Seeking some constructive criticism

[Nick_Neuhaus]

I am currently working towards my goal of building a mountain bike frame for myself. I recently got a tig welder and am struggling a bit getting things figured out. I bought some scrap 4130 cromoly tubing in .050" thickness and been practicing a few pieces a day. Below are today's pieces, I feel like I'm building too much heat waiting for the puddle to form.

These were welded with the following settings.

50 amps, no pulse, #8 cup with gas lens, 1/16" 1.5% lanthanated tungsten, 1/16" er70s-2 filler rod.

[Rody]

Nick,

Here's a couple pointers to get you moving in the right direction...

Make sure your "scrap" pieces are super duper clean. Hit the entire exterior with a piece of 80 grit shop roll, then polish with a maroon scotchbrite pad. Sand the interior as well by taking the shop roll and folding it over a dowel rod, file, whatever. Wash off all the tubing with a mild detergent in hot water and then when dry, do a final wipe with a bit of acetone / alcohol.

Ensure your tungsten is sharpened parallel with it's length with a nice long point.

Set your gas for your selected cup / lens somewhere between 12-20 cfh.

I assume you are using a pedal to control amperage...set your amps to 80, that will allow the pedal to be at the sweet spot for better control during welding.

Get a thinner filler wire... .062 is way thicker than you will want. A nice .035-.045 will flow so much better for your practice.

You are definitely cooking the shit out of the material; a combination of moving too slowly and try to jam that thick filler in the puddle. Try to work in opposed 1/4 sections; run the torch across the section to be welded with no power so you can begin to build some muscle memory, then light up and re-produce the motion. Visually focus on filling the key hole of the melted material with the filler, moving consistently throughout.

Check back with some more progress...good luck!

Rody

[Nick_Neuhaus]

I haven't had a ton of time lately but have been trying to spend at least 30 minutes every couple nights running beads. Still not the prettiest but I'm definitely getting better at controlling the heat I'm putting into the tubes. I also still need to pick up the travel speed.

[Nick_Neuhaus]

Another from last night.

[Nick_Neuhaus]

Rody,

Thanks for all the tips, they definitely helped me get moving in the right direction. I think the most beneficial was upping my amperage, I have settled on 65 amps and feel I have much more control over the puddle and am able to speed up or slow down as necessary. I still have a long way to go but am feeling a little more confident.

[Nick_Neuhaus]

I ordered a nova cyclocross tubeset on sale last week and a couple of paragon items to finish it out and decided to practice my mitering skills along with welding. Things went pretty well. I am looking at this as a practice frame but plan on seeing it all the way to a finished product. I want to get all of my process figured out, and make sure I end up with something at least reasonably straight. So far it's about 90% done. The welding went very well today. I changed the settings a bit and felt much more comfortable.

I turned pulse on and went with 30 pps, 40% background, and 30% time on. I turned the amperage up to 90. I felt like I could get moving much sooner and keep the pace up until the end of the weld.

[Rody]

Nick,

Glad to see you pursuing your effort in mastering your ability to join with tig.

Did you spend any significant time running beads without the pulse? Did you reduce your filler size? Were you able to visualize the keyhole between the metals being joined and smoothly fill that, moving forward steadily?

I ask because these are critical steps that should be consistent to ensure full penetration.

What I am seeing in the above pictures is an accumulation of material, bridging the joint, in an inconsistent deposit rate. You really want enough heat to pull the material in, fillet it out at the edges, and limit the heat effected zone.

I know it is a struggle to learn a physical skill through didactic information; is there someone near you that you could engage to spend a few hours with you to enhance your knowledge? It would "connect the dots" much faster for you and bring you to a level of creating safe joins.

Keep striving for improvement!

rody

[edoz]

I'll add a few things here. Since I haven't actually seen you weld, these comments are based on what I can guess from the end result. Take them as such.

Make sure that you're feeding the rod into the molten puddle, not letting the heat melt the end and dripping it off the rod. The inconsistent deposit shape is an indication that might be happening. Feed the rod into the leading edge of the puddle, and keeping the rod as inline with the direction of weld travel as you can will make it easier.

Another thing is that many new welders start with their hand several inches up the rod and move their hand towards the weld as they consume the rod. Don't do that. Hold the rod a few inches from the weld and learn to feed it through your fingers. (practice that while sitting around reading or watching TV, and one drill I used when starting out is to push a dime across the table with the end of the rod while feeding it through your fingers - that will halp you learn to place the end of the rod where you want it) The closer to the end of the rod you place your hand, the more control you'll have over where you place it. And if you aren't already, do the same thing with the torch. Hold it like a pencil as close to the gas cup as you can, once again you'll have better control.

What Rody said about dry runs and welding quarters is spot on. It also helps you figure out how to get the most comfortable before you light up. Getting comfortable is key, always try to rest or brace your hands, forearms, or elbows somewhere.

[Nick_Neuhaus]

After spending a little time with high frequency pulse I ended up going back to no pulse. I found that once I started actually seeing what was going on I liked the control I had without pulse better. I am still working on feeding filler smoothly and feeding the rod through my fingers as I go.

I reduced my filler to .035 er70s-2. What a difference! I felt much less clumsy as I was attempting my welds.

For some reason my dry runs always go much smoother than the actual weld. I find myself getting out of position more quickly than I expect. I have gotten better at stopping as soon as I realize I'm running out of flexibility anther than pushing on and making a mess of everything.

Eric, as soon as I read your suggestion about keeping the filler in line with the path of travel I realized that I was attempting to come in from a higher angle. I'll definitely be paying more attention the that.

Hopefully the next round improves and I have something better to show.

I greatly appreciate all of the advice, thank you.

[edoz]

Eric, as soon as I read your suggestion about keeping the filler in line with the path of travel I realized that I was attempting to come in from a higher angle. I'll definitely be paying more attention the that.

Keep in mind that there's nothing actually wrong with that, I do it all the time depending on what I'm doing. It's just something that will make it easier when you're learning.

And yeah, the dry runs always go better;)

[Nick_Neuhaus]

I spent some time today running short beads around a scrap piece of tubing I had laying around. I used all of my short pieces of filler rod so it would force me to work on feeding it through my hand. I was also working on rolling my wrist as I wrapped the tube to keep proper torch angle. Some went ok, some not ok at all but I was able to focus on the puddle and concentrate on filler rod placement. Baby steps, very very small baby steps.

This was with .035 er70s-2
No pulse
40 amps

[Nick_Neuhaus]

I got a little more practice this evening. It's not great but I am starting to recognize things going wrong before I've gone too far.






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[Nick_Neuhaus]

I haven't had a considerable amount of time lately but have been getting some time under the hood. I'm still working on my dab consistency and maintaining proper torch angle but I am feeling much better about heat control.

[Nick_Neuhaus]

I cut up a bunch of scraps and got a little more practice tonight. I used my heat sink and was very surprised at how much it allowed me to "slow down" and focus on technique. I can't thank everyone enough for all of the suggestions and help up to this point.

[Rody]

Nick,

Your progression from the first pics to the last has shown good improvement in heat control...the material will thank you for it with greater durability in the heat affected zone.

It still looks like you are running a little cold; enlarge your photos and see how the filler material "sits" on the joint with a defined edge rather than flowing out to the base materials? Three factors contribute to this; amperage, filler wire size, and travel speed. You have the ability to control all three. Did you ever drop down in filler material size? Can you increase your heat input? Does your speed allow the material and heat to get good penetration? All are questions you should be asking yourself and then making small changes to improve your joint structure.

Aesthetically, I can see that your torch angle and filler position are all over the place. The shape of your puddles and the periphery of the joint should be consistent and smooth. Focus on getting your torch at a fixed angle both vertically to the joint as well as laterally in relation to the two joining tubes. As you work around the piece, your torch hand should be rotating to keep these angles consistent (this is one of the hardest physical manipulations to master). When you stop a run, note your torch position. When starting back up, go back a puddle or two, match the previous torch position as close as possible, bring the material up to heat so that the new puddle matches the existing, then move forward. This should help blend in your start and stops. As Eric pointed out earlier, your filler should be added inline and parallel with the seam you are filling. When it all clicks, you should have a welded joint that is smooth, flows to the edges, and is consistent in shape and periphery.

Here are two steel joints, welded w/o pulse as examples...

One Piece bar stem small.jpg

What is your location? Is there someone nearby that could work with you for half a day? It would really help you get over the hump.

cheers,

rody

[Nick_Neuhaus]

Consistent torch angle has been and continues to be a problem for me. My filler size is .035 and that has made things much easier. Amperage is 40 amps and controlling heat with the foot pedal. I've been focusing on moving faster which quite likely is why the weld is a bit cold. I will try upping the amperage a bit and see what happens. I've been adding the filler inline and things start going very wrong if I start increasing the angle of the filler as I move around. I've also been running a lot of straight beads on a mild steel sheet I have just to practice consistency

I am in Marin county in Northern California. Lots of frame builders around here, I'm just not sure show to approach them. I do plan on taking a frame building class but really feel that I'll get the most out of it if I show up with the basics down.

The feedback I have gotten here continues to be very helpful. I find myself taking my test pieces and rereading the previous posts while trying to analyze the part.

[Nick_Neuhaus]

A little more practice tonight. I felt like this went very well. I turned the heat up a bit more and really worked on keeping torch angle and gap consistent


aqueous ammonium sulfate

[Nick_Neuhaus]

Some more practice tonight. I'm starting to feel like I actually have control of te puddle and heat.

[Nick_Neuhaus]

I haven't gotten a ton of time under the hood lately but tonight I had an hour so I decided to make a stand for one of my bikes.

[Nick_Neuhaus]

I started this thread a little over a year ago and figured I’d update it now that I’ve had a good bit of time under the hood.

I got to the point that I felt like I could stick a frame together so I made myself a gravel bike. It’s pretty standard in terms of geometry. So far I’ve logged about 150 miles on it and been quite happy.