Hello Everyone. I have been practicing in my garage for a 3G test I am taking on May 5th. I have no one to teach me except the internet, so here I am. I have pictures below of the 4 passes I have put into the piece. I ran into a problem which I think was "Arc Blowback" near the top of the plate on one of the passes. It left a nodule on the plate as if the rod melted in place. Besides that fault, I wanted to get some opinions on my work and see if this looks like something that could pass so far.
Pictures are horizontal for some reason. I can't figure out how to fix that in the forum.
1. No arc strikes outside of the weld zone! Strike just above where you are about to weld, then drop down and start the bead.
2. Place the arc and deposit the metal a little higher into the sides to get a smoother bead. You're leaving a steep trough at the sides which makes slag inclusion very likely.
3. Fill the plate to the top on every pass. Keep running the bead up the backer bar and maybe give it a few swirls on top just to be sure.
4. Not likely arc blow, just looks like a hot blob fell out.
5. Root Pass, photo 3- Looks like a couple of big gobs of spatter on a re-start. Work on your arc striking/re-starts. Those gobs leave space for inclusion/voids.
Good luck, and be patient. Over all its not bad. Nothing a little work can't straighten out.
PeteM wrote:1. No arc strikes outside of the weld zone! Strike just above where you are about to weld, then drop down and start the bead.
2. Place the arc and deposit the metal a little higher into the sides to get a smoother bead. You're leaving a steep trough at the sides which makes slag inclusion very likely.
3. Fill the plate to the top on every pass. Keep running the bead up the backer bar and maybe give it a few swirls on top just to be sure.
4. Not likely arc blow, just looks like a hot blob fell out.
5. Root Pass, photo 3- Looks like a couple of big gobs of spatter on a re-start. Work on your arc striking/re-starts. Those gobs leave space for inclusion/voids.
Good luck, and be patient. Over all its not bad. Nothing a little work can't straighten out.
First off, Thank for the tips. This forum is wonderful. Filled with great people willing to help when they can.
1. Should I clean all the slag and brush before restarts? I also realized I was having a hard time arc striking because I had a bad ground. I then moved it closer to the piece and it went much better. This is after what I thought was arc blow.
2. The test says "stringers only". How do I flatten out a stronger? I cant yo side to side too much or it's a weave right? I almost think my 2nd pass was too much like a weave.
PeteM wrote:
First off, Thank for the tips. This forum is wonderful. Filled with great people willing to help when they can.
1. Should I clean all the slag and brush before restarts? I also realized I was having a hard time arc striking because I had a bad ground. I then moved it closer to the piece and it went much better. This is after what I thought was arc blow.
2. The test says "stringers only". How do I flatten out a stronger? I cant yo side to side too much or it's a weave right? I almost think my 2nd pass was too much like a weave.
You're welcome.
On Q #1- Some people just tap the slag out of the eye of the weld to protect the rest of it from spatter. I just clean it all off because it has never really been an issue. Personal choice, your mileage may vary either way. As long as its clean before your next pass.
Q2- You can flatten them out by using a little more current or by manipulating the electrode a little (tiny side to side, almost like wagging the tail of the electrode). What constitutes a stringer or weave is always debatable, and I just don't have much of an opinion on it. I run them a little wider than the electrode diameter. Thats just my own personal "never fail" technique.
More important is arc and deposition placement. Usually referred to as "sticking the sides", you want to put the arc and metal about half the diameter up into the beveled side of the plate to avoid making that pocket that can create void or inclusion.
PeteM wrote:
First off, Thank for the tips. This forum is wonderful. Filled with great people willing to help when they can.
1. Should I clean all the slag and brush before restarts? I also realized I was having a hard time arc striking because I had a bad ground. I then moved it closer to the piece and it went much better. This is after what I thought was arc blow.
2. The test says "stringers only". How do I flatten out a stronger? I cant yo side to side too much or it's a weave right? I almost think my 2nd pass was too much like a weave.
You're welcome.
On Q #1- Some people just tap the slag out of the eye of the weld to protect the rest of it from spatter. I just clean it all off because it has never really been an issue. Personal choice, your mileage may vary either way. As long as its clean before your next pass.
Q2- You can flatten them out by using a little more current or by manipulating the electrode a little (tiny side to side, almost like wagging the tail of the electrode). What constitutes a stringer or weave is always debatable, and I just don't have much of an opinion on it. I run them a little wider than the electrode diameter. Thats just my own personal "never fail" technique.
More important is arc and deposition placement. Usually referred to as "sticking the sides", you want to put the arc and metal about half the diameter up into the beveled side of the plate to avoid making that pocket that can create void or inclusion.
Ok I will try it this way on the fill and cap tonight and post some pics. . I get worried about the cap because I cannot go past a certain height, and if I do I cannot grind it down.
As far as current, I am getting a lot of digging ahead of the arc. I am using 115 amps. When I go higher, it gets a little crazy.
Not really. Thats one of those things you get good at keeping track of through practice. Just keep on rolling and remember it on the next one. You may be able to move a little quicker over that part and even it out a little though.
PeteM wrote:Not really. Thats one of those things you get good at keeping track of through practice. Just keep on rolling and remember it on the next one. You may be able to move a little quicker over that part and even it out a little though.
If this happened on a test, couldn't I stop short of that and build the bottom up?
The arc kept getting crazy and uncontrollable at the top. When I would terminate the weld, fireballs popped off the electrode all over the floor like Roman candle fireworks. This only happens near the top. Weird.
Just idle speculation, but make sure you're keeping your stick angle consistent and arc tight through out. No reaching with the electrode, move your whole wrist up with the weld. Too long of an arc or too much angle (dropping the wrist) will give wandering arc and crazy heat.
If this happened on a test, couldn't I stop short of that and build the bottom up?
The arc kept getting crazy and uncontrollable at the top. When I would terminate the weld, fireballs popped off the electrode all over the floor like Roman candle fireworks. This only happens near the top. Weird.[/quote]
Yes! You should be able to grind and add filler as needed until you run your cover. Even on pipe it’s not uncommon to add partial stringers to get an even fill for a clean cover pass.
Poland308 wrote:If this happened on a test, couldn't I stop short of that and build the bottom up?
The arc kept getting crazy and uncontrollable at the top. When I would terminate the weld, fireballs popped off the electrode all over the floor like Roman candle fireworks. This only happens near the top. Weird.
Yes! You should be able to grind and add filler as needed until you run your cover. Even on pipe it’s not uncommon to add partial stringers to get an even fill for a clean cover pass.[/quote]
I was under the impression that I cannot use a grinder.
Read the wps they give you closely . Often it specifically says no grind, file marks, or arc marks on the cover. But will probably say that it’s allowed on the intermediate passes.
Poland308 wrote:Read the wps they give you closely . Often it specifically says no grind, file marks, or arc marks on the cover. But will probably say that it’s allowed on the intermediate passes.
I will check that out. If that's the case, then this shouldn't be as hard as I think.
Just got up to speed on this , it sounds so much like what I went through a couple years ago on the nysdot field welder exam I took. First off, arc blow is a son of a gun, plus a few explitives, I never fixed it, I learned to deal with it. I figured it happens on the job, so might as well learn how to manage it. As Jody says, stuff that rod right in there! It does work. As far as the weld being proud at the top, same problem I had. One word, stringers! I ran stringers throughout the whole test, I never had to wait for the coupon to cool, I was done in two and a half hours! They like to see stringers nowadays, also.
