Re: What is the proper way to weld a roll cage in a car?
[Re: Medlock51]
#2839172
10/30/20 09:06 AM
10/30/20 09:06 AM
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Joined: Jan 2003
Posts: 24,562 Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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I can tell you that there are thousands of oval track cars that are built using CM and were MIG welded. While we don't generally run much over 125 mph or so (except on a mile track where straightaway speeds can reach 175 mph or higher...and big miles are few) most racing sanctions require a .063 minimum wall thickness on the main cage and supports. The main frame rails on my older chassis are .049 and my newer car are .083.
Kinda funny that the lower class cars generally must run .083/.095 tubing for their cages.
Not trying to argue with anyone just sharing my experience. We have to run 1.75 DOM in our car.
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Re: What is the proper way to weld a roll cage in a car?
[Re: Medlock51]
#2839459
10/30/20 09:00 PM
10/30/20 09:00 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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I can tell you that there are thousands of oval track cars that are built using CM and were MIG welded. While we don't generally run much over 125 mph or so (except on a mile track where straightaway speeds can reach 175 mph or higher...and big miles are few) most racing sanctions require a .063 minimum wall thickness on the main cage and supports. The main frame rails on my older chassis are .049 and my newer car are .083.
Kinda funny that the lower class cars generally must run .083/.095 tubing for their cages.
Not trying to argue with anyone just sharing my experience. Don't worry, we are all adults here on this forum. That said, I am not a big believer in speed as a useful indicator of what are the best materials or design. In that all concrete is fairly consistently hard, and #3 Dale died hitting concrete at an effective closing speed of approx 43mph.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: What is the proper way to weld a roll cage in a car?
[Re: cudaman1969]
#2839686
10/31/20 11:31 AM
10/31/20 11:31 AM
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Joined: Nov 2013
Posts: 700 Southern Alberta
Uberpube
super stock
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super stock
Joined: Nov 2013
Posts: 700
Southern Alberta
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I built 2 dom steel cages 15 years ago for a guy, welding method wasn't specified in their rule book, the only method I knew back then, was Stick welding with root and cap, the mig I had back then wasn't beefy enough.. I did a gapped fit up with a 6010 root, and then a 7018 cover pass. The guy ended up hitting a large tree with one of the cars at high speed in passenger side frontal impact. None of the welds gave, the tubing bent and the frame rail sections ripped out of the unibody in places. The driver and navigator walked away from the crash. Weld porosity is a big problem with stick welding, done wrong, its weak, done right, really strong. We use it a lot in plant construction, but we also have to do 10% xray on joints. Porosity is pretty much non existent with tig, but can have shallow penetration and be a very pretty, but weak weld. Easy to undercut the joint with too. When I do my cage for my next track car, I'm probably going to do a tig root and Mig cover pass. I don't build cages for people anymore with all the liability stuff...
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Re: What is the proper way to weld a roll cage in a car?
[Re: AndyF]
#2839845
10/31/20 06:22 PM
10/31/20 06:22 PM
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Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
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You have to plan the job and how it's going to be put together. Some of it may be partially welded and pulled out of the car to finish. And/or it may be dropped through the floor. Or, like a lot of cars with funny car cages, etc., cut the roof off.
The chassis serves two purposes. Protect the driver and be the main structure of the car supporting the suspension with the desired rigidity.
The rulebook spells out minimum requirements. They are seldom sufficient to do both jobs well without adding to it and improving on it.
If the results don't match the theory, change the theory.
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Re: What is the proper way to weld a roll cage in a car?
[Re: migsBIG]
#2841190
11/03/20 11:34 AM
11/03/20 11:34 AM
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Joined: Nov 2009
Posts: 3,082 St. Paul , Mn.
tubtar
master
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master
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
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I used Art Morrison for my 10 point kit in my Dart. I used a Competition Engineering kit for the 6 point I had in our last car. And if I do another , I will have learned enough to do it better than the last one. Hindsight tells me I should have gone through the dash and created much more room to get in and out of the car. But if I did go that way , I would seriously consider an experienced fabricator to do the job for me. My welds are Dog's Butt ugly , but I trust them. I use mild steel so I can MIG it , but the tight quarters and awkward positions required were much less of a problem , even in my 40's. That was twenty years ago. It's not the place to learn to weld , that is for sure. And you can save a lot of money by mocking it up and doing the fitting your self if you are going to have it welded by a pro. The guys I use for stuff I can't do are around 100.00 an hour and well worth it. And the fitting is the time consuming part of the project.
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Re: What is the proper way to weld a roll cage in a car?
[Re: migsBIG]
#2841220
11/03/20 12:28 PM
11/03/20 12:28 PM
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Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
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Thank you everyone! The information I received here was incredible. I never would have though up all this stuff. Even though one car would be more of a 'cosmetic' thing, I am going to completely rethink what I really need in a cage and see what fits my needs. I am starting out with the worst possible car bodies with this build (burned b-bodies) but enjoy the challenge of something different. I'll see about checking out pre-bent cages, a professional fabricator that could adjust/modify the cage to accommodate my needs. I'm thinking of going to Chris Alston's Chassisworks and see what I could use for each car (they are a short drive for me). Skimping on safety was not my intention. Finding a way to come up with the extra cash is far more easier than the added materials/work required for the job. Thank you for your info everybody, I feel this has enlightened me to a better understanding to my needs for this build. Burned? As in on fire? Bad? Not a good choice for so many reasons. A professional is not going to use a kit. Most won't anyways. They prefer to do it their way. Kits are for guys who have some fabrication skills but no bending equipment.
If the results don't match the theory, change the theory.
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Re: What is the proper way to weld a roll cage in a car?
[Re: CMcAllister]
#2841663
11/04/20 12:49 PM
11/04/20 12:49 PM
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Joined: Jan 2003
Posts: 21,645 San Jose,CA
migsBIG
OP
YouTube is my go-to news source
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OP
YouTube is my go-to news source
Joined: Jan 2003
Posts: 21,645
San Jose,CA
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Thank you everyone! The information I received here was incredible. I never would have though up all this stuff. Even though one car would be more of a 'cosmetic' thing, I am going to completely rethink what I really need in a cage and see what fits my needs. I am starting out with the worst possible car bodies with this build (burned b-bodies) but enjoy the challenge of something different. I'll see about checking out pre-bent cages, a professional fabricator that could adjust/modify the cage to accommodate my needs. I'm thinking of going to Chris Alston's Chassisworks and see what I could use for each car (they are a short drive for me). Skimping on safety was not my intention. Finding a way to come up with the extra cash is far more easier than the added materials/work required for the job. Thank you for your info everybody, I feel this has enlightened me to a better understanding to my needs for this build. Burned? As in on fire? Bad? Not a good choice for so many reasons. A professional is not going to use a kit. Most won't anyways. They prefer to do it their way. Kits are for guys who have some fabrication skills but no bending equipment. Well, it will be lighter. Like I said, these will not be typical cars. One for track use, one for street strip. If worse case happens, I can always just move onto another shell.
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