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Hydraulic Pipe bender for exhaust?

32K views 12 replies 5 participants last post by  oldred 
#1 ·
Can an hydraulic Pipe bender like the one sold at northern tool for $199 bend exhaust pipe?

I looked into this once before and was told they don't work that they will crush the pipe. But I read the other day where someone used one with no issues. And the description for the pipe bender says "Perfect for all types of automotive applications" And It bends 2"-3" pipe. Other then exhaust pipe what other tubes or pipes are over 2" round that would be used in automotive applications??
 
#3 ·
exhaust bends

I don't think they bend anything very good. But my kid spent more time than I did and made some nice bends on his race car. He then built his exhaust on his hot rod. He welded ends shut and filled with sand. Came out very nice. A little time consuming but worth it. Need to do a bit of grinding on the dies as they don't fit pipes very good.
 
#4 ·
****** said:
I don't think they bend anything very good. But my kid spent more time than I did and made some nice bends on his race car. He then built his exhaust on his hot rod. He welded ends shut and filled with sand. Came out very nice. A little time consuming but worth it. Need to do a bit of grinding on the dies as they don't fit pipes very good.

wow that would be a lot of work.
After I posted this I found a link to another forum asking about the same question.
I thought it would not work, I got to wondering when it said "Perfect for all types of automotive applications" And I noticed they had two models one that is $119.99 thats says "Not for exhaust pipe" and then this one for $199.99 that says "Perfect for all types of automotive applications".
I figured it was a "marketing" term to sell the more expensive one.


Ive been looking for a few years now for an older used exhaust bender to buy with no luck. The Bend-pak models are over $6000 new. :eek:
Im hoping I will find someone in need of cash one day to sell me one under $1500 but it's not happened yet.
Its hard to find someone selling a used bender. I talked to a muffler shop owner once about his bender. He said he paid over $10,000 for his 19 years ago.. Apparently they never go bad, They just replace parts as needed. When I asked if he would ever be interested in buying a new one and sell the old one he told me NO, Not until a new advanced technology becomes available because my machine dose the same thing the brand new ones do and it's paid for.
So even if I can locate a shop going out of business the chance to buy a cheap used bender is slim. Since most are financed and when the business goes south so does the repo men.
 
#5 ·
The fill it with sand advice works to bend exhaust tubing, but these type benders still won't make a bend beyond about 60° without starting to flatten the pipe around the bend, which is immediately followed by kinking if you try to push it farther.

I used a bender like this to bend roll cage tubing( the 1-1/2" pipe die fits 1-3/4" cage tubing real well) but it still won't do a tight enough bend to do the main hoop bends at the top of the roll cage behind your head, so I buy the main hoop pre-fab from Chassis Engineering and bend the rest as needed myself.

I used a .040"-ish sheet of aluminum to make a die formed "shoe shim" to use the same die to bend 1-5/8" roll cage tube. Laid the sheet piece on the die and used a scrap piece of 1-5/8" tube to do a bend and it formed the aluminum piece to the shape of the die. Works just fine and snaps on and off.
 
#6 ·
benders

We found a place in Canada that sells a nice rollbar kit. All prebent. gussets etc. Actually cheaper than we could buy the tubing locally, so that is where we got our 6point cage. But still had to have forward bars and bars for fuel cell. My kid got it to bend 90' bends without kinks, but again I think he used sand. I think the 119 and 199 units are the same thing. I paid 125 for mine a number of years ago. It was on sale from Northern, but same unit. I'm going to try modifying mine so It will work like the one from Speedway Motors with the jack and small framework. I've drawn up some patterns but haven't had time to make the pieces. I'll let you know how it comes out.
 
#8 · (Edited)
sand filler.

50 years ago Iwas told to fill with sand and heat but it distorted badly. Most muffler shop bends distort the pipe. I worked for a Co that had a cnc bender and we made OEM harley exhaust. that bender was about 100G It had ball type mandrels that pulled thru as you bend.. There was a good UTUBE video and the guy just put several layers of good old duct tape on the end then stood the pipe straight up and packed it with WET sand. taped the end then bent it on a HF type bender, I think the key was packing with wet sand. almost as hard as cement but it didn' kink..... Utube posted by dopescustoms
 
#9 · (Edited)
pro tools bender

Pro-tools has free plans for their hyd jack operated bender. It's the type with the follower shoe. that type usually makes good bends and can do more than 180 degrees. just reset the pipe and continue to bend. . Their plans could be changed so you could sandwich pieces and not have to use a milling machine for side plates to make slots. I was thinking of buying pre bent heavy elect conduit elbows, doing a lot of cutting and welding to make a couple different dies.
 
#10 ·
Look at how that that thing works compared to an exhaust pipe bender, it simply pushes in one spot while the die holds the center above ram and this contact point never moves it simply extends farther as the pipe bends. Think about what happens when you bend a pipe, the outside wall of the radius becomes longer than the inside if the pipe does not crush so this means it has to stretch (or the inside has to shrink that's why sometimes you see wrinkles in exhaust pipe bends). With a true exhaust pipe bender there are rollers that move along the outside wall of the pipe and continuously move, not just extend, the points of contact so the wall can stretch an even amount over the entire distance. No way can this occur with a cheap fixed die pipe bender designed for conduit, that fixed outside die will keep the main point of pressure centered and actually let it increase as the ram extends, even if you fill it with sand you still get the stretch required confined to a short area instead of being spread equally over the entire outside wall of the bend..
 
#11 ·
timothale said:
I was thinking of buying pre bent heavy elect conduit elbows, doing a lot of cutting and welding to make a couple different dies.


There's something a lot better than that, you can get MUCH stronger weld-in elbows made of steel (electrical conduit is soft as butter) made just for that purpose. Most steel suppliers have or can get them or they are available from Mcmaster carr and others. These things come in most common pipe sizes and are available in 45 deg and 90 deg but by combining or shortening as needed any angle can be produced and they are even already beveled for welding! :)

When I still ran my shop this was a "stock" item because we often used them when we needed to angle pipe, making handrails for example, and we did a couple of roll cages also along with a number of other projects requiring angled pipe .
 
#12 ·
pipe bends

I forgot about the ready made curves. Used them to make some guard rails for meters and such when we redid the alleys down town. We got them from the gas co. Nice heavy duty black pipe. Elect conduit has too much galvanizing and doesn't weld very good. Plus fumes are deadly.
 
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