How important is full penetration exactly?

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I have looked into buying/upgrading my control arms on my Jeep like these sold here:Starting at $129.99 a Pair, they certainly wouldnt be hard to make.  All they are is 1" steel rod, with 2 circles on the ends to hold the less than $10 bushings.  The thing that concerns me, is obviously the fact that I would be having my life dependent on my welds.  (Clarke 130EN 110v set for Flux Core .35) Plus even if I could penetrate 1" which I can't, wouldnt it completely burn through the 1/4" or so thick circle?So I am wondering if it was safe for me to do this (Is the Clarke capable?)  Obviously I dont want to drive down the road, hit a bump and have the Jeep fall apart...but certainly do not want to pay $130 for $30 in parts if I am capable.Thanks-PatI'm 21 and learningAvid 4wd enthusiastASE Master tech (Automotive), mechanic/fabricator by trade
Reply:Not trying to be a buzz-kill, but, I would say, make a fun project of welding something else non-critical if you're not 100% certain you know what you're doing, and leave welding the suspension/steering parts of your car to the manufacturers or custom chassis parts builders who have already figured out all the details.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:I'll second Desert Rider here.DennisThermal Arc 185-TSWMillermatic Challenger 172VictorO/AAtlas Craftsman 12 by 24 LatheEsab PCM-875Wholesalem Tool Mill-Drill
Reply:Penetration, depth of fusion, is a discussion all in itself. The factory control arms won't be "full pen" by a long shot, but hopefully they have some good depth of fusion.What would concern me is the 120 volt, amp limited machine and flux core. That 1" solid makes one heck of a heat sink and flux core needs some thought on structural loads. Especially if multi-pass is needed. Without getting real wordy I'd buy the parts.
Reply:I would third fourth fifth and one millionth not doing this yourself, as in $1,000,000+ if the part failure included your jeep killing someone else. A highly regarded local machine shop did some repair/modification on some suspension part which subsequently failed and they were sued due to their liability. Needless to say, they no longer work on suspension/drivetrain parts.SA200,Ranger8,Trailblazer251NT,MM250,Dayton225AC,T  D-XL75,SpoolMate3545SGA100C,HF-15-1  RFCS-14 When I stick it, it stays stuck!
Reply:I hope all will answer, just don't take the chance.  JohnSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:I think we have a unanimous decision. Thanks.I'm 21 and learningAvid 4wd enthusiastASE Master tech (Automotive), mechanic/fabricator by trade
Reply:If the weldment is prepared properly it would be safe to TIG weld BUTwhat about the hardness? Are they hardened?Also are you sure it is a solid bar? It could be very thick tubing which would be stronger. The inside area plus the outside area is what determines the strength of the tube. If the inside area is zero(a solid bar) it is not as strong.Just check the weight..should be easy to figure out.A lot of time invested for not much of a monetary gain.One other thing to consider is that when large production runs are set up they can buy materials at a lower cost. The metal could be 4130 and for you to by small amounts is more expensive. There are places to buy small amounts.Last edited by Donald Branscom; 01-28-2008 at 03:44 AM.
Reply:Originally Posted by Donald BranscomAlso are you sure it is a solid bar? It could be very thick tubing which would be stronger. The inside area plus the outside area is what determines the strength of the tube. If the inside area is zero(a solid bar) it is not as strong.
Reply:Originally Posted by Alan NNever heard that one before, where did you get that information?  If that were the case we would be seeing a lot of hollow shafts and hollow parts where weight is an important consideration.Granted, automotive driveshafts are hollow but that is because they come out lighter that way than a solid which could carry the same torque load.
Reply:For the penetration Vs Fusion, I did a test.  Results will be posted in projects and pictures.For the shaft, a hollow shaft is stronger and carries more torque because there is no movement in the center.  The outside holds more than the inside.I am building a trailer out of 2.5" X 2.5" square tubing 1/4" wall.  This would only be a 1/2" square bar if it wasn't tubing.  That wouldn't hold sh*t.As far as building your part, a nutter vote for don't do it.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:To clarify a little more, a 1" solid bar is stronger than a 1" tube.I'm absolutely sure that they are not hardened. Hardening a part like that would be a really, really bad idea.I would not think twice about doing that for myself. If you are not experienced enough to be totally confident then you definately should not. You would need a more powerful machine for sure.Last edited by Joe H; 01-28-2008 at 05:32 PM.Miller EconotigCutmaster 38Yes ma'am, that IS a screwdriver in my pocket!
Reply:do not build those pieces your self for all the reason above  the tube is stronger than a solid shaft do to the fact that it has more surface area to be reacted uppon.Life is tuff,so be sharp  lincoln sp 100  cutmaster101  miller bobcat  miller 250 mig  $thousands in snapon
Reply:Originally Posted by asemaster the tube is stronger than a solid shaft do to the fact that it has more surface area to be reacted uppon.
Reply:all other things being equal, how can removing material from the centre of an object make it stronger?if a round bar is subjected to a simple bending stress, one surface is placed in tension, the other in compression. the bit in the middle is relatively free from stress. the same is true if the bar is subject to torsional stress, the middle is relatively unstressedhollow/sculpted sections are not used because they're stronger than their solid equivalents. they are used because it is a more efficient use of the material.
Reply:Originally Posted by hotrodderhollow/sculpted sections are not used because they're stronger than their solid equivalents. they are used because it is a more efficient use of the material.
Reply:Donald Branscom has a good point.  These control arms are probably not garden variety, low carbon hot rolled or cold rolled.  High carbon steel changes properties when it is heated and cooled so, after welding, the manufacturer probably aneals and stress relieves them then heat treats them to a specified hardness.  You can probably make something that looks similar but, in service, it is almost guaranteed to fail.
Reply:The advice about not welding these parts up seems to be solid advice.  If the person asking has that many questions, they really shouldn't be taking on an undertaking like this.  As for the material and heat treating, does anyone really know, or are you all just throwing out guesses?  It appears that subject is all speculation, everyone is just throwing out their best guess.
Reply:I am building a trailer out of 2.5" X 2.5" square tubing 1/4" wall. This would only be a 1/2" square bar if it wasn't tubing.I think your math is wrong. That tubing mass would be close to 1 1/2" squarebar, but I still would not use it for a trailersteveBTS Welding
Reply:are you sure those are control arms?they look more like sway bar connectors, but I dont know much about jeepsBTS Welding
Reply:Originally Posted by steve buteraI am building a trailer out of 2.5" X 2.5" square tubing 1/4" wall. This would only be a 1/2" square bar if it wasn't tubing.I think your math is wrong. That tubing mass would be close to 1 1/2" squarebar, but I still would not use it for a trailersteve
Reply:Originally Posted by David RFor the penetration Vs Fusion, I did a test.  Results will be posted in projects and pictures.For the shaft, a hollow shaft is stronger and carries more torque because there is no movement in the center.  The outside holds more than the inside.I am building a trailer out of 2.5" X 2.5" square tubing 1/4" wall.  This would only be a 1/2" square bar if it wasn't tubing.  That wouldn't hold sh*t.As far as building your part, a nutter vote for don't do it.David
Reply:Originally Posted by steve buteraare you sure those are control arms?they look more like sway bar connectors, but I dont know much about jeeps
Reply:Originally Posted by lewrayExactly what I thought too.Making control arms....hmm  not rocket science
Reply:I looked up a picture of them on this website http://www.bds-suspension.com/the description is 1 3/4" x 1/4" wall tubingthey also look like they are miggedBTS WeldingAlways remember that in endeavors such as this you are taking your life into your own hands. Not a good idea. I've been at this a very long time, have a solid rep for building tough stuff that doesn't break, and I wouldn't do it.As for 2 1/2 X 2 1/2 x 1/4 wall square tube: it is actually much stronger on the cross section than 2" pipe. I know as I have used it in places where pipe was bending and cured the problem. For a trailer it is an excellent choice as long as the design is a good one. I prefer channel for framing them myself, but have used pipe and square tube. Pipe is preferred over round tubing because pipe is rigid and generally has a thicker wall than tubing. Anyone who has ever spent time in the oilfield knows this.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:Originally Posted by Jolly Roger.. I've been at this a very long time, have a solid rep for building tough stuff that doesn't break, and I wouldn't do it..
Reply:Those arms are not solid, I believe they are 1.25"x.375" DOM tube.  the toughest part of making them is assuring that the length is identical side to side.  What I do is figure out EXACTLY how long I need them, then measure that out on my welding bench, weld the appropriate sized bolts to the table so that I can set my bushing assembly over them, then I can cut the tube, notch it for a perfect mate, and tack them in place.  Then remove the bushings from the tube, and final weld.  Remove the bushings so you don't melt 'em from the welding.  But with that little welder, I wouldn't try it, you'd be REALLY pushing that thing and I don't think it's capable of the weld quality you need for this.And for the price, Iron Rock is a good company with really good guys running it, just buy their's and bolt 'em in.
Reply:Lots and lots of guys build suspension systems in their garages and run them without worry.  Most of the trucks are off-road only...but a good majority of them are daily driven on the street.  As long as you get good penetration, I'd say you would be alright:
Reply:Originally Posted by redhatmanThey are heavy so I assumed it was solid which I am pretty sure he said they were.
Reply:Well Joe, it's like this. I weld for a living and there is a thing called liability. Every single part on that Jeep or any other vehicle is engineered for it's purpose, and many of those parts are welded using computer controlled robots nowadays. I am not an engineer. As for my skills, wanna go one on one? I will any day. I have made welds that withstood far more than they were ever meant to hold. Prime example: 3 inch sked 160 (for those who don't know that is 3 inch pipe with a 1 inch hole running through it) 6010 root and hotpass, 7018 to finish it out, a 70,000 PSI weld. When they choked that blowout off my weld had over 126,000 PSI on it. In 10 years of X-ray welding I had 2, yes only 2, repairs and I was doing high pressure pipe and heated pressure vessel work. I warranty all of my welding for one year and in ten years I have only had to make one warranty repair, and I work on a lot of heavy equipment subject to serious abuse on a daily basis. I guess I know my business. So yes I would build them for my personal use and never think twice about it. I own 9 welding machines and all but one say Miller or Lincoln on them, the one that isn't says Westinghouse, is older than I am, and puts out 425 amps at 100% duty cycle. No Chinese junk allowed in this shop. The real kicker though is you don't see me on here asking how to weld components that the safety of myself and others depends on, and doing it with a hobby welder. Nuff said?The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:Originally Posted by DesertRider33Not trying to be a buzz-kill, but, I would say, make a fun project of welding something else non-critical if you're not 100% certain you know what you're doing, and leave welding the suspension/steering parts of your car to the manufacturers or custom chassis parts builders who have already figured out all the details.
Reply:Well it's like this, and the other pros will tell the same thing. As a professional I am civilly and criminally liable for any damage, injury or death caused by the results of my work. I'm not sure about advice, but don't want to take the chance and can't afford the lawyers anyway. Want to know what happens when you screw the pooch on something like this just go take a look at the thread about the happenings at John Force Racing. Poor designs and inferior welds can get you or someone else killed. Those parts are engineered for their purpose, built, tested, redesigned and tested some more, and believe me when I tell you they aren't welded together by a bunch of guys in a shop. They are made using automated systems that apply the same weld every time over and over and over, something no human can do I don't care how good they are.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:UPDATE: Called the manufacturers of them, and its 1.25" Cold Rolled Steel for the Arms. Inch and a Quarta!I'm 21 and learningAvid 4wd enthusiastASE Master tech (Automotive), mechanic/fabricator by trade
Reply:The first sign of a professional outfit is knowing when to walk away from a job you are not qualified to perform.I charge 100+ /hr for anything that somebodies life is going to be dependent upon.  Hope that makes the cost of your purchased parts easier to stomach.