Cyanoacrylates or Super Glues / Crazy Glues / instant glues, are fast setting, brittle glues which are used by many model, dolls house and miniature builders. They have some advantages, and some disadvantages for many miniature materials, and can be used in some settings where other glues won't work. There are lots of things a model or miniature builder should consider before using superglues.
Using Super Glues or Cyanoacrylate Glues for Miniatures, Models and Dolls House Miniatures
What is a super glue?
Cyanoacrylate is the name for a range of super glues and crazy glues which form quick, hard, brittle bonds. They are a form of acrylic resin, rather than a glue in the true sense. The presence of moisture causes the glue to set, so cyanoacrylate glues work best in humid environments, on materials that have some moisture present, but the presence of moisture in the air can cause a container of glue to become unusable very quickly so these glues have a shelf life of 6 to 12 months. Super Glues work best on bonds which are not subject to stress or movement. The bonds cannot easily be pulled apart with direct force, but they can be 'peeled' apart more easily. An example of where they aren't suggested would be where the weight of one of the glued parts would pull away from the other part (a heavy arm on a metal gaming miniature, a door on a glued hinge).
What Can Be Glued with Super Glues?
Cyanoacrylate glues work best on porous materials. They are not good on glass, and the bonds can give up in the presence of water, depending on the materials used. Super glues also work best on high pH (basic), non oily surfaces, so they can be problematic on some acidic hardwoods, including mahogany and oak. Regular formulations of super glue will destroy some plastics such as expanded polystyrene (foam coffee cups) and expanded poly propylene. Special formulations are available which will glue these materials.
Best Uses of Cyanoacrylate Glues for Miniatures and Models
Cyanoacrylate (CA) glues form very quick, strong bonds where the glued object won't be subjected to stress or shock. They are especially useful for:
- Holding materials together instead of clamping while a regular, stronger glue for the material dries. - In these applications the regular glue is applied to the pieces to be glued, and a small amount of CA glue is applied to the pieces at either end of the join. The pieces are then joined together under pressure and held until the CA glue takes hold.
- Very tight fitted joins where capillary action can draw in the thin glue, and where the model or miniature has little space for a thicker glue (finger joins in wood, seams in plastic models, fitted pins in resin ball joint action figures - CA glues are strongest in very thin layers.
- Small parts which are not subject to stress, where the fit must be tight - etched metal parts for example.
Before You Use Super Glues
- Safety - Make sure you are working in a well ventilated area and have some acetone (nail polish remover) or commercial 'debonder' handy in case you need to remove the glue. Work with gloves and eye protection. Avoid working with cotton or wool fibres or fabrics which can react with superglues, giving off heat and causing burns. Some people can become sensitized to superglue fumes and the glue may become a skin irritant. Always use good ventilation and avoid working directly above the glue to lessen the effect of fumes. Wear gloves.
- Test Your Materials - Check that your materials are not damaged by the application of super glue. Clear acetate (dolls house windows, case fronts, model airplane canopies) needs to be given a protective coating of clear acrylic (clear acrylic varnish or acrylic floor wax) before gluing or it will fog or 'craze'. Some materials may need to be treated with baking soda to lessen their acidity or cleaned of oils before they will bond correctly.
Tips on Working With Super Glues For Models and Miniatures
- Apply the thinnest layer of glue possible to form the strongest bond. Use special fine tips to apply glue by capillary action to fitted joins wherever possible.
- Normal bonds of cyanoacrylate glue reach full strength in two hours. Accelerators or 'kickers' which are commonly used to speed up the glue setting time, usually made from toluidine, will set glue in as little as a few seconds, but the glue bond will be weaker. Only use accelerators on one side of the bond if possible. Avoid using accelerators or try a wash of dissolved baking soda over one surface as an accelerator before applying the glue. Both a mist of water and baking soda are accelerators, baking soda is also used by modellers to fill fine gaps although the glue bond will not be as strong.
- Cyanoacrylate is occasionally used as a hard, water resistant wood finish for small projects. The trick is to apply it in very thin layers until you build up a coating. Once the coating is built up, the hard nature of CA glues allows it to be polished to a high shine with Micro Mesh Sanding Pads
- Use the correct formulation for your application. The thicker the CA glue is, the longer it will take to cure. Thicker glues can leave gaps in the bond which will make the bonds weaker.
- Low temperatures cause the cured glue to become brittle, so to weaken the bond, put something in the freezer if you want to separate it.
- For the best bonds do not shift the bond surfaces while the glue is setting up. Full cure takes up to 24 hours.
Tips on Storing Super Glues
- Unopened super glue can be stored in the freezer. Once open it should be stored in the refrigerator in an airtight container with a pack of silica gel to avoid moisture causing it to react and set. Allow it to come to room temperature before opening the glue container to avoid condensed moisture affecting the glue.
- Storing the bottles or tubes upside down also helps prevent moisture from getting into the glue and causing reactions.
- Buy small amounts of superglue at a time for most miniature and modelling projects as the glues will thicken and set in the container with regular use.
- Always cap the glue immediately after using it to avoid moisture from the air reacting with the glue.
Special formulations of Super Glues / Cyanoacrylates
- Low odor CA glue is available for people who are sensitive to the fumes. The formulation of low odor glue is in some (but not all) cases 'foam friendly' so the glue may work with some expanded polystyrene foams. Test before you apply and read the manufacturer's directions carefully.
- Flexibleor rubber toughened super glues with rubber additives can be slightly more 'shock resistant' for applications where a model will be subject to vibrations or movement. These types of glues may be useful where speakers and motors are mounted to miniatures. The additives make the superglue more elastic and less brittle.
- Gap Filling super glues are available to fill joins which are not particularly precise. This thicker formulations are slower drying and not generally as strong as thinner glues applied to tight joins.
