Monday, November 8, 2010

Of glues and solvents

When it comes to models, a lot of people talk about the quality of sculpts and how far the injection molding process has come, but few people take the time to really consider one of the most important things in the hobby. How do you plan to actually assemble that $50 piece of styrene?

When the new (and rather stunning) Daemon Prince model came out, it was praised for its quality and the many customization options. I was at the Battle Bunker the weekend it came out and I saw a younger person assembling one of these fantastic models. I asked him to take a look at it, hoping to get a close look at the sculpt. Unfortunately, I was unable to really appreciate the model under the thick layer of glue coating it. Of course, one must wonder why he was even using glue in the first place.

To consider this question, we must first know about the different types of adhesives available. Here is a short breakdown and why you should use what when.

But he seemed so mild mannered!

The first and most common glue used in model assembly is cyanoacrylate glue, commonly called super glue or CA glue. This glue bonds best to smooth surfaces and fingers. The general tenacity of CA glue makes it perfect for attaching smaller pieces of metal models together but its low sheer strength makes it very easy to torque larger pieces apart. For this reason, many in the hobby drill holes and insert metal pins into larger metal models before using CA glue to seal the deal. It is available in many varieties, from the very thin to the gap-filling gels. With so many different options, fast drying times, and versatility in bonding dissimilar materials, every hobbiest should have some sort of CA glue on hand. Just remember to be careful with it, as it tends to be very exothermic (gets hot) if it is applied (or spilled) on cotton. Significant amounts can actually start fires!

not included - clamps, a free afternoon

Many people, frustrated with poor performance of CA glues on metals, decide to go the extra mile and use an epoxy. While found in many forms, epoxies always consist of two parts: a hardener and a resin. When these two parts are mixed, the resin begins to harden and bonds metal together with a rather amazing permanence. While very attractive for this reason, even the fastest epoxy adhesives take fifteen to twenty minutes to harden significantly and upwards of 24 hours to reach full strength. That is a long time to wait and a long time for something to go wrong. Many people opt to use epoxy putties, which operate under the same principal as the liquids but in a convenient play-dough format. These are very easy to under mix and generally don't adhere as well as the liquids. Best to avoid them unless you are using them to do some actual sculpting.

Also keep out of the reach of people who like to huff things in cans.

My favorite adhesive for the hobby is not actually an adhesive at all. It's what is called "plastic cement" or "plastic weld." There are many varieties for many types of plastics, but my favorites are ones featuring butanone (also called MEK), often diluted with acetone. MEK based welds work for most plastics and are generally rather high powered. What these solvents do is actually melt the plastic slightly. When applied sparingly to each side of a joint and pressed together, the plastic melts and fuses into a continuous piece. This results in a bond nearly as strong as the plastic itself. There are only a couple of concerns when working with plastic welds. First, you must understand that these solvents will not bond anything together that isn't plastic. It is literally impossible to glue metal together with plastic weld. Second, the fumes from plastic welds are very, very, VERY bad for you. It is recommended that you use these chemicals in a well ventilated area. Inhaling all of the fumes to store in your lungs and protect your friends and family is not recommended. Lastly, you must realize that plastic welds are very powerful and very thin. If you apply too much, some can soak into the space between your fingers and your model. The solvent will soften the plastic and leave a nice (and permanent) mold of your fingerprints on the piece.

Well, at least we know it's mine.

Once you have selected your glue, it is important to decide what type to get. I prefer thin glues because they have the ability to "soak in" and carry their way deeper into a joint, but I try to keep thicker CA on hand to fill any uneven gaps and provide a nice tight grab on metal models or metal to plastic. I use plastic weld for nearly anything else. Remember that less is more with glue and the smoother the surface the easier it is to grab.

To review, my work desk has three adhesives. A bottle of "control gel" CA glue for seam filling, some incredibly thin CA glue to do any bonding on non-plastics, and a bottle of MEK-based plastic weld with a brush to do most of the model work. What's on your bench?

1 comment:

  1. My UNIQUELY styled Wallpapers. During some ten years, I have developed an extremely complex and unimitable technique that should carry some interest of anyone pursuing a serious artistic ambition and expertise. And it's quantity as well: by now close to 3 000 wallpapers, all created by me. Why not tune in on my rapidly growing art blog? Its Copyright Anyone, as it SHOULD be for this genre!

    Weathertime Wallpaper Windows

    I run Deviant Art in parallell:

    Kraxpelax on Deviant Art


    And I write poetry in several languages:


    There's much in the world that you can't explain.
    It's revealed for you to remember
    by the whispering voice of a distant train
    or a midnight rain in november.

    Horizon within! You can always find
    the keys to Enigma. Let's mention
    one basic Truth: of spirited Mind
    Is Nature naught but extension.

    Internal expanses! In dreams, ridden
    by fear and longing you roam
    that deep Southeast in your soul hidden
    ...on your random journey back home.

    Single Swingle


    Casualidad sopla la sangre
    de alguno señor desconocido
    durante los pocos restantes
    momentos del resplandor de faroles

    que se vislumbran tras el follaje
    flameando de las obsesiónes
    igual efimero como gotas
    del cinzano de la soledad –

    En aquel tiempo me levanta
    dentro uno incidente avejentado
    que en seguida palidece
    al camouflaje de abstraccion;

    chica, nadie conoce que tus grisos
    ojos significan aún; con todo
    el sueño que hube evacuado
    tu escudriñas nuevamente.

    My Spanish poetry!



    Un orage nocturne illmuna maintenant l'Amazonie, franchis les Andes, envoya des jeux de cartes gigantesques et frappantes en bas à la Pampa –

    Puis: petit déjeuner à melon; café fumant !

    À la bague du cigare tu lis, étonné: GÉOGRAPHIE.



    Das Leben dergleichen Halbfaßung
    der Welt wahr immer nicht wahr,
    nicht wahr? Die fristlos Entlaßung
    am Ende wird kaum wunderbar.

    So laßen uns Menschlingen viele
    besonders besonnene zum
    Zeitweilegem Zeiten als Ziele
    des Lebens halbfaßen darum.

    Fremde Gedichte


    Time travel is by up to date confused "expertise" considered logically impossible albeit physically allowed for by Einstein's equations, as Gödel pointed out. Strange fallacy! The Guy travelling "backwards" in his time machine immediately goes into "hypertime", so to speak, and what was "time" is simply one more spatial dimension. No logical problem whatever; I utterly fail to see, even, how this awful misconception could persist for about a century. OK, on return he happened to crash into my poor would be dad, so what? This calamity occurring somewhere in Universe imperceivable to me, the Flatlander. Etc. Do you follow? You should.

    My philosophy:



    And: reciprocity. You do me a favor promoting your blog on mine!

    - Peter Ingestad, Sweden