Ask Dr. Dave
Question: I am looking for an adhesive that, when coated on a rubber or plastic back device, will attach itself to a canvas, metal, wood, or plastic surface. The glue area should be covered with a film that is resistant to the adhesive, and the adhesive must be permanent. Do you have any suggestions?
Answer: It sounds like you need a good general-purpose pressure-sensitive adhesive (PSA) coated on your back device along with a release paper. Pressure-sensitives are defined as adhesives that, when dried or fully cured, are permanently tacky and will adhere to surfaces when applied with pressure. The adhesives can be based on several technologies (e.g., rubbers, block co-polymers, polyisobutylene, ethylene vinyl acetate and acrylics). I would suggest that you talk to PSA suppliers and tell them any other key properties you might require, such as temperature resistance or humidity resistance.
Question: We want to bond an aluminum part (heat sink) to the wall of a stainless-steel tank. We need a flexible adhesive with resistance to temperatures ranging from -30°F to 140°F. After curing, the adhesive must provide a watertight seal with no leaks, and must also have FDA/NSF 51 standard compliance.
Answer: The only adhesives/sealants that seem suitable for your application are RTV silicones. They should have all the properties that you require. These are the only adhesive products that are certified to NSF Standard 51, and you can find a list of suppliers at www.nsf.org under “Food Equipment” materials.