ignoring the propeller issue, you need parts which are not included (rod or wire to secure the propeller bosses to the back end and a pin vice to drill into the torpedo to set the rod) and a great deal of patience to smooth the resin to emulate the carefully machined finish of an actual torpedo, This entails removal of the onion-peel before rescribing lost detail and replacing the fins with ..10 sheet after cutting slots into the resin body. Only then can you attach the propellers and tail protector box.
It can be done. But especially if you want a late war or Korean era Torpedo with the shroud ring;, you are basically only getting a very rough body shape from which to scratch build the rest of the torpedo. At 9-14 dollars, it is not inexpensive either. Look for alternatives (Shapeways?) from similar British or German torpedos, cut to size. Or pick up an Accurate Miniature’s weapon set off of EBay. This is not a well designed product.