Most plastic glues or plastic welding cements are solvents which dissolve and join closely fitted plastic parts. They are used for a wide range of plastic models, doll house furniture and building parts, and other miniatures made from common plastics. They will not work on all plastics, so you should know what your miniature or model is made of before you choose a plastic cement or glue. These types of glues will only bond plastics to the same type of plastic, or one type of plastic to another. They cannot generally be used to glue metal or resin parts to plastic, although some of the tube cements may be used for this purpose.
Using Plastic Glues or Plastic Cements for Miniatures, Models and Dolls House Miniatures
What are plastic cements or plastic weld glues?
Plastic weld glues are chemical solvents for particular types of plastics which dissolve the plastic, then evaporate leaving two closely joined plastic surfaces bonded together. Most are composed of dichloromethane (methylene chloride) with trichloroethylene in varying amounts. Others, mainly the tube model cements are toluene based, and still others are methyl or ethyl acetates. All are substances which can be harmful if not correctly used.
What Can Be Glued with Plastic Welds and Plastic Cements?
Plastic welding glues and plastic cements work by dissolving and rebonding the plastic surfaces so they work only on particular plastics. These include acrylics, vinyl, styrene, abs, and poly carbonate plastics. Plexiglass,(a form of acrylic), styrene sheets and extruded model parts, clear poly carbonate plastic canopies, and a range of parts for plastic doll house furniture as well as abs and pvc plastic pipe and construction parts can all be glued with these cements. Plastics which cannot be solvent glued include polyethylene, polypropylene, Teflon, Delrin, Nylon and some others. A fairly simple way to tell if you can use a plastic welding cement on a particular type of plastic is to apply a bit of the cement to a scrap of the plastic, or apply a bit of acetone (nail polish remover) to a scrap of the plastic. If the plastic turns tacky when the plastic cement or acetone is applied, you can use a plastic cement or plastic weld to glue it together.
Best Uses of Plastic Welding Glues for Miniatures and Models
Plastic welding glues come in a wide range of formulations, some of which form better bonds than others on particular types of joins. 'Tube' types of plastic cement work more slowly than thinner 'liquid' formulations, and contain fillers to allow them to work with rougher fit joins. Tube glues do not form as tight or strong a bond as do the liquid forms. The liquid glues work best where they can be wicked into very tight fitting gaps via capillary action. Most of the liquid glues are 'hotter' than the tube types. They dissolve the plastic faster, and then 'flash' or evaporate faster than the thickened forms of glue. As the glues work via a chemical bond, they don't require clamping, unless the pieces require a clamp to be held tight together.
Before You Use Plastic Welding Glues or Plastic Cements
- Safety - Make sure you are working in a well ventilated area. Work with gloves and eye protection. Always use good ventilation and avoid working directly above the glue to lessen the effect of fumes. These glues should not be used by children.
- Test Your Materials - Check that your materials are not damaged by the application of a plastic cement or plastic welding glue. If you are working with a plastic which is too thin for the strength of the glue, or a glue which is too fast, you can damage your parts. As the thin, liquid formulations of glue are usually applied by capillary action into the join, excess glue can run down the join and drip onto another area and damage it, or run past your fingers, leaving a perfect impression of your finger on the surface of your model or miniature.
Tips on Working With Plastic Welding Glues or Plastic Cements For Models and Miniatures
- Make sure your plastic parts are clean (use alcohol or wash them with soap and water and allow them to dry before you apply the glue)
- 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 plastic welding glues reach full strength in twenty four to forty eight hours, avoid moving your assembly until the glue has had time to cure properly.
- Use the correct formulation for your application. Several commercial producers have online lists of particular formulations which work best for particular plastics, or bonds of one type of plastic to another. One such chart can be found in PDF (Acrobat Reader) format on the IPS corp. web site (producers of Weld - On Plastic Solvent Cements). It is the sheet titled Assembly Adhesive Product Selection Guide
- For the best bonds do not shift the bond surfaces while the glue is setting up. Although some plastic cements will set up in under half an hour, full cure takes up to 24 hours and the bond continues to harden for an additional twenty-four hours afterwards.