Best Way To Apply Solvent Type Plastic Cement

[tlaswell]

I like the touch-n-flow applicator but in trying to use the bottle it came with to apply suction I ended up breaking it into small and smaller pieces. 

Not recommended but I did find I could apply enough suction and air pressure with my lips.  (MEK doesn't taste good so be careful)

[peteski]

I like the touch-n-flow applicator but in trying to use the bottle it came with to apply suction I ended up breaking it into small and smaller pieces. 

Not recommended but I did find I could apply enough suction and air pressure with my lips.  (MEK doesn't taste good so be careful)

If you follow the included instruction, you should not have to apply *ANY* suction. The liquid cement will be drawn into the glass tube by capillary action. 
But if the metal needle gets clogged up by some small debris in the liquid, it will not work properly.  That does happen.

[robert3985]

I used to do that. Anymore, I use brush-on Krazy Glue, which allows you to apply a really nice thin, well-controlled layer of CA. I've found it to be a bit more reliable than the dissolved-plastic-pseudo-bond technique.

@David K. Smith  , DKS, I didn't even know Krazy Glue made a "brush-on" variant!  I think I'll have to try this option on my next Golden West CA-4 I've got on the bench right now! 

Thanks!

Cheerio!
Bob Gilmore

[MK]

Any Thin CA (or CA-) can be brush on.  It has a viscosity of water (perhaps less).

[peteski]

Any Thin CA (or CA-) can be brush on.  It has a viscosity of water (perhaps less).

Well, same goes for medium and gel viscosity.  Thin CA spread over larger areas gets really pungent (it seems to emit strong fumes) and it sets fairly fast.  I think what makes that specific one brushable is the fact that it includes a brush in the cap.

[MK]

Well, same goes for medium and gel viscosity.  Thin CA spread over larger areas gets really pungent (it seems to emit strong fumes) and it sets fairly fast.  I think what makes that specific one brushable is the fact that it includes a brush in the cap.

No, you really can't brush on medium or thick CA as they won't get into the seams.  It'll be like brushing on Shoe Goo. 

The idea here is to imitate the characteristics of liquid solvent type plastic cement.  Only thin CA can flow like that.

BTW, all CA gives off door regardless of viscosity.  Some people develop a sensitivity to the odor over time and have to switch to odorless CA, often called foam safe CA.

[peteski]

No, you really can't brush on medium or thick CA as they won't get into the seams.  It'll be like brushing on Shoe Goo. 

The idea here is to imitate the characteristics of liquid solvent type plastic cement.  Only thin CA can flow like that.

BTW, all CA gives off door regardless of viscosity.  Some people develop a sensitivity to the odor over time and have to switch to odorless CA, often called foam safe CA.

But in this example (attaching etched walkways to the roof), there is no need for the CA to flow into any seams. Actually it is beneficial for it to stay on the surface and no flow out anywhere.  And if one brushes on CA to glue large surfaces together, there is also no need for the brushed-on liquid to flow.

Actually, brushing thin CA onto model's surface in hopes that it will slow into seams seems to me like a huge mess on the model's surface.  Why not just apply a drop of the thin CA anywhere on the seam, and it will then cleanly flow along the seam - clean an neat!

As for the fumes yes, all CA glues emit fumes, but from my own experience I can state that when spread over larger areas, the thinner CA is, the more concentrated odor it emits.

[DKS]

@David K. Smith  , DKS, I didn't even know Krazy Glue made a "brush-on" variant!  I think I'll have to try this option on my next Golden West CA-4 I've got on the bench right now! 

Thanks!

I've only ever seen it sold in Michael's, although I imagine it can be purchased online easily enough. But I don't like waiting for it to ship--I go through the stuff way faster than any other form of adhesive, and I'm back to the store at regular intervals. It's especially useful for assembling laser-cut wood kits--just brush some on along an inner seam, and wham, it's done. I even use it on styrene kits in situations where neatness isn't an issue--faster than anything else. IMO, brush-on CA is the best thing to come along since CA itself.

As for the fumes, a small fan nearby, or an open window, solves the problem.

And yes, you can brush on other CAs, but the brush itself is the key; I've tried using other brushes, and have never found one that works right. Plus, the brush-on bottle is spill-proof, and having the brush in the cap is really handy. Not worth the trouble, IMO, to bother with anything else.

 

[randgust]

I think I'm with DKS.   I'm finding that I use solvent-based glue less and less and ACC a lot more.  If I really need a structural bond - like holding walls together, or putting reinforcements on to the back of sheet styrene, I may still use solvent.   But for basic work, I'm using more and more ACC applied with a needle or a piece of wire.   

I've had some really bad results with shrinkage/warping/deformation over the years from solvent glues on Evergreen styrene, that's what forced me to re-evaluate my process.   It may not show up even for a year or two, but eventually, you start to see it.    Particularly bad on laminating thinner materials, long edge bonds, stuff like that.    I've seen no similar impacts using ACC, however it's a lot more brittle and isn't suitable for anything that might get a shock load to it.

If you have Intermountain 'anything' you know that even if it derails or falls over, some detail is going to fall off of break loose.  That's when it's time to not use ACC.   The classic case is how many times I've had to repair the stainless grilles on my F-units that keep popping loose.

[Maletrain]

Isn't there a problem with getting new CA to stick to already cured CA?  That would seem to say that you probably can't use CA for a joint that you may need to repair if it breaks from use.

[randgust]

I think there is.  I make a practice of trying to remove as much 'old' ACC as possible and make a smooth joint.    ACC hates rough surfaces.    Less is usually more with ACC.

One of the things it works really, really well with is laminating up layers of styrene to get a specific target thickness.   It won't warp, it's incredibly stiff, and it's not coming apart.   Just laminate first and cut to final size later because you'll only get one shot at putting it together - bang!

[peteski]

Isn't there a problem with getting new CA to stick to already cured CA?  That would seem to say that you probably can't use CA for a joint that you may need to repair if it breaks from use.

I have never heard of that or experienced that problem.  And I use CA (and accelerator) or epoxy for most of my modeling glue needs. I only use solvent-type cements for only few select applications.

[CRL]

This is a very informative thread guys.

Keep it up.

[Jbub]

This is a very informative thread guys.

Keep it up.

Agreed! It's always nice to learn from those who know from experience and testing and not because that's how we've always done it.

[Santa Fe Guy]

Yep according to Intermountain guys way back when we had roof walk separation on some new box cars, they told us that CA will not stick to itself second time around.
It either needs to be totally cleaned off or another type of adhesive used.
Rod.