Xgenturbo

Well my smiley still works great and I'm slowly learning how to run good beads on MS and SS. I am having problems welding exhaust piping, its aluminized/galvanized and while welding with the MS filler rod I keep getting porousity at the end of every bead I run.

I keep the welder positioned after the flame out so the gas soaks the spot and I still get it. its no biggie but looks like ----.

Just wondering what type of materials I can use as a filler rod for this type of metal.

gon3r

martin, are you dragging the puddle and following it with the filler, or pushing the puddle and leading it with the filler? you might have better results with pushing the puddle. what cfm is your argon at? i've used 70s-2 with the aluminized stuff and it worked fine, but you do get some contamination from the coating. i'd rather just go with ss though.

Xgenturbo

I push the puddle and fill in front. I guess it might be the coating, I know on SS these smiley tig welds look a lot better. my CFM is at 17 usually with a size 5 nozzle.

Its no big deal its just for my dump tube. I'll grind the welds down and paint with high heat coating anyway when I'm done welding the flange on.

SpankedYA!

You need to grind the coating off.

jinxy

if its aluminum dip it in a hot aqueous solution of potassium chloride [might be harder to get, also known as potash lye] and if its zinc (galvanized) dip it in hydrochloric acid [probably sitting around your house, but don't do it inside as it releases a lot of hydrogen.]

Xgenturbo

I did grind it off on an angle so I can fill in between the 2 pieces of pipe. problem is that its not a coating its the material itself. MS is much easier to weld than this ----. I mean it is weldable it just looks like crap.

Oh well going to get some SS for the downpipe and I just picked up some stainless tig rods and will be doing the DP this week.

darksol2005

The coating on aluminized/galvanized steel is horrible for welding. Not to mention toxic when burned. I usually just MIG my aluminized exhaust piping for customers because it's so much faster and cost effective

bumblezc

Dip you welding area in Muriatic Acid. You can find it in the paint ailse at Crappy Tire. I't's what I use for stripping Galvanized/Aluminized pipe.

Xgenturbo

Sweet. I'll try that on the rest of my dump tube this week.

jinxy

Just make sure you use sand paper to get the oxidation layer off the aluminum first if you want to use HCl. I recommended a base because its less messy to dissolve aluminum in. Also with the alumnium oxide there's a possibility of releasing chlorine gas as oxygen is present. So be SURE you do that outside.