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n9viw
02-13-2008, 10:49 AM
After bending the handle of the wife's favorite snow shovel last night, I decided I'd get some practice on welding tube steel. I fired up the Century, ran the output all the way down on the AC low side ("min", probably somewhere around 40-50A), and used 1/16" 7014 rods.

Had no problems striking and maintaining an arc, and with judicious movement, was able to move a puddle without blowing through (mostly). The thing that really pissed me off though, was that when I went to chip the slag off, I had massive slag intrusion into the seam of the weld! I would get good metal adhesion to either piece (area of the problem was the valley between two tubes laid side-by-side), but not in the very center of the seam. I had to clean and re-weld each one several times before I got metal to span the gap. I knew it was good when the weld didn't crack as it cooled; the problem ones would cool, and then crack right down the middle. Chip away the slag, and sure enough, no bridge.

Is it just the nature of welding two tubes side-by-side, is it the size or grade of the rod, could it have to do with the fact that it was bloody f'n cold out? I want to do as much practice as I can before I do it "for real" on my Bandito.

(EDIT: I should mention that the handle was 1.25" x .060 tubing; the brace piece was 1/2" ERW conduit.)

bgcustoms
02-13-2008, 01:33 PM
if the handel you were welding was galvanized, you'll get that effect from it

n9viw
02-13-2008, 05:24 PM
Bugger.

The handle wasn't, but the conduit was/is.

Oh well, lesson learned. At least now I know, for next time! :D

macka
02-14-2008, 11:49 AM
a few issues I see. first is 2 different metal sizes, so you select your rod for the thinnest piece. Also you weld from thicker to thinner and "whip" your puddle into the thinner piece. Prep is the key, also if you had cladding on your conduit, it makes for crapola welds with lots of schmutz getting into the puddle and uneven cooling results which may (in your case did) cause cracking.

savarin
02-15-2008, 10:21 PM
another way is to weld vertical. With rods weld from the bottom to the top, move the rod upwards angled upwards,it will more than likely burn a hole, just keep moving upwards a little then downwards to fill that hole.
With wire feed start at the top and feed into the top of the hole whilst moving downwards.
Some side to side movement to keep a puddle flowing down.
As the previous post if dissimilar thicknesses aim at the thicker side.
If galv then clean it off before welding.
Charles

macka
02-18-2008, 04:28 PM
I know that to remove the cladding from fender washers household lye does the trick. Just immerse the cladded object in the lye solution, then wash off well, once the cladding has disappeared. I know it works well to remove zinc coating, haven't tried it on galvanised metal yet. Oh and if you don't know how to make the lye solution don't freehand it, talk to someone who knows, and see if they will teach you.

TheKid
02-18-2008, 04:42 PM
Galvanized metal is metal with a zinc coating, so it will work. Most oven cleaners made for non-self cleaning ovens contain lye, and they work well for removing zinc coatings on EMT conduit.

Wood Butcher
02-18-2008, 08:03 PM
Muriatic acid also does a marvelous job of removing both galvanizing from EMT and zinc plating from nuts, washers and bolts. Look for it in stores that sell supplies for swimming pools.

Be very careful when using muriatic acid. Not only is it rather nasty on the skin, but when using it to remove galvanizing and/or zinc plating, the reaction produces heat and some very noxious fumes. Do not attempt to do this indoors and do not breathe the fumes.

TheKid
02-18-2008, 08:54 PM
That's why I started using Easy-Off instead. I stopped using chemicals when I found out how easy it is to just sand off the zinc. Unless I run out of dust masks, I use an 80 grit flap disk mounted on a drill to remove zinc from an area that will be welded. If I run out of dust masks, spraying a little Easy-Off on the area and letting it sit for an hour does the trick. The fumes are far less than the concentration of muriatic needed to remove the zinc, and the foaming action gives added effectiveness. Then you just have to hose it off.

n9viw
02-19-2008, 05:10 PM
Thanks for all the suggestions! I usually keep a grinding or flap wheel chucked up in the angle grinder, so I can just grind that crap off there and go.

macka
02-19-2008, 11:26 PM
That's why I started using Easy-Off instead. I stopped using chemicals when I found out how easy it is to just sand off the zinc. Unless I run out of dust masks, I use an 80 grit flap disk mounted on a drill to remove zinc from an area that will be welded. If I run out of dust masks, spraying a little Easy-Off on the area and letting it sit for an hour does the trick. The fumes are far less than the concentration of muriatic needed to remove the zinc, and the foaming action gives added effectiveness. Then you just have to hose it off.


nice I have to try easy off, it is less work then mixing the lye solution up.

TheKid
02-20-2008, 03:42 AM
flap discs are even less work, with no fumes. You can keep protect yourself from the dust by not breathing, or wearing a mask. I wear a mask, and keep a shop vac hose right where I sand. Sanding also gives you a clean surface that doesn't have to be flushed.