S-II/S-IVB INTERSTAGE
[Saturn V Second Stage]

Parts Needed:

I have opted to use the original Revell Interstage kit part on my model. I updated the four separation rockets using the New Ware upgrade kit.  Someone with vacuform experience and a lot of patience to lay in the stringers could probably construct this part without too much of a problem.

S-II

The Revell kit S-II consists of two heavy styrene rings for the fore and aft skirts along with a flimsy styrene wrap to represent the body. The S-II stage real hardware is 759" tall and 396" in diameter.  In 1/96, this scales down to 7.91" tall and 4.125" in diameter [which this non-purist used Plastruct 4.25" o.d. ABS tubing].

The aft skirt and stringers are pretty straightforward.  Rick Sternbach's article suggests that Evergreen "Corrugated Metal Siding" 4527 comes close to duplicating the 216 stringers. A wrap was made to a scaled height of .91" and glued to the aft section of the ABS tube. However, the forward skirt presented a different set of problems.

According to David Weeks' plans, the forward skirt is composed of a couple of different types and widths of stringers that are set at different spacing intervals. Rick suggests either using Evergreen 4527 as an approximation for all of the stringers, or to use a combination of 4527 and 4542 "Board and batten".  A purist streak hit me while I was building this section, so I used the combination of the two different densities.  Careful measuring, clean reading glasses and abstinence from caffeine is called for here. The scale height for the forward stringers is approximately 1.11"

A strip of .020 or .030 plain sheet styrene needs to be added below the forward stringers and above the aft stringers to simulate insulations. Pieces of insulation also need to be added to where the LH² fairings will be placed.  All edges will need be be beveled. The photo to the left was taken before any puttying and sanding took place. It also shows my black measuring lines and spacing intervals. It is purposely out of focus so you can't make fun of all of my mistakes. Again, paint and putty will cover most of my sins.

After I was happy with the insulation, I gave the entire S-II stage a coat of white primer [to further see my mistakes] and attached the umbilicals from the New Ware kit. Since I chose to use the Evergreen wraps to depict the stringers, the top of each umbilical didn't quite lay between the stringers. They're depicted below, and I have no problem living with it. This is a great detail to the project!