You may be surprised to know that there are a multitude of glues out there, all with their own properties, and you will need a mixture of these glues to produce a quality build. There are basically two ways that glue works. One is where the glue itself is sticky (like the tacky side of masking tape). The glue sticks to the two parts because of its stickiness and holds them like strong tape – this is called a mechanical bond. The second is a where the chemicals in the glue actually melt the pieces a little bit, and when the glue dries, the two pieces are “welded” together – this is called a chemical bond, and is the stronger of the two. The three main glues used in car modelling are modelling glue, super glue and white glue.
Modelling glue gives a chemical bond. It is very strong, but can be weakened with Acetone (nail polish remover) to separate parts after gluing. It will struggle to work on plated parts (the shiny chrome pieces) and if it gets on acrylic paint, it will remove the paint. It will haze clear parts (like windshields). It should typically be used before painting – especially if the pieces are visible (like body parts). Using modelling glue after painting for parts that are less obvious is less of an issue.
Superglue (aka Cyanoacrylates, aka CA glue). Superglue gives a mechanical bond. It is very fast drying and can also be weakened with Acetone. It usually works ok on plated parts, although it doesn’t like smooth surfaces. A quick sand or file of plated parts will help them stick together. Superglue will generally not haze clear parts or painted parts (patch test on the parts tree to be sure). Superglue can be applied before or after painting. For accuracy, place some superglue onto a surface such as a piece of card and use a toothpick to apply it to the surface to be glued. Superglue is available in a liquid (fastest drying) or a gel (slower drying). WARNING: Superglue will bond skin almost instantly. Exercise extreme caution when using superglue during modelling.
White glue (aka PVA, aka Wood Glue, aka Elmer’s (US), aka Aquadhere (AU)). White glue gives a mechanical bond, dries clear and keeps a strong hold but dries much slower than the other glues. It will not haze clear parts and is one of the main glues used for this purpose (windshields, headlight covers, etc). It will not damage painted parts and is suitable for gluing after painting, however its slow drying time can cause issues, as parts need to be held in place for several minutes. Generally, any parts which need to be glued to a painted body (side mirrors, spoilers/wings, bumpers, etc) should be glued with white glue.