Hydraulic Pipe Bender

[diz]

Hi All,
I was planning to make some side steps for my dual cab and do the 90 deg bends myself with a metal pipe bender. Problem is when I went to bend the pipe today it began to kink. From what I have read on the net it may be that the formers I have are not good enough to support the round steel. I am using 40mm steel with 2.5mm side walls. The former I had in the bender was a 40mm. Any experience or tips that might help?

[joe greiner]

Pack it with sand before bending; plug with corks if necessary. Shake out afterwards.

Cheers,
Joe

[China]

Packing with sand may help, what you realy need is a mandrel bender not worth it for one job

[danielhobby]

a quick way to achieve your bend is to push the next size down pipe into bend length and bend both,it stops the collapse of thin walled pipe.

[Stringy]

The old pipe was mild steel and thicker wall, the old style formers for this have a tighter radius. The new pipe is thin wall and high tensile requiring formers with a larger radius made for the new style of pipe.

As joe said, fill it with sand. The sand packs and you will find that a bit of masking tape to stop the sand falling out of the ends is all that is needed, make sure the sand is dry!

[festy_]

As Stringy said, the OD is a bit less than it used to be... and cheapo Chinese cast dies aren't the most accurate either.

Heat your die until it's glowing nicely, then stick a piece of pipe in the die and massage the sides with a big hammer until it hugs the pipe snuggly.

Here's a problematic 15nb die that kinked everything I tried to bend, in the process of being adjusted for proper fit...

http://www.festy.org/files/bender/Image021.JPG



And the resulting bends - top is what happened every time I bent over about 45 deg with this die, and bottom is after closing it up about 1 mm - no packing with sand, or pre-heating pipe, just bend as fast as you can pump the handle ;)
http://www.festy.org/files/bender/Image022.JPG


Sorry about the grainy photos, that's what passed as a phone camera 5 years ago :(

[Woodwould]

[...]make sure the sand is dry!
Why does the sand need to be dry?

[Stringy]

Why does the sand need to be dry?

If damp it will clump and not flow down into the pipe, also creates gaps between the clumps of sand. If heating, the moisture will boil into steam/expand and cause problems.

Cat s**t in the sand also causes problems, either wet or dry.

The best source of sand seems to be the local pre-school:2tsup:!

[gallegos]

This guide from onesteel on bending is worth a read, it gives guidance on minimum radii and die fits and stuff.
http://www.onesteel.com/images/db_images/productspecs/Bending_Nov2004p.pdf

also have a look at this thread because i am too lazy to post what I posted there ;)
http://www.woodworkforums.com/f65/pipe-bending-fail-120570/

[diz]

Hi all,
Thanks for the info. Turns out I went to one of the local boilermakers when picking up steel for work and asked him about bends. He sold me 4 x 90deg bends for under $20 that come pre made. No need to worry about working out the radius etc now. Just weld them to the steel and cut everything to length.

[Karl Robbers]

[QUOTE=festy_;1339176]As Stringy said, the OD is a bit less than it used to be... and cheapo Chinese cast dies aren't the most accurate either.
Not trying to cause an argument, but the OD of pipe has not changed at all, only the wall thickness and material grade change, (the old Gal pipe was 3.2mm wall thickness and grade 250, the newer light and extra light is grade 350 and thinner in the wall)
You need a larger bend radius and better support to bend the newer pipes. Sometimes Medium Gal pipe will work, sometimes not. Typically the formers on the chinese benders are too tight in the radius and do not support out to the centerline of the pipe, or preferably past it.