pipe bender

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aucklander

477 posts

Ultimate Geek

#130802 28-Sep-2013 15:19

Hi,
A project I am really planning to proceed with, involves some steel pipe bending. I expect to be using standard steel pipe, 1" (approx 33mm OD), 1-1/4" or 1-1/2" (48mm OD). Before rushing to buy one of those 12T hydraulic pipe benders off TradeMe ($165 - will do pipe up to 2"), I would really need to be able to run a test first and see how much deformation I get in the cross section of the pipe (how oval does it gets). I know these pipe benders are not suitable for tube (thin wall), but I will use standard steel pipe (which I assume is sch 40).

Is there anyone (preferably in West Auckland) able to allow me to run a test on few pipe sizes with such pipe bender?
I have 48mm OD (3.5mm wall) steel pipe, I will have to get some 1" pipe from somewhere for the purpose of this test.

I can try some of the engineering workshops in the area, but I guess they would have better pipe benders (maybe with a mandrel, which guarantees the pipe stays circular along the bend), I need to see in action the bender which I am able to get for myself. A reply will be much appreciated, I would hate to spend $165 and then try to return or sell it for half price if it does not work as needed.

Many thanks in advance,
Chris.

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RunningMan

8965 posts

Uber Geek

#904210 28-Sep-2013 16:26

The ones I've seen in the past tend to deform the tube quite badly for anything more than a slight bend.

Depending on exactly what you are doing, try a motorsport roll cage builder as they will be able to do mandrel bends of pretty much any angle.

chevrolux

4962 posts

Uber Geek
Inactive user

#904215 28-Sep-2013 16:37

The 'bow and arrow' style benders on trademe are fine for their money. But are a bit limited if you want to get nice 90* bends.
I built a rollcage for my 4x4 and used a combination of the cheap trademe hydraulic bender as well as 'manual' bender.
The 'manual' bender was one that bolted to the ground on a stand and had a big long arm. The formers were 270* (ish) so you could roll the pipe all the way around if you really wanted to.
To get nice 90's I used the manual bender. I was using heavy walled pipe too so to combat crushing heat was the key. You heat the pipe until it is too hot too touch but not 'red hot'. Then it just rolls around nicely without kinks. The boys on the 4x4 forums made mention of stuffing wet sand in the pipe to maintain shape but I couldn't really figure out that with a 6m length of pipe.
To get a 90 out of the bow and arrow style bender meant a very deformed bend but was excellent for the more techinical bends..
Will get a photo up of the cage if it stops raining here.....

aucklander

477 posts

Ultimate Geek

#904280 28-Sep-2013 18:56

Hi, thank you for the reply.
It is for a garden feature, imagine 1.8 height fixed to the ground and at the top it turn horizontally for 250mm, for something to hang off that arm. Not critical application, but I believe a squashed bent would look awful.

I will see what the "bow and arrow" bender can do with the pipe I am thinking to use and make a decision afterwards. One of the shops agreed to allow me to run a test, but I suspect they will be very dissapointed if I do not purchase the bender... I will see how it goes.

If the bend is really squashed, I might look at welding a proper 90 deg elbow and grind the welds nicely? It is definitely more work... (and my welding skills are not tested yet, even if I got a small arc welder last month).

chevrolux

4962 posts

Uber Geek
Inactive user

#904283 28-Sep-2013 19:14

aucklander: Hi, thank you for the reply.
It is for a garden feature, imagine 1.8 height fixed to the ground and at the top it turn horizontally for 250mm, for something to hang off that arm. Not critical application, but I believe a squashed bent would look awful.

I will see what the "bow and arrow" bender can do with the pipe I am thinking to use and make a decision afterwards. One of the shops agreed to allow me to run a test, but I suspect they will be very dissapointed if I do not purchase the bender... I will see how it goes.

If the bend is really squashed, I might look at welding a proper 90 deg elbow and grind the welds nicely? It is definitely more work... (and my welding skills are not tested yet, even if I got a small arc welder last month).

If you are going to do a 90 with a bow and arrow just don't try and do it all at once. Work your way around the bend doing a bit at a time. Won't be as tight as doing it all at once but won't squash it that way.

Welded bends are all good if structure is important. Just invest in g-clamps and some 'sanding' discs for your grinder and you will get the weld flat as a pancake. If you go to steel and tube and ask for a 'multi bend' in the size you require you will get a twisted piece of pipe and will be able to just cut out the angle of bend you want.

Don't buy an Arc welder. Get a MIG. Same price and so much easier to use. Plus your welds will be better. Either rent or buy gas from BOC and you will be away. Argoshield is my personal favourite but plenty of people like using pure C02. It is just a bit more 'angry' than the Argoshield which is an Argon/C02 mix. Supposedly when using pure C02 you are venturing in to MAG territory rather than MIG. MAG means the weld is technically stronger but as I mention it is slightly more 'angry' and not as pretty when using Argon or Argoshield.