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macBdog · Posted: Sat Apr 14, 2007 6:15 pm Post subject: How to use a pipe bender?

Hey guys,

I recently bought a pipe bender, the crush type like this:

Its a 16 ton one and has formers up to 3" pipe. I am trying to bend 2.5" pipe for my exhaust but when I try to bend the pipe in the 2.5" former it just kinks and crushes in the worst way. I've tried the 2" former and that fits heaps more snug and the result is better but its still kinked to hell. Not a pretty and smooth bend at all like I was expecting.

Has anyone had experience with one of these and how do you use them properly? Is it to do with the pipe wall thickness or speed or do you have to heat the pipe first? Im confused

Thanks in advance.
_________________
1979 931 with a 350 chev
1973 911E with EFI

Ozzie · Posted: Sat Apr 14, 2007 6:32 pm Post subject:

When I was taught to bend pipe (the hard way) it had to be packed with dry sand to prevent crushing.
Dry because we used heat but no 16 ton press back then.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Min · Posted: Sat Apr 14, 2007 11:41 pm Post subject:

macBdog · Posted: Sun Apr 15, 2007 7:54 am Post subject:

Wow that sounds interesting, how did you guys perform the bending after the pipe was full of sand if there was no press?

Welding the ends shut for every bend sounds like a bunch of work but I guess whatever is required...

Would heat help the situation?
_________________
1979 931 with a 350 chev
1973 911E with EFI

Ozzie · Posted: Sun Apr 15, 2007 8:55 am Post subject:

If you use wet sand, weld the ends shut and then use heat you have a bomb on your hands as the steam pressurises the pipe.

We used dry sand, packed and sealed with a wooden plug and lots of heat.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

PORSCHEV · Posted: Sun Apr 15, 2007 9:57 am Post subject:

Do you have any picture of the stamps/die that come with it. They should match the contour of the pipe, otherwise they will just crush. I bought a small bender for making go kart frames but the same thing happened if you try to bend hollow pipe. It will bend solid and flat bar perfect..but not pipe.
_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

Ozzie · Posted: Sun Apr 15, 2007 10:10 am Post subject:

With wooden plugs which are cone shaped you need to get soft wood not hard wood.
Soft wood will mold and seal the ends where hard wood will split the end.
The idea with plugs instead of welding the ends is the plugs will blow out if there is any pressure build up.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

macBdog · Posted: Sun Apr 15, 2007 12:43 pm Post subject:

So you can't hollow tube with one of these benders? Or you can if you fill it with sand first?
_________________
1979 931 with a 350 chev
1973 911E with EFI

Ozzie · Posted: Sun Apr 15, 2007 3:35 pm Post subject:

If it will bend solid it will bend pipe filled with sand.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

PORSCHEV · Posted: Sun Apr 15, 2007 9:34 pm Post subject:

With the proper dies you don't need sand and plugs or heat.

Look at the dies with this bender on ebay...do you have those Mac?

http://cgi.ebay.ca/16-TON-HYDRAULIC-PIPE-BENDER-W-6X-3-DIES-ROLL-CAGE_W0QQitemZ160105403947QQihZ006QQcategoryZ104220QQrdZ1QQcmdZViewItem
_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

macBdog · Posted: Sun Apr 15, 2007 10:03 pm Post subject:

Yea those are the dies that I got with it. 2.5" OD pipe in the 2.5" die has plenty of room to kink and bend. Even in the 2" die it still kinks.
_________________
1979 931 with a 350 chev
1973 911E with EFI

Paul · Posted: Sun Apr 15, 2007 10:19 pm Post subject:

What are you using for pipe?
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

PORSCHEV · Posted: Sun Apr 15, 2007 10:21 pm Post subject:

Where does it kink..on the inside against the die or on the outside of the pipe? It looks like you'll be packing sand. Thats too bad.
_________________
1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

macBdog · Posted: Sun Apr 15, 2007 10:23 pm Post subject:

I went down to the local exhaust shop and bought some 2.5" pipe. Its mild steel, wall thickness between 1 and 2mm (got a few bits).
_________________
1979 931 with a 350 chev
1973 911E with EFI

macBdog · Posted: Sun Apr 15, 2007 10:44 pm Post subject:

It kinks on the inside against the die and on the sides. The outer edge of the bend is alright. I'm happy to pack sand or whatever needs to be done to get a good result. Will get some more pipe and experiment.

Oh and thanks for the tips Ozzie, Min, Porschev et al. Without that kind of know how I would just be scratching my head and wondering.
_________________
1979 931 with a 350 chev
1973 911E with EFI