Basic bead question

[root]

I'm playing with TIG'ing 1/16" aluminum and have a question.

After running just a straight bead on a simple plate, when you turn over the plate, should you be able to see where you welded? I guess the question is should the weld penetrate the top-side enough that it imprints the back-side as well, or is that to far?

For some reason I had it in my head that you wanted (nearly) complete penetration when running beads, but then as I play with a T-joint I started thinking maybe that wasn't really what I should be aiming for? On the other hand, maybe there isn't a single right answer and each joint type expects a different level of penetration. And, I guess again, that a simple bead on plate isn't even a joint, so maybe the answer is a bit moot.

I expect I might get the old RTFM response to this question, but maybe some kind sole will humor me.

[Craig in Denver]

Hey....Hi root:

I'm playing with TIG'ing 1/16" aluminum and have a question.

After running just a straight bead on a simple plate, when you turn over the plate, should you be able to see where you welded?
I guess the question is should the weld penetrate the top-side enough that it imprints the back-side as well, or is that to far?

Heck Yes. Even if you're not adding filler, on 1/16" there should still be 'droop through'. Not a big glob, just a convex bulge, 1/16" or less. On 1/8" you can get a good penetration bead without 'droop'.

For some reason I had it in my head that you wanted (nearly) complete penetration when running beads, but then as I play with a T-joint I started thinking maybe that wasn't really what I should be aiming for?

T-joints are a nightmare, almost as hard as butt welds, in 1/16". If you can, back-up your welds with something, anything to keep it from 'falling through'. Some will tell you copper, I've used alum. or clean steel. Anything to disipate the heat. An aluminum backing will weld to your project, though. Obviously, you can't back-up an intercooler. 1/8" butts and tees are a LOT easier; but I use a backing anytime I can. Insurance, ya know.

On the other hand, maybe there isn't a single right answer

Yes there is........mine.

and each joint type expects a different level of penetration. And, I guess again, that a simple bead on plate isn't even a joint, so maybe the answer is a bit moot.

Yep, a bead on a plate is childs's play; you'll fit right in.

I expect I might get the old RTFM response to this question, but maybe some kind sole will humor me.

Oh, I kin do this.

The following starts after you're welding two pieces together:
I'm learning in my oxy class that: if you can see a straight line on the backside; that's where it's going to break when you bend it. Your bead should show through and be convex on the bottom. The bottom side of the weld should be wider than the gap you started with.

Ok, Root, your turn to teach me:
How do I insert my comments, without including them in your post. You know, why are my inserts red (I changed color later) instead of showing up white, like yours in earlier replies?

[root]

Hey....Hi root:

Why do I feel like I'm being stalked?

Heck Yes. Even if you're not adding filler, on 1/16" there should still be 'droop through'. Not a big glob, just a convex bulge, 1/16" or less. On 1/8" you can get a good penetration bead without 'droop'.

OK. Cool thanks. That's what I initially thought, but after a while, wasn't sure why I thought that.

T-joints are a nightmare, almost as hard as butt welds, in 1/16".

Yeah. My first attempts at a T-joint were pretty scary. I finally got one last night that wasn't, hmmm, quite as scary? Still laughable, but it held pretty strong. Almost amazing how strong even an ugly weld can be. I've made some decent butt welds on the flat plate. I need to try welding together some round tube next.

If you can, back-up your welds with something, anything to keep it from 'falling through'. Some will tell you copper, I've used alum. or clean steel. Anything to disipate the heat. An aluminum backing will weld to your project, though.

I have been using a sheet of copper (thanks McMaster-Carr). For the T-joint though, it seemed the copper was acting like too much of a heat sink on the base of the joint and making it harder to get the puddle setup evenly between the base and the faster melting leg. But that could easily just be inexperience on my part (yeah, yeah, I can admit it might take me two full weeks to mastery instead of the single week first anticipated ).

Ok, Root, your turn to teach me:
How do I insert my comments, without including them in your post. You know, why are my inserts red (I changed color later) instead of showing up white, like yours in earlier replies?

The trick is to manually add extra quote tags as needed. When you press the quote button, the forum software automatically adds the quote tags around all the text. You just need to add more. Remember to use the backslash character in the end tag.

Just as an example (you need to replace the following curly braces { } with square brackets [ ] in the actual post)...

{quote}root asking stupid question...{/quote}

I'm Craig in Denver answering root's stupid question. Blah blah blah.

{quote}another root quote{/quote}

I'm Craig in Denver and I'm superior. Root is a looser newb. Blah blah blah.

[Craig in Denver]

Nascar's Back!!!

Why do I feel like I'm being stalked?

You are.

Yeah. My first attempts at a T-joint were pretty scary. I finally got one last night that wasn't, hmmm, quite as scary? Still laughable, but it held pretty strong. Almost amazing how strong even an ugly weld can be. I've made some decent butt welds on the flat plate. I need to try welding together some round tube next.

I have been using a sheet of copper (thanks McMaster-Carr). For the T-joint though, it seemed the copper was acting like too much of a heat sink on the base of the joint and making it harder to get the puddle setup evenly between the base and the faster melting leg.

The copper goes behind the faster melting leg, not behind the base.

But that could easily just be inexperience on my part (yeah, yeah, I can admit it might take me two full weeks to mastery instead of the single week first anticipated).

HEHEHE

The trick is to manually add extra quote tags as needed. When you press the quote button, the forum software automatically adds the quote tags around all the text. You just need to add more. Remember to use the backslash character in the end tag.

BINGO

Just as an example (you need to replace the following curly braces { } with square brackets [ ] in the actual post)...

{quote}root asking stupid question...{/quote}

I'm Craig in Denver answering root's stupid question. Blah blah blah.

Just to make sure others know: There's no way I think root's questions are stupid. If I did, I'd leave the thread. Just a short while ago, I had those same questions; with nowhere to get answers. The solutions/aggravations are still fresh in my mind.

{quote}another root quote{/quote}

I'm Craig in Denver and I'm superior.

OUCH

Root is a looser newb. Blah blah blah.

Since Root has more posts than me and his tool is newer than mine; I'm the looser newb.
These barbed responses would be impossible without the emoticons.
I will, however, stand behind the "Blah blah blah".

[root]

You are.

Cool. I'm one step closer to celebrity status!

The copper goes behind the faster melting leg, not behind the base.

Aye. Makes sense for heatsink purposes. I'll give it a try. Thanks.

Just to make sure others know: There's no way I think root's questions are stupid.

Indeed. No worries. I am just joking around as well.

Since Root has more posts than me and his tool is newer than mine; I'm the looser newb.

Is this supposed to be one of those reverse psychology tricks? And, I'm not sure you should be discussing my tool. Or did you mean my welder?

These barbed responses would be impossible without the emoticons.
I will, however, stand behind the "Blah blah blah".

It was a perfectly good blah blah blah. One I couldn't argue with. You should be proud of it. And, I agree about emoticons. I wouldn't dare type some of what I do if I wasn't able to show that I was joking.

[DSW]

Thanks to you both for lessons in both cases. As one of the computerly challenged I'm finding it easier to learn tig than it is to learn how to ask the questions here. (still trying to figure out how I get my pictures into a format I can post? hmmm.) anway at least I've moved up from computer illiterate. I've at least got a teacher for the tig, but the info on that was real useful to. Knew it just hadn't considdered applying it that way.

Thanks again to you both!

[root]

Glad we helped.

still trying to figure out how I get my pictures into a format I can post?

What format are your pictures in now?

[root]

Just a little update. I actually managed a relatively decent T-joint. OK. Maybe not the entire length of the joint. But the last 1.5" looks pretty darn good (by my standards, ymmv).

Three things helped. First, I realized I kept putting the filler rod into the arc path instead of edge of the puddle and letting it get pulled in. Second, the Miller tech articles mention that since the leg will melt faster, the filler rod should be targetting that puddle more so. Third, I switched to 3/32" rod (I hate to say this, but thanks Craig ).

I guess a fourth thing that helped was remembering to actively modulate the pedal when things looked like they were about to get to hot/cold. Still going to take a while to get this down without having to think about the need to do it.

[DSW]

Root, they are in JPEG format in the computer. Do I have to set up a personal website and put them there first or can I just insert them into the thread?

Thanks

[root]

Root, they are in JPEG format in the computer. Do I have to set up a personal website and put them there first or can I just insert them into the thread?

If you want them to appear inline so you see the picture in the message, you need to host them on a website and then use the {img}url_goes_here{/img} tags.

If you just want to post them as attachments, in the Reply To Thread editor screen, below the Submit Reply/Preview Post buttons, there is a Manage Attachments button. Use that to upload the photos.

You might want to resize the images a little first so they aren't too large. You can do this in Microsoft Paint which comes with Windows. Open the picture and select Resize from the Image menu (and the save it). There are other ways, but it depends on what software you have.

[Craig in Denver]

Just a little update. I actually managed a relatively decent T-joint. OK. Maybe not the entire length of the joint. But the last 1.5" looks pretty darn good (by my standards, ymmv).

Three things helped. First, I realized I kept putting the filler rod into the arc path instead of edge of the puddle and letting it get pulled in. Second, the Miller tech articles mention that since the leg will melt faster, the filler rod should be targetting that puddle more so. Third, I switched to 3/32" rod (I hate to say this, but thanks Craig ).

And I hate to say this, you're welcome.

I guess a fourth thing that helped was remembering to actively modulate the pedal when things looked like they were about to get to hot/cold. Still going to take a while to get this down without having to think about the need to do it.

I spent a lifetime learning that the more steady I could keep my foot on my vehicle's gas pedal, the better gas mileage I'd get. Running the TIG pedal up-n-down like a newly wed has been really hard for me to learn.

OBTW: Be very carful of heat build-up in your work piece. You'll be wondering why everything has turned to doo-doo. It's real easy to get so focused on your welding that the piece will overheat. You'll start blowing holes or having disastrous droop-outs. And DON'T quench alum. Just walk away until you can touch it again.

[root]

Running the TIG pedal up-n-down like a newly wed has been really hard for me to learn.

Not enough practice, eh?

OBTW: Be very carful of heat build-up in your work piece. You'll be wondering why everything has turned to doo-doo. It's real easy to get so focused on your welding that the piece will overheat. You'll start blowing holes or having disastorous droop-outs. And DON'T quench alum. Just walk away until you can touch it again.

Oh no. Not more advice from you!?!? Darn it. Useful advice just sucks!

[Craig in Denver]

Lmao

Not enough practice, eh?

Women rule the world, and that's the saddest thing I'll ever tell you.

Oh no. Not more advice from you!?!? Darn it. Useful advice just sucks!

Being one up on you, makes my day. Lucky for you, I'm not good at keeping secrets.