GEC's Layout Progress

[Green_Elite_Cab]

Well, I've finally gotten free from my college stuff, so I've begun working on my models again.


Jersey Arrow I

I've finally begun the molding process. I have completed the one piece floor mold, which appears to be very successful. I used Alumilite High-Strength 3 (HS3), which is a HIGHLY stretchy and floppy molding rubber. since I intend to mold this while flat on a table, the floppy nature of the mold should not be a problem. I mixed and molded it Saturday, and demolded it last night. I haven't yet tried to make a cast with it, but it looks promising, with no bubbles anywhere along the casting. Some trimming might be necessary, but otherwise, there have been few problems with the floor/underbody details.


That said, the body is a little more frustrating, and must be done as a two piece mold. It took all of my High Strength 2 (HS2) to mold the outside of the body. The primary problem is the "clay" provided to help create dams and block the mold rubber from leaking in through windows and such. While very little of it has stuck to the model, a LOT of it is sticking to the mold. This clay is supposed to be able to peel away from the rubber, which is why this is so frustrating. This is bad, since if the clay sticks somewhere its not supposed to, then comes out later, it can create trouble making a proper mold.

That said, it could have been a lot worse. One of the problems I had casting body shells was positioning the "master" properly. I tried to cast an E44 so that the body shell was standing normally, with the clay poured on top. Unfortuneately, after only a few minutes, the model floated up out of the rubber, and so the mold was ruined. Next, I tried casting the GP40FH-2, this time upside down. This was easier, but it resulted in bubbles becoming trapped on the roof of the model, making any such cast highly labor intensive and ultimately undesirable.

This time, I tried to cast the body shell the same way as I did with the E44, but this time I cut a hole in the bottom of the mold box, so that the body shell would not float. I packed in the clay along the edges to make sure that the mold rubber could not leak out the bottom of the mold box or enter the interior of the model. There was only minor leaking from the sides of the box, and not from the clay dams. I quickly plugged that leak. So far, though there are bubbles on the "top" of the surface of the mold, I don't see any along the sides or bottom of the mold, so I'm hoping this is a promising sign that most of the bubbles have drifted up and away from the master. Any imperfections on the fluted sides of the model will be difficult to fix, even tiny minor issues (if only there were a way to sand between flutes!)

In any event, I think I need to purchase more casting rubber. I still have a pound of HS3 left, but its VERY floppy, so i'm thinking another jar or HS2 will do the trick, and might even leave some left over. I intend to use the remaining HS3 to make casts of small parts that might break easily before I assemble my Jersey Arrow II, III, and Reading Company Green Car MUs, as all of these kits are discontinued, and I'm not sure how much parts support I can get.

The floor mold-



The body shell being prepped for molding-



The flash on this side of the model was very thin, and definitely not water tight, so it needed to be backed up with the clay.



Both models sit while the rubber cures.