Roll cage welding

We had a customer come in to have us tig weld his chrome moly cage kit he tacked in with a mig. His top bars were tight against the roof. I told him we would have to cut the lower bars loose to lower the cage to weld the top of the cage. He told us that was not needed and that NHRA doesn't require the cage to be welded all the way around. My first reaction was WHAT??? That was a first for me and not what I would consider safe or proper. I tried to reason with him and eventually declined to do the job and sent the disgruntled customer on his way. Has anyone ever heard of this? How can that possibly be legal? Even if it's legal I will not let any job leave this shop in a condition I feel is unsafe or not up to our standards.

He is correct... but you need to add gusset plates
but there is a percentage that has to be welded

I would have said you were dead wrong P.... that's interesting, but I agree with the OP.

Well us old guy's learn something every day...lol. As tight as the pipes were to the roof I don't think we could've got the percentage needed. I believe we will continue to do fully welded cages and add gussets as needed. Thanks for the reply Mr.P!!!

Not that we'd ever do it do you know what the percentage is? Just for me to store some more useless information. lol...

I dont know for fact but I think its 75%-80% but
I agree.. I drop the cage and fully weld them..
you would have to ask a chassis inspector for the answer

It's in the SFI spec!! Don't have my spec handy.

Mike is right.

Per the SFI 25.5 Specs. Section 2, point 5,

Where it is not practical to fully weld the windshield/roof bar (#12A & 12 B) and or the main hoop (#10) to their adjacent structure (ie: where the weld is in close proximity to the OEM roof), the use of two 1.75 x 1.75 x .110 plate gussets per affected joint is allowed to replace up to 25% of the weld. Each plate gusset must be fully welded on one side. Two fully welded tube gussets per affected joint, 3/4 x .049 moly or 3/4 x .108 mild steel, a minimum of 4" long may also be used. This option is applicable, only to welds in the OEM roof area.

I'm sure if it's good for a 25.5 cert, it would be good for any random 12 point cage of a lesser spec.

Rulebook says:

two 1.75 x 1.75 x .110" or .75 x 4"min. x .049 CM gussets may be used to replace up to 25% of the weld.

That's for 8.50 and slower. The SFI specs may allow something similar but I couldn't find it in a quick search of the book. Regardless, I would NOT do one like this. Nor would I touch something that the design of was not safe and proper IMO. That's just me and the OP is within his rights to not compromise his standards to satisfy a customer who's standards are not as strict. It's your name on it.


ETA, boy, I'm a slow typist.

He's well in his right, if he's not confortable. The way I look at it is, If the NHRA and SFI Foundation accept it as a rule, I do not see a problem with. And, I'd have to think there's been plenty of destructive testing by the governing bodies, to come to the rules as written. I'm going to have to do it on my own car in the near future, as I will be finishing a cage from an existing roll bar and I want the roof bars tight to the OEM roof.

I was talking with a guy in the staging lanes a couple of weeks ago that I noted had recently added a bar to his car, a Dart, that has a real nice interior. I specifically asked about the upper welds and the headliner. His answer was simple, yet brilliant. He cut holes in the floor where the plates were to be welded in, dropped the bar through the holes to give room to weld the upper section of the rear supports to the main hoop, then raised it back up and slid in the mounting plates and made those welds. He then replaced the holes in the floor under the plates, tacking them and filling with seamseal adhesive.

This may be an old trick, but I hadn't thought of it nor ever heard of anyone using it; and it allowed him to get the bar tight to the roof and fully welded without even removing the headliner.

Thats what most of us do

I took my roof off

That's what I suggested. He didn't want any holes in the floor. My background from years ago was circle track and sprint cars. Not welding the tubing totally would not fly. They tend to spend more time on their roof that the street and drag cars we do now...lol. We will continue to supply totally welded cages for safety of our clients and so I can sleep at nights. Thanks for the reply's guy's and I will keep this info. in my notebook even if I never use it.

i never could understand why the upper most part of the joint was allowed to be not welded [even using gussets] yet a perfectly good set of seat belts need replaced every two years if they are three inches wide. meanwhile, a 45 year old factory lap belt is ok to use in certain classes. i guess it's the golden rule : "he with the gold rules".

I remember reading something about welds not being complete and adding gussets, just can't remember where. I just went through my 25.4 book, and there is absolutely nothing that says anything about that. I guess that means that it is NOT acceptable in the faster classes. If I had a full interior car and there was an option to fully weld the cage without gutting the car, I would pay the extra for it.

Charging extra???hmmm... now there's a thought...lol.

4 holes in the floor(where you would be welding
the plates in) is the easiest way to do it.. no clue
why he didnt want to

One thing I've learned is you can't please everyone. We try to please the other 99%.

Holes in the floor under the plates, and even if they're not, can be welded, ground up and made invisible. I cut a pie shaped area on two sides, fold it down, and when finished on top, fold it back up against the plate, weld and grind it. Dust it with primer. Can't tell it was done.

25.x cages with a lot of bars and a funny car cage? Just take the roof off.

Where in the heck did you find 99% of the people that are remotely easy to please? lol Beep

Dumb luck!!!lol

Like I said in the beginning.. it doesnt have to be
100% welded... do I like that .. NO.. but some dont
want to hear what the rules say... all I tried to do
was say the facts

My thinking is to remove the roof during construction and put it back on when done No compromizing