# Forum Home Renovation Metalwork & Welding  Bending channel

## phild01

I have two 300 long 180x75x5 duragal channel that is out of square.  I put the car jack in it to sort it out but it just bows the middle flat part instead.  Releaasing the jack and it springs back to where it was, can't seem to budge it.  Any ideas other than oxy appreciated.

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## cyclic

Depends what the purpose is as in just how neat it has to be. 
I would put it in my 20 tonne workshop press, or 
place one inside the other plus brace with heavy (10mm) flat or angle, then try jacking that way with my hydraulic bottle jack, even over jack a little. 
Failing that, I would place 2 pieces of hardwood about 200 + long against the concrete kerb or solid wall, with another piece of hardwood across the end, then place channel over hardwood and kawallop with large sledge hammer toward kerb etc. 
Of course you may not have any of these items laying around. 
Last resort, yes, I would use the oxy while holding it in my 50 year old dawn vice then bend it up or down with probably my stillsons (2 Pair) using 10mm flat as a brace so it bends evenly. 
Like I said, depends what the purpose is and how neat, may be cheaper to get 2 more if necessary. 
From what I can see in the pic, the ends closest to camera are out, but the other end looks ok. 
Or you could turn it upside down and kawallop the 180 flat with large sledge hammer which will bend 180 flat down but in turn, bend the 75 sections out.

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## phild01

I do have limited resources, hence the car jack.  When I used the jack, it seemed I was on the verge of it breaking as the channel flange is only 70mm internal, so the jacks base has limited purchase.  Did think about the sledge hammer but I think the rebound of the steel is just too strong to achieve much.  I have a 20 tonne jack but it won't fit.  The flanges need to move outwards, more so one end than the other.  The channel was left over from the 12m length I had. 
I wonder if I should try welding along the outside bend, though that wrecks the protection and makes a mess of it

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## PlatypusGardens

Well if you have to get creative....maybe weld up a "fork" to sit snugly around the part of the channel you need to correct....see crude drawing...   
If the channel is 5mm you should be able to bend it if the fork is strong enough and you put a long piece of tube at the end to get plenty of leverage.  
Of course you need to be able to secure the rest of the channel, probably with clamps....to.....something.....dunno what you have available.  
Correcting warped steel by welding is probably not as easy as it may seem....  
What are you using them for anyway?

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## PlatypusGardens

It's quite common for "U"-channels and "L"-angle steel NOT to be 100% accurate square 90 degrees....

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## PlatypusGardens

Having said all of that.......if you can secure the "middle part" with clamps and put the car jack on the sides/one side you may be able to bend it to where you want it.  
Either way, you need to secure the piece, or it will spring back to where it is regardless of what you do.   :Smilie:

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## CraigandKate

Do you have a MAP torch? That should get it hot enough in combination with the jack to permanently bend it back straight. 
If you don't have one go buy one at the big green shed, they are great for everything and only 100 bucks or so..

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## phild01

> Do you have a MAP torch? That should get it hot enough in combination with the jack to permanently bend it back straight. 
> If you don't have one go buy one at the big green shed, they are great for everything and only 100 bucks or so..

   Already have this but it's quite a bit of steel to get hot.  The torch would struggle to get it cherry red.  The duragal steel seems to be different with a lot of spring in it.  Clamping it flat would be ideal but it has to be clamped flat for the entire flat surface area as it just springs back.

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## PlatypusGardens

So....again...what are you using it for?

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## phild01

It's a support bracket for a patio post.  It will be attached to the steel bearer with one flange and the opposite flange will be attached to a 75mm SHS post.  It needs it's tensile strength and I fear heating it up will reduce this.
It will be fitted vertically to the steel bearer and it's face bolted to the cantilevered joist. Then it is ready to receive the post on the opposing flange.  I might resign myself to just packing out the error which is not ideal, otherwise the post will not be square to the deck.

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## Marc

When you say out of square ... which way is it out? from the picture it seems the left side is a bit more open than the right ... (?) anyway ... heat  and a hammer or just a hammer if you have something to bang against. 
Without a decent size vice or an anvil, you will need to get creative. 
5mm is no big deal if you can fit it in a vice. Failing that, do you have a block of steel to fit inside the C channel and hold it vertical in a vice? or clamp it with two G clamps inside the channel and against a big lump of wood? 
The idea of the packing inside is to add some inertia to the whole so that the hammer blows are absorbed by the spot you are hitting. 
You will need a 1.5 or 2k hammer and place decisive but not too exaggerated blows and check with each blow the result.  C Channel steel is mild and bends easy, the springiness you experience is from the shape it is rolled in not any special quality of the steel. Trying to bend it back with a car jack without any way to retain the unit is wasting your time. 
Big lump of steel inside and clamp down against another big lump of whatever you have, hardwood I gather. Two large G clamps, the F clamps will loosen up with each blow.

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## phild01

Unfortunately the flanges are closing in rather than out, hence the use of a jack.  I might try again by clamping them together, face to face in the hope of stopping the face bowing.  It seems to me that duragal c channel has a tensile property different to a regular pfc. 
edit: just read a bit about the product and yes it has a higher tensile strength to regular steel.

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## Marc

if you need to open the flanges out it is easier. Get a piece of steel inside the channel and hit the corner at the base of the flange.
You can place the biggest lump of steel you have in your vice and place the C channel on this piece and hit the corner from the outside against this improvised anvil.
Use hearing protection and thick gloves on your left hand. Bending back steel with only force is not the way to go. You need to use a large hammer to make small dents to the steel and get it to go where you want. Of course much easier to do hot but you will lose your galvo.

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## phild01

> if you need to open the flanges out it is easier. Get a piece of steel inside the channel and hit the corner at the base of the flange.
> You can place the biggest lump of steel you have in your vice and place the C channel on this piece and hit the corner from the outside against this improvised anvil.
> Use hearing protection and thick gloves on your left hand. Bending back steel with only force is not the way to go. You need to use a large hammer to make small dents to the steel and get it to go where you want. Of course much easier to do hot but you will lose your galvo.

  Marc, you would have a laugh if you knew what I have available.  Having something to rest it on (anvil) is the biggest challenge but yes I agree, a mighty blow to the elbow should get it moving, though with little control.  The out of square is worse at one end of it's 300mm length.  Hammer blows to the corner might be better than a hefty piece of steel though. 
No, got what you said back the front, I have a length of 100 shs 5mm, might be worth placing it over that and bang away.  It also has a 10mm plate welded to it and that might be better.  
Just one issue is that the bend has quite a curvature and that may be troublesome.

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## Marc

Ok ... lets backtrack a bit. Do you have a large hammer? Does it have a decent handle so that you don't kill your neighbour?
Good ... put the channel on the dirt, flanges down. Mark with chalk the area that needs to be bent and place a controlled hit at 45 degree to the edge, and check the results. Go easy and check every time you don't want to go the other way.

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## phild01

haha is that 45 degrees K, no that was the hail  :Wink 1: .
  Okay, I'll try and work something out with that Marc, thanks.

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## Marc

A piece or railway track would do wonders in this case place the C channel over the track and bang away. on the corner at 45 degrees to it.

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## phild01

Yeah, not far from the railway line though will be tricky explaining what I am up to :Biggrin:  :Sneaktongue:

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## phild01

Just realised I have a 90x 5mm steel pipe filled with concrete lying about.  That will be a perfect for this I reckon.

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## Marc

A round pipe? 
I suppose if nothing else is available it will need to do.

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## phild01

All sorted now, I used a headsplitter (logsplitter head rebound, was close)  and smashed it around a bit.

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## Marc

Yes, the right hammer hit does it every time  :Smilie: 
A log splitter? 
Mm ... reminds me of a friend who came to visit and wanted to adjust the hinges of a door that was dragging yet I had no carpentry tools at all there so he used an axe .... well ... it worked  :Smilie:

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## phild01

The blunt end Marc  :Rolleyes:  :Wink 1:

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## lazydays

FYI...In a former life when I was a heat treater we sometimes had to straighten long drills or reamers of HSS after they were heat treated and had bowed more than we could grind off in the sharpening process.
We made a little peening hammer with a tungsten carbide bit. Checked for the bend by using a dial gauge and two centres and I "think" it was the HIGH side we used little but many , tap, tap tap until they were straight. Mmmmmm maybe it was the low side as the many little blows added "length" to that side and forced it straight.

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## Marc

[QUOTE]Mmmmmm maybe it was the low side as the many little blows added "length" to that side and forced it straight.[/QUOTE] 
I think the only 'tapping' Phil has done is with his feet aiming a mighty blow with that sledge hammer.

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## phild01

Damn thing brought back my tennis elbow :Frown:

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