Question I’ve read plenty of modelers talkingabout using capillary action when gluing their models, as opposed to applying the glue to both parts to be glued.
When would one choose one over the other? Which forms the stronger bond?
Is capillary action better suited to a particular type of glue? I would think that probably the thin glues would be better suited then a thick glue, but beyond that, is one glue type better than another?
I use CA exclusively. I don’t have the patience for any other and have been using CA for 20 years. Although I typically use medium viscosity, I will occasionally use the capillary ability of thin.
Capillary action means touching the join with a drop of thin glue and it flows along the gap. Thick glue will just sit there in a blob. Thin weld type glues are good for seams where you touch it and it will flow itself through the gap. They also tend to bite and cure quicker, ( which can be a pain sometimes!) Thicker glues, especially CA, are good for gap filling too.
Misty,
I know what capillary action is, I was curious as to when and why one would use it as opposed to “painting” glue on both pieces and then joining them together. As well as other than the obvious of thin glues which glues lend themselves best to the technique. As well as which forms the stronger bond.
I guess it comes down to preference. Some like using CA exclusively, others for special applications, etc…
The strongest bond on styrene will be a liquid ‘welder’ solvent cement, and these are easiest appliied by capillary action, i.e. a touch-n-flow applicator. CA glue is brittle but strong, welding cements make two pieces of styrene one, but do not work well on painted parts. Just my 2 cents, hope it helps.
Solvent glues are by far the strongest, much stronger than CA. Man, I can’t imagine using that stuff exclusively!!??[:S] With a thin solvent glue, there is no need to brush it on the parts first, then join them. Just put the parts together, dab a little solvent on the seam, apply pressure-bingo. Done! Welded together. Any extra glue that oozes out can be sanded down and actually acts as filler. This all happens almost instantly. I can’t imagine how using CA saves time over solvent glues, unless its absolutely necessary.
D_C,
It’s hard to say which is better all around. I use both, but it depends on the situation.
I use liquid solvent cements (Tamiya extra thin, Tenax) with capillary action whenever I want the seam to disappear. Fuselage halves, wing halves, are a good example of this. The capillary action technique really lends itself to hiding the seam.
If the seem does not need to disappear, I use Testors cement in a black bottle with the applicator. (This glue is underrated, IMHO). Pilot seat, control stick, some wing to fuselage joints, are good examples of when I use this stuff. This stuff is thicker and gives me some working time to make sure I can get proper alignment. Obviously, the higher viscosity of this glue means capillary action won’t work. I just apply the glue to one part, not both. I apply this stuff sparingly because it will ooze out too much if I don’t. (In fact, I don’t use the needle applicator–it applies too much glue).
I have no idea which one makes a stronger bond. Both have solvents that fuse plastic together, but the thicker stuff in the black bottle also has a solid binder. I once used the black bottle cement to glue a fiddly bit on a Sherman tank (looks like a pair of tiny wings on the back of the turret, not sure what those things are called). I decided to model a different version and so had to remove the bits. I had a devil of a time doing so. I grabbed it, pulled it, twisted it. The thing wouldn’t come off. Usually fiddly bits will just “ping” right off with a flick of a finger (usually accidentally). But these things were holding on tenaciously! This stuff is surprisingly strong!
Chris
The “capillary action” method works best with very smooth, close fit. The method prevents too much glue and too thick a bond layer. But it means the joint must fit super smooth (little natural gap) in order to achieve that.
BlackSheep TwoOneFour,
Agreed, from what I have seen it appears that those who us CA generally use it for joining two dissimilar pieces together, i.e. PE to styrene, or vinyl ot styrene. Although as has been noted some use it exclusively, or almost exclusively.
AndrewW,
I agree, as I recall seeing styrene “melt” due to the chemical reaction between the cement and the styrene. Does capillary action produce a stronger bond then applying it to the two pieces and holding them together?
roll eyes…
Nathan T,
Right now, I’ve only used CA for joining dissimilar materials, i.e. chrome plated and regular unplated styrene. Or when attaching vinyl seats to the inside of a car.
I am not sure about applying to each piece, Cowboy, as most of the solvent cements I use have a very fast drying time. Because of the drying time, this is where capillary action is preferable. The touch -n- flow I use is just a clean way of applying, and aligning the parts before joining prevents any gaps or screw ups. Of course, I am referring to large pieces, wng halves, fuselage halves. For tiny bits, I set a dop on a surface with the touch -n- flow, set my piece into the drop, and later allow a drop to work around the outside of it. I think with melt and evaporation time, you’d not have time to paint the solvent on, align the pieces and clamp them. Also, the application is very neat, there’s no risk of accidentally applying to an unwanted area and melting detail or giving yourself a soft spot to leave a fingerprint impression in. Remember, the solvent does soften the styrene during the weld, until it ‘cools’ again. For the price of the touch-n-flow, which as I recall is not much, I think all the benefits are worth it.
Chris,
Thank you for the information. Right now i am using the Testors that comes with a purple lable, it is number 3502. I haven’t seen the stuff in a black bottle, but will have to look around for it.
Again, thank you for the information, it would be interesting to learn if there is or isn’t a difference in strength between the two types of joining pieces together, i.e. using capillary action or applying to one or both sides.
And I know what you mean, and it seems like “Murphy’s Law” goes into full force sending that little “fiddly bit” off somewhere where it won’t be found until years later.
Don,
Thank you for the information. Obviously I haven’t tried it yet, but I have read people talking about it and was courious to learn more about it. Thank you and everyone else who has helped.
I’ts all preference. It seems some guys think I’m off my rocker, but I have learned to use CA with all it’s strengths and weaknesses over the last 20 years. That’s my preference. Plastic glues just take too long IMHO and you run into the possibility of marring the plastic as it melts. I just don’t care to clamp, tape, hold the piece while it dries.
Yup… I agree modelcrazy.
From what I’ve found some glues just work best for certain applications, IMHO, I like CA for photoetch and those tiny bits that I want a little extra time to set but want a good strong adhesion that likely wont get bumped (interior details or small parts on landing gear). I like the plastic glue like Plastistruct and Tenex, especially for fuselage seams and wings. I too like the black Testors glue as well, it will fill a gap and seems very strong as well, even if it does take awhile to dry.
Steve, after seeing your kits first hand, I’d say you are a master with the CA! Keep it up!
MC,
I can see what you’re saying, up to a point. But given that plastic cement/glue is forumlated to work with styrene plastic does it not make sense to use it? And yes, I can see using CA for attaching PE, vinyl or resin to styrene.
And of course it goes without saying that it likewise makes sense to use a cement/glue that isn’t quite so volatile, as it were when attaching clear plastic.
Just asking.