Saturday, October 5, 2013

How to glue lexan - food processor bowl fix

Small tab from our old food processor lid broke off. The tab is pressing on the button which prevents food processor from running if the lid is not latched. Without this tab the unit would not turn on. We have this unit for many years (more than 10, I think) and definitely got our money worth, but I felt like it was a waste to throw away working unit because of the small plastic tab.
I started looking for suitable way to put this tab back. My first attempt was epoxy glue which turned out does not work on food processor plastic. It does not adhere to the plastic itself and breaks off easy and cleanly.
My research turned to figuring out what type of plastic this was and it appears to be Lexan or polycarbonate plastic.  After researching various glues for plastics I found that PCV pipe glue works by dissolving plastic at the point of contact and making a kind of weld. I did not know if the glue would work on the Lexan plastic but as I got nothing to loose I decided to try it. The glue was readily available to me at home so it was an easy choice. If you do not have it handy it is available at any hardware store in the plumbing section.
To glue it I followed the recommended process - primer goes first then glue and finally parts are connected and held together. The primer makes everything purple so be careful and use small amount with the small brush or Q-tip. To make sure that tab went on correctly I attached food processor lid to the container with the painter's tape and masked off under the tab with the same tape to protect the bowl from the primer and the glue.
To my surprise it worked very well. The glue took a few hours to dry and while drying the whole thing should be left alone. Until the glue is completely dry the tab was flexing but after drying out it appears to be one solid piece. I did not try to break off the tab to test the strength of the bond but it holds well enough for food processor to work as before.
When using the glue do this outside as the primer and the glue stink and most likely vapors are not good for you. When dry it should be harmless as this glue is used to bond PVC pipes with drinking water. In my case the connection point does not come in contact with the food so I am not worried.
If you know what glue will work best on Lexan or you can confirm that the plastic is indeed Lexan please leave a comment. After more searching online I found that some people used PVC cement to bind Lexan parts successfully. I am still interested in the glue that creates the strongest bond.
I also discovered that you can not buy the new bowl 10 years after the food processor manufacturing date. If you like your machine buy the spare parts while it is still in production.

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