Step 94 : Flak
Time to complete : 19 hours.
Total time to date : 785 hours.
A mold was made for the 20mm and 37mm cannons as well as the pedestals and gun magazines. All other parts would be scratch built out of brass, aluminum, or styrene. To make the masters for the 20mm cannons, I chucked a piece of brass rod into my drill press with the speed on high and then shaped it with a file.....a REAL poor man's lathe but I was able to make a fairly decent master using this technique. (gotta get a hobby lathe some day) The 37mm barrel was made the same way. The 37mm receiver was made from a piece of aluminum square stock that I put a little shape into with a file. Once the rubber molds were made, these parts were cast from the same Smooth Cast 305 resin that I have made all my other casted parts with. If you notice in the photo of this master mold, there are no channels / vents in place for the 20mm cannons. I have discovered that it is much easier to cut these channels / vents into the rubber with a hobby knife once the mold is made. The purpose of the channels is to allow the resin into the mold, the purpose of the vents is to allow the air to escape as the mold fills with resin. There is no need to have these channels / vents a nice shape. The cuts with the hobby knife work just fine. It is very important that no indexing holes are placed where the channels / vents are going to be cut, as can be seen in the photo. I just started using this technique on my last few molds as an experiment. I could have saved myself a lot of time had a done it this way with all my molds.
The remainder of the 37mm Flak gun was scratch built as I could not cast these parts given their shape. For the most part, all the scratch building on the 37mm is out of brass with the exception of the shield, which is styrene of the right scale thickness. I used a template for the seats and cut them from brass sheet. After the basic shape of the seat was attained by filing, I gave it that "seat" shape (kind of, more or less), by hammer/dollying it with a piece of brass rod that I put a rounded shape on the end.....in other words, I pounded this rounded brass rod onto the flat seat shaped piece of brass until it rounded a bit. (important to put a self healing mat underneath to allow for some "give"). A little bit of tweaking with some plyars and the seats have a reasonably convincing look. Putting some foot rests, aiming wheels, and gun sights on gave these 37mm crew positions some nice detail. The 37mm Flak was sprayed with the same grey primer as was used for the upper colour of the boat. The barrel was hand painted with Gun Metal Blue.
The mounts for the 20mm were made from styrene while the shaft up from the pedestal is aluminum round stock. The mount was attached to the shaft by drilling a hole through the side of the mount and through the shaft in order to insert a brass pin, or hinge...basically. This allows the mount to pivot up and down as well as making for a very secure attachment. The counter weights, shoulder rests, and adjustment wheels were added to complete the detail of the 20mm Flak. The mount, shaft, and pedestal was painted grey, the upper part of the mount, and 20mm cannons painted Gun Metal Blue.
My goal with the Flak is to have them be a "reasonable" facsimile, and not a perfect 1:25 scale model. To model the Flak with any kind of scale detail would take a whole other build thread.....I just didn't want to invest that kind of time. I believe I accomplished my goal. The Flak look pretty good from......oh.......3 feet away or so. They do compliment the conning tower nicely.
Much thanks to raalst for providing me with some real good 20mm and 37 mm Flak pics for me to use as reference. I had to use a lot of "artistic licence" to come up with my model pieces, but the pics that raalst sent me were instrumental in building them. Again, thanks Ronald.
More to come.
"I don't have anything else planned for this afternoon." - Lt. Col J.O.E. Vandeleur
A Bridge Too Far (1977)