Apr 062017

I was originally going to post this progress update on Monday; but since we had just gotten back from Tatsu Hobby’s contest; I wanted that post to stand on its own. So a few days later, I’ve continued to plug away at the kit as I got some new ideas flowing but still need to finish off the old ideas that I’ve already started. I also finalized the work on the new toe and will show the process of making resin copies. Since a majority of the build work is done; I also took some time and sprayed the initial layer of primer over the legs and other parts. At this point, it is about 90% primed. Here’s a quick teaser picture.

More after the jump.

Going back a few weeks, I was actually working on getting a new visor. The clear green visor wasn’t cutting it for me and I wanted to use some aurora film with the visor but also keep some of the transparency – since there is quite a bit of detail work under the visor. The clear green messes with the aurora film, so I needed to make a mold and some resin copies. While doing this, I tried casting the clear resin with the aurora film. It didn’t work out at all. So I ended up just casting a clear piece that I will then just glue some aurora film over. For now, I have a clear visor piece.

Next, we return to the toe. The top part is sanded down and everything looks good. The bottom part is also sanded down leaving a completely blank area. I know that if this kit is standing on a base, there’s no way you can see any sort of detail. But I haven’t really decided on the final pose or how this will be displayed; so it’s best to just add in some new details. So here’s a comparison picture from the blank bottom of the toe to the detailed primed toe. Doesn’t look too bad.

Playing Gundam Battle Operation; I was looking at some of the suit designs on there and got some ideas for more details. For the lower part of the feet, I measured out and cut some dymo tape and scribed out a few 1mm cuts. I also did this to the toe piece.

To detail the bottom of the toe piece. I just glued some cut styrene strips. A priming session left me with a plain looking area even with the added styrene. So some details needed to be added to the styrene. I scribed cuts, some bevels, a few more lines, and drilled out the styrene to add in some punched out vents to finish the bottom toe details. Things are starting to come together and there are a few prime/sand/putty/prime sessions to finish up the toe and get it ready for duplication.

The crotch area needed some detailing, so I added some cut styrene here. Granted, once the skirts are on, all of this detail will be hidden, but if you look, you’ll still be able to see it. So again, depending on the final pose, this could be good, or a complete waste of effort.

The legs were done, so time for the first priming session to find all the areas that will need fixing. Because there will always be areas to fix. At this point, I have 90% of the kit primed. There are a few small bits here and there that still need work. Notice too that there’s only one toe. That’s because I only built one toe. I was originally working on both then realized that I was doubling the work for something that may not even match when I’m done. I want the toe to be identical. I am very far from a perfect builder, so there is no way I could build two toe pieces and have them even remotely identical. So I only built one.

It is good to see most of the kit primed. It is a significant milestone. The kit doesn’t look like a mishmash of parts and there is some uniformity. Now to take it all apart and get to fixing the problems that the primer found for me.

One of the parts that didn’t get primed yet are the ankle covers and front foot armor piece. The part needed to be glued together as there is a horrible seam down the sides. Once glued, I first attempted to add some details with the scriber. But after scribing one, I didn’t like how it came out I grabbed some dissolved putty and went to repairing the ugly scribing. I then just cut .1mm thick styrene strips and used this as the detail method. So instead of some scribed lines, I have a .1mm raised bit of detail.

Next bit of unprimed plastic is the beam saber. Since I added in a forearm saber holder, I need to modify the saber to actually look a little better when displayed in the holder. I drilled out to top part of the holder so I can glue in a metal collar piece. Then in the middle, I glued in a thin brass rod. The back of the saber was cut slightly to shorten the overall length and some magnets are added to the holder and beam saber handle to hold it all together. Now there is functionality to the beam saber and the new holster too.

Here’s what the arm/beam saber holster/beam saber assembly looks like now. Once primed, this should match up nicely.

Now that I’m satisfied with the toe piece. I can get to making copies. First step is to make the mold. My holding box is made from legos. And lining the bottom is playdough. The playdough works to hold the part in place while the silicone sets up. It also help when I make two part molds. I just find it easier to work with two part molds. The silicone I use is a shore weight of about 20. Mixed by weight at 1 part activator to 10 parts silicone and it is ready to pour over the master piece.

The mixed silicone is poured into the lego box with the toe piece sitting at the bottom. The cure time is a couple of hours. So this whole assembly goes into the pressure pot to help reduce bubbles.

Left to cure overnight. The next day the assembly is disassembled and I have a block of solid silicone rubber topped with playdough.

The playdough is removed and then the mold is washed to remove excess playdough and dried. The lego box is reassembled and the mold is placed inside with what was the top part, now sitting on the bottom. Before adding a new layer of freshly mixed silicone, I apply a small amount of vaseline around the part and half the mold. This keeps the mold from sticking together in areas I don’t want it to stick together. And when I’m done, this will make removing the part as well as removing casts much easier.

Here’s the next layer of freshly mixed silicone. And thrown into the pressure pot again to reduce bubbles.

Several hours later, the mold comes out of the lego box and the area where I applied the vaseline comes apart easily and I can remove the master piece. Now I have a mold to create an endless supply of modified toes.

I did not take pictures of mixing the urethane resin because my work time is VERY limited. However, what’s not shown is that the mold internals are sprayed with a mold release agent and the entire mold is placed into my workshop’s toaster oven set at about 90 degrees F to heat the mold and activate the release agent. Once that is done, I just mixed equal parts of the resin by weight, pour it into the mold – squeezing while doing so to help remove air bubbles that may get trapped in the undercuts of the mold. Then quickly placed into the pressure pot to remove as much air bubbles as possible.

And 15 minutes later, I have an exact copy. Granted it needs a little bit of sanding and some filling for a pinhole – but this beats trying to scratch build an exact copy.

Last but not least is a quick scratch build knife. Since I relocated one of the beam saber hilts to the forearm, I will not be using the rear skirt beam saber holder. Time to create a new weapon to put back there. Just using some cut styrene strips and glue, I get a rough shape. Once the glue sets up, I can start sanding and shaping the blade edges and get some general clean up work done. I also get to work on building a sheath for the knife that will replace the rear piece on the skirt. I used the same GM Spartan waist piece, but cut it to fit the knife’s width and glued it back together. I will be removing quite a bit of plastic then adding more details. So this is a good starting point for how rough something is at the beginning.

I have ideas for the paint scheme forming and I also have ideas for a base too. But I need to focus on getting this damn thing completely ready for painting to even bother considering the ten other steps I have down the road for this project. Motivation is still pretty high and I’m enjoying the hell out of this build so far.

Oh yeah, and since we’re at the end of this post. Shameless plug time. We just reprinted the Shiki T-shirt

So click on the store link above and order yours before they run out again!

  8 Responses to “GM Sniper 2: priming and resin casting”

  1. Amazing work.

    Just one suggestion, I’d hyperlink your aurora film article http://gamerabaenre.com/?p=4238 to the first mention, I’d never heard of it before and googling mainly gave me movie results.

    I can’t wait to see your gm sniper finished.

  2. I’m SO jealous of your gorgeous radiator at the back of your GM. I’ve spent a week trying to scratchbuild something similar to no avail.

  3. I acutally learned a different yet more precise way to make those radiators.

    1: get a cutting tool such as the chopper II
    2: Measure and cut rectangular strips with the number of radiator strips you want to end up with.
    3: Cut up one strip into sections that will be the different shapes along the edge of the radiator. For example, in my radiator, I have three main detail lines, a long angle cut, a short angle cut, and a under cut in the middle. The plan is to cut this into three sections so I have one that has the long angle, one with the short angle, then one that is just a rectangle, but trimmed down.
    4: Cut all the strips from step 2 into these sections
    5: Organize your strips into like piles
    6: Glue one strip together using the atomic parts
    7: repeat step 6 for all the strips you have for the radiator
    8: Let the glue cure and then sand the flat sides of the glued together strip to clean up the connection points – you should now have one strip with a straight edge on the bottom and your design on the other edge.
    9: glue the strips with a spacer strip along the bottom to assemble the radiator
    10: Let that glue set, then trim off the excess plastic spacer bits and you’re done.

  4. Thanks for the answer. Any idea where to order that cutting tool online ? I’ve been eyeing it for a while, but the shipping cost is usually prohibitive.

  5. That’s about $60 shipping included… I’ll take it, thanks !

  6. I don’t know if you do this or not. I do quite a bit of molding and casting at the museum where I work and we make “keys’ for our molds. You just put a rounded piece of playdoh around the edge of your mold in the first step. Then remove it for the second step. This will make a tongue and groove and your mold will always align.
    Don’t know if you have this issue with such small molds or not, but thought I’d help.

  7. Thanks eric. Yeah it helps. But most of my molds two part molds are actually attached at one end so it’s more like a two part clamshell mold. For making bigger things I’ll add in keys to help align molds! Thanks again!

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