Ok, I've got a question. I've read that styrene glue is better than Super glue on styrene models.  Due to the fact that it melts the plastic together and forms little beads where the glue is that helps with the seam filling.  How long does it take the styrene glue to "totally cure" before it is safe to sand??  Most of the time I use super glue because it does not take long for it to dry therefore sanding can be done almost immediately afterward.  Is styrene glue better than super glue??

No glue expert here, but I experimented with CAs and went happily back to styrene glue. CAs have no wiggle time for adjusting and aligning, and glues made for styrene will take more pressure without snapping back apart.  Don't know cure time, as there's usually enough to do on other areas before continuing on with a subassembly, giving each bit plenty of time to cure.

Have you tried the stuff like Ambroid Pro Weld?

dreamer

Normal Testors glue, both liquid and tube, give it a full day before you start sanding.

There is another liquid plastic cement called Tenax 7R that sets up in just a few minutes.  I have a friend who swears by it.  You can sand almost immediately.  The problem I have with it is that it evaporates VERY fast, so you really can't do any big seams with it.  Like, by the time you've brushed it on a whole fuselage, it dries before you can get the fuselage halves together.  I'm told it's best used by holding parts together and using the brush to let the glue "bleed" into the seam by capillary action.  I have yet to master that.  But it IS great on smaller models with smaller joining seams.

John P

I use Testors and Tenax... for different things.  If I have a seam to put together (like 2 halves of a fuselage) I use Tenax.  I use a capillary applicator; start at the place where the parts fit best.  I do just a couple of inches (or less) and let it set, then do a little more, and let it set.  It takes a while to get the whole thing done, but I only have to aline one small section at a time, so I end up with a very good fit all the way around.

Since Tenax creeps thru a joint, the parts are best glued when they are already together, so this approach works well... requires little if any clamping... and makes it easier to get it lined up properly all the way around.

Tenax does evaporate very quickly, so you lose a lot of it before you even use it... make sure you have a good supply!

If I have a smaller contact point (like landing gear) I use Testors tube glue for more control.  And I use AC where I am connecting different materials, or have tiny contact point... like putting on spark plug wires.

They all have advantages... and I am sure that with practice they all wok equally well.  One big difference though... for Testors & Tenax, I allow at least 6-8 hours before sanding (12-24 is better) but with CA you want to sand it soon, because it will get hard and harder with time.

naplak

That's the way I've been doing it for years and it's the ONLY way I ever join fuselage halves.  I'm surprised that you say you haven't mastered it because it's not hard and, having seen your work, you're abilities are quite obviously above average.

I apply it with a long, thin, soft artists brush.

It makes lining up seams significantly easier.  My standard method is to start at the tail of the plane.  I will usually use tube glue on the fin/rudder because they have flat, broad mating surfaces.  After gluing the fin, I hold it with tape and start on the fuselage.  That's where the advantage of applying liquid cement to the seam with capillary action is ideal.  You can line up a small portion of the seam to perfection (say the seam from the rear of the cockpit to the vertical fin) and then apply the cement.  You don't have to worry about what's happening on any part of the fuselage seam.  Just get those few inches perfect.  Then do the same thing on the bottom (maybe from the rear of the wing root to the tail).  By doing a few inches at a time, you can get each section of seam perfect.

That might not be critical if you're doing a Tamiya kit where everything lines up perfectly to start with.  You can put thicker cement on the seam and be reasonably assured that everything will line up just fines when you join the halves.  But if you're a poor boy like me building kits from old monogram molds (like the Voodoo), doing the seams a few inches at a time is big help.  I put that Voodoo fuselage together with liquid cement and polished away the seam to invisibility without a drop of filler.

BTW, Just last night, I was test fitting the fuselage on my AMT B-52G.  OY!  I dare anybody to put tube glue on those seams and line it up within 3 HOURS!

TO THE ORIGINAL QUESTION: Styrene cement is preferred when practical.  I use CA for joining some smaller components when it's not practical to use regular glue (i.e. attaching landing gear doors, antennae, missiles).  But styrene glue is definitely stronger in the long term.

Brent G.

Another liquid cement that works about as well as the Tenax 7R is Plastruct Bondene, and it has the advantage of being about half the price of the Tenax.  Tenax/Plastruct can also be used as an accelerant to the Testors tube glue.  Just use the tube stuff as you normally would, when everything’s in position, apply the liquid over it and hold a few moments. Instead of waiting a day, the seam can be worked in a few hours.

renegade

I only just started using Tenax recently, Brent, give me time.  It's hard to break the old habit of applying it to both seams before joining the halves.  I find it hard to believe one can "bleed" enough glue into a seam to hold it well.

I did use Tenax to glue the Trumpeter F-107 fuselage together.  One thing I love about it its sandability in seams.  Tube glue often seams to sand differently than the surrounding plastic, leaving a slightly visible seam. Tenax doesn't do that, and now I know why.

John P.

Ah...therein lies the difference between liquid cements and most other products (under the generic umbrella of "glue").

Many products create a bond that's primarily chemical.  CA is the best example of this.  Epoxy is another obvious example.  Also included are any of the various wood glues (although people don't use Elmer's for plastic models...well, except on the clear parts).  And, to a lesser (but still measurable) degree, it also applies to the thicker "tube" type glue we use on plastic.  This generally has a filler not chemically unlike celluloid.  These glues all add a third agent in the seam to hold the parts together.

Liquid cements of the Tenax type create a mechanical bond.  They are not designed to remain in the seam or become part of the joint.  They are designed to dissolve the plastic and then evaporate.  It's analogous to welding...two components "melt" together with no third agent binding them.

So you don't have to get enough glue into the seam to hold it.  You only have to get enough glue into the seam to dissolve the plastic for a few seconds.

Brent G

ed.note... to recap, a "glue" remains in the joint to bond, a "cement" causes the materials to weld together

For your run of the mill styrene kit I usually use Testors styrene glue in the triangular bottle with the needle nose applicator.  But there are times when you have to pre-paint a part before assembling...such as the Land of the Giants Snake Scene.  The mouth is best assembled and painted before 'trapping' it inside the two head halves and here is where regular styrene just didn't seem to want to bond a painted surface to an unpainted one.  My solution was to use Super Glue Gel.  The Gel bonds the two surfaces together but doesn't dry as fast as regular super glue and gives you ample "play" time when aligning/adjusting.

Mark S.

I use both types, but found Tenax very useful.  I tried dipping my #11 blade into the stuff and applying it that way. It goes right where you want it, not too much and can get into those fine cracks that need just a little.  It may take a little longer, but no fuss or muss.  Just be careful that you don't get too much Tenax on your blade.

Ken M.