having problems with hydraulic pipe bender?

[R1 Indy]

im making an exhaust manifold for the 7, and bought this hydraulic pipe bender to make the bends: http://cgi.ebay.co.uk/New-12-Ton-Hydraulic-Pipe-Be...

im using 1 1/2" stainless steel tubing.

but whilst its doing a nice bend, where the pipe goes onto the die in the middle its pushing the pipe inwards quite a bit. rather than it being nice and smooth.

this is no good as its going to restrict the exhaust massivly.


am i doing something wrong? or is there something i can do to stop it doing this?

i can post some pics if that would help?

cheers

[SlimRick]

Have you tried filling the pipe with sand prior to bending? Supposed to stop the pipe from compressing.

[R1 Indy]

not tryed anything like this.

so if i was to completely fill the tube with sand, and weld a plate on each end to keep the sand in, then do the bend, and cut the ends off.

will this work? or will the sand just compress?

[R1 Indy]

and ideas wheather sand would work? or have i wasted my money?

[HellDiver]

R1 Indy said:

and ideas wheather sand would work? or have i wasted my money?

No. Yes.

[v8will]

doogz said:

You bought a pipe bender.

You wanted a mandrel pipe bender.

This.

[littleredrooster]

• sucks teeth* Stainless is funny stuff to work with....

[GAjon]

What wall thickness is the tube you are trying to form? It may be to thin for cold forming.

[R1 Indy]

Well im giving it a go wirh the sand.

Ive welded a plate on one end, then filled with gritty sand, welded plate on other end, then drilled hole in one end and forced as much in as poss with a rod then welded the hole back up.

Im now about to give it a go.

I do have this feeling it may go wrong

Oh and its 1.5mm thick

[GAjon]

1.5mm is to thin to cold form; Also if its welded tube it may split at the seam.
Ideally it should be sand filled, with very dry sand, packed in ( and I mean hammered in tight)then hot formed, using Oxy / Propane or Acytelene with a pepper pot torch to heat it then form around a jig.
But you've bought the bender now so you might as well have a go cold!

Edited by GAjon on Monday 24th January 17:28

[R1 Indy]

it failed, made absolutly no difference.

when you say hot formed, would i be able to get it hot enough with a blow torch?

ive just looked and hss don't have any for hire.

so it looks like im going to have to stick with the manufactured 45/90D bends.

[GAjon]

R1 Indy said:

it failed, made absolutly no difference.

when you say hot formed, would i be able to get it hot enough with a blow torch?

ive just looked and hss don't have any for hire.

so it looks like im going to have to stick with the manufactured 45/90D bends.

Blow torch wont do it, if you can get the pre formed bends it might be more cost effective, (by 90's and cut them to the angles you need) what tube are you using?

[R1 Indy]

ahh i hadnt thought about cutting down the angle.

ive just found somewhere on ebay selling some 90's for 7 quid so i think i might just get them, and make them fit.

im using 1.5" for the manifold.

[Tallbut Buxomly]

R1 did you try filling a stocking with fine grade sand then drop it down the pipe? Weld a plate on one end so it sits on the bottom and will compress through the pipe.

[PhillipM]

doogz said:

You bought a pipe bender.

You wanted a rotary draw tube bender.

Fixed.

Fill 'em with fine grade, kiln dried sand (packed in and capped) or anneal the tube and some of your problem should go away. Put some moly grease on the formers too.


Pipe is a different size to tube so it may well be you've got the wrong formers for the job.

Edited by PhillipM on Monday 24th January 18:51

[R1 Indy]

doogz said:

R1 Indy said:

ahh i hadnt thought about cutting down the angle.

ive just found somewhere on ebay selling some 90's for 7 quid so i think i might just get them, and make them fit.

im using 1.5" for the manifold.

Yeah, best to buy pre-formed elbows and cut them to suit.

Pics when it's done, i love stuff like this, it's more hassle than buying one, and by the time you add your time on to it, probably not any cheaper than just buying one.

But that's not the point, making stuff yourself rules.

i will put some pics up once im done.

and your right i could have probably almost bought a manifold for the cost of materials/my time, but what is the fun in building a kitcar when everything has been made for you.

[eliot]

Better of purchasing some ready made mandrel bends. Those pipe benders are hopeless.

[PhillipM]

The other option is to cap the ends fill with water and weld the cap on the other end, the heat from the welding should pressurise the tube slightly on it's own, but cold water and heating the tube after with a heat gun works too.
That generally will get it far, far better.

The problem is:

It's slow.
It's messy.
It takes stloads more pressure to bend the tube.
If you don't get the weld cock on you might find the pressurised water makes a very effective waterjet when a pinhole blows through. This is about the time you realise:

a)You're stood very close.
b)Your bks are at tube level.

Buy some bends and chop + weld 'em!

[R1 Indy]

PhillipM said:

The other option is to cap the ends fill with water and weld the cap on the other end, the heat from the welding should pressurise the tube slightly on it's own, but cold water and heating the tube after with a heat gun works too.
That generally will get it far, far better.

The problem is:

It's slow.
It's messy.
It takes stloads more pressure to bend the tube.
If you don't get the weld cock on you might find the pressurised water makes a very effective waterjet when a pinhole blows through. This is about the time you realise:

a)You're stood very close.
b)Your bks are at tube level.

Buy some bends and chop + weld 'em!

i like the plan, but i feel it will probably end very badly

and ive just ordered 8 90D bends off ebay for 50 quid, so not too bad.