Page 1 of 1

New to TIG - Auto Body Panels, the correct approach ?

Posted: Tue Apr 24, 2018 4:15 am
by sparklyman
Hi All,

New to the forum and "self-taught" in TIG, so seeking guidance on the best way to approach various tasks.

I'm able to wled Carbon Steel OK, have welded a SS tube OK (no backing gas though) and finally managed to get an Aluminium box together, however all welds are not pretty and required a lot of cleanup afterwards so I'm obviously lacking technique that proper tutoring may have brought !

I'm heavily involved in the restoration of a 1959 Pontiac and am approaching the time where I need to start on a few repair panels etc. I had thought about MIG, primarily as it avoids the need to manually apply filler rod, however it's probably wiser for me to stick with TIG, developer my skills and spend the extra money on Argon, rather than a new MIG machine.

I watched countless videos on butt welding thin sheet, but there appears to be various approaches, so I#'m seeking guidance on the correct way to proceed

In relation to repair patches and panel work, should I be considering;

a) Welding or Brazing ?
b) If welding, autogenous or filler rod ?

I get the impression brazing may be easier as your not meting base metal, therefore distortion may be reduced. I am assuming you do not need the structural integrity of a weld on a 18-19Ga body panel ? (I've found the 1959 panels are heavier gauge than todays vehicles) - remember also, this is a body on frame vehicle, not a structural unibody.

I have tried autogenous approach on 18Ga using pulse and get some very good looking results, but find penetration an issue. Winding up peak current or peak on-time gets the penetration but the welds end up a lot messier and I start getting blow-throughs more regularly. Generally, unsure if autogenous is good enough for panel repairs ?

Hence, was wondering if I should not get some practice time in on brazing as the correct approach for this work ?

Can anybody offer some concise guidance please ?

Regards
WIll

Re: New to TIG - Auto Body Panels, the correct approach ?

Posted: Tue Apr 24, 2018 4:30 pm
by cj737
MOG is much easier, but TIG works great. You might try a filler rod of Silicon Bronze TIG rod. It’s brazing, reduces warpage, less heat, and softer so cleanuo is easier ;)

A really tight arc is critical for heat control. I mean just barely above the puddle. The farther you are away, the more heat you’re putting into the metal. Also, a larger cup 7-8 with a gas lens makes things much easier. Remember, all metal (both sides) must be shiny clean for TIG.

Re: New to TIG - Auto Body Panels, the correct approach ?

Posted: Tue Apr 24, 2018 8:10 pm
by Mike Westbrook
I've done quite a bit of body repair honestly all processes make to much heat and you get warpage even spot welds if done in a row will warp gas brazing seems way too hot and I've found mig welding the whole seem is a nightmare to grind cause the weld will be much harder than the sheet metal I've had some success with Tig no filler but its only ideal for all new construction like we're two new panels meet usually I find it best to drill and alternate spot welds a couple inches apart work back and forth use .23/24/25 size wire so the spot fills slowly and you get good penetration then grind the spots most all vehicles are built with spot welds just remember lots of clamps if a clamp won't fit run a drill screw in some of the drilled spot welds you can buy an air tool that will punch 1/4 inch holes and press an overlap on edges Image

Sent from my XT1254 using Tapatalk

Re: New to TIG - Auto Body Panels, the correct approach ?

Posted: Thu Apr 26, 2018 3:53 pm
by sparklyman
Thanks for the input.

Currently fabricating new 18GA trunk drop offs. Originals were quite complex pressings to the extent that I'm having to make them in two pieces. These will be welded, but I think i'll get some Silicon Bronze rods ordered and start practising brazing for when I start on the various repair panels required.

So you find autogenous only works on new steel ? This is good information, probably saved me from finding out the hard way. I could have zeroed in on settings and technique on the bench with new steel, only to find problems when attempting repair on the the old 59' body

Re: New to TIG - Auto Body Panels, the correct approach ?

Posted: Thu Apr 26, 2018 4:00 pm
by Mike Westbrook
sparklyman wrote:Thanks for the input.

Currently fabricating new 18GA trunk drop offs. Originals were quite complex pressings to the extent that I'm having to make them in two pieces. These will be welded, but I think i'll get some Silicon Bronze rods ordered and start practising brazing for when I start on the various repair panels required.

So you find autogenous only works on new steel ? This is good information, probably saved me from finding out the hard way. I could have zeroed in on settings and technique on the bench with new steel, only to find problems when attempting repair on the the old 59' body
Yeh seems you can never get all the old crud off of car body's alot of them were actually galv dipped and that stuff soaks in just try different methods on scrap in the position your final repairs will be and see what works also if it's possible make your lower panels go over your uppers so water can't get trapped behind them in the pocket it would create then any filler will seal on the outside caulk prime and paint anything you can get to

Sent from my XT1254 using Tapatalk

Re: New to TIG - Auto Body Panels, the correct approach ?

Posted: Thu Apr 26, 2018 4:28 pm
by cj737
If you are going to use your TIG with SilBr, just make sure you get SilBr TIG wire, not brazing rods.