Modern Marvels: Welders Forge the Backbone of Civilization (S14, E15) | Full Episode | History

it arcs explodes and blisters steel it's  used to make 50 of all products and it puts   the power to build a skyscraper in a man's  hands by friction or robot even underwater   these are the tools that the world can't  live without now welding on modern marbles las vegas nevada perhaps nowhere else in the  world does the old come down as spectacularly and the new rise up as quickly right now you're  in the east wing the new palazzo hotel we're on a   38th floor there we go laying deck the palazzo  hotel will be the central hub of the world's   largest resort hotel and casino complex and  without the power of welding it couldn't be built   armed with high power welding guns and with  nothing more than a safety harness between   them and the ground below these iron workers  will weld a quantity of steel nearly equal   to the amount in the brooklyn bridge statue  of liberty and empire state building combined   that is just shy of seventy  thousand tons of structural flooring adrenaline runs high for  welders working at such heights and with so much electricity in use   the dangers are real this particular machine  runs on 483 phase it's fed with 200 amps   at 480. if you make a mistake you're not  here tomorrow he's almost instantaneous depth   by definition welding joins two separate pieces  of material through high energy no other joining   method forms a more direct and powerful bond all  the other methods whether it's rivets whether it's   bolts even if it's glues and adhesives you wind  up putting in extra material in order to make the   connection in the case welding connections bring  the two pieces together put a weld in between this   is a very efficient way of joining materials but  efficiency is only half the story because welding   creates a bond along a seam or joint that is  nearly always stronger than the face metals used   to form it the tensile strength of the welded  material itself is actually greater than the   material you're welding at good weld the material  itself will tear before the weld will tear   the source of this strength  is more than just surface deep   and goes right down to the steel's very atoms  every atom within a beam possesses electrons   that encircle it in what is called an electron  cloud when a welder applies intense heat the atoms   are slammed together so forcefully that they  begin to share a single united electron cloud   now locked as one these new molecules  are more powerful together than separate   for many centuries the only way to make these  welded bonds was with furnace and hammer   a process now known as forge welding with forged  welding two pieces of material are put flapped   over each other heated not to the point of melting  but until they're hot and then hammered together   that hammering together the two metals  will achieve the same metallic bonds   that today we formed with an electric arm today  electricity has replaced the brute force of the   forger's hammer to construct our world from the  car you drive to the plane you fly and everywhere   in between the most common method is known as  electric arc welding which is based on principles   first discovered at the turn of the 19th century  those principles revealed that electric current   will jump the gap between two nearby metal  conductors to form a completed electrical circuit this jump known as an electric arc generates a  spark-like discharge that is both extremely bright   and intensely hot the arc is estimated to be  between six thousand and eight thousand degrees   fahrenheit that's the same temperature as the sun  steel melts in and around three thousand degrees   so this six to eight thousand degree arc  is more than ample uh heat to melt the   steel that was joining by the 1890s engineers  had harnessed this intense new found energy   to create the first electric arc welds a work lead  or ground was attached to one corner of the metal   to be welded electric current then flowed from a  generator through a long conductive metal stick   known as an electrode as the stick neared  the grounded metal an electric arc was   formed causing heat to melt the metal the  apparatus was crude but the basics were sound   and are now reflected in the simplest arc welding  form in use today stick welding the basics of the   process are you have an electrode holder you  have a cable that runs back to the machine to   pick up the welding current and you place the bare  end of the electrode in the holder and it picks   up electrical contact there conducts current  down to the end of the electrode which is bare   the technique is touching the electrode against  the work and then moving it far enough away to   establish an arc but not so far it goes out and  if you leave it too close it'll stick you pull   away too far it'll go out so the trick is to get  your get your bounce where it's just about right   when the ark is struck and positioned near the  middle pieces the intense heat causes both the   electrode and the metal along the seam to melt  together into what is called the puddle until   it hardens this molten puddle must be protected  even from the very air that we breathe the air we   breathe is about 80 percent nitrogen and about  19 oxygen it's really good for breathing but   it's not good for liquid metal and just like we  dissolve sugar in hot coffee these gases dissolve   in liquid metal when the metal solidify the gas  percolates out and that makes holes in the well the dangerous result could  be a weak even brittle weld   so to shield the puddle a chemical  coating is applied to the electrode   as it melts under the heat of the arc this  chemical coating dissolves into shielding gases   that envelop and protect the weld keeping it free  of air this is known as shielded metal arc welding   and as the technology evolved the  coating took on even greater significance   the chemical coating has three functions some  of the coating forms shielding gases at the   heat of the arc to protect the weld from the  atmosphere some of the chemicals at the heat   of that arc form a liquid slag which protects  the welds as the shielding gases move along   and some of the elements are alloyed into  the deposit to make a high strength deposit   so three things happen while you're moving this  arc along the work when the weld is complete   and is cooled the slag is chipped away to  reveal the trail of welded metal known as the   bead getting the proper length depth and form of  the puddle along the bead takes years of practice   there's so many variables when you weld  there's very few times that two things you   weld together the same either the metal changes  the thickness of metal the environment you're in   the conditions the metal is used  for there's just so many things   changed that you have to know a lot  of different things about welding   complicating matters are the safety  requirements beginning with the welder's mask   just as staring into the sun can damage your eyes  so too can an electric arc therefore protection is   crucial when you first flip it down it's dark you  can't see anything but you quickly get comfortable   with it once you strike the arc it's like a  big flashlight you can see what you're doing   although electric arc welding was first discovered  in the 1800s its acceptance was slow in coming   anything new they fight it  wasn't thoroughly accepted   so it took time to make the  transition into the welding process no company was more influential in changing the   tide than lincoln electric  company of cleveland ohio   today lincoln electric is the largest manufacturer  of welding equipment and consumables in the world that success is rooted in lincoln's  commitment to proving the viability of welding   even in the face of constant doubters and no industry was initially more skeptical than  the biggest one of all building construction where   rivets were king well into the 1940s rivets  were intuitive if you think about it putting   in something with head on either side that  makes sense welding had some mystery about it   but riveting was also extremely difficult work it  required fabricators to hole punch the steel beams   then a team of workers aligned those holes to  their exact counterpart rivets were heated in   a central oven then hurled to the proper joint he  would heat the rivets and once they got heated he   would throw them to the person who was actually  standing at the point waiting for the first river   so you had a pitcher a catcher with a set of tongs  who would slide it into the hole and then you had   a guy bucket and then you had a riveter and the  river would round the head on the opposite side   significantly rivets limited the design  options for architects and building engineers   a lot of very famous and and beautiful work is  done with rivets but basically you're building   a box with a design to the inside of the box you  can only carry so much shear on that connection   in 1928 lincoln electric joined  with a local architectural firm   to erect the first commercial building  wholly constructed from arc welded steel   in the upper carnegie building the typical  dense network of riveted steel was replaced   by a series of continuously welded beams that  ran the entire length and height of the building   not only did welding free up space but these  continuous beams carried even greater loads and   stresses than their riveted counterparts  are always the weak point in a structure   connecting things together is always a challenge  but welding changed all that literally if you   could get the material in the configuration you  wanted it there was a way to weld it together   today skyscrapers come in many  shapes and sizes in large part   because continuous beams can be fabricated  and welded into curves and unique angles   to construct these beams welders will  make 30 to 40 passes on the crucial joints   using lincoln electric's latest  flux core welding technology here the traditional stick electrode has been  replaced by wire on a roll that feeds directly   into the welder's gun the chemical flux  that protects the weld from the air is now   contained within the wire itself and melts just as  before there's approximately 90 tons of weld wire   will be used and consumed in this project alone  that's somewhere around 180 million inches   or 2 800 miles of weld wire you could stretch  single wire from la to new york and have leftover   on the largest beams which can weigh  as much as 900 pounds per linear foot   a team of welders can work on a single weld for  hours the columns that we're looking at right now   are basically supporting the entire east wing of  this tower originally these pieces were so long   the capacity of the cranes would  not pick them up and set them   so we had to cut them down make them lighter  so the crank could set them and the engineers   wouldn't allow us to make that a bolted splice  it had to become a welded splice it's about a   30 hour weld i believe we had two guys working  on that simultaneously for 30 hours of welding welding really enabled the architect the  engineer to drink bigger dreams make bigger   bridges make taller skyscrapers and to do so in  a reliable and dependable way but at the end of   the day those big dreams are only as solid  as the iron workers who weld them together   we're not presidents we don't get monuments  built to us but when you look across the skyline   iron workers have changed the way that looks   but electric arcs aren't the only way to  make a weld in fact others are a real blast pennsylvania's allegheny mountains  birthplace of american steel   here in the hillsides that  surround historic mill towns   the most powerful welding process of all occurs  more than half a mile underground fire no it's called explosion welding and with a force measured in millions of pounds  per square inch explosion welding does what no   other welding method can join nearly every  kind of metal together no matter the type   or composition explosion welding allows highly  dissimilar metals such as aluminum carbon steel   alloy steel stainless steels alloys of copper  all can be welded to one another the result a   single welded piece known as clad that combines  the best characteristics of each metal involved wherever there is high heat intense pressure or  corrosive liquids and gases clad is probably there   it could be a column it could be a heat exchanger  it could be a horizontal tank but when you   see a chemical complex or an oil refinery  there will be a lot of clad metal in there   to create an explosion weld two large  pieces of metal are stacked atop one another then covered with a high-powered explosive when detonated the downward force of the  explosion welds the two pieces together   through a combination of intense force and  remarkable physics what you can see here   and it's very clear you have two different  materials stainless steel is a darker gray   a lighter gray for the carbon steel material  the detonation was initiated at this point   and you can see the deformation from our initiator  that starts the explosion and the explosion   rolls across the entire top surface  of the plate zipping the two together no one would have ever thought such a violent  process could be controlled and mastered   had it not been for the devastation  and havoc of world war one   and later world war ii the origin of explosion  welding was first observed during the first world   war when shrapnel may have stuck to armament  it wasn't just stuck but it was actually welded there was only one possible explanation the  explosive force these metal pieces had endured   it was a observed phenomenon that was  later duplicated in the laboratories and   in practice commercially today dynamics  materials corporation is a world leader   in explosion welding technology here the  decades-old discoveries from the battlefield   have been refined into an exacting science the explosion welding process begins as soon as  the two metal plates arrive at dmc's main plant   outside of pittsburgh pennsylvania to maximize the welding force of the explosion  the surfaces of each plate are ground as   uniformly flat as possible a process that also  removes any rust oxides and other surface floors they're then ready to be assembled into the  pack which locks the plates into position   for the explosion to build a pack the stronger  and thicker of the two plates is laid face up   from now on this plate will  be identified as the backer   small metal spacers of equal height are  then tacked onto the surface of the backer   in a uniform grid these spacers will maintain a  set gap between the backer and the second plate   which is placed on top this second plate is  thinner than the backer and is called the clatter   the standoff gap between the backer and  clatter is less than an inch in height   yet without it the explosion  weld would be impossible in the final stage of assembling the pack  a folding wooden frame is constructed along   the edges of the clatter when this frame is later  unfolded inside the underground explosion chamber   it serves as the bed for the  explosive powder that is poured on top   the three essential variables of an explosion weld  are first the standoff gap the spacing between the   two metals needs to be very tightly controlled  to ensure the highest quality weld the second   two parameters deal with the explosive one is the  velocity of the explosive the speed at which it   burns and the height of the bed or the quantity of  explosive which is evenly spread on the top plate   the explosive powder is a proprietary blend  of common and unique explosive chemicals   the amount and exact formulation is  always matched to the types of metal involved once the pack is set everyone  evacuates the chamber except the blaster   in charge who remains to wire the detonator  he will be the last to leave the chamber   after all personnel are accounted for  the blaster connects his initiator switch   to the detonator wires and fires the explosion  fire no the explosion is detonated from one   edge of the clatter and moves across the  upper level of the pack at a uniform speed this explosive front progressively drives  the clatter plate downward toward the backer   at the slight collision angle caused by the  standoff gap forward of the collision point   air is forced out of the gap at high velocity all  oxides and impurities are expelled rendering the   plate surfaces metallurgically pure and ideal  for a weld as the backer and cladder collide   the weld is created nearly instantaneously  across the entire surface of the plate because of the intense dust  created by the explosion   workers can't retrieve the newly formed clad  from the explosion chamber for more than 18 hours not surprisingly the power of the explosion  can cause significant deformation to the newly   formed clad therefore upon its return  to dmc's central processing facility   the clad undergoes a final series of corrections these include heating the clad in an  oven that causes the metals to soften slightly   this relieves stress from the blunt  force of the explosion's impact any bowing or misshapen curves are flattened  out by either a three million pound press   or for thinner clad by a series  of rollers known as levelers finally before the material is shipped  stringent testing is conducted to ensure   a solid weld between the two plates there's a lot  of testing because generally these metals will go   into a very high pressure vessel their stakes are  extremely high if there's a failure so the owners   of big plants and chemical manufacturing  and oil refineries are extremely concerned   that their materials are what they ordered and  specified there's really no room for air once   the material has been proven to meet exacting  specs it's ready to be shipped to the customer but explosion welding isn't  the only adventurous business   it may look downright tame compared to  welding 325 feet below the ocean service it's a rule that defines common sense  don't mix water with electricity   it can kill you but there is a rare breed of  experts who dare to swim against convention   and perform a job that most consider downright  crazy underwater diver welders thrive on the   dangers of the deep where visibility  can be zero and deadly hazards the norm   why to perform the perfect weld you're  underwater and playing with electricity   it doesn't seem like a good combination but  it it works quite well over the last 30 years   the ocean depths have become vast job sites  for the energy and communication industries   this encompasses everything from pipelines to  platforms to subsidy wells to inspection repair   and maintenance we're working in water depths up  to ten thousand feet global industries is a leader   in offshore construction engineering and support  for the oil and gas industries around the world   and to meet this constant demand global  industries requires their welding teams   to undergo years of specialized training  for all types of offshore environments we're here at our uh our research and development  training center here in new iberia louisiana   uh we're dressing out our diver now getting  ready to get into the tank and and do some   training do some welding there are two basic forms  of underwater welding wet welding and dry welding   wet welds are the most common  and can be shielded metal arc   or stick welds made by a fully  submerged diver welder in a wetsuit   the electrode is waterproof and inserted into  an electrically charged rubber encased stinger once struck the electric arc burns just as if it  were on dry land since water is equally conductive   likewise the electrodes unique waterproof  coating shields the weld from water contamination but in case you're wondering his rubber gloves  are the only things that stand between the diver   welder and electric shock if you have a hole  in that glove then you you grab a hold of that   live stinger and that will give you a real good  one and you'll taste your fillings in your mouth fortunately the odds of a fatal shock are slim  because the welding equipment operates on dc   current which is far less dangerous than the  ordinary ac current found in a typical home check calm check to get the diver welder fully  suited two other diver welders act as his tenders   checking and testing every piece  of equipment including the helmet   not only does the helmet provide  air for the diver welder to breathe   it also serves as a full welding mask  protecting his eyes from the intense arc light   right here we have the lens plate the face lens  that a diver will flip down when he's ready to   start welding he'll flip it up when he's finished  welding and take a look and see what he's doing   after the diver welder is suited  up he carefully enters the water   and makes his way to the bottom of the tank from the moment he puts on his helmet the diver  welder is in constant communication with the   control room via audio links and a video feed  tom check one two three how do you got me john all right set up the welder the trainee must  not only learn to strike and maintain an ark   but he must also be able to connect and reset  all of his equipment including the electrode once in the water the electrode  is inserted into the stinger   which is termed cold because the control  room has not yet turned on the electricity   when the diver is ready to weld he  requests that the current be turned on like every surface welder the diver welder  must be a master of concentration and stability you're going to have a lot of things that can  interfere with what you're doing when you're   welding just the surge of the ocean can push you  around some divers like to actually put their   hands up hold the rod itself because it gives  you a lot of feel on it if you just have the   rod in your back way back here from where you're  working you don't have the feel that you need even fish can become distracting and potentially  dangerous obstacles barracuda like the watch   it's a giant fish it looks like a torpedo  with nasty teeth that stick out everywhere   and then like just to kind of hover over your  shoulder to see what you're doing all the time   and you're just kind of like what's uh but  is doing their own thing but sometimes a job   requires a diver welder to go to extreme depths  and stay in that environment for days even weeks   this is called saturation diving  and requires serious courage   it may also require the highly sophisticated  technologies of dry underwater welding the difference between wet and dry underwater  welding the dry underwater weld will require   a habitat a habitat is lowered down and put in  place on the member or on the pipeline that's   going to be repaired once it's installed they  seal it and then they actually put the air down   to it and pump all the water out of it this  allows that piece to be basically dry now   and and so the divers can go down and  they'll actually climb up inside the habitat   remove their helmets and actually be able to go  to work and weld that particular item in the drive dry underwater diver welders work in  pairs and in six to eight hour shifts   when done they return to  the surface in a diving bell   then enter a second habitat maintained aboard ship   within these on-ship habitats they will eat sleep  and relax before returning to the ocean floor both the diving bell and on-ship habitat  maintain the same pressure as if the divers   were still a thousand feet under  water this is the only efficient   and practical way for their bodies to  remain adjusted to such extreme pressures   otherwise the diver welders may experience  the bends and other physical perils even depth to prepare diver welders for these conditions  global industries has built an unparalleled   underwater simulator this facility that you  see behind me right here it's really the only   one of its kind in the united  states we call this the dry pot   we can carry out dry welding scenarios down to  a thousand feet a hyperbaric chamber simulates   the high pressures the human body must  endure when working at great ocean depths akin to being an astronaut the trainee will  spend more than a week living in this simulated   environment and conditions are tight it's very  very cramped inside there there's a place for   everything to go and you have to be sure that  you put everything in its place before you go and   and start doing things because they will there  are a lot of things that can bite you in there unlike the wet welder the dry welder can perform  more than stick welds in his cramped habitat i'm   staying right in from the entrance to the  drive pot hatch royce is doing gas tungsten   arc welding it's also known as tig welding  which is an old word for tungsten inner gas   once his training is finished the  trainee enters this decompression chamber   to slowly acclimate his body  back to the normal atmosphere but while even these adrenaline  junkies need to rest once in a while   some welders never take a  break of course they're robots welding the heart and soul of making a car and for  major automobile manufacturers like general motors   no process is more vital or more automated when i first started with general motors  there weren't any robots in the body shop   i worked in two years later there were 40  of them in the body shop we're standing in   now there's approximately 1200 robots over  a third of them 480 some are welding robots here at gm's lake orient assembly plant more  than 16 000 cars roll off the lines every month   by the time each car is fully assembled  it will contain thousands of welds on this structure as it sits right  here there's approximately 3 800 welds   once the outer structure goes on there'll  be approximately 1200 more welds added to it   for approximately 5 000  welds overall on the vehicle nearly all those welds are  completed by robotic welding systems which load position and weld  more than 240 component parts   most of the robots that are used for  welding are actually used for spot welding   and probably 60 of the welding robots that  are out there are actually spot welding robots   unlike arc welding spot welding does not create a  bead nor is it designed for heavy steel items like   beams instead spot welds bond thin metal sheets  as in car doors or hoods energy is focused to a   single spot where two electrodes make direct  contact with the metal sheets to be joined   the electrodes are made of copper because  it has low electrical resistance and high   thermal conductivity this means it can deliver  some serious juice this particular unit is a   pneumatic operated spot welding system it's got a  75 kva transformer back here the uh the electrodes   up here are all water cooled this particular setup  here probably runs about 10 to 12 000 amps through   these electrodes right here it's not uncommon to  see 40 50 000 amps run through those electrodes   given that most houses run on less than 200  amps that's a lot of power but it's not the   only factor in a reliable spot weld you need  pressure when the two electrodes come together   they pinch the two metal sheets at the  spot and cause a small indentation in both electric current then begins to pass from one  electrode to the other through this spot in   the sheet metal as it does so the current  that flowed so smoothly through the copper   now encounters resistance in  the less conductive metal pieces   this resistance results in heat and the metal  begins to melt causing a molten nugget to form   when the molten nugget cools and coalesces it  locks the two metal sheets together the electrodes   then release the pinch point and move on a robot  can make a series of spot welds in a relatively   short period of time for a man it's a heavier  task a typical spot welding gun might weigh   anywhere from 100 pounds to 200 pounds that's a  lot of physical labor to move a spot welding gun   and so a robot that's designed to handle that  kind of weight is an ideal setup because the   robot can just handle the spot welding gun and  consistently put it in the same place every time   factor in the sheer number of spot  welds required to assemble a car   and robots make an incredibly practical  solution for car manufacturers and advances in recent technology  allow robots to reach further   work closer together and execute a  greater variety of welds than ever before the robot can pretty much  weld the same speed as a man   where the payoff is the robot is  always welding a man has to weld   and then lift his hood up and adjust the part  and put the hood back down and re-weld again   where the robot's just going to weld well  well it might have a 85 percent arc time   compared to a manual of 20 it took a man about  three hours to make this particular product now   that the robot's welding it it takes essentially  about a half an hour to weld the entire part but today robots aren't just spot welders here at  robot works a leader in robot system integration   robots execute nearly every form of  welding and often in surprising ways this system has a capability of running at about  30 to 40 inches per minute of weld this system   is unique in that there's two technologies that  are actually integrated into it one called touch   sensing another called seam tracking what touch  sensing allows the robot to do is actually find   the scene it would come down sense that it has  touched the part in one specific spot record that   data save that positional data it would then come  up since the next spot doing the same process and   at that point in time the robot would know from  the trigonometry where that seam starts there's   another technology called seam tracking what that  allows you to do is once the robot has found the   seam it actually allows the robot to stay within  the seam throughout the course of the weldment but even as robots become more sophisticated and  commonplace they will still require hmi human   machine interface after all someone still needs  to program them and he or she better know welding   for the program we always suggest to take a guy  that's a good welder because he's going to know   like if he hears an arc and it's not right here  know that it might be because of his shielding gas   or the stick out the robot's using because he  just he knows welding but a guy that doesn't   know welding might think it's because of the  robot controller or something to do with the   robot somebody that understands the process is  the best kind of a robot operator programmer   think robots are innovative well you haven't seen  or should we say you haven't heard anything yet say welding and you immediately think  iron steel metal on metal but today you   can weld just about anything including  plastic plastic toys plastic packaging   and lots of household items are welded  together by a process known as friction welding   friction welding comes in many forms  it all work essentially the same   they generate heat through mechanical action like  the high speed rubbing of two sticks together with plastics the best friction welds  are made through the power of sound   it's called ultrasonics ultrasonics utilizes  the high-intensity acoustic energy that occurs   in frequencies beyond human hearing the  sound waves cause the plastic pieces to   literally vibrate against one another  at high intensities at that interface   heat is generated and the two pieces fuse together  it happens so fast that the naked eye can't see it people don't realize the amount of power that is  available in sound waves if the sound waves are   focused properly and these materials are vibrating  in many cases 20 000 times per second 40 000 times   per second that frictional heat is so intense that  the plastic wells within a fraction of a second in 1964 robert soloff received the first  ever patent for ultrasonic plastic welding   today his company sonics and materials   builds the technology that welds everything from  toothpaste tubes to coffee makers to simple toys   at their headquarters in newtown connecticut  ultrasonic welding machines are manufactured   to precise specifications or else  the welds wouldn't be perfect there are four main parts in an ultrasonic welder  a power supply and three components known as the   ultrasonic stack this is the ultrasonic  stack for the ultrasonic welding press   which is comprised of the ultrasonic converter the  booster and the ultrasonic horn the power supply   takes standard 60 hertz power and pumps  it up to 20 000 hertz of acoustic energy   this acoustic energy causes coin-sized  ceramic discs within the converter to   physically expand and contract creating  20 000 mechanical vibrations per second   these vibrations are then focused to the  plastic parts first through the booster then   through the horn which delivers the vibrations  directly onto the plastic parts to be welded   although sparks don't fly during ultrasonic  welding it still gets the job done this happens   to be a two-piece uh whistle so we take the the  two pieces of plastic we put them in a lower   fixture the fixture is made to the application  to the piece of plastic and then we have a very   basic flat-faced ultrasonic horn because the  part is flat there's no contours to the part so that quickly we just welded the two  pieces of plastic together in 0.24 seconds what i'm going to do is take a screwdriver  and break the plastic apart at the weld area and in turn this will show the molten white  plastic where it bonded to the red plastic and thank ultrasonics for the hermetic  seal on clear plastic packaging   you know the plastic you can never quite get open   we have these pvc clam shells they're tamper-proof  clam shells so that the product can't be easily   removed from it or put in a pocket ultrasonics  is commonly used to seal these clam shells and now we have ultrasonically  welded the edge of the clam shell while ultrasonics occurs in the wink of an eye   another form of friction welding will keep your  head spinning pin welding is rotary friction under   pressure which generates heat in the joint area  to melt the plastic and fuse the parts together a typical insulated coffee mug  is spin welded from two parts a suction device grabs hold of the inner shell  and rotates as it descends into the outer shell the collision of the stationary  and rotating pieces generates heat   causing the plastics to soften  when a braking system stops the   rotation the softened plastic seams  of the two shells fuse as they cool the result a perfect hermetic seal   so from ordinary household items to  structures of extraordinary heights   and depths welding plays a crucial role in  everyday life by simply joining the world together you

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Id: U4k4VgeXtQ0

Length: 43min 22sec (2602 seconds)

Published: Thu Mar 11 2021

Reddit Comments

[u/Wargaming_Super_Noob]

I'm back 43 minutes later. That video was too short for me. Now I want my hood, my rods and my coffee even more!