Tools we’ll need:

• Plastic cement;
• Some clamps to squeeze the parts (not pictured);
• Your favorite putty;
• Hobby knife;
• Sanding sticks, sponges or sandpaper;
• Flat file;
• Nippers;
• (Optional) Your preferred scribing tools;

Step 1 – Apply Glue

First off, we need to apply glue to the parts. You can apply it to each part separately, but keep in mind that thin cement dries rather fast. This method allows more precision, letting you avoid applying glue onto details, which may ruin them.

As you can see, I leave some polycaps inside. It’s usually a good idea when one or both ends of the part have a female polycap. Also saves a lot of time, as you don’t have to worry about modding the part to fit them in later. It’s perfectly safe, as the plastic they’re made of doesn’t react with cement (and most other chemicals).

Another way to apply glue is to put the part together first and then drop it into the gap. It’s faster, at the cost of precision.

For bigger surfaces, consider using thicker, slower drying glue instead. It gives you much more working time, so you can apply it over the entire area before it starts to dry.

Step 2 – Squeeze!

Next up, squeeze both halves together. Don’t worry, if the plastic runs out of the seam line. This plastic lip is something we actually want, as it shows the parts have joined together well and there won’t be much need for putty later.

Use the clamps to hold the part together until the glue dries.

You might be tempted to clean this plastic lip right away, especially in panel lines and other detail areas. Leave it be. Dragging melted plastic across the surface is a rather bad idea. It might cause some serious damage.

Step 3 – Sanding

Next step is to sand the part flush.

To save yourself some time, you can use the back of your hobby knife (or mould line removal tool) to scrape off the plastic lip.

As with nub removal, use a stiff sanding stick, fine flat file or a sandpaper wrapped around a file/piece of plastic for flat surfaces. For rounded ones use a circular motion and, preferably, a soft sanding sponge.

Step 4 – Fixes

With seam lines removed, we must now inspect the parts for any obvious mistakes.

Most common ones will be the gaps and other imperfections where seam lines didn’t close properly. We’ll need to fill those with putty. My choice is a homemade plastic putty. If you don’t want to paint your kit, you can make it from spare runners to match the color of the piece. Once dry, sand it flush and repeat this step if needed.

Another issue you might come across are removed panel lines. They often get filled if a seam goes across them and need to be rescribed. Since scribing is a huge subject, which requires its own tutorial or two, I won’t be covering it here in detail. Basic idea is to place the guide (usually plastic tape) along the panel line and lightly drag your scriber along it. Apply very little pressure and repeat it until the panel line has a uniform depth once again.

If you’re going to paint your kit, spray some primer on the parts to help you spot mistakes.

Scribing

Scribing is rather straightforward. Drag your scriber lightly along panel line a couple times and you’re pretty much done.

It gets tricky, when both sides of the body use the same pieces, rather than mirrored ones though. As you can see on the picture, shoulder armors on HGGT RX-79[GS] are identical. When assembled, one seam line will be at the front, while the other in the back.

To deal with it, I had to measure the distance from the seam line to the edge of the piece, and then scribe a symmetrical panel line on the other side.

Covering

Another way of hiding a seam lines is adding extra piece on top of them.

The trick to this technique is gluing only half of this extra piece, on one side of the part. Leave the other half hanging over the edge. When the part is assembled, it’ll sit right over the seam line, hiding it from view.

I combined scribing and covering methods to hide the seam line on the head of my Barbatos Nemesis.

Head

Many HG Gundam heads come in two pieces – front and back, with the face mounted from the inside. Big downside of those is obviously a giant seam line, running across the entire head.

Problem is, they need to be separated to mount the face in. So we have to either paint and install the face first, or mod it, so it can be mounted from the bottom instead.

To do so, we’ll need to turn the T-shaped piece into a peg, as well as cut out any obstacles which might block the movement – both inside the head and on the face piece itself. I marked those in red on the second picture.

If you want to use the eye sticker, hold off until final assembly. Repeated test fits will tear it off.

Don’t worry if it’s loose, you can always glue it in during the final assembly.

Upper Arms

Another tricky mod I encountered were upper arms on RX-79[GS].

As you can see, the armor pieces sandwich over the elbow joint, with each half connecting at two points. Best way to go about it would be for the finished piece to slide in from above. Those round pegs at the elbow make it impossible though. We need to do something about them.

Using the Madworks zero chisel, I cut the round details from the main armor piece. Since the cut was a bit rough, I had to use some epoxy putty to make them fully round again.

They fit right into the elbow pegs and can be mounted independently.  It also creates a slight gap between them and the armor, making it look consistent with the knee joints.