Our last post on glues, cements, and solvents for plastic model building promised a part two – tips to help you know which adhesive is best for your particular project, as well as useful tools for precision placement of your adhesive.
First, let’s talk about the pros and cons of each adhesive …
Tube Glue or Model Cement is a gel-like substance that contains a chemical, such as Toluene, that when applied to the joining surfaces of a plastic model forms a membrane that bonds the two surfaces together. A tube of model cement is inexpensive and can be purchased at most hobby, craft and hardware stores. It’s also available in a non-toxic, odorless version. But, model cement can be stringy and messy if proper technique isn’t used. It yellows with age. It also crystallizes and loses its adhesion properties over time.
Super Glue® or Cyanoacrylate (CA) is a fast-curing, strong adhesive. The bond is strong as it applies to weight-bearing, but weak torsionally. If you glue two objects together and try to pull them apart, CA will hold firm. However, if you push the two pieces along the seam in opposite directions it will break the bond.
Remember the classic TV commercial where a guy superglues a block fastened to the top of his hard hat to a goal post? He can hang there all day. But if you were to tap the block that is glued to the goal post, he and the helmet would fall to the ground. It can hold the tension of the load, but not any torsion applied to the load.
What does that mean to a scale model project? The joint of any parts glued together subject to twisting or swinging action could fail.
- CA is great for affixing small bits or pieces that need to be held in place until other means, necessary to fasten or connect them, are in place.
- CA comes in a variety of consistencies…water thin and jello-like thick, as well as fast and slow-curing formulas.
- Glue something together with CA and you can reverse the process by using a CA debonder. This is a must-have item even if you only use it to unstick your fingers from each other or from the parts you’re working with.
- CA can also be used as a filler…but that’s another topic for another post.
CA is best applied with an applicator. The applicator that I prefer is the Glue Looper® because it’s pretty much idiot proof. For precision application, this is the tool you want.
Other options include purchasing Teflon™ tubing from a CA manufacturer or making your own applicator out of a loop of fine wire or by cutting of the end of the eye of a needle. Find what works best for you.
Liquid solvents: There are several popular brands out there specifically for plastic modelers … and most who use them regularly have a favorite. Each solvent has its own properties as far as its liquidity and ‘hotness.’
Liquidity is its weight compared to water. Some are water-like; others are thinner/lighter than water so they flow differently when applied. Some evaporate slower allowing more working time; others evaporate moments after application.
Hotness or heat refers to a chemical reaction and penetration into the plastic surface. A drop of some solvents can melt a hole through a piece of plastic in seconds; some will melt or distort delicate or thin pieces.
Liquid Solvents can be applied using a brush (just make sure it’s not some synthetic plastic bristle that will melt once dipped into the solvent), a quill or a specialized applicator such as the Touch-N-Flow.
Using a liquid solvent to bond plastic parts together is like welding two pieces of metal together. It creates the strongest, longest-lasting bond you can have. It also allows for consistency in the materials at the seam or joint so shaping and smoothing is trouble free. Whereas when using a glue you’re adding a dissimilar material into the mix which will have a different hardness quality, so when you sand or shape, the glue material will remove/shape at a different rate. You might find yourself sanding away wanted plastic while barely affecting the glue.
Liquid solvents dry fast! If you make a mistake and accidently have a misplaced drop of it on a surface … no fear … just leave it alone until it completely dries. Then it’s just a matter of polishing out the blemish it left behind. If you touch it with your finger or towel it will set your fingerprint or texture of the towel into the plastic.
Xuron Corp. has the tools to help you with glues and adhesives. Take a look at the #860 Dispensing Bottle: it holds up to 2 ounces and comes with three applicator needle sizes, .010”, .020” and .040”. The .010 is suitable for use with most liquid solvents used in scale modeling.
The larger needles are great for applying wood, white and other craft type glues.
These bottles are NOT suitable for use with CA’s. But great for the precise and controlled application of the Kicker used to set CA instantly instead of using the pump spray applicator the CA manufacturer provides on their bottles.
What would you add? Do you have a tip for working with glues, cements, or solvents? Please comment below.