Unibody welding

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Y'all were so NICE to this guy! http://weldingweb.com/vbb/showthread.php...-A-Truck-Frame Maybe you'll tolerate another noob with a bad idea. I have a 2002 Toyota Sienna minivan. I can't stand driving it--the body roll is extreme. A year ago I replaced the struts/shocks (the most expensive ones available at tirerack.com, which were still pretty crappy--there's limited selection for minivans, go figure), and cut 1 coil off the springs.  I have had great results from this before on other cars, but this time pretty much all I got was a squeakier rear hatch. It just moved the flex from the suspension to the body.My darling wife is giving me a mig welding class for Xmas. After that, I will be a total beginner.The van's frame has deep rails formed in the floorpan--two main rail systems that run from the rear suspension to the front subframe, and crossmembers behind the front doors and sliding doors. No rust anywhere. I want to stiffen the frame, without intruding into the interior with a cage or braces. There is enough room for some triangulation across the rails, and some areas that seem like obvious candidates for stiffening.Any tips or warnings about welding a unibody? On the car forums, the VW people think getting a welder near your car will kill you. The Jeep Cherokee people are into all kinds of crazy chassis torture. Assuming I don't blow myself up with gas fumes, how likely am I to screw up the car? I'm not too worried about aesthetics or doing a "good" job, but I don't want to ignorantly nuke the frame with too much heat or something. Resale value isn't important, but I don't really want to ruin a perfectly good driver.Any input is very appreciated. Merry Xmas!
Reply:I'll just say it.....It's a mini-van!!!  Respectfully, It's not a sports car - if you want good handling, buy a different vehicle bud.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:But seriously, welcome to welding and post up project ideas for some help and encouragement Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I tend to agree with Dave but i also understand that the "want to" drives many of us to do things that others wouldn't consider worthwhile.How many miles does this thing have on it?GravelThe difference between theory and practice is that in theory there is no difference.
Reply:Careful.   Fuel lines are often made of plastic and burn very quickly, don't know about your car but I found out the hard way that they can be hidden inside the structure imitating a frame section.  My advise is to let your wife drive it and buy yourself something that you want,  it's the only way you will be happy....after all it's just a van and a mini one at that......Measure with a micrometre, mark with chalk,  cut with a torch.Never force anything...just get a bigger hammer.RoyOld Airco buzz box approx 1974Lincoln mig pack 15Lincoln 175 square wave1954 9" south bend lathe
Reply:Maybe I was too hasty - here are the types of vans you should buy and work on Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by MinnesotaDaveMaybe I was too hasty - here are the types of vans you should buy and work on
Reply:Originally Posted by M J DYou left out the McKenzie brother's Strange Brew van.
Reply:Originally Posted by MinnesotaDaveTake off eh?!
Reply:I think I'm in love with Juicy Lucy... until Jessi Combs comes over to help me with my "project". GravelThe difference between theory and practice is that in theory there is no difference.
Reply:Originally Posted by GravelI think I'm in love with Juicy Lucy... until Jessi Combs comes over to help me with my "project".
Reply:Originally Posted by MinnesotaDaveOh yeah!
Reply:It's true, you can only do so much with a minivan. But it would be fun to make it handle "less bad"--I would enjoy the project. (And full-size vans handle much, much worse, even if they do get bonus creepy-guy points and come with rad retro-ironic murals.) The minivan is pretty damn handy for Home Depot runs and stealth camping. It has ~150k miles, runs like a top, no longer worth much $ but cosmetically inoffensive. Point well taken about the fuel lines--I have seen them tucked away down there and they do appear to be plastic. How close to them can I get?
Reply:If something is on the way to the scrap pile, I see no problem trying to salvage it.  Can't be any worse than it is now.Most frames on these things are likely mild steel, and suitable for welding.Fuel lines, brake lines, and electric runs, are something to be cautious around.  Shield them with a piece of metal when welding, or remove them.Watch for areas where there's grease, or other things that can ignite.  Sound deadening insulation is flammable.  Various plastics are flammable.  Undercoatings can be flammable.  Just use common sense.  I weld around stuff like this sometimes, and use a water wet-down coupled with welding blankets or any other thing to prevent ignition.  Keep a dry extinguisher handy.  And stay away from the gas tank, or any fuel vapor recovery systems.If you do decide to do any under-car work, make sure to get a good FOUR SENSOR welding hood.  AD helmets with only 2 sensors can sometimes be a PITA in a confined area with a lot of projections that can block the sensors."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Yeah, the old vans were cool......................But you were the first one at the scene of the accident."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Dave, those forward control Chevy vans are ugly as sin but check out that Vista Cruiser roof on itIf I could find a 2nd gen Econoline that wasn't rotted to the roof line I would buy it......love the Econolines.
Reply:Originally Posted by vwguy3Dave, those forward control Chevy vans are ugly as sin but check out that Vista Cruiser roof on itIf I could find a 2nd gen Econoline that wasn't rotted to the roof line I would buy it......love the Econolines.
Reply:Originally Posted by MinnesotaDaveI like the 66-67, pretty sure that's the year range.Here's a double roof treatment
Reply:Originally Posted by SlobThe side marker lamps were mandated for the 1968 model year as were the use of collapable steering columns.
Reply:Originally Posted by MinnesotaDaveInteresting, didn't even know there was a time without side markers.I don't actually know what this van is, just thought the roof was cool
Reply:Originally Posted by farmersammIf something is on the way to the scrap pile, I see no problem trying to salvage it.  Can't be any worse than it is now.Most frames on these things are likely mild steel, and suitable for welding.Fuel lines, brake lines, and electric runs, are something to be cautious around.  Shield them with a piece of metal when welding, or remove them.Watch for areas where there's grease, or other things that can ignite.  Sound deadening insulation is flammable.  Various plastics are flammable.  Undercoatings can be flammable.  Just use common sense.  I weld around stuff like this sometimes, and use a water wet-down coupled with welding blankets or any other thing to prevent ignition.  Keep a dry extinguisher handy.  And stay away from the gas tank, or any fuel vapor recovery systems.If you do decide to do any under-car work, make sure to get a good FOUR SENSOR welding hood.  AD helmets with only 2 sensors can sometimes be a PITA in a confined area with a lot of projections that can block the sensors.
Reply:Welding on a vehicle, with it's interior still in the vehicle, is an excellent way to start a fire.Gas lines (including the vapor lines), and brake lines are both good fire starters.My old boss burned a truck to the ground when he burned a brake line.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I will say this I was a frame man in the paint and body business for a long time , welding in frame rails strut tower and such isn't a big deal just about anything can be done and don't take this the wrong way I mean no harm and everyone starts some were but please leave it to a professional when it comes to welding on a frame or anything like that it's not only u on the rd if u do attempt it have someone there to guide u we spent hrs in a heap of classes to get certified through insurance companies to be able to do this . Please don't take this wrong I mean no harm.
Reply:Oh and unhook battery at least 15 mins before welding computers are expensive and airbags are violent when they go off and scare cap out of ya I've seen it happen
Reply:Thanks, dockman, no offense taken! I wouldn't try it if I couldn't afford to walk away from it, financially. Hopefully if I screw it up so badly that it is a danger to others on the road I will be able to tell that. I do have the advantage of having a more or less functional unibody frame in place that I am trying to augment, not repair. If I and the van survive the actual welding process....well, I will try not to be overconfident behind the wheel!Yup, welding on some outside pieces with the interior in will certainly give you instant tinted windows.....for a short time anyway.
Reply:Well my 2 cents would say do NOT do it.  You might get away with doing it on such an old 2002 vehicle but over the last 10 years or so the auto manufacturers have really put the Science and Engineering into those unibody structures for crash safety.  What looks like plain steel is often some exotic high strength steel.  This is done to promote strength without adding weight for the engineers to tune and place the crumple zones for energy absorption where the occupant is well protected in a crash.  Welding can destroy those special metals properties....Do not get me wrong, Handling is important but being able to walk away uninjured from a crash is much more important IMOP.If you really want sports car handling in a Minivan:  Drive a Honda Odessy minivan sometime (2004 to 2011 years).  While I do not own one, I have driven several of them.  Handling is dare I say it almost sports car'ish for a minivan and the V6 is a beast for a minivan delivering sprightly accleration.
Reply:Just a mini vanold Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:That hilarious
Reply:Sway bars, get them and install them, big ones!12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:Originally Posted by PhileI have a 2002 Toyota Sienna minivan. I can't stand driving it--the body roll is extreme. ...Any input is very appreciated. Merry Xmas!
Reply:Hey, I give you credit for doing this. Its your ride and you can modify it in any way you want to.Stitch welding it will most definitely stiffen it up. I wouldn't completely weld the seams though. The best way to do it would be to gut it and do the entire interior as well as the engine compartment. While you're stiffening the chassis from underneath it, you can also stitch the seams up there to.I agree about the sway bars. I think his biggest hurdle will be finding them for his specific vehicle. More than likely will have to have them made for it.
Reply:Originally Posted by sqznbyI agree about the sway bars. I think his biggest hurdle will be finding them for his specific vehicle. More than likely will have to have them made for it.
Reply:Originally Posted by G-sonOr taking some measurments off the van, and going treasure hunting on the local salvage yard. Sure, stock sway bars off other cars will probably not be very stiff (most cars are made for comfort, not handling, and as I said, a van is extra difficult due to high CG), but something should be better than nothing, and if the price is right it might be a good enough compromize.
Reply:The van was mfg'd from high strength steel on most of the skeleton anything mild would be the outer sheet stock. Way back when I was in school we were taught that unitized vehicles would never get into an accident and twist; I disagree. But if you want to strengthen your van the only practical and safe way may be to buy some preformed box sections with outward bent flanges and reinforce the floor with spot welds only following the contour. You may also go to a sheet metal shop and have some box section or triangle sections made to run along your rocker panels. I mean allot of unitized cards race so the stock to modify cars is available. Make sure if your windshield had been changed that it is properly installed with hard setting adhesive because it to ads rigidity to the van. Remember this will make your van worthless in the end and always use sells though primers. Best Dlh Sent from my SGH-I747M using Tapatalk
Reply:The idea of plating the frame to reduce body roll doesn't even make logical sense.Body roll is a matter of the suspension, not the frame twisting...pressurized shocks and anti sway/roll bars control body roll.The jeep cherokee guys are massively flexing out their vehicles and get a small amount of twist (usually the doors will still open and close fine under maximum suspension flex). It's a completely different thing than body roll on the road.Last edited by MikeGyver; 12-27-2014 at 11:34 PM.Welding/Fab Pics: www.UtahWeld.com
Reply:Thanks all, yes, stiffening the swaybars is the next thing I'll do after stiffening the chassis. Like I mentioned, the stiffer springs and fresh shocks just highlighted the weak link of the floppy chassis. It can't handle any more suspension stiffness than it is currently dealing with.The rear is a torsion beam setup, and can very easily be stiffened by adding material to the beam or simply welding across the open C section of the beam, both of which reduce the degree to which either side can move independently of the other--voila, swaybar. The front swaybar can easily be beefed up without even removing it.Most of the places that are candidates for bracing are within the wheelbase, so the crumple zones will be largely intact. It's hard to imagine screwing it up badly enough that it becomes less safe than a motorcycle; maybe that's just setting the bar too low.Interesting point about the windshield adhesive! Seems like a place on the body where you'd want as much bonus stiffness as you could get.
Reply:How would a tube structure like a minivan be imparted with a significant torque along it length by turning a corner? Are you running high speed slaloms through the walmart parking lot or something? One end isn't being pulled in a direction opposite of the other end. It's going to act more like a rigid tube rolling on it's suspension as one whole entity. You might be getting an actual flex of a small fraction of an inch over the entire structure. This doesn't account for the inches of body roll you're feeling. The unibody obviously isn't flexing on the order of inches or the windows would pop out, body panels would crumple, and the doors would permanently bind shut etc. If you stiffen the structure you're just going to have a more rigid body still rolling around on it's suspension... Minivans actually have a very inherently strong geometric shape, they're basically a tube, and tubes deal with longitudinal torque very effectively. Also it's worth noting that most shocks don't really limit body roll anyway, they just dampen quick movements, not limit slow movements like the body leaning as you're mario andretti-ing your grocery getter around your local racetrack (aka neighborhood). If you don't want body roll, lower the center of gravity, make sure the tires aren't seeing excessive sidewall deformation, and mainly use sway bars that give desired results. Body roll also might just be somewhat inherent to that particular suspension geometry (since the designers didn't want to give it the characteristics of a ferarri) and you would need to alter that regardless of anything else. I think in stiffening the frame you're going after that last 2% first...I'll add I drove a pos 2004ish nissan quest around the block, and I swear that thing cornered flatter than my z06 vette and soaked up every little bump, it was unreal lolLast edited by MikeGyver; 12-28-2014 at 04:37 AM.Welding/Fab Pics: www.UtahWeld.com
Reply:Stiffening one section can and probably will cause another section to flex in a way that was not designed and lead to cracks and failures. Happens on big trucks alot when people modify the body.
Reply:Many people believe that the bodies of unibody vehicles twist and move around allot which they don't. I have friends that spent the time welding up every joint in cars, spending entire winters just grinding out sealer and welding. Come time to put the car back on the track and oddly no one can tell a difference.There is a huge market for strut tower braces, pillar braces, fender braces, this brace, that brace, braces everywhere. Then the stock car in the same class beats the guy with all the braces.Simply put, the time it take to weld up all the seams isn't worth it. The best bang for the buck is and always will be suspension, all of it, this includes sway bars. 12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:Originally Posted by VPTThere is a huge market for strut tower braces, pillar braces, fender braces, this brace, that brace, braces everywhere. Then the stock car in the same class beats the guy with all the braces.
Reply:Originally Posted by OxfordI don't think this can be used as a blanket statement.  It really depends on what car you are starting with and how much the braces effect it.
Reply:I should say the G-force figure can be wrong. There is lots of gray area in there and I suppose a car can get up to 2'gs or more without body stiffening. Hell I suppose up to 4 or 5 lol I guess I should say body stiffening isn't really needed or won't benefit as much as other parts until you are at that "race car" stage. Just saying I haven't seen it worth the time to weld seams in any vehicle yet. At the point of thinking you "need" to weld seams you are probably at the point of "needing" a tube chassis.12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:I spent a few years in the autobody racket as well, and I have to say that I doubt chassis flex is your problem. Cutting coils is making your back doors squeak because you have stiffened the ride, not because the body is twisting. I think you should spend your time and money on the suspension as noted above.... shorter stiffer springs, heavy duty sway bars and shocks, wider tires etc. Good tires will also go a long way to improving cornering performance. If you still want to try stiffening the body, I would drill any braces that cross and add a bolt between them if you feel they are flexing too much. Running around the body adding extra welds seems like a plan to add unwanted cracks or worse yet torching a vehicle to me. Spend some more time researching performance suspensions and I think you will be money ahead at the end of the day. Your V-6 just isn't putting enough torque into that chassis to require the body stiffening full race cars need.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:In the last few days I've been scouring the web for more info. Based on people's experiences with Mustangs (welded subframe connectors) and unibody XJ Cherokee bracing, I'm increasingly convinced that stiffening the chassis will be useful. After that, I fully intend to add more bar, and potentially stiffer springs. Lower profile tires once the current ones are done also.The layout under the car looks very easy to deal with--without extending below the exh manifold or catalytic converter, you can draw a straight line between the rear suspension mounts and from them forward to the front subframe attachment points, with room for triangulated X bracing between those 4 hard points.Regarding the squeaks being a product of the stiffer suspension--true true, point taken. But I want to lose the squeaks AND run a stiffer suspension. Even if the improvement is just subjective/NVH--that's fine, I'm not going up against a clock, so I'm really looking for *perceived* handling.Regarding the honda odyssey--yeah, that's the one I wanted. When I was shopping a few years ago, the Hondas had a fragile transmission that scared me away.Regarding the minivan chassis resisting torsional forces well--no, I actually don't think it does. Too many big holes (a huge rear hatch and two big, symmetrical sliding doors), and no rear bulkhead tied to a C pillar as in a sedan.Now I just need to learn how to weld.
Reply:You obviously just want to weld something so have at it, but the fact is that XJ's unibody has absolutely nothing to do with body roll, as is the case with your van.Welding/Fab Pics: www.UtahWeld.com
Reply:not a unibody, but i took a welder to do some exterior work on my old toyota. filling 1/4" or so holes left over from slide hammer.thing caught on fire, inside, between interior and exterior sheet. i ended up soaking the interior of the truck and couldn't touch the cab for about 20 mins. no idea what was burning but i dont suggest you try it and compare resultsbosses stuff:trailblazer 325maxstar 200my stuff:sa 200fronius transpocket 180100 amp Lincoln w/f97 f350 DITKevin
Reply:Originally Posted by MikeGyverYou obviously just want to weld something so have at it,
Reply:Seriously man you don't need to weld your unibody. Try these few things first, bigger wheels with a wider offset and low profile tires. ADJUSTABLE coil over suspension, eccentric camber bolts. Moving the lower strut mounts outward to compensate for roll. Remove as much weight as you can from the floor up. Urethane bushings,urethane body mounts, and urethane motor mounts. How the drivetrain and suspension connect to the chassis are the number one most important factor in handling. You can have the most rigid brick in the world, it isn't going to do any good when the pieces that hit the road are wiggling all over. Adjustable Tubular control arms, INDEPENDENT rear suspension. Heck since you don't want a cage inside, build an exo skeleton! Then you'll be just like those jeeps that go 3 mph off road. You're putting the cart before the horse, I hate to be negative but there are so many more important areas that need to be covered before chassis rigidity becomes an issue. Whatever you decide to do, keep a man on fire watch cause that chit burns really hot really fast. Good luckThermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter
Reply:Oh I forgot something, you can also weld all the doors shut. That would save you a bunch of time and you wouldn't even have to get dirty. It worked for the general lee Thermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter