So a guy calls me up today he got my card from a buddy (i do welding and fab on the side of my everyday fab job) wants me to look at his buggy to put a cage in it....he has the materials..so i take a look he has nice thin exhasut tubing all layed out how he wants it to go,and wants it welded to the floor pan its in a vw bug, i go i wont do it, goes why not i said i dont half-*** cages, they get done right or not at all..
So he goes well how much to weld this stuff in, i'm not planning on rolling it, i said i will weld it in for you under a contract that will be written out saying i'm not responsible for anything that happens or injury or death resulting in a faulty cage, i say 1k$ to do it to shut him up, he goes no way.SO i told him if he got a good kit for it i would do it for around 600, done em before and actually had a 3000gt roll on a rainy day and the troopers said the guy wouldnt have lived if it weren't for the cage, he walked away from it with a broken arm(same guy wants me to do one in his new wrx)......

Moral of the story....PLEASE people do not go cheap when it comes to this area, its not a matter of damage if it happens it can be a matter of life or death...I cannot stress enough how important it is to have a good solid cage...When it comes to heavily modified or offroad vehicles its not a matter of if, but when!! i would have no problem racing or offroading in a vehicle that had a cage i built....theres a reason they cost what they do for a good one.

 

do you know what the different types of cages cost? say from a roll bar to a 4-point cage?

 

My friend and I recently fabbed a chromoly cage for an SVO Mustang in his shop, people don't realize how much work goes into a solid, *good fitting* cage.

This story reminds me of a show of Trucks! I saw where the rollbar in a truck he bought was PVC pipe covered with padding.

 

Yeah a cage is only as good as its installer. And I too remember the PVC roll bar. I still laugh at that.

 

When I did my cage I bought the tubing through a local supplier, and made my own jigs out of plywood. I then took the jigs up to a local circle track outfit (rocket chassis) and had them bend the tubes for me. I notched and welded all the tubes in and ended up with a very good fitting cage that I can live with everyday. I had 200$ in the tubing and another 50$ to bend it up. Thats cheaper than a kit, and came out much nicer.

The local dirt track guys have some of the scariest looking cages ever built. It looks like they arc welded them, and didn't even bother notching the tubes. Just filled in the gap with slag. They are deffinetly the minority, rocket does damn good work, but you always get the back-woods hacks who are too lazy to do a good job.

 

Must be sweet to live by Rocket, especially if they'll bend stuff for $50!

Anyway, people always diss SMAW (shielded metal arc welding aka stick welding) when it comes to welding cages, but that's all the average person could afford 20-30 years ago.

My uncle used to fabricate chassis for dirt (sportsman, late models, etc) back in the late 70s/early 80s and everything they did was SMAW and it held up when wrecked. Just because some hillbilly doesn't notch tubes doesn't mean stick welds are bad. MIG is definitely a lot nicer to use though given the chance.

 

I understand that the kids's old swing set makes for a good light cage too.

$10 tube for a $10 head.

 

there used to be a kid with a honduh that came to the local car hangout that had a bar made out of exhaust tubing. i told him to let me know how it goes when he rolls over, but he hasnt been around lately

 

Summit and Jegs offer nice Competition Engeering roll bars and cages. You just need to take your time with notching and welding.

 

im assuming you have a cage i your camaro, do you have pictures of it?

 

I'm not knocking arc welding, I work in the oil field industry and I watch guys turn out welds that make my TIG'd stuff look sloppy. These guys have to treat every weld like their lives depend on it....some times it does. We do whats called a hot tap, where we tap into a pipe while there's still 1000 psi of gas running through the line. You weld a fitting to the pipe, then an apparatus ataches to the fitting and you cut a hole in the pipe inside of a sealed chamber. I haven' t got to witness this yet, but it should be interesting. The welds I was talking about looked like they filled the gap with weld and never bothered to knock the slag off.

Rocket is truelly a top notch facility, the shear volume of cars they turn out of there every year is amazing, I think its like 280 chassis a year! One thing I noticed that bothered me is that they mig weld 4130. Every book I have ever read says not to do this. They don't have any problems....but it bothers me. We got some 1" tubing jaws for MTS tensil tester at school. We....well I guess I mean "they" since I graduated, are going to do some tests to see how much weaker mig'd 4130 is compared to tig'd, and also try some tubing that was preheated prior to being Tig'd . Should be interesting.

 

Has anyone used aluminum as a cage/frame on a sand buggy? what thickness would you reccommend? My friend has a sand rail and it seems waaayy over-built and not even in the correct areas as far as strength and safety(homemade by the looks of it). If not aluminum I at least plan on modifying the existing steel frame to make it lighter and stronger.

-Ben

 

That is the scariest thing I've read, ever!

 

Late Model guys seem to like to run things that break, if you ever saw any of the plastic/composite wheels they used to run. Rub someone touch the wall and it'd be destroyed.

That is interesting though, my godfather's nephew runs a LM and he just had to have a front stub put on his car after he bent it up. Wasn't Rocket though, some company in TN or KY. The name escapes me.

 

Thats intresting Bmonte, i've never seen 4130 done mig, buddy of mine works for a shop that build aircraft components for out of production aircraft stuff like that and its all tig, i "interned" at a local refinery when i was still in school and the welds i saw there were some of the best i had ever seen, payed great but the dirty, dangerous and colorado winters kinda shyed me away..I now work for a place that builds aluminum livestock and grain trailers....THE big ones too 53' and its all aluminum mig, nice clean work indoors
www.merritt-equip.com
Thats what i make everyday

 

One of my three welding instructors used to work for columbia gas, and told me basically the same thing. He said while not common, there were times when they'd be welding on a line and there would be a blow through. They'd stick a screw in it, weld around it, and keep going. He described the hot tap to me as well. I'm not 100% sure anymore how it works, but basically had to do with the way they routed lines when working on it.

Mathius

 

1- are you sure that they’re welding 4130? Chomolly is illegal in most circle track classes and even if not the do not get the weigth/thickness breaks that you get in NHRA/IHRA rules for running it. I’d be pretty surprised if they were actually doing 4130…
2- Seems like most people TIG or gas weld 4130 with mild steel filler anyway, so it would make no difference if you TIGed, MIGed or even gas welded it as long as you did it just as fast. Real world the problem with welding 4130 is that you make a localized hard/brittle spot on either side of the weld where the 4130 self quenches after you run the bead, the shorter you take to make the weld the less heat you put in to the whole assembly… That being the case and if you’re going to use anything but a 4130 filler AND heat treat the entire assembly after you finish welding it, real world, whatever you can lay down the fastest bead with will give you the strongest weld, which in 99.9% of cases will be MIG (assuming done correctly). That being said (and I’ve said this before), the NHRA/IHRA rules about using 4130 in cages don’t make any sense and they are consistent in that WRT to the fact that they require tig welds for 4130. With the aircraft industry TIG welds are the standard because you’re not as likely to make a nice looking weld that has no penetration with it (IE, someone without a clue can pick up a mig and get what looks like an acceptable weld that is really trash).

I bet that you’ll find that it depends on the weld more then the process. If you want to try something interesting try the same test with 1018, 1020 and especially 1025(if you can find it) mild steel tube.

Unless out of some of the more pricy grades or hardened aluminum is roughly as strong/weight as steel, but half the weight (it takes 2x as much to get the same strength). The problem is that where you can weld steel to be as strong as a solid piece, aluminum welds can have as little as 30% the strength of the base metal when done correctly. Aluminum also work hardens, stress cracks and has assorted other structural problems easier/faster then steel.

If it was me I’d just go with mild steel unless a significant portion of what you need to build does not need the strength of the lightest/smallest steel pieces available, at that point it starts making sense to use aluminum.

 

IMO if you are fast enough that the NHRA requires you to bu\e running a cage 1. you have teh money to do it right
2. You probaly have enough power that the extra weight of the cage wont be to big of a deal

 

there is a lot of new data on how to weld chromoly. They are finding that mild steel filler makes for a more ductile weld that is more likely to deform than crack. Mig is now considered acceptable although a lot of sanctioning bodies (nhra) don't accept it. Ironically, there is an argument that TIG is somewhat unfavorable due to its very localized heat. According to my research chromoly doesn't like thermal shock or localized heating. The old timers would heat to cherry red after welding to stress relieve. If you go with OAW (original aircraft welding method) the heat input is greater and the whole part tends to get very hot eliminating the localized heating and resulting stresses. Tig is of course acceptable (now preffered) with a mild steel filler (er70s2??) and a slight preheat to insure all moisture is gone. Supposedly the AWS is releasing a new spec detailing this.

 

Really? Sweet, the head of the department where I go to school is the out-going president of the AWS. Hopefully, I can dig something up next time I talk to him.

If it's OK to MIG 4130, then it might be worth the extra cost on the tubing.

 

I also know a few dirt track guys and most of them make dam sure that their cages are spot on. Safety first you know

 

The Competition Engineering cage is the only one that I have any experience in doing.

Took a back seat and learned something while I helped cut/fit/weld/etc into a friends car.

The entire thing was test fittied and tacked in place then bent to fin with full interior and everything was notched one way or another to fit with no gap at all bars and floor plate meeting points.

Our friend is a iron worker and we used pipe benders to tweak the entire kit to fit the car for my friend and followed the NHRa guide book for install. Nicks car for the guys who know me here.

Its an altogether slick install and safe to boot

I know someone who put in the same cage and was proud they did it completley by themselves. I shudder to think what happens if he ever rolls it and his bar to floor plates that are built up 1/2 inch weld ever decide to let go :-( Such a shame, we tried to tell him, but he didnt want to hear it.

later
Jeremy

 

I know this is an old post, but I had to put my .02 in. I-44 Speedway in Lebanon Missouri had a young stud show up for race night in his newly built street stock. Awesome looking cage that he had built out of exaust tubing. He painted it with several coats of paint and it past tech. The track was fairly new and had only one roll over to date. The kid rolled the car the first night out. Now the track is almost 20 years old and he is still the only death that has happened at that track. But on the bright side, he saved alot of money. This is an easily verifiable story. As the guy who started this thread said. Build it right or don't build it at all. I know they are expensive, but what is your life worth?

 

Yep. Doesn't matter how much money you've got when you're 6' under.

Hell, overbuild it a little if it makes you feel safe enough to not worry. So what if you give up some weight, there are other things to play with if you have to get to a minimum weight. The cage is not a place to skimp.

 

irocbuilder-great dedication in your sig.

 

ok ive got a question for you guys.i have an 84 bird. i want to put a mild cage for a street strip car should i just buy the materials and do it my self or fork the cash out at a shop? also where is a shop in the lansing area that does it? whats a good price to expect to pay for it? also if i do a cage should i still have to do sfc?

 

These guys are awesome for cages, if you wanna bring it all the way here For price, they do a complete legal one for $1000. http://www.cscracing.com/ck.htm

 

Do you guys think it is a really big deal if your cage is not totally pro, for just a street car? I did mine for the added ridgidiy. Thats it. I never plan to race the car. Just beat on it on the street. And I was short on $ so I couldn't afford the 4 digit price tags. I ordered a jegs kit and welded it in myself.


And one other thing. Is it hard for a place to cut out the bars I have put in and have them do a REAL cage? I would assume not, since plasma cutter goes through steel like butter.

Oh well. I guess I will run my bars till next summer and then get a pro to do it.

 

I ordered the S&W 8 point mild kit for mine. Mine included: dual swing outs and clearanced side bars (to retain arm rests). Kit total'd ~$280 shipped I believe because of a GP at the time. I spent another $300 at the local welding shop helping the guy put it in. I did all interior removal and installation myself to keep the cost down. I added some Por-15 paint and some padding. Came to around $650 finished project cost.

I researched throughly and believe it meets all NHRA Tech Specs for a roll bar. I had SFCs in the car before, but did not tie them directly in due to a rule stating if the floorboard/firewall wasn't mod'd over a certain cubic foot a roll bar is good to 10.0 Secs in a hard top. If I ever run fast enough for a cage, I'll buy the conversion kit and install it at that time.

After the install it was noticeable over just the SFCs and wonderbar.

 

Nice install story. I hope my REAL bar job can go as easy as that.

 

It depends on how well you can weld and if you know the goals you're trying to achieve during welding. Just because you laid down metal doesn't mean it's strong. If it's just roped together, it's more of a danger to you then not having a cage.

Here's an example of a dangerous, home built cage: http://www.rochelle.net/~playa01/82ta/82forsale.html

Check out all the booger welds and tubing that looks like it was bent over the hitch of a trailer.

 

Thats horrible! Its so intrusive too, a lot of the nice ones I've seen are just noticeable. It looks like that guy went around stealing a bunch of galvanized fence posts, fired up his wal-mart welder, and went to town

 

Wow I thought mine was a bit shotty. But that is nuts. At least I bought roll cage pipes. haha.

 

how hard is it to get the carpet to fit properly after installing a cage?...(i'm thinking 8 pt. cage and i can see having minor problems getting the carpet to fit right after it's installed?) could be wrong tho but just a thought...

 

Not hard, probably took me 5 to 10 minutes to make all my cuts. Measure twice, cut once. I used a carpenter's knife to make my cuts.

 

Same here. Little slices. and at the pipes I just cut a little hole with scissors. Really not hard at all. Good luck.