Hey, A buddy of mine's young son was patching some rusted areas on the fender of an old Chevy and was wanting to show off some new found metal working skills, but was having some problems- He said " I cut out the rusty metal, and cut some patches of metal from a fender I got from a body shop scrap pile, but somethin' ain't cool! The patches I cut from the new fender are hard to form and don't weld too good." I asked, "what was the fender off of you cut the patches from?" He said he didn't know, but was probably something Asian, given that's what the body shop worked on from where he sourced the fender. I said "It sounds to me like you gota hold of some HSLA!" Some WHAT?"' he said. "HSLA, high strength -low alloy -steel" I said. For over thirty years now automobile builders have been using this to improve crash strength in vehicles, but also to save weight! Less weight = better gas mileage. Floor panels, wheel houses, firewalls, top panels, rockers, doors, quarters and fenders all can have HSLA in them. HSLA cannot be welded well ,with a gas torch (which is what the young lad was trying to do) and some alloys will only form with heavy force from a press. I suggested he cut out the patches, and replace them with some CR 1020 (cold rolled carbon steel) he could source from a hardware store. Clean, cheap, formable and most weldable witha torch. No funny alloys to contend with. Scrap metal from older vehicles, like 35+ year old would probably be o.k., but the late model material can spell trouble! Swankey Devils C.C. "Your head would look good on a pike"
I engineer automotive body structures for a living. You're right, there are very few panels now that are "mild" steel. Much of body sheet metal is now HSLA, Dual Phase, Martensite, and even hot-stamped boron steel. We still do most of our body side's (quarter panels) and roof panels in mild steel, but even some of those are higher strength for dent resistance.
I found out a long time ago that mid 70's and earlier pickup hoods an bed sides make pretty good patch panels. My buddy always seemed to have a bad hood or rear quarter that I could cut panels out of around his place so the free part may have had some influence. <input id="gwProxy" type="hidden"><!--Session data--><input onclick="jsCall();" id="jsProxy" type="hidden">
Hey, This brings to mind another thought/question- Anyway to tell HSLA by a visual test? I had a customer want me to consider designing a chop, and cutting his late model Ford F150 Club Cab pick up roof to match that chop. I told him, "although I've never chopped anything built past 1970, that I didn't think that would be possible! Most late model vehicles A, B, C & D posts contain HSLA steels, and some are foam filled for added structural benefit in the event of a roll-over collision. To design a chop in a late model vehicle with many changes in shapes and contours would require many cuts and welds through areas of those posts/ panels that should not be cut or welded! Collision repair manuals are very careful to point out that all welds MUST be made at oem/factory lap seams and pinch welds. To cut and weld the posts as I would on an early chop ( traditional vehicle) with butt welds and carbon steel panels added to HSLA panels would be to produce a potential death trap in waiting!" I guess he's still lookin' for a fool to chop it! Swankey Devils C.C. "All great turths begin as blasphemies"
Which would explain why I hate welding inner panels back in later model hoods when I louver them. This is the stuff that smells like bad breath when you mig weld it, right?
Hey, I don't know 'bout the smell (my nose hasn't worked rite in years)but some of this new steel has "weird "electro" coatings to help guard against rust outs in new car body panels. It grinds weirdly, and may well have a funny smell! I do know that you can't weld HSLA steel with a gas torch and not expect that weld to fail under impact. The higher heat of a oxy/acc. weld overheats the alloy in HSLA. The mig welding process is what all repair direction calls for as its' HAZ (heat affected zone) is much less than an oxy/acc. weld. Swankey Devils C.C. "Spending a nation into generational debt is not an act of compassion!"
OK, this begs to ask the question, how many of you have priced a sheet of 18 or 20 gauge steal? Its so cheap there is no reason to be cutting crap out of old hoods to reuse!! You can't afford to cut it, clean it, and deal with any damage dents or curvature already built into it for what you can buy a new piece of steal for! If you shop around a 4x8 sheet will run you less then 50 bucks and I have recently purchased it for as low as 25 and that is alot of steal!!
To my knowledge, no. However, if it's Dual Phase, Martensite, or Boron, they're typically stamped somewhere on the part with a symbol (DP, MS, B, etc.) If your looking to chop a new car or truck, don't. You're likely going to get into some very high strength steel, especially in the A & B-pillars. Hydroformed tubes & composite structural inserts are also fairly common. I believe the new F-150 has a tube in the A-pillar.
Late model chops can also get into a sticky area of safety with regards to the effectiveness of side curtain airbags, bonded glass, crumple zones, deformable panels, etc. What if an airbag goes off and it's in the wrong place and breaks someones' neck? Too much scary legal risk, I'd back away from it. -KK
all this hlsa and high carbon, blah blah blah sounds too familiar to me. i work in a steel mill, i'm sitting here watching some 1005rc material run right now... well i'm mostly sitting here surfing the H.A.M.B. hahaha!!!!
So does this mean I can't use a Volvo station wagon roof for the top insert of my '28 tudor? I'd planned to mig-weld it.
Don't forget the galvanizing under that paint, bad to weld on. Same with panels from a fridge or washing machine.
Hey Gary, I do not think you'll have a problem with the Volva roof panel to '28 Ford! Short burst welds, plug welds, tack welds 'till you run out of whatever needs welding all will work well with a "squirtgun'' welder. It's guys like me, who still do most of our sheetmetal welding with a torch and "Extra-Virgin" coat hanger for filler rod, that will run into trouble! I'm not an expert in metallurgy, and I don't play one on T.V., but I'm told the heat generated by an oxygen/acetylene weld's flame is much greater, for much longer and this destroys the alloy/s in HSLA steel. HSLA, as used in the body panels of late model vehicles is sometimes much thinner than what you would find in an older(traditional) vehicle. Thinner= less weight+ it is much stronger. If you take an early Ford Falcon (early unitized constructed vehicle) and take a late model Ford Focus (late model unitized constructed vehicle built from HSLA steel) and if it were possible to cause frame damage to both, exactly the same, you'd find the Focus to be much harder to pull the frame damage out, if possible, over the older Falcon not built with HSLA steel. Swankey Devils C.C. "Your not smart enought to tell me how to live"
Last year I made my son an Iron Man costume out of an Asian car hood from the junkyard. It was pretty easy to form the shapes I needed on the anvil, but it was not easy to weld. My MIG does not have a setting low enough, so it would quickly burn through. I was able to braze to it, but it was not as easy as on 'regular' sheet metal. How do the body shops repair these late model cars, like when they are replacing a front or back clip? For example, on a front clip swap the A pillars are usually rewelded. How do body shops deal with these HLSA materials?
It's all about what we learn. If any of you are in the auto body trade when you know you can do the same things to the new cars as the old. You just have to do it differently. If you follow the ICAR rules for sectioning pillars, rockers Etc. then your good to go. Basically you have to make a sleeve twice the lenght of the cut of the pillar. So if the pillar is 2" thick then the sleeve has to be 4 " long and fit inside the pillar. Then you seam weld the joint and plug weld in a spaced triangle around the pillar the same distance as the factory welds. (About 1 1/2" apart.) this way in a collision or roll over the the force goes through the panel into the sleeve through the sleeve into the panel. Yes it works, it was tested on vehicles years ago when ICAR started in 1979 or was it 1980. I know because I made up the first test pieces to be destructed by the Lab in Buffalo. As for welding HSLA a good 180 to 200 amp MIG welder is all you need to do structural welds. a 140 to 160 amp MIG is the best for sheet metal. This is what I use to butt weld and Hammerweld with the MIG. Feel free to ask Questions: The Old Tinbasher [email protected]
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