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Much progress on this project--


What you see here is the end result of a BUNCH of fixing... I thought the Pod Bay door bezels were going to be the only challenge to getting this thing into rubber. I didn't document any of the tiny fixes that kept popping up, mainly because I kept thinking I'd done the last of them. But, as soon as one got fixed, one or two others would show up. None of them were hard to fix, but given how I handled this thing (very gently) I was just amazed at what was lifting, cracking, bulging-- sheesh!! Anyway...

In this photo the CM is finished, with the exception of plugging the door openings. It is mounted to a circular hunk of MDF, which will be waxed so the mold jacket won't stick to it. The white 'wall' you see, with the metal rods sticking through it, is called a venting fin. When a casting is made, this is where all the air goes out of the mold. The resin that winds up in this part of the mold will contain the last of the air. Since this fin is extraneous and gets cut off the part, the idea is that there won't be any bubbles left in the part.

To make this mold, the CM master has to be attached to the base so it can't move. It also has to be mounted in such a way that it can be removed from the base once the exterior part of the mold and the hard jacket have been made. It has to be removed so the interior part of the mold can be made.


Here you can see how well the door bezel has been joined to the surface of the master.


Once the bezels were mounted, they had to be faired in on the inside because they are thicker than the wall of the master. To do this, I simply poured small amounts of resin around each. To make this work, the master had to be positioned so each bezel was dead 'down', allowing gravity to pool the resin evenly in place. Care had to be taken so that there wasn't too much resin as it would just overflow and dribble down the face of the bezel. That would just about ruin it and it would have to be replaced-- again!


Now the plugs are in place. The one on the left is the Pod Bay Door that will be molded in place, the one that never opened in the film. The other two are styrene disks that have registration domes on the outside. These two will be removed once the first half of the mold has been poured so that when the second, interior, half is poured, the two halves of the mold will come into contact through the openings.


This is the mounting ring and base. When the whole thing is put together, the mounting ring will be screwed to the base from the underside.


Here you can see how the mounting ring is attached to the master. Each of the 3 brass rods go through the ring and seat into the venting fin. Their ends are flush with the surface of the venting fin. With the mounting ring attached to the master and then attached to the base by screws from the underside, the master will be held securely in place. But because everything that holds the master in place can be reached without removing the mold and jacket, then the ability to pour the second, inner half of the mold cleanly is assured.


This is the final assembly, with the master mounted and the plugs in place. You can see the registration domes on the center plug. Once the molding process is started, there will be other things added to assure proper mold alignment. I'll point them out as we go along. The mold should be poured over the next 3 or 4 days, so you'll see the results of all this careful work very soon!

I never said the photo showed all the rubber that got poured. I took the photo at a time I was switching from an empty bucket to a full one, to continue the pour. I simply took a moment to shoot a photo to show you could see the level of the rubber. However, pouring new rubber against cured rubber has always resulted in a good bond, in my experience. It may be true that chemically there is no bond, but why else do people use a release when making the second half of a mold!

Scott