Everyone knows how to remove parts from sprues as it’s impossible to build kits without doing so, duh! So after removing the part, it leaves an ugly plastic bit. They’re called nubs or nubmarks. Instead of dealing with nubmarks, we can do various things in order to prevent or lessen them. So how do we do these?
1. Good nipper/sidecutter
You know those tools that most modelers use and wonder what they do? They are meant to cut the gate connecting the part from the sprue/tree. So why not just use your hands or nail cutter, they perfectly work too. Yes they do of course, but very good nipper cuts so straight that it often leaves a clean separated part. Godhand is the most popular brand, but pretty expensive. I’d rather have the Xuron something that’s much cheaper but does almost the same, if not totally the same. Tamiya is decent, but IMO, there are way better ones for the same or even cheaper price.
2. Don’t cut it right away
When you cut the part away, always leave a bit of plastic then cut the remaining afterwards. What it does is it lessens the stress and thus preventing stressmarks from occurring. Stressmark is the slight discoloration that happens once the nubmark is gone. For OOTB builders, this is a PITA to deal with. Sometimes, it’s not just stressmarks but premature cutting might result to pavements that is impossible to fix unless you either sand too much, making the part ugly, or put some putty. Again, for OOTB, adding putty is a no-no.
If you are to paint the parts, this might not be much an issue. But imagine if every cut you make, it’ll leave pavements, then that’ll give you harder time.
3. Shave it carefully
Most of the time, even a very good nipper will leave a slight nub. That’s alright. Aside form it’s a natural occurrence, it’s nothing difficult to deal with. By using hobby knife, carefully shave the excess plastic diagonally then slightly adjust the angle everytime until you take them all away. A very clean shave will leave you a surface that’s almost like nothing was there.
So those are the steps in order to prevent stressmarks, pavements and dealing with nubmarks overall. So what happens if you fail then? Well, these steps are unavoidable IMO so better take note of each very carefully.
1. Just Enough Sanding
If I can’t shave of the nubmark straight, I deal with it by sanding it down. It’ll make the surface smooth. However, after sanding, some discoloration might occur and for OOTBers, it’s another no-no. That could be fixed but I’ll discuss them later on.
Again, as the title says, be careful when you’re sanding. By sanding, some stressmarks can disappear, but if you sand too much, the surface will become uneven and trust me, it’ll be obvious. I have no fix for uneven surfaces, sorry so be very mindful of how much you’ve sanded. If the stressmark won’t go away, then use other means.
2. Progressive Sanding
This technique involves the use of different kind of sand papers. I use 400-600 when painting, but use additional 1000 when I topcoat, then I use further grits when it’s a OOTB. Ideally, the first grit is meant to quickly get rid of the uneven surface. Once that is done, it’s followed by a grit that will get rid or at least even out the scratches that the first grit made. Finish it off using the final grit to get rid of every scratchmarks. Why not just use the finest grit you say? Well, why don’t you try it yourself? For severe type of nubmarks, a 1000 grit won’t last long. For even higher grits, it might actually rip the sandpaper, trust me :3 The power of progressive sanding makes it easier for both of your sandpaper and yourself :3
3. Wet Sanding
Wet sanding has numerous advantages over sanding right away. But basically, wet sanding gets rid of flying plastic powder that might to straight to your lungs. If you are to sand resin kits, then wt sanding is a must! Also, wet sanding makes the surface smoother. So instead of using a higher grit, I oftenly add a bit of water in my final step of sanding.
4. Gundam Markers / Real Touch Marker + Sanding / Tidbit Painting
After doing all of the above and still no luck, don’t give-in to despair yet. Depending on your building method, there should still be a way to fix this. Large nubmarks is unavoidable. Almost every kit has one connection that’s so big that’s impossible to prevent from stressmarks form appearing.
If you’re doing an OOTB, Gundam Markers is your best best. Just shake the pen prior you use. You can then either put it directly on the part or pour some in a tray, then use a brush so you’ll have more control on where the paint goes. Do note that if you are to top coat the kit, then make sure that the type of topcoat you’ll be using is acrylic or else, these paints will greatly differ in color. Another disadvantage of using these is the limited amount of colors they have. They have the most popular and common colors, but from gold, chrome and some exclusive colors, you’ll end crying T_T
Mixing your own paint to match the kit’s color is a hassle, so I don’t really recommend doing this but if you’d rather not go hassle yourself in repainting the kit overall, then by all means do this.
My favorite way of fixing these back then is by using Gundam Real Touch Markers. If I have dark part and my real touch marker doesn’t match the exact color of the part, then after sanding the nub down, I put some around and spread it afterwards. The dark colored ink from the marker will blend well and will make the stress mark visible if not totally remove it. I think I’m the only one doing these, most people have used to cover parts instead of lending it. You can do weathering too using these markers and I apply that technique to get rid of stressmarks :3
5. Topcoating It Flat
Topcaoting the kit will either flaunt the stressmark of help lessen it, if not totally hiding it. Why flat then? Using flat lightens the shade of the kit. Changing the shade of a part is known to blend different colors altogether. So slight discoloration will greatly be lessened. For some scratchmarks that you weren’t able to remove, depending how how deep they are, topcoating it should greatly help and it won’t matter if you used gloss or flat.
Last tip, if all else fails and you often end up doing the last step, totally annoyed by stressmarks, then I can assure you that repainting all the parts is the answer :3 Tedious, but at least it’s a guarantee OC free :3