Product review: Tamiya Extra Thin Cement

The finest plastic cement I’ve ever had the pleasure of using.

I’ve decided to do some basic product reviews on the site, and the obvious first choice that sprang to mind was Tamiya Extra Thin Cement. I was turned onto the stuff by Subtle Discord of   The Dark Works fame. He uses it all the time when he works with styrene scratch-builds.

I thought I’d give it a shot and see what all the fuss was about. I’d seen it around at my local scale model shop, but they have so many funky chemicals I never know what’s actually good.

The short version: Get this stuff right now.

I have a pile of plastic cements sitting around, some old, some new. I’ve used so many over the years and I have to say, this one is a game changer. Even though I thought it would be a very niche product, I now use it for 90% of every plastic model I glue. Let me tell you why.

Powered by capillary action

Tamiya Extra Thin Cement.

Tamiya Extra Thin Cement. Otherwise known as magic in a bottle.

Capillary action is what allows your blood to flow into the tiny little capillary veins in your body. I’m no scientist, but I understand It’s a natural property of many liquids (especially water) that causes them to pull themselves into tiny gaps and cracks, due to surface tension. This glue uses it to powerful effect by filling every tiny crack between the two surfaces you’re trying to join. That’s how the magic begins.

This glue is so thin (as its name suggests) that it literally pulls itself into the gap while you just sit there and relax. It works so well, you can simply hold the model together and touch the tiny brush (built into the cap) to the joint, and wait. You can also paint it onto a surface. If you do this, make sure you remove most of the glue by running it across the lip of the bottle. If there’s too much loaded up, it can (and will) find cracks and seams on the detail of the model and run along them. I haven’t experienced any major issue when this happens, but surely it must obscure a little detail and it can be messy if you’re not careful. It doesn’t take very much of this stuff to form a strong bond, so use it sparingly.

Once you get the hang of it, Tamiya Extra Thin Cement’s capillary action allows you to be far more precise when you’re gluing something together. You can get it all set up, even rubber band the items together or hold them tightly, all without attaching anything permanently. Then you just touch the brush to the join and chill. Go from dry-fit to permanent join in minutes, basically.

But wait, there’s more.

If the thin nature of the glue was the only benefit, it would still be an excellent product and I’d recommend it to you all. But it gets better. The bond is really, really strong with this stuff. I had assumed, for whatever reason, that it would be weaker than Citadel plastic cement or other similar products. Maybe I thought it would be watered down or something. I was very surprised to find the joins even stronger than what I was used to. It took some playing around, but I realized this glue makes good on the promise of all plastic cements: It melts and welds plastic together. I mean really melts it. Because the chemicals are so powerful, and the glue’s so thin, the same capillary action works in reverse on the plastic it melts. It pulls the plastic into the glue. When it does this from two pieces, it pulls them together and mixes them at the seam. This is especially evident when you use plastics of different colors, such as the gray Citadel plastic and white Evergreen plastic sheets. The color has a smooth gradient from gray to white, and the join is super strong. I think I had been using too much glue before, so the joins were a little weak as the plastic wasn’t thoroughly mixed in the middle.

The other indication of the powerful melting is that, when it’s had some time to work, if you squeeze the pieces together really hard, liquid plastic will seep out of the joint. This isn’t really a desirable thing but it only happened to me when I did it on purpose to test it. When I’ve done the same with regular plastic cement, only glue would seep out.

My favorite way to use this glue now is to ‘tack’ pieces together with little dabs, let it set for a few minutes, and then make any small adjustments it needs. Once I’m happy with the pose or fit, I then ‘flood’ the cement around the joint and let it fill in on its own. If you do a lot of conversion and kit-bashing, you’ll know that sometimes your cuts and joins can be a little rough. This cement, on its own, smooths out those rough spots where you get a little carried away with a chisel cut or something and reduces gap filling and cleanup to virtually non-existent levels of work.

Using Tamiya Extra Thin as a gap eraser

One thing that really surprised me about this cement was its ability to fill and ‘erase’ seams and gaps. It takes a couple of treatments, but if you go over a seam that’s already glued, yet still visible, it will fill in and pull some of that plastic up to sit closer to flush. Think about spots like space marine torsos. No matter how hard you try, the neck space and sides always have visible seams. After gluing them together, I was able to give it another shot after it dried fully (it can take a while) and they all but disappeared. After 3 treatments they were gone. Vanished. I’ve seen tutorials online for using different chemicals to do this same thing — the craziest one was using scale modeling water effects to fill in. I think this glue might be the easiest way to fill gaps I’ve ever used. It won’t replace Liquid Green Stuff, regular Green Stuff, putties like Tamiya White Putty or Squadron Green, but it will definitely take a place alongside them. Just one more tool in the arsenal.

This might not seem like a big deal, but…

The glass bottle is really nice. It’s heavy, has a very low center of balance, is big enough to get a good grip on and is incredible stable. When I do assembly work, I often work on my couch so I can watch a movie. Sometimes I use a lap desk, sometimes I don’t. With this bottle, I’m able to just leave it sitting on one of my legs or even a couch cushion and screw or unscrew the top with one hand. That means less reaching and grabbing and fewer chances to knock over all the tools and bits that inevitable end up balanced all across the folds of clothes on my legs and shirt or blanket. Like I said, it might not seem like it’s that cool, but the bottle is actually one of the reasons I really appreciate this stuff. Oh, and the little brush is pretty great, too. Just the right size.

The cons? Er…

I guess, if there’s a downside at all, it’s that you have to be a little careful since this stuff really likes to run across seams. Like I said before, though, even when this has happened to me I haven’t seen it distort any details. There have been a couple of times where it’s ran down to where I was holding a piece and if you don’t notice right away, you can put a fingerprint in a flat surface. It’s kind of cool that it can do that, but be careful if you’re working on a space marine shoulder pad or a tank or something broad and flat like that. Once you’re used to the way it works, the results are very predictable and controllable but it takes some getting used to before you feel totally comfortable with it.

The other thing worth mentioning is that, since it does melt the plastic so thoroughly, you might notice that brushing over the same spot you’ve already done will actually pull a little plastic onto the tip of the brush. I noticed this with some dark plastic, where it seemed to tint the brush tip a little. Once you put the brush back in the bottle I think it just disperses in, and hasn’t caused any problems with the brush getting gunked up or anything like that. Just worth noting that it works that fast. EDIT: The stuff in the pot gets pretty cloudy/gunky after a long time. I haven’t noticed any change in the effectiveness, so don’t sweat it if you notice you’re gunking up the brush. It will clean itself off, but all that melted plastic will disperse into the pot.

What I use it for:

Everything. Just about, anyway. I’ve been putting together a Land Raider, some Vanguard Veterans, two Stormtalons and the entire set of Space Hulk genestealers, plus the Blood Angel librarian and objectives. I’ve used this glue for all of that. It’s made the plastic work cleaner and easier than anything I’ve done in the last 20 plus years. I’m not just saying that, either. Real talk: Tamiya Extra Thin Cement is a game-changer.

On larger flat areas, I wipe most of the excess off the brush, smooth a very thin layer across just one side, press the pieces together and then load up the brush and just touch it to one part of the gap. If it’s a really long seam, I’ll dip the brush one or two more times and touch around the other corners or sides. So, so easy.

On smaller bits, as I mentioned earlier, I usually just hold the two sides together with my fingers and touch a loaded brush on the join. I might just touch the brush to the lip of the bottle so it takes a drop off, but sometimes I don’t even do that if I want to flood a good amount into the area or erase a seam like I mentioned above.

I have yet to find a job that made me think, “hey, I want to get out my thick glue for this one” but maybe sooner or later it will happen. I think I’m in a weird honeymoon period with this glue, but it’s about as exciting as a grade-school crush at this point.

So, how about it? Have you used it? Do you have a favorite that you think can trump Tamiya Extra Thin Cement? Let me know in the comments below.