This was a set of Zoomies that were already on the Car, but the two Pipes closest to the Firewall were Modified for clearence. To clean it up a little, I made two new ones. I capped them and compressed fine Sand inside, and then bent them with a Rosebud on my O/A set. Its tricky, and I'm still learning what I can get away with, but I think they came out cool...
Cool work. A safety tip for you kids trying this at home. Make sure the sand you use is DRY. Moisture + heat + contained space = BOOM. Wet sand will allow steam pressure to build up when you heat the tubing and if you've sealed the tube up, you've made a steam bomb.
Few questions... did you use a form for the bend, or just work a small section at a time? Did you heat it evenly, or more/less on the inside or outside of the radius? I have been wanting to try this for some time...gotta get a tip for the torch. Looks like it worked pretty well for ya. --reed
No Form, I eyeballed it. More heat on the outside seems to work best. Getting a larger area redhot seems to work better too. And putting more pressure back on after heating and bending ( one side is capped by welding it shut, the other has a wooden Dowel in it. So I hammered the Dowel in deeper, every once in a while. I was warned about using dry sand only ( but not why...)
I like sand bending tubing. Your able to get some really cool shapes that would be hard to get with pre formed bends. And to everyone out there who does not know, HEED THE DRY SAND WARNING!!!! I had one end blow off one time. Luckily it just embedded itself into the wall and not me.
Good tip about dry sand, I have done this and baked the sand in an oven overnite in a large flat pan at 350 Degrees F. , stir every once and a while.
I made a Bell style 4 spoke steering wheel not so long ago. 1" thick wall pipe, filled with sand and welded shut. I bent it cold in the vice, little by little. It took some grunting but I got it there. Just a few small tool marks that will be covered with upholstery. I'd like to try some thin tube like exhaust tubing. Those zoomies came out great. Pete
metalshapes: old timer stuff I forgot about. We used to chuckle about the "dry" sand stuff in HOTROD mags, and, sand bending was used to keep flow characteristics in tact for a given pipe...vs. mandrel bending which "pinched down " the bend diameter (causing hot spots/discoloration/flow restriction) . As you develop your expertise/technology... consider the heat leaching effects of dry sand vs. wetted sand (remember wet sand does not need to imply "water" wetted). The "moveable plug" end needs to be constantly adjusted as the bend occurs, "if" the pipe diameter is to be consistant, we have used worm type radiator clamps as tensioners over the plug...it can be cranked down as the bending moment is executed. (you will develop your own torque value to hold, as time goes on...60 # is a good starter) Wood end plugs (oak) should be multiple drilled for venting, and a fine SS screen placed beneath to keep from clogging. oil soaked sand worked best for us, chevron made the 900 degree stuff.... its used for thermal solar storage use nowadays... Competition wise, the object is to enter a ball .010" smaller than the I.D. of the pipe (drill the ball and weld in a flex cable) and be able to push it through the length w/o binding or being too sloppy in the bend apex... Nowadays even the big boys do not look for these "fine points" in building, just some thoughts for your next bend job
The zoomies look sweet - I dig the one tube that bends back around the others. The sand bending process gives you results that couldn't be duplicated on most mandrel benders without some seriously expensive compound dies. Very cool. Hank
i am seriously digging the look of those pipes...fuck the functionality of them, they just look killer as hell!!!
Back in 92 this was still taught in HT "A" school in the Navy. The navy weld schools are excellent might I add. I never needed it in the navy but I played with it in real life with limited success. Your pipes look good.
They look sweet.A little time and effort and a great product. And the price is right. Thanks for the tec . got to try that . ..with dry sand.
So what exactly is this? You pound the pipe full of dry sand and then heat n' bend to move it where you want? I have a set of fenderwells I need to cut apart and move the can a couple of inches forward. Also wanted to adapt some headers onto a small block Buick later on....
Yeah, the sand is to make the tube not kink when you bend it. I'll try and take some pics tomorrow and post them...
Steam!!! Anytime water, a liquid, is heated enough to change it into a gas (steam), it will need 16 times the volumn or space that it needed as a liquid. 1 CI of water heated to steam will now take up 16 CI. At that rate of expansion it doesn't take much dampness to create a big problem. This is what turns your radiator into a geyser when the 212 deg. water turns into 212 deg. steam. (at sea level pressures) And yes if sealed it can rupture a tube spraying hot sand all over the place just like ice (a liquid changed into a solid) (which only expands 4 times the volumn of water) cracks cast iron cylinder blocks in the winter. If you've ever run a torch over concrete, you've seen the concrete pop. Pieces of the surface explode into the air. That's caused by the water that is still trapped in the concrete. The torch turns the water to steam. It has to go somewhere so it makes it's own space exploding the surface.
Great! Thanks! One more Q and I'll shut up (for at least five minutes).... Where do y'all find the right kind of sand to use?
First Pipe I tried, I swept some sand off the sidewalk... Second one kinked on me (pic ), so I went for the high Dollar approach and bought a bag of sand at the Home Depot. Last 2 pics are why I really want to learn how to do this. Bending with sand will let you bend a pipe in two directions at the same time. Make the Pipe coil around something in one seamless curve ( hopefully... )
This is what I came up with to keep pressure on the sand ( pic ) The wooden peg has a loose fit inside the Pipe, and I force it inside the Pipe by tightening the nuts on top of the piece of Aluminum. I'll keep posting about this, thanks for the Tips and Suggestions from the guys that have done this before...
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