The Welding Thread

[pantelones]

Has anyone else bought argon lately? I basically paid $100 for a 125cf tank :rippedoff:

Anyways, I'm almost done with my project :) It just needs some bolts to hold the muffler on and to be polished. I started off filling holes since my first idea didn't work out as planned, but it metal right?

IMG_0206 by Los Pantelones!, on Flickr

:hitler:

IMG_0205 by Los Pantelones!, on Flickr

IMG_0211 by Los Pantelones!, on Flickr

IMG_0212 by Los Pantelones!, on Flickr

IMG_0213 by Los Pantelones!, on Flickr

The other end sugared when I left it open - duh so I closed it this time, and it was okay :up:

IMG_0214 by Los Pantelones!, on Flickr

Starting to get the hang of fillets... Arc length is key ;D

IMG_0216 by Los Pantelones!, on Flickr

IMG_0217 by Los Pantelones!, on Flickr

[IronFreak]

Dual shield is where it's at. We have a bunch of customers that have switched because of how far it's come in terms of finished weld quality with minimal cleaning, like you said. It's quite impressive actually!

It really is, and when you can lay 5/16" fillet welds in a single pass......a lot of welding gets done. We have gotten heavy into bridge spans for the railroad and D1.1 bridge code crap...fracture critical shit......CRAZY amount of work sometimes. We've procured some cool tools too, auto trackers, doing a LOT more submerge arc welding. Love walking through the shop, the shear magnitude of the parts we build is impressive. I'll have to get some pictures and post them up.

[red2.4srt]

We use dual shield fluxcore as our primary process here at my shop (heavy structural steel). ITS AMAZING with the right equipment, straight Co2 for shielding to promote penetration. You get the amps and voltage just right the flux will peal itself off.

Dual shield is where it's at. We have a bunch of customers that have switched because of how far it's come in terms of finished weld quality with minimal cleaning, like you said. It's quite impressive actually!

[IronFreak]

We use dual shield fluxcore as our primary process here at my shop (heavy structural steel). ITS AMAZING with the right equipment, straight Co2 for shielding to promote penetration. You get the amps and voltage just right the flux will peal itself off.

[red2.4srt]

The main issue with flux core is not having enough voltage to run it, which seems to be a big issue with the 110V machines. I've noticed a big switch while running flux core on a 230V machine, for instance the new Millermatic 190 runs it fantastic and that's an inverter machine to boot.

I used to do structural steel with both stick and flux core .045 wire running off a Trailblazer 302 generator with a MIG box and it was more than capable of laying down a very nice bead. Naturally it was a lot more cleanup, but the integrity of the weld was great.

Small machines benefit so much from running .023"-.030" solid wire with gas. Another issue could be not reversing the polarity, most all the small Lincoln welders come setup to run flux core on reverse polarity, but trying to run solid wire without changing to straight polarity will give you bunches of spatter and a terrible puddle.

[McGyver]

Fluxcore blows ass on small welders. My suggestion.....run it hotter than normal (control the heat with your finger/trigger), REALLY clean the weld surface......and pull....not push the puddle. you have to look at mig/flux like auto-feed stick welding. you need to pull or you'll get flux inclusions/porosity in your welds. Obviously this isn't structural but it'll make your life easier.

Thanks, that's good advice.

I agree, fluxcore really sucks. My machine didn't come with a gas bottle so I've been running flux. The shop where i was welding has the exact same machine, but has the CO2/Argon setup. I was really surprised how much better/easier my welds came out using gas.

And that makes sense about pulling fluxcored to keep out the inclusions. Yeah, I've only patched my floor pan in a couple of spots and fixed my exhaust a bunch of time. Although my welds are getting better and I'm starting to learn how to dial in the machine for good penetration, I still don't feel confident in my ability to weld structural stuff.

[jalopi]

anyone got experience with miller's multimatic? i've been thinking about replacing my hobart with one since i want a tig but don't want to sacrifice more room in my garage with more stuff

[IronFreak]

Awesome info man! Hopefully I'll be welding up my m20 exhaust to the m30 down pipes tomorrow. I'll try out this technique!

So many tacks for a butt joint, stream on lap joints. got it.

Also, for tomorrow's welding I'll have to use flux core wire. Anything extra i should do beyond what a gas shielded mig would do?

Fluxcore blows ass on small welders. My suggestion.....run it hotter than normal (control the heat with your finger/trigger), REALLY clean the weld surface......and pull....not push the puddle. you have to look at mig/flux like auto-feed stick welding. you need to pull or you'll get flux inclusions/porosity in your welds. Obviously this isn't structural but it'll make your life easier.

[McGyver]

MIG welding exhaust tubing is often misunderstood... You are not really laying a bead, but more so a series of tack welds. The setting in the video are for a more complex MIG machine, but the little 130 amp units can do the same thing. They just combined the amps/heat and wire feed together, and the voltage is deep or shallow penetration control. The idea of a high heat tack weld is still your goal for a more precise way to control heat input and penetration.

Awesome info man! Hopefully I'll be welding up my m20 exhaust to the m30 down pipes tomorrow. I'll try out this technique!

So many tacks for a butt joint, stream on lap joints. got it.

Also, for tomorrow's welding I'll have to use flux core wire. Anything extra i should do beyond what a gas shielded mig would do?

[IronFreak]

I tend to only do that on butt-welding exhaust. With a slip joint like the pic, you can just weld it with a steady stream if you have the heat and feed correct

This^

The key with exhaust like anything other application is to really spend time cleaning the weld surface (If possible, I've welded under cars where its not not feasible). it'll really help arc and puddle control. I try to get it as close to full penetration settings as possible and just control heat input with my finger. Thats talking mig applications......Tig.......I like the deep penetration....

Those welds still look solid especially for your first go at it. good job man.

[ForcedFirebird]

^^^

MIG welding exhaust tubing is often misunderstood... You are not really laying a bead, but more so a series of tack welds. The setting in the video are for a more complex MIG machine, but the little 130 amp units can do the same thing. They just combined the amps/heat and wire feed together, and the voltage is deep or shallow penetration control. The idea of a high heat tack weld is still your goal for a more precise way to control heat input and penetration.



Pretty example

I tend to only do that on butt-welding exhaust. With a slip joint like the pic, you can just weld it with a steady stream if you have the heat and feed correct

[pantelones]

^^^

MIG welding exhaust tubing is often misunderstood... You are not really laying a bead, but more so a series of tack welds. The setting in the video are for a more complex MIG machine, but the little 130 amp units can do the same thing. They just combined the amps/heat and wire feed together, and the voltage is deep or shallow penetration control. The idea of a high heat tack weld is still your goal for a more precise way to control heat input and penetration.



Pretty example

[McGyver]

I backed up onto a little 12" wide by 6" tall curb separating my friend's driveway from his neighbor's and ended up beaching my car. The carnage was so bad that I had to rebuild the exhaust from the cat back. I used a Lincoln 125-SP Plus with solid wire and CO2/Argon mix.



I admit most of the welds are complete shit, but I was pretty proud of this one given how inexperienced I am and how shitty the metal was (I was cutting up old exhausts and putting them together)



The PO had the exhaust "fixed" but it was at a wonky angle. So it didn't fit in the tunnel and twisted the engine/trans when it was put in place. That resulted in BAD vibrations from the u-joint on the drive shaft and a terrible rattle. Now it's ugly, but functional!

[IronFreak]

yeah I have my purge meter set at 10, I have a valved Y fitting coming off that so I can run 2 lines if I have too....now granted I was welding 1.25" sch10. but by the time I install my line, pop the gas on, sit down, setup and drop hood....it's been 25-35 seconds. when you're only purging say 12-18cu. in. at a time, 10 scfh will clear out the garbage quickly. And think for a minute on what the diffuser accomplishes with purging, instead of a 3/16' stream of argon flowing into the pipe you get this massive cloud.

I do need to get one of those tools to measure flow at the outlet, but I figure with 10 on the dial, and 12' of line I have to be somewhere between 5-10 at my diffuser.

[pantelones]

1000psi on a 300cf tank seems like a lot of gas to go through on those few welds.

125cf tank... I also did 6 or so practice pieces as a warm up so I used a bit more than just the welds shown. And I think I left the gas on once for 5-10min when I dipped my tungsten and took a frustration dump haha

I agree......you might want to invest in a better purge setup. I back purged my entire manifold and didn't use that much argon. I went and bought a small gas lens and made an adapter to screw it into the end of my purge line. I don't purge over 10scfh and have no issues with penetration or proper coverage. There is no reason you should have to purge that high for that long, that pipe can't be more that 2" in diameter.

diffusing is your friend....not just at the torch.

Edit:

All that being said, very nice job! looks like a fun little minibike!

Edit #2:



I've learned to be smarter about how I purge as well. In this case, you're purging several inches away from your joint. I would have balled up some foil, stuffed it into the long piece 1-2" past the welded end, and purged into the small piece. Then you're only purge a few cu.in. instead of that entire piece. Just food for thought. One you're done shove a coat hanger in there and yank out the foil.

First off, :thankyou: My brother is quite happy with the way it's turning out :D

I didn't even think about diffusing the purge line... And again, I have a 125cf tank so it's not that excessive, but it still was a lot more than I should have used. As with everything in TIG welding, work smarter not harder haha Thanks for the tips!

You also state that you don't purge over 10SCFH, and is that during welding, or including prepping the tubing? I read almost everyone that works with stainless will do a 20-40SCFH purge for a time per volume for the work piece, then drop it down to 5 while welding.