Shop Cheats: Welder's Brake




Introduction: Shop Cheats: Welder's Brake

About: I am a shop body. Give me a job, the tools to do it, and I will be happy as can be. I get along best with metal and machines. Back in the day my Dad was a welder by trade. I managed to learn a lot of that tr...

Bending metal is always a pain if you don't have the right tools. But luckily I happen to have a neat cheat to bend metal without the right tools. This is a cheat I have wanted to write an Instructable about for quite some time to add to my Shop Cheat series. But I hadn't had a project to demonstrate the Welder's Brake until now!

Here's the problem. I want to bend a piece of steel, but it is too heavy for my sheet metal brake. It has a maximum capacity of 18 gauge steel and this stuff is 14 gauge steel. Which shouldn't be a problem any more since I built my own DIY Press Brake. But the piece of steel is too big to fit in my press, even when I fudge it. Which effectively leaves me without the "correct" tooling.

Step 1: Overview

Incorrect or insufficient tooling is the perfect place for a Shop Cheat. This is something my Dad taught me and he always called it the Welder's Brake. Essentially the metal is scored by cutting something like a dotted line into it. The theory here is that instead of bending the whole piece of metal you instead remove metal so there is less metal to be bent. And once the bend has been made you replace the removed metal with weld fill.

The simplified explanation is cut, bend, weld.

Step 2: Cut

Everyone has heard the saying: "Measure twice cut once". I know I have written it into at least one of my other Instructables. But it is a good habit to get into. Before cutting I layout where the cut needs to happen. Then I further measure how I want to break up the cut into multiple smaller cuts.

A plasma cutter works pretty slick here. Since I need to start and stop my cut I really don't have a lot of other options. I could use a cut-off wheel, but it would take longer and may not be as straight. When using a plasma cutter on straight lines I always try to use some sort of straight edge. That way the line is straight. Because if this line is crooked or curved so will the piece I am bending. Which in this particular instance isn't a deal breaker. It's just nice to make thinks square and straight.

This is also where the safety disclaimer will show up. These interrupted lines mean I have to start cutting in the middle of the piece of metal. On light sheet metal like this it isn't too big a deal. But starting a cut in the middle of the metal will send sparks flying right back at the torch. If you're wearing your safety glasses and proper welding clothes you'll be just fine.

Step 3: Bend

Now that the line is scored it's time to bend the metal. I could try to do it entirely by hand but it would probably end up really wavy. It would be best if I had some sort of straight and rigid clamp that could hold the the metal while I bend it. Luckily my sheet metal brake can be used as a clamp. Otherwise I would have to rig something up with some angle iron on the edge of my welding table.

The metal will have to be properly aligned in the clamp. Which is really easy since there's a distinct line right where I want the bend. Once the clamp is tight it's time to start bending. Because I don't want to hurt my tool I will be bending the metal with my hands. Slow and steady is the way to win this race. If you try to bend too much too quickly you can over-bend the metal. And if you are using the hand bending route you could make things worse by bending the metal unevenly.

Step 4: Weld

With the bending done it's time to weld the metal where I cut it. This is pretty straight forward. But because of the width of the cut compared to the thickness of the metal, I have decided to add a little bit of metal to the seam. This extra bit of metal will help to fill the gap faster without heating the metal more than I want. So I'll just cut a piece of welding rod to the length and use it to fill the gap.

When welding I like to weld in small steps in an attempt to manage heat from welding. This is important because the heat from welding will distort and draw the metal in directions I may not be able to control. Ultimately these heat distortions could ruin whatever I'm welding, even big beefy bits of metal are susceptible to this.

In this particular case I will be welding about an inch and a half or less at a time. Laying one bead then moving on to the next seam in a leapfrogging pattern. After every step is made across the whole piece I take a little break to let the metal cool down a bit then resume the work. Working like this does eat up a lot of time but the results are hard to argue with.

After the welding is done I could stop and move on to finishing steps like painting but I want it to be a showy shiny part. And I have not been careful enough to make pretty welds. Which is nothing a little time with a grinder can't fix. After that I can move on to paint and finish.

All in all this project didn't turn out half bad. In fact I'm quite happy with the results.

Step 5: Missteps and Mistakes

Unfortunately there are limitations to this technique. Up to a certain thickness of steel, and presumably other metals, it becomes increasingly difficult to successfully use the Welder's Brake. I tried it on an earlier project and found that I would have been better off using separate pieces of steel rather than all one piece.

This attempt was made using 1/4 inch steel. After having to make multiple cuts because the steel was too rigid even when nearly severed. And once it did yield it cracked so badly that I had essentially cut the metal and welded it back together. Needless to say I was very disappointed with the results. But with any luck you can learn from my mistakes.



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    13 Discussions

    "Up to a certain thickness of steel, and presumably other metals, it becomes increasingly difficult to successfully use the Welder's Brake. I tried it on an earlier project and found that I would have been better off using separate pieces of steel rather than all one piece.
    This attempt was made using 1/4 inch steel."

    You could still make that bend by first perforating the metal like you had done, then scoring halfway through the remainder with a wafer (to 1/8" in this case), and finally heating with a torch if necessary.
    This way, working from one piece, you won't have to deal with the fit-up issues encountered when starting from two separate pieces.

    We have a brake that fits in a press. It will bend 19" of 1/8" and 5" of 3/8" with the factory angle iron base. We have made inserts to make tighter radii so we can't bend that heavy of material with a tight radius. When we cut parts out that need bent, we just cut line segments on the CNC Plasma table which makes it much easier to bend.

    I have been successful on the thin stuff by scoring the inside of the bend with a cut off wheel (straightedge guide,of course) and using the clamp n edge assembly to bend it. then I weld the inside corner, which will be hidden,to beef it up.hadn't tried this method,but i' give it a whirl next time the situation comes up. nicely written,by the way.

    I am aware of once instance where a 'welder' working on coded work did that 'trick'. It was found on xray examination and it cost him his job and reputation and the company that employed him thousands of pounds to get ALL other welds irrespective of who welded them checked. Having held 4 ASME IX certificates I know how difficult it can be to produce quality work every time and it could be tempting to think you can get away with short-cuts - but it just is not worth the risk. Root inserts or Backing strips specifically made for welding operations are fine, but improvised uncontrolled 'modifications' to joint design are not

    1 reply

    with 30 years exp welding behind me, anyone who tries that 'fill trick' on code or critical structure should be fired and have his hood confiscated


    7 months ago

    As you stated this method may be suitable for some jobs and you have pointed out where cutting and fabricating from separate pieces would be better.

    I would like to make a suggestion for your press brake - ditch the springs and alignment pins. I have made these for putting curves in 10 mm plate and welded a collar on the finger to mount on the spear and then seated in the trough before bending. You can sneak up on a long bend by working along a line.

    It is common practice in the fabrication industry to break-up long welding seams to reduce/eliminate distortion. The purpose of these sequences is to prevent the continual expansion and contraction as the welding operation proceeds. The exception to this is with processes such as submerged arc welding which are used for long uninterpreted welding seams on items such as fabricated support structures on heavy gauge materials. Welding sequences are also used on metals known to distort easily, stainless steel being a notable example due to its low coefficient of thermal conductivity and high coefficient of expansion (that means it distorts extensively with minimal heat input). Where you weld a short section then miss a short section, then weld a short section is called 'skip welding'. Where you weld a short section then move back a short distance from the weld start, then weld that section toward the start of the previous weld is called 'back-step' welding. There is nothing wrong in the way you achieved the result you wanted. But it is 'bad practice' to fill a proposed weld with welding rod since root penetration/fusion cannot be guaranteed. It looks as though necessity was the mother of invention in this case.

    1 reply

    Back in the '70s oilfield piece welders, after the root pass, would put welding rods inside bevels and jack up the current so they could get done faster and make more money. Not something I could do, my pipe and structural welds were X-rayed. I have, however, used inserts and put filler wire in a bevel while doing tig.

    If it works for ulyou, fine. Me, if it won’t fit in my 48” brake I would weld two pieces at whatever angle the finished piece is supposed to be OR take it to a local shop with a brake or press.
    If it was something I were going to do on a regular basis I would fab a hydraulic press.

    A nice description of how to bend metal with limited resources and interesting comments. I work on heavy equipment and without the 40 foot long 200 ton [exaggeration] press brake this is the way to do it.

    If you encounter cracking and/or lack of penetration use the following as necessary:

    - Heat the bends red [before bending]

    - weld the outside bend as a sealer

    - crank up the heat and weld the inside as hot as you can from middle to ends

    - remember as you near the end of the weld it will get hotter.

    - Overlap the weld starting points

    - Overlap the weld onto the uncut material..

    - Flip it over, grind out your seal weld down to metal and pour on a hot pass to boil out the crud.

    - Heat the whole joint red and let it cool and grind as necessary.

    This applies to mild steel. Alloys [T1, AR for example] require more procedure.

    Thank you for bring this topic up.

    If you're cutting thicker metal and your plasma won't pierce it, take a drill and a small bit, say 1/8 and drill a hole to start the cut. I worked with a very good metal worker from Guatemala who used a cold chisel he rounded the edge on to crease some sheet metal he was bending with no break, and then he bent the metal with the crease on the inside. In this case there was no need to weld where the bend was and it did a neat job.

    on the mistakes the thicker plates i think i would work if you perheat the taps before you bent them preheat till its cherry red

    1 reply

    I had the thought of that. And that would definitely solve the cracking issue. It's just I get stuck using sheet metal thinking when trying to form plate.,,,,,,,,,,