How to glue acrylic and Perspex

Steps

1. 1.Choose the right adhesive

   Thin, water-like solvent cement (acrylic cement) is for tight, square joints: it runs into the joint by capillary action. Thickened cement fills small gaps and suits slightly uneven edges. Two-part structural adhesives join acrylic to other materials. Avoid superglue and general-purpose glues on clear work: they fog the surface and leave a white bloom.

2. 2.Prepare the edges

   Joint edges must be flat, square and clean. Scrape or sand off saw marks so the parts meet with no light showing between them, but do not flame-polish or buff a glued edge: polished edges hold stress and can craze when cement touches them.

3. 3.Clean and mask

   Wipe the joint with water and a mild detergent and let it dry fully. Leave the protective film on the faces, or mask either side of the joint, so stray cement cannot mark the show faces.

4. 4.Hold the parts still

   Set the parts up in a square or jig, on a flat bench, so they touch along the whole joint and cannot move. Clamp lightly if you must; heavy pressure squeezes the softened acrylic out of the joint.

5. 5.Run the cement in

   With the joint horizontal, run the needle tip slowly along the seam and let the cement wick into the joint. Do not wipe it; wiping smears softened acrylic across the face.

6. 6.Leave it to cure

   Leave the joint undisturbed while it sets, then handle it gently until it reaches full strength. Follow the cement maker's handling and cure times, which vary with the product and the temperature.

Tips

• Practise on offcuts first: a test joint tells you how fast your cement runs.
• Work in a ventilated space and keep the cement away from heat and flame.
• Cement can craze acrylic that is under stress, so glue sheet that has been cut cleanly and is not bent or clamped hard.
• Cast and extruded acrylic both glue well; cast sheet is a little more forgiving.