Welding Tips and Tricks

OK, never welded aluminum before. Been many many years since I did tig steel. Been stick welding mostly.

The issue: My folks have a Handi-cap ramp with aluminum hand rails. One got totally broken off. Don't ask Suffice to say it's not vehicle rated.

Rail (horizontal) is 1 1/2" X 3/16 round tube. Supports (vertical) are 1 1/2" X 1/8 square tube. Nothing is bent, sort of. The 4 welds that are about 1 1/2" long that hold the round tube to the square broke.

Been reading and watching as many videos as I can. I have a bunch of coupons ordered up but this is gonna be an RFN repair. Sooo, I swung by the scrap steel place and grabbed various aluminum cut offs. Pretty sure it's all 6061. 3/16 flat, 1/8 flat, 1 1/2" square tube, 1" block, 1 1/2 block ( for heat sink if needed) and some bigger angle.

I have:
New Primeweld 225
the CK 17 torch that came with it
3/32 2% Tungstens
1/16 and 3/32 4043 and 5356 filler
Right angle grinder with new disc
File
SS brushes
Acetone

Can someone with experience with the PW 225 point me in the direction of approximate settings so I can get right at it. Amps, pulse / no pulse, balance /cleaning, ramp up / down, frequency, etc. I need 4 GOOD welds 1 1/2" long.

Not looking to cheat as I know that a'int happening with welding. Just don't want to waste valuable time trying to reinvent the wheel while this hand rail is missing...with the snow...and the ice..

The one in the picture looks plenty easy. Clean it up with a wire brush good, then just go over it with no filler rod and with the AC balance set around 60% or something like that. Do a lot of cleaning and just get the whole surface too wet out without any attempt at joining the two parts. Once you're happy that it's all clean, grab a 4043 filler rod and lay a bead on top of that crack and Bob's your uncle.

When it came time to weld I would probably set the welder around 150 amps and AC balance around 70%. Use a 3/32 filler rod and Bing Bang Boom, you'll be done.

Thanks for your reply. Some additional pics of what the situation was. I didn't realize that my initial post required mod approval. This project has repaired, at least temporarily, until I can do more with my machine. Like I said, there was NO rail so it had to be done ASAP.

I'll try to post some pics of my fugly welds.

From my view, that weld broke because there was a complete lack of fusion. Aluminum is finicky stuff. A cold, thick bead can look great, but its weaker than overcooked pasta.

You can almost never be too hot welding aluminum. 1/8 to 3/16 material can withstand 180 amps all day long for the short duration of those welds. Better to pound it in than to leave it "on the surface" only as the prior weld was.

Material selection matters a bit here too. Depending upon the climate, 4043 filler doesn't take well to extreme cold. Aluminum has a lot of shrinkage in the cold, and the 4043 will tear apart. 5052 is better in my experience as a filler wire.

For settings, I would have you at 65% Balance, 60Hz, and 165-180 amps. No pulse. Mash it, melt it, and stuff it in there. 3/32 filler rod. That way you are forced to stuff it in and fill the joint. With 1/8 rod you can end up with barely enough heat and the filler over-cools the puddle. Then the weld is much weaker than you think.

Make sure to run about 8 seconds of post flow argon on over the weld while it cools too. And avoid leaving that little crate at the end of the weld. Put an extra dab in there (that's usually right where the weld will begin it's crack).

cj737 wrote:Make sure to run about 8 seconds of post flow argon on over the weld while it cools too. And avoid leaving that little crate at the end of the weld. Put an extra dab in there (that's usually right where the weld will begin it's crack).

Looks like exactly what happened.

Well, sh*t. In reading your replies, I'm betting while these may look ok-ish, they probably are no better than what was there. Probably shoulda used more amperage.

My settings were 130 amps, mashed pedal
3/32 4043 filler
15 cfh with about 1 sec pre flow and about 8 post
Frequency was about 100
balance was about 60
no pulse

I know comparatively these are rough, but for a first crack and needing to get that rail back up in the middle of winter, they'll do.

Now, next question......when the weather breaks, should I grind these down and re weld, having had more time to practice, and re-do them with a bit more juice?

Oh, and what's the soot near the end of a couple of my welds? Pulling the torch away too fast?

Thanks and I appreciate all the patience and advice.

Some of them look like the "root" is not welded, so those need better (re)doing.

Your weld ends that have the crater, those need a bit of touch up with a dab of filler added to prevent cracking.

I suspect the soot at the end could also be an indication of trapped air below the weld (lack of fusion in the root) blowing out on you.

the original cracked because someone didn't crater fill and left fisheyes. i think jody might have a video of it happening straight after welding.

i really detest people welding over the top of aluminium cracks, or simply running the torch over it and remelting the weld.
one of the problems is the crack has aluminum oxide in it and usually a fair bit of it as they tend to sit around a long time before people notice. if you remelt it, you can end up with linier porosity (jody has a good video on that) and it has high risk of cracking again. it should be ground out (and cleaned) so you can get the arc in there and then refill it.

Pretty sure the reason it cracked is that it was never meant / designed to withstand the impact and force of a vehicle backing into it. Designed to provide a steady grip while walking and to help stabilize.

That said, Your assessment of the weld's lack of penetration was my first impression as well. Pretty obvious when the tubing looks mostly pristine.

I'll get after them when it gets a bit nicer out.

eelman308 wrote:Pretty sure the reason it cracked is that it was never meant / designed to withstand the impact and force of a vehicle backing into it. Designed to provide a steady grip while walking and to help stabilize.

That said, Your assessment of the weld's lack of penetration was my first impression as well. Pretty obvious when the tubing looks mostly pristine.

I'll get after them when it gets a bit nicer out.

still it should not break at the welds regardless of what its designed for.
penetration in the material is ok, it broke through the centre of the weld rather than the weld coming off the material.
whats lacking is penetration into the root. thats often lack of amps and not getting it to flow in there.

tweake wrote:the original cracked because someone didn't crater fill and left fisheyes. i think jody might have a video of it happening straight after welding.

When smashed, it does appear that was the weak spot, but probably would still look like original had it not been backed into.

i really detest people welding over the top of aluminium cracks, or simply running the torch over it and remelting the weld.
one of the problems is the crack has aluminum oxide in it and usually a fair bit of it as they tend to sit around a long time before people notice. if you remelt it, you can end up with linier porosity (jody has a good video on that) and it has high risk of cracking again. it should be ground out (and cleaned) so you can get the arc in there and then refill it.

True if it really is a "Crack", but this part is broken. This isn't a crack in the sense I think of it, where the part is more or less still in the same position as it was before the crack formed. He's got a chasm to fill in unless he can bend the thing back in place, which likely ain't happening. When the opening is wide like that, I don't see any trouble with cleaning the opening out with the torch with no filler and a lot of EP, till you're satisfied it's clean enough that it's all wetting out and will fill back in like an open root weld. That's precisely the technique I've seen recommended to weld aluminum cast (and that I've done before) when there's no real way to clean it.

YMMV.

That said, I don't disagree that grinding (cutting) it out to open and clean is a good idea. But his is already open.

I realize all this discussion is after the fact, but some more info. It still helps me analyze the what's and why's for further / different repairs, so thanks again.

As you can see in the pic, the rail sustained a linear push which shoved the vertical supports back as far as they could go before something HAD to give. I think we all agree that the original welds didn't penetrate very well. This was a considerable impact, not a gentle nudge. Maybe I'm blessed that the welds broke BEFORE bending / breaking of the main struture occurred. I don't know.

Again, just soaking up all the discussion and thoughts here. I gotta believe there is more than one way to skin this, so maybe there's a "OK method", better technique, best route, or a "grind it clean, get new supports, and start over."

the impact doesn't look all that big. typically aluminum will bend well before welds start breaking. tho what changes it a bit is that its bolted at the bottom giving it a pivot point. still i think if that had been welded properly to start with the welds would not have broken, the bars would have bent a bit instead. that might be minor enough to not bother fixing or its a real pain in the butt to fix.

you can even see in that pic they didn't crater fill the welds, which is why they broke so easily. craters can cause cracks without any force being applied.

i usually grind the cracks before welding. make sure there is a gap the arc can get into.
i usually just use a die grinder, but you could use a thick cutting wheel and do a U groove.

Cut the uprights. Bend them vertical and reels them back to the bar.