NHRA Welding rules??

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mechanic190

mechanic190

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Well I am not a welder just to clarify. I have been trying to do the welding on my dart myself. (at least I am giving her a go). I cut out my rusty drivers side floor pan and welded in a new one, not the best job but once again at least I tried. After the floor pan I decided to install my own 2 x 3 frame connectors through the floor. So far I have just the drivers side most of the way done just needs some more floor patching. My welds do not look the best, are these welds gonna make me fail tech when I finally get her going down the track? Future plans for welding are motor plate mounts, driveshaft loop, 6 pt minimum roll cage, and more body work. I know the cage will fail me but do they really inspect frame connector and floorboard welds that close?
 
Bad welds on a cage will fail inspection for sure (but you need to get to the point of needing the cage first).

Bad structural welds can kill you.
 
Well I am stitch welding the floor back in and to the frame connector, not too worried there. I put a 3 x 3 plate on the torsion bar cross member first and started welding it there and forgot to turn on the gas. So what should I do there now? I am not real confident mostly due to lack of exp with welding. And also where I cut the rear frame rail open I opened it up to far and the 2 x 3 tubing does not fit tight, How do I go about closing the gaps maybe 1/8 to 1/4 inch wide? Also cleaned the holes further back in the original frame and welded connector there also
 
In 30 yrs of racing in Vegas, I have never had a tech inspector look at a weld......Do you feel your welds are safe?...

Are going to to have the Cage certified? or are you just installing a roll bar?
 
mechanic190 said:
And also where I cut the rear frame rail open I opened it up to far and the 2 x 3 tubing does not fit tight, How do I go about closing the gaps maybe 1/8 to 1/4 inch wide? Also cleaned the holes further back in the original frame and welded connector there also
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If the gap is too big...take some 1/8 flat plate, cut a piece to fit over the gap ..welding it to the tubing and frame rail.....make a template using cardboard or construction paper...
 
First of all, don't practice on your project. Use scrap metal. Make sure all pieces are very clean. Weld all different types of joints, at all sorts of angles. Check out some welding forums like Miller welds or other non-sponsored ones, and you can ask general questions there. Treat every weld like its gonna be the best weld you will ever lay down. Don't think "nobody will see it, so it doesn't matter".

I tech cars at my local track, and we don't ofter check frame connector welds and such, unless it is a quick car, or maybe if there is a roll cage and it's tied into the connectors (recommended).

The best advice I can give you though is don't be afraid to ask a pro for help or lessons, it's ok if you're not good at it, it is better to admit now rather than hurt yourself later.
 
This is what nhra rule book says about welding on roll bars and cages...

All 4130 chromoly tube welding must be done by
approved TIG heliarc process; mild steel welding must be done by
approved MIG wire feed or approved TIG heliarc process. Welding
must be free of slag and porosity. Any grinding of welds prohibited.

yeah..nobody ever grinds welds....lol
 
70aarcuda said:
This is what nhra rule book says about welding on roll bars and cages...

All 4130 chromoly tube welding must be done by
approved TIG heliarc process; mild steel welding must be done by
approved MIG wire feed or approved TIG heliarc process. Welding
must be free of slag and porosity. Any grinding of welds prohibited.

yeah..nobody ever grinds welds....lol
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I've never ground a cage weld. There are a few tech guys around here that are pretty sticky, especially our local chassis inspector. Weld quality and 360 degree welds are the first thing he looks for. Kinda like a robot lol.
 
I'll see if I can get some good pictures of the welds I'm questioning this weekend if I get a chance to work on it. Then you guys could give me some pointers and ideas. Right now I'm thinking about grinding it down as far as I can get and try again on one weld that I forgot to turn the gas on. Otherwise I think it'll hold
 
No offense but learn to weld or take it to someone. Your wasting your time right now. If you cant weld and you can tell its not right, its not going to hold. As stated get scrap, clean it to bare steel, then weld. set the pressure to 30psi flowing (left gauge) and start practicing.

Tony when we had our chassis certed for 8.50 on the landy dart they didn't X ray it but they did due a ton of tube thickness measurements. I thought X ray was only on Chrome moly tube.
 
I have seen some horrific welding that passes tech. As Tony has mentioned they don't look at the welds.

There is a guy at Barona, Chevy Hack...... He brags that he built his car all by himself. The whole front end clip was built by him, cage etc. I tell you what that car is some scary ****, total junk work.... Worst I have ever seen in my life. All of the welds look like Vulture ****. Cage is certed to 7.50 tagged and all.

It has a Twin Turbo SBC in it that runs like crap. I have never seen it make a clean pass. It does the same thing right out of the hole. Spit, pop , crack and engine breaks up every single time.
 
Mad Dart said:
look like Vulture ****. .
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Can you post some photos, 'cause I have no idea what that looks like, LMFAO

0511-1005-2214-0249_Cartoon_vulture_or_buzzard_snickering_while_sitting_on_a_tree_branch_clipart_image.jpg
 
Scrap is a good way to practice,but I learned a lot by doing. Other than the rollcage, if you make a mistake, that's what a grinder is for, then weld it again.
 
Mad Dart said:
I have seen some horrific welding that passes tech. As Tony has mentioned they don't look at the welds.

All of the welds look like Vulture ****. Cage is certed to 7.50 tagged and all.
Click to expand...


Ha!

I've seen another 7.50 cert car that the funny cage welds looked like a chicken shitting molten metal. Giant polyps comparable to the worst looking colonoscopy! If a CM bar could have giant warts, this cage had them. Even had slaggy looking junk inches away from any joint.

OP... If you are using mig, I hope it's at least a 175 class machine.
 
crackedback said:
Ha!

I've seen another 7.50 cert car that the funny cage welds looked like a chicken shitting molten metal. Giant polyps comparable to the worst looking colonoscopy! If a CM bar could have giant warts, this cage had them. Even had slaggy looking junk inches away from any joint.

OP... If you are using mig, I hope it's at least a 175 class machine.
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Yeah when I did mine there are 2 spots where the tungsten was contaminated and messed up the weld a bit. I fixed both and then I made 2 more passes on both sides of the original weld. If my cage comes apart, they may as well bury me in the car! Cause it will be a mess.
 
When they say no grinding on a cage..... They mean there better not be any marks from doing it!!. Do it clean and how would anybody ever know?
 
Mad Dart said:
When they say no grinding on a cage..... They mean there better not be any marks from doing it!!. Do it clean and how would anybody ever know?
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The "no grinding" on the cage is a bit difficult in the real world.

What if you run out of gas mid pass or have a blast of wind interrupting shielding gas and get cupcakes for a small area. Since you can't grind, how do you fix that? Glob more material over the top? Take both bars out and start over? Neither of those are acceptable solutions.

I grind that stuff out and start over. Don't use a 7" grinder to do it! :)
 
I'm probably late on the trigger, I spent 36 years as welding engineer and certified inspector. If you forgot the gas most likely the welds suffer from a lot of porosity. The solution is to grind them out and re-weld them. Of course it's your life, you get just blow it off too. Use a dye grinder to clean out the welds and ere-weld.
 
crackedback said:
The "no grinding" on the cage is a bit difficult in the real world.

What if you run out of gas mid pass or have a blast of wind interrupting shielding gas and get cupcakes for a small area. Since you can't grind, how do you fix that? Glob more material over the top? Take both bars out and start over? Neither of those are acceptable solutions.

I grind that stuff out and start over. Don't use a 7" grinder to do it! :)
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I hear you all day long!
 
the no grind is in reference to trying to pretty up the weld and smoth out the welds for a finished look.
you cand grind the welds all you want to make a reweld for good penetration or a weld that has craters in it from contamination on the material. allways clean the surface to be welded with a flap disc on a angle grinder. all roll bar material has a mill scale on it that needs to be removed. also use something to clean any oil off the metal.

DO NOT I REPEAT DO NOT USE BRAKE CLEAN to clean the meterial to be welded !!!!!!!!
 
mopwr2004a said:
the no grind is in reference to trying to pretty up the weld and smoth out the welds for a finished look.
you cand grind the welds all you want to make a reweld for good penetration or a weld that has craters in it from contamination on the material. allways clean the surface to be welded with a flap disc on a angle grinder. all roll bar material has a mill scale on it that needs to be removed. also use something to clean any oil off the metal.

DO NOT I REPEAT DO NOT USE BRAKE CLEAN to clean the meterial to be welded !!!!!!!!
Click to expand...

The man is right. Clorinated brake cleaners produce poison phosgene gas when heated.

http://www2.worksafebc.com/i/posters/2013/ws_13_09.html
 
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