Hey all. A few months back I began work on re contouring the floor pan of one of may cars make if more comfortible to me and my anatomy (Tall person problems).
The issue I am running into is the floor of the car is composed of x2 pieces of metal pressed together with some sort of adhesive. When I begin welding in my new metal the top level of metal will form a nice puddle (TIG welder, #17, 3/32nd, 14lbs/min, 100% argon, 35 AMPs, DC) and then blows through the top layer of metlal in the perfect shape of the puddle I just made. My guess is it is air pushing up through the metal when it becomes soft.
I tried to lower the amps, but then there is not enough heat to generate a puddle. Just for giggles I hooked up the asp and the stick welder and achieved very quickly the same blow through effect.
I consider myself a good welder and have done many successful welding projects for several years. I am a little stumped here...
Anyone have any thoughts?
Spray bottle or wet rag to quickly cool puddle. Is the adhesive volcanoing your puddle?
TRoglodyte wrote:
Spray bottle or wet rag to quickly cool puddle. Is the adhesive volcanoing your puddle?
Yes. The puddle pops before I can add any filler rod.
Adhesive is a problem, since it is already there have you considered gluing the new piece in? Some amazing adhesives are available today.
TRoglodyte wrote:
Adhesive is a problem, since it is already there have you considered gluing the new piece in? Some amazing adhesives are available today.
I would consider that if it is an option. The problem Is I am re contouring the floor plan to mount the stock seats directly to the floor. The other thing I was going to consider doing is using a large piece of filler rod (1/8") in between the weld surfaces and get it just hot enough to puddle to the floor. Hopefully keep the adhesive cool enough to not blow through... Just a thought.
So... I think I found a solution. Despite have a ton of $$$ into my TIG welder E6011 2.4mm stick welder set to 25A AC seems to work well. I hate that it is a "dirty" looking weld. but it will work. I will just need to take the time to clean it up with a die grinder afterward.
Crazy how sometimes an old and simple way of doing things just works.
The flux in the 6011 was able to cope with the contamination from the adhesive. Nothing sticks dirty, oily, rusty steel back together better than E6011.
You might also consider brazing it. The lower temps might keep the steel from blowing out.
Yes, brazing.
Take something that should be welded and add enough copper to it that welding becomes impossible.
If the blowthrough is contaminating arc welding it will sure as hell contaminate brazing.
Brazing is considerably less tolerant of dirt and poor fit than welding.
In reply to Trans_Maro:
The last brazing I did involved no copper and was a set of floor pans on a VW Bug. Pretty sure the filler was 7018 rods and a coat hanger. That was before I owned a MIG welder, 10 years ago, but the Bug is still on the road.
Lucky for me, none of the cars I own are glued together. 
In reply to Toyman01:
That's called gas welding.
