Time we had a serious talk about pesky glue strings

Model Railroader General Discussion (Model Railroader)
1

I now remember one of the most frustrating things about building models when I was a kid. No matter how careful I was, plastic model cement left strings of glue across all my models, like some tiny but horrific spider in a haunted Scooby Doo attic. I’m even more careful these days – a little dab’ll do ya – but I still get it everywhere. And replacing the cap after each application doesn’t help, it only makes the top of the tube nozzle crusty with half-congealed cement, which upon the gentlest of next squeezes forms a magma bubble that, once started, cannot for love or money be persuaded to get back down into the tube. It explodes and the tube attempts to disgorge all of its contents onto my work space, which I cannot deal with quickly because all three of my hands are tied up waving off strings.

I just saw something on MicoroMark’s flyer that looked promising: a very tiny-tipped applicator for such adhesives. Have you tried them? Do they work? They advertise its ability to apply the merest dab, but they don’t say anything about string reduction.

What products have you used or what tricks have you employed? I’m hoping that this post will prove to be a bonding experience for us all here.

-Matt

2

Liquid or thinned cement was one of the alternatives I used. Another was the use of round toothpicks, which are ‘spun’ in the fingers as withdrawn to keep the threading down, much as drafting pencils are rotated to keep the line width constant.

If you must apply from the tube, remember the first rule of soldering which is keep your tip wiped clean. I in fact kept a little solvent-dampened rag in a Baggie so I could keep up with this. Note that you may be able to work a solvent-moistened tool with your other hand to break the glue bead you laid down on the model away from the material still in the nozzle before you pull it out and it flash-hardens on the surface of a forming string or thread…

The little solid applicators can be used much like long toothpicks. Part of the trick is not to use an excessive glob on them in the first place, and to spread the glue in such a way that you’re not withdrawing the tip from a wet pool of applied glue, but off to the side where you can pinch the bead off as you withdraw.

Something I made use of (although I wouldn’t write home as to its safety) was to use a small bead of the adhesive on a piece of glass, and apply a small amount of a specific solvent over the glue to make it thin on the surface of what I picked up on the toothpick. I think this also helped keep the glue workable longer == admittedly these were solvent-type glues more than celluloid types like Ambroid or rubber ones like Goo or Pliobond.

Be very careful and alert if you use the kind of applicator that has a fine needle tip with a capillary passage in it. I’ve never used these for anything but pure solvent ‘glue’ (for example, when fabricating acrylic) – and in particular never, ever, ever succumb to the temptation to use one with cyanoacrylate. No matter what, and no matter how quickly you stick the tip in

3

I haven’t used tube-type glue since pre-teen days, building cars and boats. I don’t recall having any problems with glue strings.

When I finally discovered Testors Liquid cement, the tube glues were abandoned.

When the Testors cement was used-up, I simply refilled the bottle with lacquer thinner, and carried on (at a much more affordable cost).

Several years ago, some lacquer thinners were reformulated to be “safer”, and while they still worked well as a thinner for lacquer-based paints, the new version became useless as a cement for styrene.
At the suggestion of some other modellers, I switched to MEK (methyl-ethyl-ketone), which works fairly well with styrene. However, at least one of the components seems to be more volatile than was lacquer thinner, and if left uncapped, it doesn’t work all that well.

I bought a gallon of MEK for about $40.00 (more than double the price of the original lacquer thinner) and simply use a length of brass tubing, with my thumb over the top of it, to transfer the MEK from the can to a re-purposed Solvaset bottle. The brush-in-cap of the Solvaset bottle works just fine for applying MEK.

Since the Solvaset bottle is fairly tall, it’s easy to accidently knock-over (and make a real mess of anything plastic that might be nearby) I drilled a hole in a scrap of 2"x4", then used a rasp to square it off to accommodate the bottle…

Time to make a change in your glue choices, I think, and get rid of the strings.

And, if you’re going to use contact cement for other projects, get the gelled version in a can - no strings and easy to apply.

Wayne

4

Matt,

I use the thin liquid adhesives like Testors, Tamiya, and Plastruct. Of the three, Plastruct is the most aggressive and I use that for applications where I really want two pieces of styrene to bond together well.

You can apply them with the built-in applicator brush. You can also purchase finer, natural-hair paint brushes from art supply stores. I like 10-0 paint brushes for applying liquid adhesives inside stirrup and handrail holes when building kits.

Tom

5

I, too, use MEK.

And I, too, apply it with a paint brush.

Ed

6

You have an abundance of Sound Advice here Matt.

I agree with what you are being told by a lot of great modelers here. I have built a lot of styrene bridges and kit bash different types of plastics together. I haven’t tried the MEK yet but have been wanting to give that a shot. I just haven’t found it yet.

I prefer the Tamiya because it’s the thinnest stuff on the market that I know of as it seeks the best. Each of these two solvents have a built-in-brush attached to the cap and you can accidentally over apply it on your modeling and it doesn’t hurt anything unless you touch it too soon after the application.

If the Tamiya doesn’t work, the orange label (Forget the white) Plastruct multi-purpose always does well for me.

TF

7

I have not used tube glue since…I can not remember. Kind of like Doctorwayne. But I have a tube in my stash just in case.

8

I’ve discovered that the tube type glue is ideal for putting together models like the Walthers roundhouse, because without a LOT of sanding and filing, the walls don’t fit to the floor, or to each other, very well. Lots of hidden gaps, and the liquid type cements don’t fill them at all. The parts wind up stuck together in one or two small spots along the length of the joint, with the rest loose. This does not make for a sound structure. Last Christmas Eve my roundhouse reverted to kit form when I dropped a roof section on it.

So I went back and used Testors gooey glue to put it back together. Used judiciously, it fills in the gap but doesn’t show on the finished model.

I carefully applied the glue directly to the mating surface of one part (using the tube itself), then put the connecting part in place. I didn’t have a problem with strings, or with the glue bubbling out all over.

It just takes a bit of practice, and a light touch when squeezing the tube. I always used a wiping motion as I finished applying the bead of glue (dragging the entire opening across the end of the bead, whiched seemed to eliminate the string issue.

9

I have used different types of glues but like the gel types. I always seem to come back to the orange tube testors. When I use CA, I try to always use the gel types also.

Like Mark, I prefer the schmutzing bond between two pieces the orange tube gel provides.

I get glue strings when I work the tube for too long of a time for a small amount. Also resorting to round tipped toothpicks for those applications.

10

I use the orange tube for heavy duty welding, like the thicker wall panels of DPM structures.

11

Yes sometimes you need tube glue. In those rare cases put more on the card or whatever you use to hold the dab of glue before you pick it up and deposit it where needed. Also use a pin, the long type with a ball on the top. Change glue dabs often as they dont work without strings for long. Last a thinner can make the glue any consitincy you need.

12

“Reverted to kit form,” I got a good larf out of that.

Great tips here, gang. My thanks. But seriously? No one noticed my brilliant quip about “a bonding experience”?

I’m gratified to hear that some of you have known the frustration of glue strings, even if it turns out that the problem is not with the tool but with the workman. I do use a toothpick, but it sounds as though I need to incorporate some more deft wiping and twisting motions into my application process. These other materials will take some research. Thanks for all the ideas.

@Wayne, your woodblock glue bottle holder – that there is the very picture of American ingenuity.

13

I agree.

These are all ditched WAY in the back of my “supply” drawer. There are so many more alternatives today.

Dope_60s by Edmund, on Flickr

One product I occasionally use is the GS Hypo Cement and it IS very stringy but there are times when no other cement will do. It is more of an adhesive than a solvent. Another big drawback is that the cement continues to ooze out of the nozzle between applications so you have to be ready to cap it right away.

Tenax R7 was probably my first thin solvent cement and that stuff kind of spoiled me. Today I use the several grades of Tamiya and I also like the needlepoint applicators of the Faller Expert cement.

It takes more than one kind of nail to build a house, likewise with cements and adhesives on a typical MR structure.

I can’t recall the last time I used the traditional Testors tube cement. Still have a few unopened tubes on hand, just in case.

Regards, Ed

14

I believe, in this case, that you’re observing Canadian ingenuity.

15

I seem to recall a glue-bottle tipping thread here a while back?

Cheers, Ed

16

I noticed the play-on-words in the last paragraph of your OP, Matt. It stuck out for me because I adhere to a similar sense of humor. [;)]

Since our hobby is very international, it maybe better worded as “MRR ingenuity”. A good idea is a good idea - no matter who came up with it first.

Tom

17

[:D] I have to smile at that statement.

When I show pictures of my layout, sometimes I get readers saying they are ‘going to pinch my idea’. I reply 'Not my idea. It has been around since 1930s/40s (and possibly before that). I just revive them.

David

18

I use Testors 1 oz. Liquid Cement with Precision Applicator. This brand replaced the Model Master adhesive glue. It comes in an odd shaped plastic bottle with a needle nosed applicator.

This is an excellent adhesive for gluing styrene plastic parts together.

Rich

19

Here’s how you stop THAT from happening: When a bubble starts to form or when glue starts incessantly pouring out of the tube, all you have to do is grab the top of the tube and pull really hard on the bottom. This forces the air bubble out of the tube. You will see the air bubble come out of the tube and then your glue will magically stop flowing.

I’ve been using a tube for years without any problems. You just have to be careful not to use too much. I’ve found that the strings can be scraped away quite easily with a hobby knife after they have dried for a few minutes.

-Matt

20

It literally never occurred to me that you could get an air bubble inside a tube of glue.

I thought he was describing the phenomenon where cement sludges in the nozzle, requiring you to squeeze harder to get it to move… then when you get to thinner glue down in the tube the pressure causes the ‘eruption’ – the action being analogous to dribble out of a trigger caulking gun.

The problem is that a tube doesn’t have an easy pressure release like the little toggle on a caulking gun. What I used to try to do was squeeze the tube in such a way that ‘sideways’ pressure would open the tube up a bit which would stop the emergence. I confess to having experimented with gluing a little knob onto the face of the tube that would let me ‘pull’ it open, out of frustration that I couldn’t do that easily on a ‘stock’ tube.

I think the ‘pressurization’ problem was/is worse on the older metal tubes than modern ones. Perhaps the air-bubble issue is more notable on modern plastic tubes.