Roll cage welding issues

[BELLBOYMOTORSPORTS]

I'm having an issue with welding the base plates to the floor of the vehicle. I'm TIG welding the whole cage and when I try to weld the 1/8th in plates to the floor I'm getting some sort of blowback that extremely contaminates my tungsten. My question is, is this caused by body filler that is still trapped between floor panels and if so what is the best most effective way to remedy this problem. Any form of dip or blasting are not really an option. Any help would be appreciated.

[eecervantes83]

Bolt it down

[H80N]

You need to have clean shiny metal back about 2 inches from the weld area...

TIG is very intolerant of unclean metal..

can you post some pics..??

[Cgotto6]

I prefer to mig the base plates to the tub when I do cages, it tends to have less contamination issues. Does the governing body mandate tig?

[bigtow30t]

I always thought that they were to be bolted down. The base plate has to be a certain Sq in also, then the backing plate Needs to be a different size (bigger or smaller) or it would sheer right through the floor board

[BELLBOYMOTORSPORTS]

Roll cage welding issues

Governing body dosent care but my boss wants it welded preferably TIG. The problem mainly occurs where panels overlap and are spot welded together trapping whatever seam sealer the manufacturer used between the panels. I ended up pulse miging the plates to the floor. Just not overly fond of pulse mig as I consider myself a TIG welder when it comes to most automotive stuff. Base plates must be 2sq in at min. and 6sq in at max. per nasa spec

[Cgotto6]

I always thought that they were to be bolted down. The base plate has to be a certain Sq in also, then the backing plate Needs to be a different size (bigger or smaller) or it would sheer right through the floor board

Welding in is by far preferred by most sanctioning bodies, given the welds are proper. There is square area requirements for base plates, these vary between sanctioning bodies, and specs vary if it's bolt in or weld in in certain cases. Look at any professtional racecar, you will not see a bolted in cage unless it's a car with an aluminum frame or similar weird constraints. Virtually every aspect of cage specs are spelled out in the sanctioning bodies handbook. There is no hard cut rules that can be applied across the spectrum either, what's normal in nhra may have no or even conflicting rules in nasa, or SCCA, or stock car....you gotta build it for where it's gonna get used.

[H80N]

I prefer to mig the base plates to the tub when I do cages, it tends to have less contamination issues. Does the governing body mandate tig?

Makes perfect sense.. you could MIG the baseplates to the car tub and TIG the tubes to the plates and to each other..

Are you cutting holes through the plates so you can drop the cage down to weld all the way around... then raising the cage all the way up into position to final weld..??

Like this..

http://www.youtube.com/watch?v=uxUIx3vZfRA

[BELLBOYMOTORSPORTS]

Are you cutting holes through the plates so you can drop the cage down to weld all the way around... then raising the cage all the way up into position to final weld..??

Like this..

http://www.youtube.com/watch?v=uxUIx3vZfRA[/QUOTE]

It's actually a 4 point roll bar in a old Porsche, was able to completely remove and weld outside the car and reinstall, however this is the second time I have had this issue with 2 different vehicles. So I was just hoping to get a little advice. I do appreciate all the advice I have gotten

[H80N]

Porsches and other German stuff are liberally shot full of and coated with "Body Schutz" ..... murder to remove and stinky when heated..
have run into that many times...

We were lucky enough in the 70s and early 80s while working on Porsche 934 & 935 racers.. that we got tubs that were "body in white" with none of that rubbery urethane coating...

[spence648]

Is it happening when u were finishing the last weld? It could be the air trapped between the 2.. and when you try to seal it up the trapped air is blowing a hole out onto your tungsten. . If its happening right away.. it is probably just dirty

[BELLBOYMOTORSPORTS]

Roll cage welding issues

It's happening at random so I believe it is the body seam filler. It has done it on the 2 2015 project cars I have caged as well as the mid to early 80's Porsche I just did. The only consistent thing is that I was not the person who was tasked to clean the cars just welding the cage at which point there is only so much I could do but any more cages will fall strictly on me this time so I would like to save my self the heartache and clean the **** out of the cars. Thanks for the info.

[Nathan128]

Roll cage welding issues

Could the steal be galvanized? Or some sort of zinc coating under paint? Cuz galv/ zinc really makes a mess of the tungsten.

[BELLBOYMOTORSPORTS]

Roll cage welding issues

I've TIG welded galv. before it's not like that I honestly think it's the sealant the manufacture used that I didn't/ couldn't get out from between the panels

[H80N]

Any chance of posting some pics..??

what model and age Porsche??

BTW..newer models of VW/Porsche Audi do have some galvanized panels... As well as LOTS of body/seam sealant & shutz....