Welding Tips and Tricks

I have to do a 22" aluminum butt joint in the horizontal position. Has anyone heard of this? What are they going to do as far as inspection? How much should I gap? SHould I bevel it?

Butt joint, horizontal...

So, 2G test? 22" total weld length? Backing bar and run-off? Open root?

How thick is the material? What alloy? What filler rod?

What equipment?

Enquiring minds want to know...



Steve S

OK 1/8 material with a backig plate, tig welded with 4043 filler, miller sycrowave machine. What else?

Syncrowave is a good machine for that.

1/8" with backing, I'd bevel 37-40* to a knife edge, or at most 1/32 land. Gap 1/8"

Machine set at 200A, arc balance at 8-9 (above "balanced", since you've freshly ground it). Grind the top face of the backing strip, too. That step bites people all the time.

Tack each end and every 4" in between. This is where that 200A comes in handy. Feed extra rod when tailing off... don't leave a crater in the tack. Tacks should be about 3/4 inch. Grind the edges of the tack to the backing bar.

Weld a bit from each end. It's easier to close an end while starting than while finishing. Grind each end you must tie another weld to. Expect to use most of the pedal when starting, but be prepared to back off quickly; that 1/8 will heat-soak quickly.

Move around, working between tacks. You'll distort it less than if you try to do it in one go.

I'm sure you know most of this, but it's the best advice I can give without my hands on the piece.

Good luck,

Steve S

I think this will get me through it thanks

What Steve said.

If it's a 1/8 gap and say the tolerance is + or - 1/32 I always try to use all of it if I can.
Ask what the tolerances for the test are.

Hey,

Clean your filler rod scotch brite and wipe with acetone as well, right before you use it. I have heard of the oxide on the wire causing porosity in the weld.

Mick

Otto Nobedder.

Enjoyed reading your post.

Why did you include the following recommendation?
"... Grind the edges of the tack to the backing bar. ..."

Tanks.
Alexa

Alexa wrote:Otto Nobedder.

Enjoyed reading your post.

Why did you include the following recommendation?
"... Grind the edges of the tack to the backing bar. ..."

Tanks.
Alexa

I should have said "ends" of the tacks, rather than "edges". Poor wording. When they're tapered down to the backing bar, you don't have to work the pedal to assure tie-in when you reach the tack. Just back off on the rod feed as you climb the taper ground into the tack, and tail off in the middle of the tack.

Steve S

rr41mag wrote:I have to do a 22" aluminum butt joint in the horizontal position. Has anyone heard of this? What are they going to do as far as inspection? How much should I gap? SHould I bevel it?

=====

Rr41mag.

Did you happen to note what the welding code or company specification was that required the 22" long test?

Tanks.
Alexa

Alexa, No I don't know. Warpage is a PITA on this particular coupon. I literally had to clamp the test coupons down and put tacks all over. Then I was dealing with the gap closing. I'm gonna weld it up monday and I think I've got it. The knife edge was the trick, no landing at all! Now I'm wondering what are they going to do to this? Bend?

A bend test is likely. They'll remove the backing bar with a combination of gouging and grinding. Using ASME IX as an example, they'll likely discard the two inches closest to each end, then slice pieces out of the rest for two face bends, two root bends, and maybe two side bends, though this seems unlikely on 1/8". Two tensile tests are also possible.

If they don't designate where to tack, mark your tack locations (each end) with a Sharpie. In some tests, the examiner will make a point of not slicing through a tack, setting them instead in the middle of the sample if possible. Other tests don't give a damn.

I can't imagine any other reason for a coupon that long... For X-Ray, I'd expect a 16" coupon, with 14" shot... Then again, that's an ASME thing and may have nothing to do with your circumstance.

It's also possible to be "looked out", meaning failed visual examination before they take a slice. If you're able to minimize warpage and keep an even, clean bead, this is not likely to be a problem... They expect some warpage in a coupon that's not actually attached to anything. Just beware of tieing in to tacks... This is why I suggested grinding the ends of tacks to the backing bar... The end of the tack is now a knife-edge to weld, just like the rest.

Let us know how they test it, and how it turns out for you!

Steve S

My project manager told me it would minimlly quailify me to weld aluminum for the navy.

That makes sense.

Testing on 1/8 will probably certify you up to 1/4", but only in the position you're welding the coupon.

I hope they give you the opportunity to study and test in other positions and other thicknesses. The more you certify for, the more money you can ask. I once took home $2800/wk welding aluminum pipe on a contract for a private company, so it wasn't even prevailing wage for the work.

I'm no fan of shipyard work, to be kind about it, but Navy work is a different animal, and at the top of the heap.

Keep us updated!

Steve S

they told me this would cover me to weld for the navy

Yeah, you already said that.

This test will qualify you to weld certain thicknesses in one position for the Navy,

The Navy will make you qualify for every material, thickness range, and position in a separate test.

Steve S