Sprue detective

Have you guys actually looked at a sprue of parts? Not just looked for parts or looked to see where the flash is. I mean really take a good look at the details and art of the sprue.

Of course, older models may not have the best molding or design. But many newer models have improved molding technology and improved master molds.

Take a look at the sprue from a recent model kit and you’ll be amazed. If you know your models, everything is there: bolts, nuts, weld seams, barrel jackets, charging handles, individual tank treads, car trim and the list goes on.

To make a model kit, someone has to find a 1:1 vehicle and measure everything about it and take many photos. But the work is not over.

Next, workers make pattern models of each part, several sizes bigger than the final parts, carving them from soft wood, making sure each part fits together properly. The pattern models get covered in epoxy resin. When the resin dries, the wooden pattern models are removed and the cavity filled with resin.

These resin model parts are copied by pantograph onto steel “tools” or large pieces of metal to form the molds for the parts. Using the pantograph allows for the scaling of parts down to the final scale. The location of each piece on the tool is planned ahead of time along with the sprue and gates that guide the molten plastic.

That is a basic description of how the molds for models are made, and they might differ between companies, but that’s generally how they’re made. Read more about this process at How Products Are Made.

So remember all the work that goes into making the sprues of parts we use to assemble our models or lose in the carpet monster.

Decal troubles

Hello everybody! I just wanted to fill you in on the progress of the F-19 stealth decals. They don’t seem to be sitting too well. It could be my technique or the age of the decals but I’ve tried a few so far and they don’t seem to be setting too well. Going to look into some decal setting solutions and other things. Anyone have any ideas or suggestions?

Coloring plaster part 2

So last time I mentioned the fact that I was casting things in Plaster of Paris and coloring the plaster. At first, I did some research on the internet and a few options came up, including using weathering powders, Rit dye, tempera paint powder and cement pigments.

Now what you’ll notice about all these options is that they are powders. Some of them work and some don’t, or at least not very well.

I first saw how to color plaster for modeling purposes on this Youtube video, which I do recommend. He does a great job on all his videos.

His method is to combine weathering pigments with water and then “paint” the mold he’s using. The results looked pretty good in his video.

I tried to replicate his efforts, but after several failed attempts with weathering powders, I rewatched the video and realized that he was painting the pigment into the mold and also putting it into the plaster.

Now he does say it would take a lot of weathering pigment to color a lot of castings. When I got the method to work, it did not color the plaster completely, but did give it more of a tint.

In this example, I put the powder directly into the mold, then poured the plaster. Didn’t turn out so well.
Second try. I painted the mold with the powder after using homemade mold release. Enough powder stuck to the bottom of the mold to coat the bricks, but the rest of the plaster is still white.
In this example, I painted the mold with the weathering powder and mixed some into the plaster. Looks better!
In this casting, I tried another color of weathering powder, just for kicks. This casting only has weathering powder on the brick face.

Using more weathering powder is the way to intensify the color, but how much more is up to you. If you use powders like Vallejo (like I did) or AK, it could add up to a lot of money.

In any case, weathering powders can only color plaster so much. Next time, how using Rit Dye works.

Coloring Plaster

I’ve been learning to cast plaster lately and I’ve learned a few things here and there, mostly how important it is to make a proper mold and the consistency of the plaster. I don’t use anything fancy, just regular Plaster of Paris. I use it because I can easily damage it and make rubble if necessary. Other types of casting materials are much harder and great for purposes such as wargaming, but I just use it for dioramas.

So to get to the point, why would you want to color plaster? Well, for one thing, if you have a plaster piece that gets chipped, that spot will stand out quite brightly among your terrain or diorama. Not good. This is worse if you are a wargamer and your terrain pices get a bright white ding to repair.

So what to do? I’ll tell you in the next post.

Vacuforming: It Really Sucks

I remember reading in Finescale Modeler magazine or on their website about people trying to get or build their own vacuforming machine. Vacuforming is a way to mold objects by heating a sheet of plastic, then pulling it down over a vacuum table, which sucks the plastic over a pattern. Ta da, a copy of the surface is born. This has been used in model kits for quite awhile, especially in MiniArt kits.

I was flipping around YouTube and came across some videos that show you how to make a vacuforming machine, so I decided to post them here. Some of these machines are pretty big and not made for modeling purposes, but I think they’re still useful.

Hopefully you can use this info.

How to make a larger vacuum former

Adam Savage vacuum forming machine

Prop shop: how to make a vacuum forming machine

Simple DIY vacuum forming