Registered: 1359070732 Posts: 2,240
Reply with quote #1
You can bend rigid PVC drain pipe (1.25-inch or 1.5-inch diameter) by first softening it with boiling water.
Allow the water to go off-boil for around one minute. Lay the length of pipe on the floor, and pour water all along it from a kettle. Wait another minute or two, then gently flex the pipe as it cools. If you have got a particular dimension to meet, make a mark on a wall, and another on the ground, then stand the pipe on the ground mark, hold it with your boot, then gently bring the other end down, till it meets the mark on the wall. While pulling the end down, work in stages, and don't forget to let the pipe *flex back* from time to time, in order to relieve STRESS in the material. Then hold the pipe firm while it cools. Once cool, it will still have some residual "reverse "spring", but should still nonetheless return to the marks you set it to... FINAL TIP: You can make a softening chamber out of a length of wide-gage pipe, say 4-inch diameter, and cap each end, then cut slots in the upper surface, to allow inserting and remove your work-material pipes. Pipes can then be filled with spray-foam urethane if required. G_H __________________
(1) "Heat goes from hot to cold, there is no directional bias" (2) It's wrote, "voilà" unless talking musical instruments...
Registered: 1352981942 Posts: 2,173
Reply with quote #2
Good tip GH-
Have you tried bending the PVC after heating by clamping one end and bending the pipe over a jig that will hold it in place until it cools? Please add this to the quick tips section. Greg in MN
Registered: 1414937162 Posts: 13
Reply with quote #3
Being a commercial / industrial electrician I've had to bend loads of Schedule 40 PVC pipe. When a commercial "hot box heater" or an "electric heating blanket" isn't available we have other methods we've resorted to on construction sites..... the exhaust from a running vehicle can soften a pipe enough to bend it, a propane torch run back and forth while turning the pipe also works well. Always tape both ends of the pipe shut with duct tape to hold the air in the pipe which helps it to bend without kinking. If you can, make yourself a "jig" out of small blocks of wood screwed down to a sheet of plywood to the shape of the pipe you need, and once the pipe is heated and bent to your needed shape run a soaking wet rag along the pipe to set the bend. Now the easiest way for the home owner to bend PVC pipe is to tape both ends real well like I said above, wear heavy leather gloves or welding gloves, fire up the old gas grill and lay the pipe right on the grill and constantly rotate the pipe while also sliding it back and forth along its length. The PVC pipe will get EXTREMELY hot and soft like a cooked noodle so be carefull! Lay the pipe on your jig or simply on the ground and shape it as needed. Have a bucket of cold water and some rags handy to cool down the pipe. I once did a whole commercial green house containing thousands of feet of PVC pipe with this method to make all my saddles, offsets and 90* bends using pre-made jigs and an old gas grill. I notched the lid on both sides to fit my largest pipe so I could close the lid and keep more heat inside the for bending.... worked like a charm and saved money in labor and fittings!