Perfect bends with this tool, insert and alot of patients
This is a must have for any open cooling system builder. This tool with the proper silicone insert will allow very nice crisp bends in hard tubing. I was using it for 16mm acrylic tube. Most youtube videos say to use soapy water to lube the insert before bending. I found that the moisture evaporates under the required heat to bend the tube. I was using talcum powder with very good results. If your piece requires more than one bend pull the insert past that bend after cooling before making the next bend. Otherwise the insert may get pinched by the bends and bind the insert from pulling free.Another piece of advice is to let the tube cool at it's own pace. If you quench it in water it will cause stress cracks that will leave little lines along the length of the tube and make it very brittle. Just be patient. Don't rush the heating, let the tube bend on its own before forcing on the curve of the tool. Hold it in place for a couple minutes to allow enough time to cool otherwise the insert will exude force to straighten the bend back out and then you will have to heat it again.