Help with notching control arm

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Hey guys,Lots of people chimed in to help me out with my tub job thread so thanks for that. Current project is notching the control arms for my drag radials. I have the control arm notched and ready for the pieces to be welded up but have a couple questions.1.) Once the notch was made I noticed some surface rust inside the control arm, I realize these aren't air tight and are bare steel, but just wanted to make sure it wasn't something I should worry about2.) As you can see Im welding some pretty large pieces of 1/8 inch for the notch. Once this is welded up wont the backsides of these new pieces just rust out, or is it not a concern?Thanks.
Reply:You could try this:http://www.eastwood.com/internal-fra...nozzle-qt.htmlJust a thought.kidtigger24  They think I’m crazy, but I know better. It is not I who am crazy. It is I who am MAD!
Reply:Apparently there's no concern as to the strength of the arm after platingwith sharp corner, big notching?Blackbird
Reply:Originally Posted by dave powelsonApparently there's no concern as to the strength of the arm after platingwith sharp corner, big notching?
Reply:Hello schmen, I believe that Dave might be referring to the sharp corners that you made when you cut out the section of the arm. Generally, it is a much better method to incorporate as much radius in the corners as is allowable for your given scenario. Sharp corners readily invite a place for cracks to start and also concentrate stresses that will often propagate their way away from and into the materials directly behind them, leading to cracking. Using a large radius in the corner will provide for radial distribution of stresses and there will be less likelihood of cracking issues and also yield higher strengths.It would also be better to use a single plate with bent corners as opposed to three separate plates welded together to do the fill-in work.  I attempted to get something sketched up in paint to show this, guess my mouse just doesn't want to cooperate this morning though. Good luck and best regards, Allanaevald
Reply:I see what you mean, thanks. I tried to bend my 1/8 inch with a torch and hammer the other day with no luck, so I didn't think that as option for me (no specialized tools etc). Hopefully it ill hold up OK.
Reply:Suspension components are not the place to say "hopefully it will be ok."I seriously frown on people doing this type of work without the proper experience.Having said that - I am puzzled you can't bend 1/8" stock with an oxy/acetylene rig.  That's pretty thin steel.Without a torch, a good solid vise and a hammer bends that thickness.  Same with a large crescent wrench and a vise.I agree with the advice to put a nice radius on the inside corners as well.Dave J.Last edited by MinnesotaDave; 07-19-2013 at 05:52 PM.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:If you need to make a few bends, cut the outline out of a block of wood, then hammer the steel to fit.
Reply:Originally Posted by dave powelsonApparently there's no concern as to the strength of the arm after platingwith sharp corner, big notching?
Reply:Talk about a negative Nancy jeez. Do you guys really feel that the square tubing I plan to use under the length of the control arm won't be enough?
Reply:Talk about a negative Nancy jeez. Do you guys really feel that the square tubing I plan to use under the length of the control arm won't be enough?
Reply:You have to expect people will be negative when you mess with suspension components as a novice.I'm sure you will be running more than a stock motor since you are running drag radials.  More power + hacked components = negative folks.I could be wrong - post more pics of your welds and how the build progresses - maybe you'll surprise people with your fit, finish, and proper welding/engineering Dave J.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 can undstand your point of view, but do my square corners really make this a hack job? Just finished the tubs and had great results. Novice yes, incapable of doing good work... no. Forums like this are designed to share information and help you one another, not bash someone for trying. Any actual help or insight is appreciated.Last edited by schmen; 07-19-2013 at 09:36 PM.
Reply:schmen, depending upon the speeds/stresses that this vehicle will see and whether you are the driver or not, there could be some real safety/liability issues, especially in the suspension arena. No one wants to see anyone suffer serious injuries or lose their hind end in court over something that could have been prevented by exercising due dilligence or taking the correct precautions. Consider that NHRA requires any frame/suspension modifications to their various race classes be performed by certified shops/welders. They also generally require specific minimum requirements for frame design and likely approved engineered drawings. I am not privy to all of these items but I do know that a shirt-tail relative of mine who races nostalgic dragster class has, on more occasions than one, been required to have his car evaluated and then modified in this manner by a qualified facility with a certified welder doing the work. Just remember that all of the folks who are being critical of your statements or to your proposed work are truly thinking of your safety and that of the others who may be around you, including your family. Good luck and best regards, Allanaevald
Reply:but do my square corners really make this a hack job?
Reply:Originally Posted by schmenTalk about a negative Nancy jeez. Do you guys really feel that the square tubing I plan to use under the length of the control arm won't be enough?
Reply:Is it possible to just replace the arms with ones made out of ROUND tubing?Kill 2 birds with one stone..Clearance and safety.If worse comes to worse I could always make what you need if I had one of your stock arms to go by......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by schmenI can undstand your point of view, but do my square corners really make this a hack job? Just finished the tubs and had great results. Novice yes, incapable of doing good work... no. Forums like this are designed to share information and help you one another, not bash someone for trying. Any actual help or insight is appreciated.
Reply:I do these all the time for newer body GTO's you have to add a X brace inside the tubing before your plate it over to close it up. because it has a samller cross area it will be much weaker by adding the x brace in the inside run up passed the notch it spreads the load out much safer.I will try and post pic or add more info later but my computer is freaking out right now. think some spilled water on the thingLast edited by Bigrich954rr; 07-20-2013 at 10:23 AM.
Reply:Originally Posted by Bigrich954rrI do these all the time for newer body GTO's you have to add a X brace inside the tubing before your plate it over to close it up. because it has a samller cross area it will be much weaker by adding the x brace in the inside run up passed the notch it spreads the load out much safer.I will try and post pic or add more info later but my computer is freaking out right now. think some spilled water on the thing
Reply:Originally Posted by zapsterIs it possible to just replace the arms with ones made out of ROUND tubing?Kill 2 birds with one stone..Clearance and safety.If worse comes to worse I could always make what you need if I had one of your stock arms to go by......zap!
Reply:LOL wait is this control arm on a new style GTO ?  I knew it looks close to what   I do I thought it might be a bmw or some other car.  maybe its the pic but it looks like you took a lot out with the notch ? what size tire you trying to run ?I use to be on LS1GTO all the time im one of the first guys with a Warhawk 427 with 17 lbs of boost I was such  a noob in 2006 Fill out you info what state are you in ?
Reply:Yep its a 2004, I did  cut a large notch as you can see by the pictures... the reason for the large notch is to accommodate two different size set ups. My track set up (315/ 50/ 17) and my street set up (305/ 35/19).
Reply:At this point I am thinking about cutting more material out to achieve the circular shape discussed earlier, and using one piece of plate that is bent. I have found a picture of this (located below) and looking at the work done by a professional, I can see why it would have much more strength. If Im not confident in the end result, I may just go with the Gforce Engineering modified arms.
Reply:Originally Posted by schmenAt this point I am thinking about cutting more material out to achieve the circular shape discussed earlier, and using one piece of plate that is bent. I have found a picture of this (located below) and looking at the work done by a professional, I can see why it would have much more strength. If Im not confident in the end result, I may just go with the Gforce Engineering modified arms.[/IMG]It continues to amaze me that folks think that the people who designed the part in the first place just threw some old steel together and called it close enough.  You can bet your hat that there's very little excess material in that arm.  A lot of hours went into design, computer simulation, lab test, and vehicle test to arrive at the final configuration.  No car company can afford to make stuff with a lot of excess material in it and stay competitive.So now, somebody doesn't like the shape of the part and they figure they can just whack off a bit of the original material and change the section stiffness by...oh....60 or 70 percent.  And then expect that the thing won't snap off when it's used in a very high load environment.How do I know?  Oh, maybe 35 years in suspension engineering for one of the big US car companies taught me some stuff.  My advice is to find some other way to get the clearance you need.  You're headed for a major scale disaster if you continue with your proposed solution!!
Reply:Disregard this postLast edited by Dobermann; 07-22-2013 at 06:17 PM.Reason: not needed
Reply:Originally Posted by zapsterIs it possible to just replace the arms with ones made out of ROUND tubing?Kill 2 birds with one stone..Clearance and safety.If worse comes to worse I could always make what you need if I had one of your stock arms to go by......zap!