How to remove or clean nubmarks (a.k.a sprue marks) properly has been a problem that has bugged everyone who has (and ever will) build a Gundam kit. How do you get rid of those ugly nubs on your Gundam’s armor? Your friendly neighborhood Spiderbeef is here again, this time to share with you some nubmark removal tricks that I’ve learned over eight months of Gunpla building.
NUB MARK alert! Below is a nub mark! (Of course you know what that is right?)
There are 3 ways to do this, depending on the tools available to you so we could remove those pesky nub marks like the one above. Grrrr!
1. Cleaning the nub using side cutters.
Use this method if you only have side cutters around. It happens… many of us do not have the luxury or access to tools. If you really do not have a side cutter, then your alternatives may be nail clippers and nippers, scissors and even diagonal cutters.
Just a side note:
I started out with the Bandai side cutters (the one that comes with a pair of tweezers, small metal file and parts separator in a set), but it quickly got worn out and rusty. I now use the one I bought from Alexan; it’s chrome-plated so it’s virtually rust-proof. For this technique, I found that you can minimize damage to your Gunpla if you cut the nub off gradually, instead of cutting it off in one fell swoop. Always keep your cutters sharp.
Anyway, moving along… Here’s a part of MG Char’s Gelgoog’s inner frame with a big, nasty nub on its side. The idea is to cut the part bit by bit (slowly but surely) as if you are biting on the nubs. Do it carefully, so you don’t damage the surrounding area, until you manage to level the nub nicely.
And here’s how it looked like after cutting. I cleaned it afterwards with a piece of cloth so it wasn’t very noticeable. See, it still has a little white mark left, but most of the time you will hardly notice the nub mark.
We get this question a lot, too: what’s the difference between side cutters and diagonal cutters? The cutting edges of the side cutter are straight and level with one side (I guess that’s why they’re called side cutters), while the diagonal’s cutting edges are sloped inward.
Step 1 Conclusion
Pros: fast and easy
Cons: still leaves visible marks, especially with the bigger nub marks that will almost surely have a rough and whitish surface; may damage the area surrounding the nub when you apply too much pressure
2. Shave off the nub with a hobby knife.
Do this when you have side cutters and a sharp hobby knife. I heard some use blade cutters, scalpels and knives as an alternative. My say, do as you wish, anyway the general idea is like this.
Remove the piece from the runners with the side cutters cutting as near as you can leaving some nub in the process. Then shave it off little by little with the knife. If done properly, it’s good enough to hide nub marks even on armor pieces. The key here is patience…
Big nub mark
Nub mark being shaved
Voila! Almost no nub mark!
Step 2 Conclusion
Pros: much cleaner compared to approach number 1’s results
Cons: the constant threat of slicing off your finger with the hobby knife
3. Progressive sanding.
Do this when you have side cutters, sanding sponges (or regular sand paper) and hobby knives (optional).
I just recently tried this out, and I really liked the results. It is almost the same as number two, but this time we use sand paper in place of the hobby knife. You can still use the hobby knife if you want. The basic concept is to sand the nub off progressively, so as not to damage the surrounding area. Start with a rough grit like 600, then use finer grits to give it a smoother surface.
Here’s an armor piece from Gelgoog again. After trimming down the nub with my trusty hobby knife, I sanded it off and along the edge of the armor piece with a 600 grit sanding sponge. Yep, I got to use my cheap sanding sponges!
Sanded with 600 grit: Sand it until you level the nub. Beware! – 600 grit can really do some damage if you over-sand the part.
Sanded with 800 grit:
Sanded with 1200 grit:
Sanded with 2000 grit:
And finally, I cleaned it up with a piece of cloth:
Not bad, huh? This technique even fooled me – I sanded the leg armor part below for this blog post, threw it onto the pile of other Gelgoog parts and promptly forgot all about it. When I went back to removing the nubs from the rest of the parts, I happened to pick up this certain piece again… and went, “WTF?? Where are the nubs?? How come this one doesn’t have any nubs??”
You can have your choice of grits, obviously; some people use up to 2500 or 3000 grit to ensure a smooth finish. I’m just too lazy to hunt those sandpapers down 🙂 Some also prefer to start with 800 grit, but I think 600 is safe enough for Gunpla. Be careful not to inhale the plastic dust, so wear a mask to be safe.
Step 3 Conclusion
Pros: leaves almost no trace of nub marks
Cons: takes a LOT of time and patience
That is all! Hope you enjoyed this post, fellow Gunpla builders. Till next time!