Approved MIG process????

Looking at the NHRA rule book on cages and it mentions that the welds have to be done with an approved mig or tig process but I can't find what the process is in the rule book. Can someone point me to the spec for this "process"?

You can only use mig for mounting brackets and such. Any welds done to the structure will have to be done with TIG.

I have built several chassis that needed to be certified all the way down to 6.0 moly stuff with tig and or mig.

Never been challenged for any kind of ticket or documentation on the welds.

I think this is a typical blanket cya statement inserted in the book to allow NHRA to absolve themselves of any responsibillity as far as the welder or his equipment etc. etc.

Mild steel chassis you can use mig anywhere.

Chromeoly has to be Tig on everything critical as stated.

As far as I know they dont even xray anything on top fuel cars.

dkp

Ok, Does the mig have to be shielded gas or gasless? Thats what I can't find. I have had my mig for years and used the snot out of it, but just haven't bitten the bullet and got gas yet.

gas is cleaner. I used mig on all my welds on my '88 cert. 8:50 the inspector asked that I gussett the corners to pass

Flux Core arc welding and Metal Inert Gas welding although done with the same machine are really not.

Don't bother with flux core unless you're patching up a busted plow or something. Without the gas, it's not MIG. Get a bottle and be amazed at how much better your welds turn out.

Yea, I've been wanting to switch to gas instead of flux core, but the flux core was working, so I spent the money on other stuff. Looks like this is the excuse I've been needing to make the switch.

the thing about tig welding vs mig is directed at 4130 steel. 4130 or "chromoly" should be tig welded to control the heat put into it as you weld. it dont like too much heat or it'll get brittle. i dont like to tig but i've been learning with my new build,lol. i learned the wire in a mig is the same er70 as the tig rod. get you some gas for your mig and you'll see that your a better welder than you think.

Curt wrote:You can only use mig for mounting brackets and such. Any welds done to the structure will have to be done with TIG.

you can weld the joints with mig also as long as its mild steel.....


id use gas though.

one thing about flux core if you don't get every bit of flux off the weld when you paint it it will flake off then when they see that they will with the gas you want have the flux problem to worry about.

HorsinAround wrote:Looking at the NHRA rule book on cages and it mentions that the welds have to be done with an approved mig or tig process but I can't find what the process is in the rule book. Can someone point me to the spec for this "process"?

When they talk about the Mig/Tig "process" they are referring to using only these types of welding procedures, (metal inert gas/tungsen inert gas) and no other types/forms of "welding" (like stick welding, or oxy/acetylene gas welding, brazing, or soldering, etc, etc). And that 'moly tubing can only be Tig welded, mild steel can be either Tig or Mig welded.

Since the NHRA rule book & the SFI books use the term "MIG" (metal inert gas, aka "GMAW" - gas metal arc welding) I have always assumed they wanted only solid core wire + a shielding gas when Mig welding. In my opinion if they had included the term "FCAW" (flux cored arc welding) in the rule/SFI books then using flux core wire would be acceptable (but again thats just my opinion).

For Mig welding ms tubing I prefer an E70S-6 wire (strong ms Mig wire) & straight co2 gas (deeper heat penetration than co2/argon mix) For Tig welding both 'moly and/or mild steel I like the ER70S2 flagged/certified filler rod & straight Argon gas.

Thanks for the information. I stopped by the local weld shop and got a tank, regulator and a 2lb roll of solid wire and a refill for my acetylene tank. Shot the crap out of my roll cage budget for this month, but should be worth the wait. Now, I just have to get some scraps out and relearn welding and the settings for different thicknesses.

How big is the Mig machine & what OD solid wire are you using?

It is a 220v/150a and the manual mentions .023 and .030 for solid wire and .035 for flux core. I bought .030 wire to use, but thought about trying a 2lb roll of .035 just to see what happens.

Just laid my first welds with gas. Wow, s'all I can say. I don't know why I waited so long to switch..

HorsinAround wrote:It is a 220v/150a and the manual mentions .023 and .030 for solid wire and .035 for flux core. I bought .030 wire to use, but thought about trying a 2lb roll of .035 just to see what happens.

For Mig I use .035" solid wire probably 90-95% of the time. I did get some thinner Mig wire for sheetmetal work, but hardly ever use it since Tig is usually easier to do sheetmetal with anyway.

Yea I wanted to go with .035 wire but since my owners manual only mentioned .023 and .035 for solid wire, I didn't know if there was a reason it didn't mention .035 solid. It does mention .035 flux, so the rollers are set up to handle that diameter, and the unit has enough amperage for .035 I think.

Yep,.....

Once you use gas & solid wire, you'll never go back to the flux core stuff.


I use .023 mainly on exhaust work and .035 for anything else.