Handy hints and tips for gluing plastics

PROCEDURE:
1. Smaller items with flat surfaces can be bonded by placing the pieces together and applying the solvent along the edges using a needle applicator or hypodermic syringe. Make sure the solvent flows along the entire joint. For bonding larger items, immerse the surfaces to be joined in the solvent until the material is softened.
2. Clamp them in position and hold until the bond is set.

HELPFUL HINTS:
Edges must be clean and free from dirt. Light sanding of factory polished surfaces will aid in adhesion. Surfaces should be smooth and properly aligned. Recommended solvents are WELD-On #3 If joint whitening occurs, it may be caused by excessive moisture. Several techniques reduce whitening. Fabricate in a climate-controlled area with low relative humidity. The addition of 10% glacial acetic acid in the solvent reduces whitening. Thickening the solvent with resin or sawdust promotes slower curing and reduces whitening. Be sure to retain fixture pressure until the joint is solid.

It should be noted that some plastics such as polypropylene and polyethylene are designed to be resistant to chemicals. These plastics that are not dissolved by chemicals cannot be glued and to join them they need to be hot-air welded.
PVC will glue, but in most cases a stronger joint will be achieved by hot-air welding.
Plastics that can be dissolved by a chemical are generally glue able.
Most engineering plastics cannot be glued with solvent adhesives, although a contact adhesive or silicone may be acceptable for your application.
If in doubt talk to our staff about the right adhesive for your job.

See more hints at the pages below