Weld-On #4 - Fast Set Solvent Cement For Acrylics (1/4 Pint)
Weld-On 4 is a water-thin, somewhat flammable cement formulated to quickly develop very clear and high strength bonds for many thermoplastic substrates. The bond is achieved by first softening the surfaces to be joined and then fusing them together with the dissipation of the solvent. The initial bond forms within a matter of minutes and is followed by a significant and continual increase in bond strength over the next several hours. Weld-On 4 may be preferred by some plastic fabricators because it is less likely to leave white marks (commonly called blushing). For similar applications but faster setting cement, Weld-On 3 is recommended.
Substrate Recommendations
Weld-On 4 is formulated as a blush-resistant cement for bonding acrylic (poly-methyl methacrylate) to itself. It is not recommended for crosslinked acrylic.
Bonding Recommendations
Weld-On 4 is used extensively in sign fabrication for cementing acrylic letters to flat acrylic presentation panels and trim-capping of cut out acrylic letters. Strong butt joints are made with flat sheets by using the soak method. Weld-On 4 is also widely used in many applications (e.g. fabrication of display and presentation cases, medical equipment assembly, the bonding of plastic containers and pre-forms, and in the manufacture of numerous solvent welded structures and subassemblies using the capillary method).
Additional Information
This product is not for general consumer use. It is an industrial product intended for professional use only. Plastic-Craft Products reserves the right to substitute similar quantity Weld-On 4SC for Weld-On 3 or Weld-On 4 when ordered by an individual consumer.
This product may not be shipped into Los Angeles, San Bernardino, Orange, or Riverside Counties. Plastic-Craft Products reserves the right to substitute Weld-On 4SC for Weld-On 3 or Weld-On 4 when ordered for delivery to zip codes in those counties.
Directions for Use
General: Surfaces to be joined must be clean, dry, and fit intimately without forcing. Apply cement with syringe, eyedropper or brush. Assemble while parts are still wet. If cement is applied to one surface, let the two surfaces be in gentle contact for a few seconds to allow the cement to soften the dry surfaces, then press parts together in firm contact. Initial bonds form very quickly. 65 – 80% of the ultimate bond strength will be obtained within 24 – 72 hours. Strength will continue to increase for several weeks.
Capillary Method: Parts are placed lightly together and cement is applied to the edge of the joint with syringe or eyedropper. By capillary action, the cement will flow a considerable distance, approximately 0.25 inch (0.64 cm), between two such surfaces. Allow a few seconds for the cement to soften the surfaces. Press parts firmly together.
Soak Method: Vertically dip surfaces until softened (approximately 2 to 5 minutes), then join pieces firmly together.
Shelf Life
Two years in tightly sealed containers. The date code of manufacture is stamped on the bottom of the container. Stability of the product is limited by the evaporation of the solvent when the container is opened. Evaporation of solvent will cause the cement to thicken and reduce its effectiveness. Adding of thinners to change viscosity is not recommended and may significantly change the properties of the cement.