Plastic Welding

Discussion in 'The Garage' started by CR_TurboGuy, Mar 14, 2007.

  1. CR_TurboGuy

    CR_TurboGuy Iowhat?

    Aug 8, 2006
    Cedar Rapids, IA
    Anyone have any experience using one of those Harbor Freight plastic welding deals? I picked up some of those $10 Pelican cases, and HF sells the plastic welding rods that are polypropylene which is supposedly what the Pelicans are made of. Any tips/tricks to using a plastic welder before I get started?

  2. CaveDave

    CaveDave Long timer

    Dec 11, 2006
    I was using one yesterday to fix a broken taillight/ license plate bracket, and made a few observations. PSI around 5, let it heat up a little first. Heat the rod before you start to heat the plastic to be welded. Apply the heat to the plastic, and as it starts to melt, apply the rod. Keep the heat moving around all sides of the rod, and keep heating the plastic ahead of the rod. Every little bit, as the weld you have layed out is still hot, take a metal tool, and press the weld into the surrounding plastic. We were welding something that required a lot of pressure to hold it together, and some funky angles, so one would weld, while the other held the piece together. The holder would then press the weld into the plastic, we were using a pair of side cutter pliers, which we also used to cut the rod at the end of each weld. This worked very well, as trying to pull the rod off pulls the weld back off while it was hot.
    It works pretty well, the trick is definitely to get the feel for the amount of heat needed to melt everything together, without melting too much.
  3. JayBo1

    JayBo1 Long timer

    Aug 11, 2007
    Perth, Western Australia
    Hi all. I have a couple of little "projects" that I could use a plastic welder for. Been looking on eBay for some ideas. Anyone have any experience with plastic welding? Any advice out there?:ear

    Just found this old thread through the search function. Any other input from the inmates?
  4. Range Motorsport

    Range Motorsport Junk collector

    Nov 17, 2007
    Da UP Eh!
    I have a Mini-Weld Model 5 airless plastic welding kit.
    I have used it only about 100 times to repair mostly snowmobile and ATV parts but they work great and can save you $100's over buying a new part. It works like a combination of a soldering iron and a glue gun. You are basically heating the existing plastic while forcing new plastic into the crack or void. You then can smooth the weld or just leave it the way it is. It really does work great and you can't really screw up too bad if you follow the directions provided.

    You can also buy replacement rods and use a big flat blade on your soldering iron but you run the risk of total meltdown because of the high heat.