There is some new progress to report. I’ve continued working on the S-II stage. I also made a modification to the Monogram third stage interstage. The ullage motors as molded are squared off on the forward facing part. On the actual vehicle they were rounded off. I masked off the areas that I didn’t want sanded, to protect the molded in stringers. Then I used my sanding sticks and rounded off the motors to resemble the ones on the David Weeks drawings that I’m using as reference on this build. You can see the process below.
I also noted that the molded in stringers on the S-II were too long on both the forward and aft skirts. The Apollo 15 S-II stage had some raised insulation bands on the forward and aft skirts. It seems that the molded stringers are too long by the width of the raised insulation bands. So I masked off the section of stringers that needed to be modified into raised insulation and used some Tamya putty to fill in the stringers. When it was dry, I sanded the area smooth. I think it turned out pretty well.
I also added some additional raised areas that were under the LH2 feed lines. I used .005 inch styrene sheet stock cut to the proper dimensions. I glued these on in the proper places and they matched up with my putty raised areas that I had already done. You can see them on the picture below.
I’ll add a bit of filler putty to blend them in with the raised band. The next thing I did was to remove the remaining S-II resin parts from their pour plug. These were the Engine Cutoff Sensors. They are TINY! It was quite a challenge to cut them off the pour plug without sending them across the table. It wasn’t any easier smoothing the backside so it would lay down properly on the S-II. All five turned out fine.
The last thing to report is the completion of adding the PE parts to the S-II. These required removing some of the raised stringers. They are now attached.
The next thing to do with the S-II is add a few of the resin parts. I’ll wait to add the LH2 feed lines until it is painted. If I did it now masking for paint would be a royal pain. I’ll put on the LH2 fill and drain port and the engine cutoff sensors, but the rest will have to wait.
I’d like to get some primer on the parts that are ready, but winter just won’t give up. The garage where I do my painting is just too cold. Hopefully spring will show up soon.