Hydroforming in the Garage with a Pressure Washer

Ever heard of hydroforming? It’s a manufacturing process used to form sheet metal into shapes using water at extremely high pressures. Not something you can do at home… unless of course you’re [Colin Furze].

Hydroforming works by evenly distributing pressure via water (conveniently, in-compressible) against sheet metal inside of a mold. Many automotive parts are created in this fashion. Typical systems run at around 15,000 PSI.

After building a giant pulse jet engine (complete with butt) to fart on France, [Colin] got the idea from a YouTube comment to try to do hydroforming at home — bending the sheet metal for the giant derriere wasn’t that easy. Hydroforming on the other hand is a surprisingly simple process. Weld some sheet metal together, add a pipe fitting to connect your cheap pressure washer and boom — hydoformed metal parts.

Whoa — aren’t we missing a step here? Typical hydroforming uses a mold to push the sheet metal against in order to form a shape. [Colin’s] first attempts are mold-less which limits the complexity of parts he’s able to form — although he is able to make a pretty nice conical exhaust for his souped up mobility scooter…

In the next video he promises to make something very functional out of the process so we’re excited to see what he comes up with. It might be feasible to make molds using concrete, so that may be a possibility.

Don’t forget your safety tie if you’re going to try this!

72 thoughts on “Hydroforming in the Garage with a Pressure Washer

  1. Nice, but dangerous. I use systems which generate 1000 bar, but the only thing which makes them safe is the fact that they have low flow rate capacity. As soon as something springs a leak or ruptures the pressure drops immediately.

    By connecting a pressure washer, you’re using a pump which has a much higher capacity. If you spring a pinhole leak, the pump could continue to pressurize the system to a very high level, ejecting liquid as a tiny jet under high pressure… and they you have a hydraulic injection injury.

    1. If you watch the video you will see that isn’t the case. He springs a number of leaks and it doesn’t go injuring anyone or cutting anything. Consumer pressure washers don’t go to 1000 bar and they don’t really have that much flow.

      1. Springing lots of substantial leaks would actually be safer than one pinhole leak of course.

        Pressurizing metal from 3 feet away without even wearing safety glasses? Nice shop though.

      2. Hydraulic injection is still a risk at the pressure levels a washer can generate, but they’re reasonably easy to avoid in this particular case by simply keeping a distance from the work piece.

      3. That’s true, I forgot to consider that a single test without injury clearly demonstrates that it’s fundamentally safe.

        An electric pressure washer can easily hit 2000 psi, and is rated for over a gallon a minute. I’m not sure what the flow rate is at max pressure, I’m guessing substantially less than 1.5 gpm, but a pressure washer such as the one he used in the video should be able to maintain 1500+ psi even in the presence of a big leak. In effect, any leak has the potential to be a high-pressure jet nozzle.

        It’s true that most of the time that won’t be the case. Most leaks will have a non-smooth aperture and will make a mist as shown in the video. The point is that the hardware is absolutely capable of generating a dangerous condition spontaneously and without warning.

        I’m not saying that we should all run screaming from hacks like this. But it is ridiculously irresponsible to not employ really simple safety precautions. In this particular case, he could have worn eye protection and maybe gloves, and the pressure gauge should have been located away from his welded sample (2:30 in the video, wtf).

        Here’s what 2000 psi will do, although obviously they’re rigging the test: http://www.youtube.com/watch?v=rxs3zzzMVWw

          1. The flow rate is actually fixed and constant.

            Pressure washers use piston pumps in order to increase the pressure of the incoming water to anywhere from 1200psi to 5000psi or higher. These piston pumps have a fixed displacement and at a constant RPM will provide a unvarying amount of water flow from the inlet to the outlet. In other words the amount of flow from the pump is determined by:

            Liters/Gallons per minute = volume of cylinders * RPM

            If you were to put a valve directly on the output of the pump and close it your pump would overpressure and break, to prevent that from happening pressure washers usually have what is called an unloader valve.

            Unloader valves are installed at the outlet of the pump, as the pressure coming into the valve tries to exceed the set point of the valve, it will open and drain the excess flow back into the inlet of the pump thereby ensuring the outlet pressure will never exceed the unloader valves set point.

            Since the maximum pressure in the system is determined by the unloader valve, the flow rate coming out the end of the wand ( or leaks from your hydro-form setup ) will be determined by the size of the orifice the water is escaping through. But above a certain orifice size and the displacement of the pump at its running RPM won’t be enough to maintain the pressure and it will begin to fall. If you continue to increase the orifice size eventually you reach a point where the pressure at the outlet of the pump will equal or go below the pressure at the inlet, and that’s the point you have to go find another nozzle because yours just shot off the end of you wand since you didn’t get it locked in properly and you have no idea where it just went. ;-)

          2. This. This is why paying attention in algebra class eventually pays dividends. They way they teach it is crap, but learn how to apply it on your own and it becomes a powerful tool.

        1. Except the bit where a pressure washer doesn’t have much of a flow rate. Even if the piece managed to sustain a pinhole leak, a few yards away the stream would be broken apart and harmless.

        2. So what you are saying is that if the pressure washer creates a leak in the piece being hydroformed, the leak could act just like a pressure washer nozzle?

          Wow. Better run away fast, you might actually get wet.
          End sarcasm.

          1. Put the smallest nozzle available on a good pump and put your hand in front of it. Call me when you get back from the hospital.

            Your typical car wash usually has a bit enough nozzle (wider spray, lower pressure) that it’s not that dangerous.

          2. As someone destined to remove myself from the genepool, I can tell you that the last time I cleaned something with a pressure washer, the stream shot through my shoe, and into the skin in my feet. It looked weird, but more importantly, it hurt really bad for many days.

    2. I understand your concern, and in many respects it isn’t misplaced. IE safety glasses are always a good idea. But I also think your comparing it to what you do daily which is a order of magnitude more pressure. While probably possible, it is unlikely this setup will produce conditions more dangerous than the original pressure washer.

      Also what videos he has done aren’t dangerous…

      The real danger is someone totally unaware of the possibilities playing with this, or rigging up a higher pressure source and your comments point this out. That is true for so much in the hacking community though. Electricity and even power tools can all be deadly in the hands of a complete novice, and more so with some one with only limited experience.

    3. I own and operate waterjets. Commercial waterjets can operate at 87,000 PSI. Not 8,700 PSI. 87,000 PSI. You are past the yield strengths of many steels at this point. Assuming you are NOT entraining abrasive into the water stream (in other words you are cutting with JUST water), the cutting power of water starts to drop off very quickly with distance. So much so that after a few inches, you are hard pressed to cut through much of anything short of thin rubbers or foams. You can’t really cut through metal at all with pure water, even with an average cutting distance of about 0.1″ between the nozzle and the metal.

      That said, the smaller the water stream gets, the more likely you are going to have an injury but the fact remains that unless you had some laminarized ultra high pressure water (never seen that, could be a neat thing), you are not likely to physically damage yourself once you distance yourself 5″ or so from the waterjet stream. At 60,000+ PSI. Again, assuming water only. Add abrasive though and all bets are off.

  2. I could tell you what he’s making next but he’d kill me….. By the the way, water is safe because you can’t compress it. Thus as soon as a leak appears the pressure dissipates.

    1. The pressure dissipates if the pump is off, or if there is a catastrophic failure. This is why gas cylinders are tested by pressurizing with water while submerged in a second tank of water (sometimes it’s dry): the second tank collects any leaks safely.

      The pressure will NOT dissipate if it’s a small leak and the pump is running.

          1. Hackaday has plenty of entries on prosthetics and synthetic vision. Dramatic injury would actually increase legitimate hacking projects. People would even start giving you money to do it.

      1. Catastrophic failures??? OH MY!!!!

        We have a civic duty to alert the world to these potential dangers. Why, it’s possible that hackers of the future could get injured, or even worse!

        Let’s you and I start a new site dedicated to pointing out potential safety problems with hacking. There are innumerable experiments and demonstrations that sould be properly commented about safety.

        Come up with a name, then let me know when you’ve registered the site and I’ll help by submitting stories, ’cause it seems like no one here believes you or cares as much about excessive attention to safety.

        As an aside, HAD has been promising a moderation feature for awhile now. They could get lots more audience involvement with such a system.

        Brian: How’s that coming?

        1. > As an aside, HAD has been promising a moderation feature for awhile now. They could get lots more audience involvement with such a system. Brian: How’s that coming?

          We never promised a moderation feature. If I recall correctly, we promised something along the lines of, “Kind of like the reddit comment system, with a touch of the slashdot comment system, only not completely stupid.” Try to imagine something like that, and you’ll know how it’s coming along. Find me IRL some time and we can talk.

          As far as the safety aspect and duty to warn bit of this post, you’re watching a youtube video.

          1. dnbut: You could say reddit is a democracy, although the /r/conspiracy guys have evidence that says otherwise. anyway, my thoughts on a “true democracy” is that it will eventually devolve into stupid puns and memes. I’m liking the /. system of tagging and moderating, as that tends to cut down on the puns and memes but they still make it to the top too often for my taste.

            Oh, before I get any hate mail, I keep just about every non-spam comment up. I *approve* things that many other people have reported, just because I don’t want a ‘this place censors stuff’ label on the Hackaday comment section.

            It’s a seriously, seriously tough nut to crack. There’s actually some cool research and demos out there of ‘tree-based’ discussion which would be awesome to implement, but an improved comment system for HaD is months down the line. We’re still using wordpress, you know…

          2. I think y’all do just fine, Brian.

            “True democracy” is BRIAN BEING ABLE TO EDIT THE COMMENTS HA HA HA

          3. Stackoverflow’s comment and moderation is the most Google friendly I find. If you’re going to copy one, go for that rather than /. or reddit.

  3. as far as mr furze’ videos go tgis ones tame, respectfull of safety, and full of information. wish the safety whores would shoosh. theres a time and a place, this isnt it. itd be like lecturing my photonicinduction on electrical safety.

    1. Photonicinduction actually had a lecture about safety on one of his videos once. He works with electricity for a living (I assume for the city council?). He’s got a ton of safety measures in place and actually knows what he’s doing. I assume it’s the same for mr Furze.

      1. According to one of photonicinductions videos he works for himself and in it he fixes a commercial washing machines drum somewhere in London, i doubt that’s all he does/has done for a living thou.

      2. afaik Photonic runs his own business doing electrical work nobody else will because it’s too dangerous/hard.

  4. Metal Pillows? F**K YEAH! Now I know this is not what he had in mind but it seems to me that one of these metal pillows could be slid into a split in a rock, inflated and BANG, you’ve split rock, a hell of a lot easier than a wedge and hammer if you have to do it.

  5. This is pretty cool, however, most hydroformers have a negative surface which they push to. This is pretty nice for making free-form surfaces though.

  6. It’s nice that everyone is so concerned about safety, but let’s face it, the people visiting hackaday are probably in one of two groups:
    1: The people who already are well aware of risks and would take precautions while repeating similar things (these are the ones who feel the need to also let everyone else know about safety in the comments and generally don’t have fun in life).
    2: The people who literally don’t care what you have to say about safety. They may be well aware of the risks, but also don’t feel the need to put on safety glasses while using a hot glue gun.
    So it’s entirely pointless to have literally the entire comment section be every single person’s 2 cents on why we shouldn’t run with scissors.

    1. Wait… Running with scissors is a bad idea? I saw an album cover with someone doing it around a track, so I thought it was a new Olympic sport.

    2. I think you’re missing a group w/ two sub-groups…

      3. The people who are well aware of some of the risks, and smart enough to know that there’s probably a bunch of other risks they don’t know about, who then decide to:
      a. Research the subject further and try to find as many of those “known unknowns” as possible. (See, I knew what you meant, Rummy! ;)
      b. Spend an extra minute or two thinking about researching it, but eventually decide everything will be okay as long as they wear their safety glasses. (Think of an experienced and slightly more intelligent group 2.)

      The people in group 3a (and generally, 3b) very much appreciate the folks in group 1 who feel that need.

    3. And yet another category: those who have absolutely nothing to actually contribute in the form of technical expertise and decide to concern-troll in an effort to bullshit people into thinking they are smart. You know, because they are the only person smart enough to see VERY clear risks.

      Same group usually thinks they are smarter than everybody else and needs to be our daddy. THAT’S why it is annoying and nobody likes them.

      Yes, they put “Do not use in shower” on hair dryers because more than likely someone was stupid enough to try it. But, isn’t the world really better off if we didn’t have those tags? If you’re stupid enough, Darwin will get you eventually no matter what.

  7. “conveniently, in-compressible”

    Except not at 15,000 PSI it’s not. It compresses a fair bit. Not enough to matter for the purposes of this hydroforming but it’s something to be aware of.

    1. At 15000psi (Colin is working at 1000 to 1500) water will compress about 5% It’s hardly going to propel chunks of metal around the workshop is it?

  8. Rule #1. Always wear gloves when opening your mail. #2 don’t look outside on a sunny day without eye protection. #3 cordon off your yard when mowing and have your wife hand out face shields to passersby. Have your kid collect face shields at other end of yard and disenfect with Lysol to kill 99% of the germs. Dang. Never mind there still remains a 1% risk. Not worth the risk.

  9. I had rtpchuckle at the eyes wide open gaze t the project wondering he was trolling everyone. The problem is that those whose only experience is with municipal water supply pressures and large orifices trying to stop a high pressure small orifice leak with a finger. My conversion ulity converts 100 bat to about 1450 PSI, beyond where forged steel fittings should be used Perhaps heavy ductile iron fitting could handle it bit that looks to be 600 PSI stanard 600PSI ductile iron T. “these are the ones who feel the need to also let everyone else know about safety in the comments and generally don’t have fun in life” respectfully that’s a gross bullshit statement. Whores get paid like many here I could be safetly slut ;)

      1. Yeah, kinda sucks you in for a second and makes you think you know where it’s going, and then, *poof*, back to lala-land.

  10. The deformation is so plastic that without knowing better, the pillow and other items look as if they were merely silver vinyl inflatables. Of course I know metals can and do behave like that under these circumstances, it’s just not something you normally see.

    Regarding the effects of a pressure washer on flesh, I have sometimes wondered if that could be put to more positive uses. For example, to inject a nice aromatic herb infused butter into the Thanksgiving turkey. Anyone know of this being tried?

    1. You are going to destroy the turkey and make a mess! I guesstimate less than half of what goes out the nozzle actually goes under the skin. This is why we get big syringes with needles in the cooking toys isle. Way less messy and it has exactly the same effect! :)

      1. I know about and use the syringes. The thing about those is that only water, and water-soluble seasonings, significantly diffuse through the meat. Injecting oil/fat, and oil-soluble or powdered/pureed seasonings, produces pockets of injection mostly concentrated at the injection sites. Not necessarily a bad thing, but…

        A “turkey hypospray” (lol, I like that name) could create thousands of tiny pockets. Think of a well-marbled ribeye, how all the tiny pockets of fat give it a wonderful mouth feel – and you’ll understand why I’m intrigued by the idea. Maybe you could artificially marble lean cuts of red meat too, with butter or melted bacon fat. Mmm.

        Silly, impractical, messy, wasteful… probably. I’ve seen worse in the pursuit of experimentation and culinary novelty, and serving something that has the guests saying “WOW… how did you make this?”

        Just as an interesting aside on injectors, there’s a local restaurant that ships Cajun fried turkeys all over the US each Thanksgiving, and can cook up to 500 in a day. Some DIY gear is used, including a super injector powered by pressurized CO2. Stick it in, pull the trigger, the turkey inflates like a balloon. Was great fun to watch.

  11. This guy talks on his website about how everyone has forgotten to repair things. I am trying to find out where on his website he stops doing fun but useless things and actually shows how to do something useful… Am I missing something? Or does this guy only like to play?

    1. That’s awesome! It imploded.

      Must remember to get famous on Youtube one day so I can afford to get myself a plasma cutter and tig welder.

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