{"id":1787,"date":"2019-03-28T05:02:21","date_gmt":"2019-03-28T05:02:21","guid":{"rendered":"https:\/\/permabond.com\/adhesive-failure\/"},"modified":"2025-02-11T10:00:09","modified_gmt":"2025-02-11T10:00:09","slug":"adhesive-failure","status":"publish","type":"post","link":"https:\/\/permabond.com\/es\/adhesive-failure\/","title":{"rendered":"How much is \u201cenough\u201d when it comes to adhesive?"},"content":{"rendered":"

More adhesive isn\u2019t necessarily better when you want an effective bond or seal. Covering the bond surface is the main requirement. The type of adhesive and the bonding environment have a lot to do with how much is \u201cenough\u201d and how much less or extra will cause adhesive failure.<\/p>\n

Adhesive failure is a common issue when using too much adhesive. Following are some examples, probable causes, and suggested solutions.<\/p>\n

Note: <\/strong><\/p>\n

    \n
  1. Always contact the manufacturer for additional assistance<\/li>\n
  2. When using adhesives<\/a> always check the safety precautions<\/li>\n<\/ol>\n

    <\/p>\n

    Problems, Causes, and Solutions by Types of Adhesives<\/h2>\n

    Cyanoacrylate (Instant) Adhesives<\/strong><\/h3>\n

    Problem – Slow cure time.<\/strong><\/p>\n

    Cause <\/strong>\u2013 Low moisture to adhesive ratio. Cyanoacrylates<\/a> bond when trace amounts of moisture deactivate the adhesive\u2019s built in stabilizer. Differing amounts of trace moisture are present in the surfaces being bonded, as well as in the air.\u00a0 Cure speed reduces when there is too much adhesive in proportion to the amount of moisture.<\/p>\n

    Solution <\/strong>– Tests should be made to determine the smallest amount of adhesive to achieve the desired bond. Production consistency can be improved with regulated temperature and humidity controls. (Testing is also a more economical and safer process when making critical bonds.)<\/p>\n

    Problem \u2013 white haze or crust on the finished piece.<\/strong><\/p>\n

    Cause <\/strong>– Cyanoacrylates<\/a> are designed to bond two mating surfaces. The amount of adhesive required is directly related to the size of the surfaces. Excess adhesive squeezed out of the bond area cures very slowly, allowing enough time for the cyanoacrylate to volatilize, cure in the air and fall back to the surface as a white residue.<\/p>\n

    Solution <\/strong>– Reduce the amount of adhesive used to eliminate squeeze out or use a surface activator \/ accelerator to cure the squeeze out.
    \nThe manufacturer\u2019s technical support staff can help with this issue.<\/p>\n

    Anaerobic Adhesives<\/strong><\/h3>\n

    Problem – Slow or incomplete cure.<\/strong><\/h4>\n
    Cause:<\/strong><\/h5>\n
      \n
    1. large gap between mating surfaces;<\/li>\n
    2. exposure to oxygen. Anaerobic adhesives<\/a> cure when metal ions on the substrates surface activate the cure – but only in the absence of oxygen.<\/li>\n<\/ol>\n
      Solution:<\/strong><\/h5>\n
        \n
      1. Check the manufacturer\u2019s recommendations for maximum gap fill. Select the grade appropriate to the application.<\/li>\n
      2. Reduce the amount of adhesive used.<\/li>\n
      3. Eliminate excessive squeeze out from the adhesive tube or container. Use a clean dry cloth to wipe away any excess.<\/li>\n<\/ol>\n

        When troubleshooting a bonding problem, the first step is to determine if the problem is cohesive or adhesive in nature. Simply put, you want to figure out if the problem is related to<\/p>\n

          \n
        1. how the adhesive sticks to the substrates (component parts) or<\/li>\n
        2. to the state of the adhesive in the bond area.<\/li>\n<\/ol>\n

          Surface Activated Structural Acrylic Adhesives<\/strong><\/h3>\n

          Problem \u2013 adhesive failure – bond strength lower than expected.<\/strong><\/h4>\n
          Cause <\/strong><\/h5>\n

          Too much initiator was used. Because initiators are very thin and water like substances, they are nearly invisible once applied to some surfaces. Overuse of an initiator can reduce the strength of the cured bond.<\/p>\n

          Solution <\/strong><\/h5>\n

          Use according to the directions on the technical data sheet.<\/p>\n

          Types of Failure<\/h2>\n

          Adhesive Failure<\/strong><\/h3>\n

          The adhesive bond to one of the surfaces fails. Also known as Interfacial Failure<\/p>\n

          Some causes of Adhesive Failure \u2013 and suggestions:<\/strong><\/h5>\n