MIG welded mild steel chassis ??

[Mr Froggy]

Hi Guys, I'm new here and enjoy the sight!  I've always loved Rails and after years of racing door slammers and just turning 50 I figured If I'm gonna do it there's no time like the present.

I'm a good welder and fabricator but have just started TIG welding.  That being said my plan is to build a simple, single carbed dragster to start with.  Will most tracks allow a mild steel Mig welded chassis?  I see the SFI 2.6A is for 7.99 and slower but I imagine that requires a TIG welded Moly chassis.  My thought is that if I keep it under 10 seconds I should be fine and if I did go faster than the 10s I'd want a Moly chassis anyway.

Thanks for your input.

[masracingtd1167]

I would have to say if you are going to build it why not use chrome moly . It is lighter because of the wall thickness and a whole lot safer . if you are good at mig welding I am shure you can be a good tig welder . Now get to work on that car!

[225digger]

10 seconds or less dont require a chassis cert . so as long as it meets the SFI specs you should be good to go  .....

[wideopen231]

IMO molly only way to go.Little more cost. As said you run thinner wall thickness, saves weight,safer,can get cert if want  to go faster later,better resale value. If no comfortable with your welding tack it together and have some one else do final welding..Most specs stop and back of motor plate or divers compartment on a RED. So after that you can pretty much do what you want.

[Mr Froggy]

Is it ok to tack weld Moly with a MIG? 

I have a friend that works maintenance at a food plant and thats about all he does is TIG.  He has told me that he would help me out while I'm learning to TIG.  If I'm not confident enough then I could have him finish weld it.

[225digger]

if you have a tig just tack it with that ..... if you have your joints nice and tight just set your amps at like 100 get the point of your tungsten close to the joint and just floor the pedal it will "fuse" the joint thus creating a tack weld ....... i know its probably not the preffered way to do it . but its the way i do it and i never had an issue doing it this way  ..... then you can come over it with filler with no issues .....