Bending iron

[ekmdgrf]

I have a pair of iron gates in the garden. 2m wide by 1.5m tall. The outside edge of the gates is made from square iron bar, 25mm. I had the gates sandblasted and somehow that managed to bend the 25mm bar in two places. On one of the gates, on both the left and right edge, near the bottom, the bars are slightly bent outwards. No idea how they did this. Any ideas for the best way to bend it back into shape? I've tried heating it with a blowtorch and hammering it back into position but the gate is quite springy, so it tends to absorb the impact. I've also considered bracing it between something solid and using a hydraulic cylinder to bend it back into place.

Anyone else any bright ideas?

Untitled

• ekmdgrf
• 10 Aug 2013
• 1

Untitled

• ekmdgrf
• 10 Aug 2013
• 1

 

[Burnerman]

If you can get hold of a joiners sash cramp, you could try heating up as much as possible (below red heat won't make much difference) then popping the cramp into place and winding it in......hammering is likely to stretch and bruise the metal, I'm afraid.
John

 

[catengineman]

The only real way to repair the stretch from the blasting would be to cut / straighten ad reweld the bent parts
See if there is a local company that can carry out this for you or you could hire a small welding machine and do it yourself
the bending would be from the blasting as it is like millions of tiny hammerings which stretch the steel, it maybe that in the affected areas there was a need to have a longer session of blasting done, did the blasting company explain this to you when you contracted them to do the job?

 

[ekmdgrf]

No, they didn't. I've heard of people getting ****ed off when the sandblasters have bent their car body parts. I'd have thought the gate would be a little more resistant. Oddly enough, despite there being a lot of ornate ironwork on the gate, that's all come back fine. It's the thickest part of the gate that bent. A piece of 25mm x 25mm bar. I've spoken to the blasters who've denied all knowledge and claimed it must have been the delivery company that transported the gates. I'm failing to see how they could have done anything which would have produced the insane amounts of energy needed to do the damage that has been done. Further the gate is bent outwards rather than inwards. Not really consistent with being dropped out of the back of a van.

 

[catengineman]

As I said there is only one way I know of which is to cut ad then re-weld the bent steel.
the ornate parts can expand within the scrolls and this would not show up unless yo put the gat onto the original former where it was made.
The reason the larger steel has suffered is that it will have a greater area to absorb the impacts from either the "shot" "grit" or the "sand" depending on what was used and at what pressures.
We try to avoid the use of blasting because the effect it has (I work on ships) and we tend to use VHP water jet as a cleaner though times are when blasting is done.

 

[Mursal]

As already said best to cut the piece out and replace with new. Failing that, if you get a piece of RSJ girder (8x4 or the like to push against) and chain the bent rail to it in two places, at both ends of the bend. Leave the chains slack, to begin with. Then place a jack (bottle type hydraulic will be best) in between the RSJ and the rail of the gate gate at the closest point of the bend (the middle).
Tighten the chains and when you are ready apply pressure with the jack. You may have to move several times as you apply pressure to follow the bend and be careful the jack or chains don't slip. You may not need heat

Doesn't have to be RSJ, as long as it doesn't bend before the rail starts to straighten.

Hope this makes sense