Solvent Glue

Workshop Tip No. 10 

There are many kinds of glue available for sticking together 'polystyrene' or 'ASB' plastic commonly found in injection moulded kits. The traditional 'polystyrene cement', 'liquid polystyrene cement' and 'model cement pens' are OK, but they all leave 'glue' between the two surfaces being fixed together to a greater or lesser extent. These glues should be applied sparingly so as not to look unsightly.

My preference are 'solvent' glues such as 'plastic weld'. This product actually welds together the two surfaces and doesn't leave a 'glue' build-up as any excesses solvent quickly evaporates. Also capillary action 'wicks' the solvent around the joint distributing the solvent producing a continuous weld. Make sure you follow the manufactures guidelines when using solvent or polystyrene glues. 

A selection of 'plastic' glue, cement, solvent.

You can also use solvent glue to stick vacuum formed parts to different kinds of wood. Simply 'wet' the area of the vacuum formed part with solvent that comes into contact with the wood and apply solvent to the wood also, this prevents the wood from absorbing the solvent applied to the plastic before it has time to do its job. Then before the solvent evaporate press the vacuumed formed part firmly onto the surface of the wood. The solvent melts the surface of the vacuum formed part and this melted plastic is transferred to the surface of the wood. This can produce a very good bond when done correctly. Practice first on a scrap piece of vacuum formed material and make sure your solvent has melted the surface of the plastic sufficiently.