A beginner's guide to building plastic model cars

Thanks.  These articles are always ineresting, even for old salty modelers.

I got to the following statement and said "WHOA"!!!

"Liquid plastic cement works best on unpainted styrene. It’s easy to use: squeeze the parts between your fingers that are being glued, collect a generous amount of liquid glue with the in-cap applicator, and touch the applicator to the joint. Capillary action will pull the cement into the joint. Within 20 seconds, the parts will be joined."

Folks you are just asking for trouble when doing this! Be VERY careful where you place your fingers as the "Capillary" action can (and will) sneak under your fingertips and ruin the plastic that you are holding together!

"It’s easy to use: squeeze the parts between your fingers that are being glued, collect a generous amount of liquid glue with the in-cap applicator, and touch the applicator to the joint. Capillary action will pull the cement into the joint. Within 20 seconds, the parts will be joined."

Just to throw my  in on this as well:  This technique works a lot better if you leave a tiny gap between the two parts before touching the applicator to the joint.  Continue to hold the parts just slightly apart for that 20 seconds, and then press them together to get a nice, even little bead of melted plastic to ooze from the joint.  That little gap gives the cement a place to hang out so it doesn't immediately evaporate before its able to fully do its job.

You can also adjust the alignment of the parts while the plastic is still soft to get panel lines lined up and make sure you don't have a step between the parts.  After 24 hours (or at least overnight to let the plastic fully re-harden), I gently sand the joint with progressively finer grits of MicroMesh and am able to eliminate a majority of any visible seam between the parts.

Speaking of seams.  CA is a much better way to fill seams and gaps than using putty.  Just put a very tiny amount of CA in the gap with a toothpick and let that cure overnight.  Then take a Fine Point Sharpie and scribble along the cured bead of CA.  Gently wet sand the blackened bead, following the curvature of the joint, until all of the black sharpie is gone.  Prime it to check how succsessful you were with filling the gap, and about 95% of the time the seam will be completely eliminated on the first try.  No putty, sand, repeat dance...and no orange, green, or white dust all over everything.  The other good thing about the CA method is that if you did miss a tiny gap here and there, you can dab a little more on the spots you missed, right over the top of the primer.  If you dab it on and leave it alone overnight, the primer and CA will have mixed and become one.  Can't do that with solvent-based putties either.  I use the same technique for filling pin marks.  CA also can be scribed without cracking, chipping, or coming loose, so re-scribing across the joint is much easier than trying the same thing with putty.

BigJim

I got to the following statement and said "WHOA"!!!

"Liquid plastic cement works best on unpainted styrene. It’s easy to use: squeeze the parts between your fingers that are being glued, collect a generous amount of liquid glue with the in-cap applicator, and touch the applicator to the joint. Capillary action will pull the cement into the joint. Within 20 seconds, the parts will be joined."

Folks you are just asking for trouble when doing this! Be VERY careful where you place your fingers as the "Capillary" action can (and will) sneak under your fingertips and ruin the plastic that you are holding together!

 

Thanks for the comment, Jim. Thin cement works via capillary action--the glue is drawn into the join or seam between the parts. You make a good point that modelers should be aware and careful of how they're holding parts when gluing (no matter the glue they're using) and painting. 

We go into more detail about using various glues on models in this Scale Model Basics video, Glues and How To Use Them.

Eaglecash867

Speaking of seams.  CA is a much better way to fill seams and gaps than using putty.  Just put a very tiny amount of CA in the gap with a toothpick and let that cure overnight.  Then take a Fine Point Sharpie and scribble along the cured bead of CA.  Gently wet sand the blackened bead, following the curvature of the joint, until all of the black sharpie is gone.  Prime it to check how succsessful you were with filling the gap, and about 95% of the time the seam will be completely eliminated on the first try.  No putty, sand, repeat dance...and no orange, green, or white dust all over everything.  The other good thing about the CA method is that if you did miss a tiny gap here and there, you can dab a little more on the spots you missed, right over the top of the primer.  If you dab it on and leave it alone overnight, the primer and CA will have mixed and become one.  Can't do that with solvent-based putties either.  I use the same technique for filling pin marks.  CA also can be scribed without cracking, chipping, or coming loose, so re-scribing across the joint is much easier than trying the same thing with putty.

 

Good stuff, Eagle. Superglue (also known as cyanoacrylate or CA for short) can definitely be useful as a filler. My only caution is that superglue, when fully cured, is harder than the surrounding plastic. Be sure to sand before it has hardened completely to avoid possibly deforming the plastic around the superglue.

We go through using superglue as a filler in our Scale Model Basics video, "How to fill gaps and seams on scale plastic models."

cbaltrin

Thanks.  These articles are always ineresting, even for old salty modelers.

 

Thanks! We like having the basics out there to help anyone and everyone.

Tim Kidwell

Good stuff, Eagle. Superglue (also known as cyanoacrylate or CA for short) can definitely be useful as a filler. My only caution is that superglue, when fully cured, is harder than the surrounding plastic. Be sure to sand before it has hardened completely to avoid possibly deforming the plastic around the superglue.

I always sand it fully hardened, using the steps in my post.  The Sharpie indicator keeps you from over-sanding.  I think the deformation comes in when trying to sand it before its fully hardened...its hard to gauge what's what when its not fully hardened.  I think a lot of problems using CA also arise from people wanting to use fillers in the CA, which makes it really difficult to sand.  I also tend to avoid using any kind of accelerator on CA when filling seams, which also leads to overly-hardened CA that is jagged.  Used all by itself, and given sufficient time to cure, the process is practically fool-proof.

Eaglecash867

 

I always sand it fully hardened, using the steps in my post.  The Sharpie indicator keeps you from over-sanding.  I think the deformation comes in when trying to sand it before its fully hardened...its hard to gauge what's what when its not fully hardened.  I think a lot of problems using CA also arise from people wanting to use fillers in the CA, which makes it really difficult to sand.  Used all by itself, and given sufficient time to cure, the process is practically fool-proof.

 

YMMV. Glad it works for you, and the Sharpie guide is a good tip. 

BigJim

I got to the following statement and said "WHOA"!!!

"Liquid plastic cement works best on unpainted styrene. It’s easy to use: squeeze the parts between your fingers that are being glued, collect a generous amount of liquid glue with the in-cap applicator, and touch the applicator to the joint. Capillary action will pull the cement into the joint. Within 20 seconds, the parts will be joined."

Folks you are just asking for trouble when doing this! Be VERY careful where you place your fingers as the "Capillary" action can (and will) sneak under your fingertips and ruin the plastic that you are holding together!

 

That process is exactly what some of those glues are designed for.  Tamiya thin cement with the green cap for example, is intended to be used this way. I love that stuff.

I also use it on small clear parts like headlight and tail light lenses. You can place the piece where it needs to go and then wick the glue in around the edges.