The construction is finished except for adding the S-I retrorockets and the S-I engines. The engines have been painted.
The two halves have been glued together with epoxy. I then applied a final primer coat after a small bit of sanding on the S-I/S-IV joint. Once that was done I gave it an overall coat of white. After letting the paint cure for a couple of days, then began the tedious task of masking off all the areas that are to remain white. Once that was done I sprayed on the black. It turned out pretty good, only a handful of leaks that had to be cleaned up. After letting the black cure a couple of more days, I started painting some of the details. The antennas got painted yellow. The half sphere on the instrument unit was painted black, the LOX and fuel fill and drain ports were painted steel, and the S-IV ullage motors got painted with some red leaving a strip of white on the top. The joint between the S-I and the S-IV interstage is supposed to be black and I’ll do that with a decal, which should be easier that painting since masking that area would be very problematic.
Next up is to scratch the S-I retrorockets. I have an idea of how I’m going to do that. Hopefully it works in the real world. Then I’ll need to finish the decals.
It’s been a while, time for an update on the SA-5 build.
There are quite a few details that need to be added to the S-IV and interstage areas. But before that I needed to add the payload section to the S-IV interstage. There are a lot of details that go on the S-IV interstage and that would make it harder to get a relatively smooth transition from the S-IV interstage to the payload section (which includes the instrument unit). I used CA to bond them and then started filling and sanding the areas to get a fairly smooth joint.
I then added the tunnel that runs down the side of the S-IV just to the left of Pos II. This was made by laminating two strips of .010 x .100 strip stock. I didn’t have any .020 x .100 stock so this worked out fine. I also cut and shaped some .005 styrene sheet to make the antennas and an access hatch for the S-IV interstage.
I added two retrorocket fairings to the top of the S-IV interstage. I thought about making some from styrene rod, but then it hit me to check my spare parts stash. I had built a Saturn V last year from a mash up of the Monogram and Airfix kits, so I had a spare Airfix S-II. It had retrorockets on the S-IVB aft interstage. I pulled it out of the stash and checked it. The angle was similar to the angle of the S-IV interstage and the size of the molded on retrorockets looked good. I got my chisel blade out and shaved two of them off. I then glued them to the S-IV interstage.
I then started adding details to the instrument unit at the base of the payload section. It has several antennas, an access door, a rounded protrusion, and a panel that appears as though it may be somewhat thicker than an access door. There are also a couple of antennas at the base of the payload section just above the instrument unit. The documentation that I could find on the instrument unit is very sparse, but from photos and the few drawings I could find I think I have all the major details added.
I made the semi-spherical detail by sanding down a half pearl from a sheet I bought some time ago from Michaels. I originally used them as rivets for a steam punk rocket I built a couple of years ago. The thick panel was made from .010 sheet stock, the access door came from .005 sheet stock. I made the large antennas at Pos II and Pos IIII with .020 x .040 strip. The medium sized antenna next to the semi-sphere was made from .020 x .030 strip. The small antennas near a couple of the circular openings were made from .020 x .020 strip. The last antennas added were the two tiny antennas at Pos I and Pos III on the payload section. They were made from .015 x .020 strip.
Now it was time to add the fairings for the gaseous hydrogen vent pipes. For this I started with the conical section of the LH2 fairings from the donor S-II. I used white glue to temporarily attach them to a popsicle stick after cutting off the excess length. I then used sanding sticks and a #11 blade to form them to the correct shape. You can see them attached to the popsicle stick in one of the above pictures. I used CA to attach them to the proper positions on the S-IV stage. Then I cut some styrene tube (the same size I used on the S-I stage) to fit between the fairing and the base of the S-I interstage. The base of the S-I interstage has an angle so I needed to try and match that angle on my tubes. I then used Tenax to attach the front of the pipes to the fairings and CA to attach the base of the pipe to the S-I interstage.
Next came adding a small umbilical panel to the left of Pos II at the base of the S-IV. I used small sections of 3/64 rod to represent two of the pipes. I then used a 1/64 drill bit to make the 10 small holes between the pipes. I did not drill to the full diameter of the bit since the holes needed to be quite small. I then used a 1/16 drill bit make the larger umbilical hole above the 10 small holes. I again did not drill to the full diameter of the bit since the hole is smaller than 1/16 and also is not very deep. Once that was done I added the four ullage motors. I had to go the spare parts stash one more time to find a spare ullage motor since one of the ones that came with the conversion kit was not cast well enough to be used. The other two came from the S-IB kit that is the base of this model.
Finally, I could put a coat of primer over the S-IV/payload part and see how it turned out.
The only detail left to add are the four S-I retrorockets. They extend at an angle past the end of the S-IV section so I cannot add them until after I glue the S-I and S-IV sections together. After that it will be time to start painting the white base coat. I will not be using the conversion kit decals and instead will make some of my own. It appears that the checkerboard pattern that goes around the S-I interstage has 10 squares from one Pos to the next. The kit decals are off on that point. There are also some other markings that are not on the decal sheets. It is getting closer, but there is still quite a bit of work to do.
Progress continues on the SA-5 model. I made the decision to replace the S-IV that came in the upgrade kit with my own that I would make out of some resin that I already had. This would give me a round S-IV stage that would match the interstage without massive amounts of filler and hours of sanding to get it round.
I started by gluing three rods into the bottom of the interstage part. Next I glued a circle made from .010 sheet stock to the top of the three rods. I applied thick CA to the edges to seal the circle to the inside of the interstage. This would be the bottom of the S-IV mold. I had previously decided that I was going to be displaying this model as a complete stack without separable stages. This allowed me to pour the new S-IV to the top of the interstage. I then glued a section of cardboard tube to the top of the styrene circle to make the walls thinner and lighten the model.
Anyway, I also cut a section of cardboard tube that was 1.5 inches in diameter on the inside, which almost exactly matches the interstage diameter. I glued a strip of styrene to the top of this tube to give me a physical indication of how far to sand down the top when the resin cured. I coated the inside with thin CA glue to seal the cardboard and then gave it a light sanding to remove some of the surface roughness. Next I sprayed the inside with some mold release to hopefully make it easier to remove the tube after casting. I also drew a line on the inside so I would know how far down to push the tube over the interstage to get the correct S-IV length.
I slid the outer tube over the interstage and then prepared to mix and pour the resin. My resin is getting a bit old and part of the resin was starting to separate out. I stirred it well to get a smooth resin and then measured out equal parts of resin and hardener and mixed them together. I poured it into the mold to just below the top edge of the styrene strip inside the tube. Unfortunately there was still too much air in the resin after I had stirred it up and the cured resin expanded and rose up out of the top of the tube.
This was not exactly desirable, but I could just cut off the excess and then remove the outer tube and it would be fine. Except that after removing the outer tube, I could see that the extra air caused a bunch of bubble holes that would need filling. Oh well, at least it is round and all I have to do is smooth the outer surface. I sanded the top down to the indention made by the styrene strip and now I had a round S-IV with the proper length.
At this point I decided to add a few details to the interstage. It needed standoffs for the three gaseous hydrogen vent pipes and also needed to have the camera canisters added next to the stub fins at positions 1 through 4.
I then sprayed on a first coat of primer. Then glued on the S-IV interstage and sanded the junction with the S-IV body to a more rounded profile.
I sprayed a coat of primer on the S-I stage and did a bit of additional filling and sanding on some of the fins. Next I sprayed on a final coat of primer to complete the S-I stage.
That’s it for now. Much more work to be done on the S-IV stage. Thanks for looking.
A little more work on the S-I stage. First I took out my Dremel and thinned the walls of the eight H-1 engines. The kit engines have nozzle walls that are far too thick. The picture doesn’t show it well but the walls are much thinner that before.
Next I glued on the stub fins with CA. When those were cured I added the large fins at Positions I, II, III and IV. After those set I added the hydrogen vent extensions to three of the stub fins.
Finally, I glued on the inboard H-1 tubopump exhaust fairings.
Now the S-I stage is now complete and ready for it’s first coat of primer. That will allow me to see where the final rough spots are and get them corrected before painting.
Here is a summary of what I added/deleted from the kit/upgrade parts.
All ribbing was removed from the base of the boat tail replaced with 14 ribs between each of the eight fin locations.
Access doors were added between each fin location and umbilical panels were added at two locations.
The engine fairings were removed from the base and glued back on after removing excess plastic.
Flame curtains were added for the four outboard H-1 engine locations.
H-1 nozzle walls were thinned.
About 1/8 inch of top of S-I was removed.
Kit fuel/LOX tank locators were trimmed before gluing the tanks in place.
Kit antennas were removed and antenna panels were added over kit locations and corrected antennas were replaced.
Electrical conduits were added to each of the four RP-1 tanks.
Gaseous hydrogen vent lines were added at three locations (replacing the update parts).
LOX and RP-1 fill and drain lines were added.
Vents were drilled at the top of three of the LOX tanks.
Vents were drilled at the top of two of the RP-1 tanks.
An umbilical door was added at the top of one of the LOX tanks.
Hydrogen vents were added to three of the stub fins.
Now it’s time to start on the interstage/S-IV stage.
Here is a quick update of the SA-5 progress. I glued on the antennas, the umbilical door, and the hydrogen vent pipes. The umbilical door is cut from .005 sheet stock while the antennas are cut from some strip stock I had that looked close. The hydrogen vent pipes look a bit different that the last update. I added the short straight section after the bend at the top of the pipes. I at first thought I could leave it off, but the more I looked at it the more I knew that the short sections needed to be added.
The bottom of the vent pipes needed to have a slit cut into them so they could fit over the stub fins. Also note that I have glued the fairings back on the base of the vehicle.
Here are a couple of pics of the stub fins dry fitted to the hydrogen vent pipes. Note in the pic on the left that I have also drilled the vent holes in the tops of the fuel and LOX tanks. The pics also show the LOX and fuel fill and drain ports.
I also fashioned some hydrogen vents for the stub fins that will be glued on later.
I have also filled the areas on the inboard nozzles where Airfix had molded in for the turbopump exhausts. The inboards on the Block II vehicles exhausted their turbopumps out the sides of the boat tail in aerodynamic ports which are not yet installed. The outboards will require some modifications to look more like the real thing. The inboards need some extra details as well, they were not simple curved bells.