splicing a tube roll cage?

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Hey guys, I've got a wrecked corvette here with a perfectly intact full 6 point crash cage in it. I would like to cut the cage out of this car, and install it into my current '00 corvette track car. In order to get it out of the old car, and into the new car, I have to make some cuts and splice it back together. I consulted AC 43.13 and see that there are approved methods for splicing and welding tube sections. Specifically, I will cut the tubing at a 30 degree angle, and make an internal sleeve extending 3" beyond the cut on either side. Plug weld it, then weld the splice back together via a 1/8" gap between both parts. All welding will be TIG. Tube looks to be around 2" OD DOM but I will verify tomorrow. I'm perfectly comfortable with all of this, but I wanted to run it by you guys as well. AC 43.13 is the only document I could find outlining this type of repair. Any firsthand advice or knowledge is appreciated!Thanks
Reply:I have spliced many of roll cages in my day and it sounds like you have got the right idea. I've actually  never  cut the splice at a 30 degree angle...but I see the point, no straight shear point and more weld surface.
Reply:cut them straight  two plug welds 1/2 inch 180 from each other on each side of the 4 inch long slug and weld up the butt weld joint penny root opening and call it a dayMiller Xmt 350Lincoln Ln-25Ahp 200xSmith Gas Mixer AR/HTig is my Kung FuThrowing down dimes and weaving aboutInstagram http://instagram.com/[email protected]
Reply:How do you guys feel about dressing the welds down so they can't be seen? I'd rather not go through the Q&A session when running through tech...
Reply:Originally Posted by moespeedsHow do you guys feel about dressing the welds down so they can't be seen? I'd rather not go through the Q&A session when running through tech...
Reply:Grinding welds?CHECK YOUR RULEBOOK!There is NO grinding of welds allowed in N.H.R.A. and I am pretty sure that's not the only association with the same rule...Trying to hide something will only open a can of worms you don't need.Show them where and how and all will be good....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:It's NASA not NHRA, my concern is that tech inspectors often put their own spin on things, and a tech inspector who knows nothing about welding may frown on a patched hoop. I'd rather just hammer it down, clean it up, and paint over it so their are no questions. I'll check the NASA and SCCA rules, but if there are no guidelines for patching, I'd rather not take the chance.
Reply:If your good at hiding welds I would hide them but be damn sure they are not going to be seen. If you dont think you can make it like it never happened then dont bother. If you leave it visable then keep pictures of the repair in stages with the car so you can show them how it was done. If it was mine I would hide them, in the end its my head bouncing off the pavement.(Home)Miller Maxstar 152 (sold)MM211/spool gunLincoln AC 225C(Work)Dynasty 350Powcon 300STLincoln SP-175TWeldlodgic AWS150sWeldlodgic AWS300Custom Resistance seam weldersCambridge Vacuum EB weldersI smell something burning.
Reply:Yeah I checked the rules last night, and there is no mention of guidelines or standards for repairs. It does mention "cage will be welded to industry standards". You know how tech inspectors get, if it's not specifically outlined in their rulebook, they tend to put their own personal spin on things. I can absolutely hide the welds to where you can't see them, I've slugged a few motorcycle frames and done plenty of bare exhaust systems. Plus I'll paint it when it's done, and take plenty of pictures of the process. Thank you everyone for the advice and replies, all of your input is appreciated!
Reply:Check the rule book about painting.  If the cage/bar needs to be inspected, sometimes you need to get it inspected before you paint.BTW, a rollbar is typically one bent hoop and a lot of straight pieces.   Sometimes its cheaper/easier etc. just to replace the straight pieces.Also, some rollbars are made from ERW - which could have a nasty bump on the inside, making it that much more fun to install an inner sleeve.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX