# Seatstay TIG welding



## BungedUP (Aug 18, 2003)

In an earlier thread, people were talking about dealing with TIG welding seatstay/seat tube clusters. I thought I'd take some photos of how I weld these areas, in case it is helpful to someone struggling with this part of the frame.

I start by placing a puddle of material that bridges both seatstays, and the seat tube. I place this puddle such that it forms an elevated platform that is higher than the true root of the 3 tubes. 








After that, I'll wrap from the inside, out around the bottom of the seatstays to the sides of the seatstays/seat tube.














continued on the next post.


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## BungedUP (Aug 18, 2003)

At this point, if things are looking too warm, I might move on to another section of the frame. Typically, I move fast, so things aren't too hot, and I'll continue welding around the seatstays from the bottom to the top, until the 2 welds join again at the top.








This is a really good time to move elsewhere, unless you are dealing with thicker tubing. In this case, the seatstays are .6mm or less, so I'll go weld near the BB or the HT for a short time, then come back.

Once I've come back, I'll start zippering the central area up. If possible, I like to either end a little above the tight space where the weld comes between the seatstays, or in the central "pad" where I started from. In this case, I chose to end above the tight space, so I welded down from the top, then started at the pad and brought the weld out to meet the central weld.









Voila! Piece of cake.

Here's a couple more photos, while I have the camera out. 







(Peter Olaf Bungum)







(Peter Olaf Bungum)

P.s. Amperage = 120 a, pulse 1.8pps, on 28%, background 5%.

Good luck, ladies and gentleman, you CAN do it!


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## J_K (Jan 18, 2010)

BungedUP said:


> Voila! Piece of cake.


That sums it up!  
Just amazing.

That's undoable for me, at least anything under .035"


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## febikes (Jan 28, 2011)

Wow, that's sweet!


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## thedudeman (Nov 10, 2006)

Awesome- This one is bookmarked for when I get there. Thanks for the clear explanation on a part I am kind of dreading!


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## zank (May 19, 2005)

Beautiful!!!


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## afwalker (Apr 26, 2012)

Thank you for sharing! Very helpful and about the hardest to do weld.
I notice the heatsink which I think is a big help.
Good point on waiting for the heat to let off, I get impatient sometimes.
And thanks for ALL the numbers!!! I have been doing 30%on and 15% background, I will try that lower background.
Do you use different background settings on other welds like the headtube/downtube?
thanks
andy walker
Walker Bicycle Company | | Walker Bicycle Company


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## TrailMaker (Sep 16, 2007)

As always;

Priceless content. Thanks, Professor!


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## Meriwether (Jul 26, 2007)

Beautiful work and thanks for the tips! 
It looks like the backs of the stays are welded together and not fully to the seat tube, similar to the DT/ST joint? 

The biggest problem I have is getting the torch head positioned and seeing the area clearly when the miter angle is so steep. Welding by brail.
Do you use a smaller cup size or pencil torch?


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## Walt (Jan 23, 2004)

Awesome. Where were you in 2003 when I was blowing holes in what felt like a hundred consecutive seatstays trying to figure this out?!? 

-Walt


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## jds2835 (May 22, 2011)

Thanks for the insight!


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## RCP FAB (Jun 15, 2011)

Is that er70 I see there? s2 or s6? I am about done with 880T when I finish up the 3 pounds I have left.


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## BungedUP (Aug 18, 2003)

Well good! Sounds like it may be of some help. I was actually thinking of you, thedudeman when I took the pictures (though also that it might help others too).

Andy - I do change things, depending on what I'm doing. Keep in mind that I come across a lot of different stuff in any given day - touring tandems, race tandems, race singles, touring singles, triples, quads, quints, 29'ers, 26ers, bikes for other companies under contract with the company I work for, aluminum frames, stainless steel parts, stems, etc. I largely keep with the same philosophy for steel frames though - keep the heat down as much as I can, by melting fast, then moving. On a typical single bike, I'd keep those same settings, except I'd boost the total amperage to 130+ on BB areas, dropouts, etc. 

Meriwether - You have it right. It's just not safe to weld down to the seat tube, as I often need to grind the sides of the seatstays to get them to sit properly on the seat tube itself (due to interference). I have only moderate eyesight anyway, so I never see anything all that well. I do often weld around corners I can't see, but I can usually get a decent line of sight in the seatstay area. Partially, by starting at the bottom and working out, it helps with that. Sometimes, You can weld the inside portion of the seatstay that is across from you, with the filler rod reached around the seat stays (hard to describe). By that I mean the first side you weld with filler toward you (coming out, welding from inside bottom with frame upside-down), then start in the middle pad again and welding out away from you, with the frame in the same orientation (does that make ANY sense?). It can help with visibility. I don't use a pencil torch - just the same WP-20 I always use, with a #6 cup. By welding down the seatstay until it opens up enough to transition the torch around, you don't really need anything else to do it. Soemtimes the tungsten gets run out a ways, but it's never too bad unless you are trying to do that AND weld past an apex (which blocks gas flow). 

Walt - Ha! You were way ahead of me in 2003 - I was probably still welding truck beds, and teaching community college biology classes up and down the Willamette Valley. I was trying to figure out how to MIG weld in a garage where the electricity was actually hooked up to my neighbors place (unbeknownst to me for awhile). I kept taking the power out, then fiddling around with my fuse box in the apartment, trying to figure out how to get the power back. I'd go back down to the garage, and magically the power would be back, but it took me awhile to realize that it was because the neighbors had to flip THEIR breaker! Yeesh - it's embarassing to think about how dumb I was sometimes back then. I'm probably even dumber now, but at least I'm willing to recognize it.


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## BungedUP (Aug 18, 2003)

RCP FAB said:


> Is that er70 I see there? s2 or s6? I am about done with 880T when I finish up the 3 pounds I have left.


That was ER70S-2, but good stuff. I also use ER70s-6 at times, and also I have used some 880T more recently. Good ER70S-2 is GREAT. BUT, there is a lot of variation in ER70s-2, so it can also be just terrible to use. I'm in the process of compiling some information about that, which I'll share when I have a whole article about it.


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## RCP FAB (Jun 15, 2011)

Theres nothing wrong with 880. I love it for mixed metals, stainless dropouts, etc. What brand er70 is your favorite?


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## BungedUP (Aug 18, 2003)

I think that 880 (or 312) has some VERY desireable qualities, especially in tight joints where undercutting is typically prone. You are right about dissimilar metals as well - it seems much better than 309L for those purposes. I don't prefer it to good er70s-2 in other areas though, although my coworker I think does prefer it universally (goes to show that personal preference has a lot to do with such things). 

As far as ER70S-2 are concerned, it isn't brand that is important, as they seem to all source wire from different places. It is country of origin that seems to make the biggest difference. Korean wire tends to have the most consistent properties, and when dealing with tubing from Reynolds or Fairing, it hides the "crusting" that those tubing products tend to exhibit. Wire from Turkey, Italy, and other places varies, such that sometimes they are ok, and other times they are quite bad. 

I have found another source that draws and cuts wire for TIG welding purposes, and has certs to verify it's content. The sample I received from them was EXCELLENT, and at a good price (less than $7 per pound). I haven't bought more material from them yet, but plan to do so personally, as well as trying to get the shop I work for to start using it, as consistency of filler has been a real issue for us. This same place also sells 312 for an EXTREMELY good price. Again, I can post more information later on.


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## RCP FAB (Jun 15, 2011)

Mind sending me some information on that place? I am getting ready to place an order of filler.

Also, I have always known weldmold 880 to be SIMILAR to ER312L. Did weldmold say it is a 312 filler or it IS ER312L? (this is just something I'm curious about, has nothing to do with frames)

Thanks


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## BungedUP (Aug 18, 2003)

RCPFAB - I am happy to disclose information on welding supplies, technique, etc., to anyone, assuming I feel halfway confident in the quality of the information, and I feel it won't get me into trouble!

The recent samples have come from Global Laser Tek. The man to contact is Dan Polto - I think they are in Ohio. They specialize in welding wire in small diameters, but Dan has been able to produce some .045" wire for us. I think they work in the 10# quantities. Maybe they'll do smaller, but I am not confident in that. 

As to the 312 question - that I don't know at the current time. If/when I find out more, I'll pipe up when I remember to. I haven't run into 312L, or at least that I noticed.


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## Crispy01 (May 4, 2011)

*Welder Setting*

Thanks for the info mate,
Just a couple of questions about your setting if it is OK.

1. Amperage, I take it 120 is the peak?
That seams to put your average around 35, which seems normalish to me, but if 120 is your average, your peak must be up near 300 at least. gotta be a heavy duty 3 phase machine. I weld 2" sch40 butts on that, and I weld hot??

2. Your pulse setting?
Is such a heavy pulse common in the bike industry, I commonly run around 60/30. But that is coming from a pipe background. I guess the heavy pulse restricts your penetration but gives the wide well defined stack of coins? also helping control blowing holes?

Thanks for your time.

PS
I am finally building my flex plate Ti dually this week. photos next week.


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## BungedUP (Aug 18, 2003)

Hi Crispy,

I am currently using a Dynasty 200 DX, and the 120 amps is "peak" amperage as set per the main amperage control knob. On a Dynasty, seeing the actual amperage is near impossible for me - it seems to jump all over the place. Analog meters like on my CP300 MIG machine are much nicer for viewing actual amps. 

I don't think that this style of pulse is common, but that is based on seeing what other welders at just 2 shops are using. I initially learned using 60/40, but after spending a lot of time fiddling, and thinking about what I was doing, I eventually settled on this style for thin-walled tubing, common to single bikes. I have suggested this style to a few other professional welders, and all have been fairly tickled with the results. 

On tandems/triple/+ frames, I use more amps yet, and sometimes with different background and peak periods, but the same idea - a big blast, followed by a "resting period". You might be familiar with titanium pipe welding techniques - I believe that this is most similar to that, though I understand that to have an even longer rest period, at least the way that some do it.


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## afwalker (Apr 26, 2012)

I think I spot a Miller Dynasty DX 200 in one of those pics, so no the peak is not 300.
The pulse of 1.8 per second is not so much. 30 pulses per second or 60 or 150 is starting to be alot, but 1.8 not so much I think. I often do 1 pps and that gives a nice metronome like rhythm, and 1.8 is good too as you get used to the dabbing of the filler. You can go a little hotter at 1.8 pps I think and move quicker
cheers
andy walker


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## RCP FAB (Jun 15, 2011)

There's not really an average amperage 2 pulses per second. Its a more defined high/low.

When you get to 30 pps and higher you will start needing more amperage than you would with out pulse.

Everything between 2 and 30 pps will cause your brain to melt.


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## Walt (Jan 23, 2004)

So I'm usually a no-pulsing old school kind of stick-in-the-mud... and I tried these settings and they're pretty great. Welds very nicely indeed but damned if I can see what the hell is going on. Pete, do you have any tips there? I'm not on any kind of fancy autodark silliness, just your basic flip-down hood and I've got no problems when foot pulsing or just welding entirely manually. 

-Walt


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## Meriwether (Jul 26, 2007)

i'd love to hear too BungedUp. 
I just switched a couple of frames ago to pulsing and even though it's going pretty well, i feel like i'm using the Force, especially in the acute angled tight spots. 
A slower PPS helps keep track of where you're going (say...1.5 instead of 2pps). On my hood i have it set at the 9 shade so if you're using a darker lens on your non-auto hood maybe a lighter one will help?


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## RCP FAB (Jun 15, 2011)

Am I the only person who uses high speed pulse?

150 amps
50 pulses per second
33% on time
33% background

I still have a hard time giving up the control, and the benefits of high speed pulse


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## Mark_BC (Sep 19, 2012)

Wow this is mostly Latin to me. I am thinking of taking a frame building course in May. It is 2 weeks and we get to build our own frame out of Chromo. I have a symmetrical 135 mm fatbike in mind I'd like to do but I have no idea about all this specific welding technique stuff. I hope / presume the instructors will be able to guide us through it.


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## Walt (Jan 23, 2004)

Don't get intimidated. This is just geeks geeking out. You do not need to waste tons of brain cells on pulse settings to weld a nice fun functional bike frame. Have a blast at your class (and remember that tire/chain clearance when doing your design!)

-Walt


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## adarn (Aug 11, 2009)

Woah, I just tried that 28%on 5% off business and it's pretty crazy! I've been sticking closer to 40/60, but I just layed some of the nicer beads that I have. Thanks!


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## BungedUP (Aug 18, 2003)

Walt - I can understand what you mean about visibility. My coworker is constantly trying to figure out ways to see better using this method. For me, I don't see that great to begin with, and I tend to sort of unfocus my eyes when welding a lot of the time. I don't mean I let my eyes go all blurry, but rather I don't really look at anything in particular, and then just feel my way around the joint. If I try to see where I'm going, I often can't. But I know where to go intuitively, probably mostly just through a tremendous quantity of repetition. I can see a change in light if something goes wrong, and I'll stop or adjust. I don't study each individual puddle too closely, at least usually. 

When I'm welding aluminum, it's very different. I can see much better (due to the brighter, more constant light), and everything is bigger. I will allow more direct attention to the placement of filler, size of bead, etc. This is the same when welding non-bicycle TIG or MIG weldments of thicker size. These often allow me to skip the pulsing and perform some type of weave. When making steel bikes though, I just "feel" my way through each joint more than see it, and I just know when it's going well, or when it's not. Sounds sorta dumb when I write it out, but that's the best way I can describe it.


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## Crispy01 (May 4, 2011)

Thanks for the rely BungedUP,

Yeah I love your pulse settings, I have only ever really gone close to that heavy of a pulse before on Inconel and some cast Iron before. My previous Ti has the same slow pulse but more of a 60/40 spread.

But guess what, Not any more. Its pretty rare for welders to share much of their pulse settings. Cheers.

With regards to peoples eyes going scewed...
Its all about being comfortable and not trying to focus on the flash but just keep your eyes on the weld pool edges or just behind the weld pool as you travel. Using your peripheral vision to see where you are going.
Shade 9 sounds right for me, because its the low side of the pulse is were you see what you are doing.

Hope this helps.


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## customfab (Jun 8, 2008)

RCP FAB said:


> Am I the only person who uses high speed pulse?
> 
> 150 amps
> 50 pulses per second
> ...


I run 250 Hz for pretty much everything. If you read the article Miller did on pulse rates it's the sweet spot. I'd say 98% of builders use pulse for vanity and not what the weld engineers designed it for.

OP, I could have misread it but it sounds like you start your final segment on your tack. That's a bit of a bad ha it. You want to weld through the tacks and normalize them. Otherwise you're only adding to the bitterness.


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## RCP FAB (Jun 15, 2011)

I use 250pps, 33% on time, 33% background for welding plate to tubes (disc tabs for example). This reduces the scaling on the back side by about 90%, and it also agitates the puddle so much that anything on the back side that gets misses with a wire brush floats right out.


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## RCP FAB (Jun 15, 2011)

Do you have a link to that article?


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## BungedUP (Aug 18, 2003)

customfab said:


> I run 250 Hz for pretty much everything. If you read the article Miller did on pulse rates it's the sweet spot. I'd say 98% of builders use pulse for vanity and not what the weld engineers designed it for.
> 
> OP, I could have misread it but it sounds like you start your final segment on your tack. That's a bit of a bad ha it. You want to weld through the tacks and normalize them. Otherwise you're only adding to the bitterness.


There are only 2 tacks - one on each seatstay near the top. The central "pad" is not a tack - it's where the weld starts. The last segment starts from the central pad, and there is no reasonable way to do it any other way. In any event, TIG welding is not really capable of "normalizing" the tubing or tacks anyway - that requires a high temperature heat treatment process to perform, with a specific cooling regime.

I'm also curious how using any particular welding technique is "vanity". I use machine parameters that allow me to get the job done quickly, with the best quality that I can achieve, and not wear me out as I have to do it for 40+ hours a week. If not using a pulser (such as when working with aluminum, or welding thick sections not related to bike fabrication) is better suited to the work, I don't. When pulsing is better suited, I do. I would imagine all other serious fabricators, including those that make bikes, probably feel the same way. I don't think one's vanity comes into play at all.


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## zank (May 19, 2005)

RCP FAB said:


> Do you have a link to that article?


Miller - Superior for Stainless: High-Speed Pulsed GTAW Boosts Productivity, Quality while Reducing Distortion


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## smudge (Jan 12, 2004)

customfab said:


> I run 250 Hz for pretty much everything. If you read the article Miller did on pulse rates it's the sweet spot. I'd say 98% of builders use pulse for vanity and not what the weld engineers designed it for.
> 
> OP, I could have misread it but it sounds like you start your final segment on your tack. That's a bit of a bad ha it. You want to weld through the tacks and normalize them. Otherwise you're only adding to the bitterness.


the slow pulses still allow you to do "what the engineers want" by reducing the overall heat input into the joints. I run my setup very close to what BungedUp is running and find myself constantly having to check my speed anyhow or I'll outrun my argon coverage. In theory, 250 hz might allow me to weld faster, but it's worthless unless I were able to use a trailing shield which is impractical.

125-150A
30% on
10% bg
1.2-1.5pps


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## Sepp (Oct 13, 2007)

I realize this is an old thread, but...maybe someone can chime in to answer the following questions:

I have a 200DX and currently practicing sharpening my tungsten (that's what I mostly do besides balling them up). So when playing with the pulse settings that were recommended by Mr. Bungum, I am still wondering: is it bad practice to push the foot control down all the way, and go faster if things get too hot, or do I better maintain a steady pace, and back off on the amperage?

Also: when pulsing...do I push/back off the pedal with every advance, or do you keep it steady?

Thanks,

Joe


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## life behind bars (May 24, 2014)

Sepp said:


> I realize this is an old thread, but...maybe someone can chime in to answer the following questions:
> 
> I have a 200DX and currently practicing sharpening my tungsten (that's what I mostly do besides balling them up). So when playing with the pulse settings that were recommended by Mr. Bungum, I am still wondering: is it bad practice to push the foot control down all the way, and go faster if things get too hot, or do I better maintain a steady pace, and back off on the amperage?
> 
> ...


YMMV. Hit it hard and get the puddle started and then start tapering off on the amperage. If you find yourself adding pedal you backed off too much. No real need to pulse the pulse so to speak if you're set up correctly. If anything, you'll probably find yourself tapering from start to finish due to the heat input. That's usually what happens to me anyway. If it gets too hot, stop, move and weld in a different location.


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## Meriwether (Jul 26, 2007)

Everyone has their own way of doing it but for me, I have experimented with what settings work for the given junction (tube thicknesses) and ramp up to get the puddle going and then floor it before tapering off at the desired stopping spot. So I end up changing pulse settings a lot. 
But for junctions with acute and obtuse angles (DT/HT and DT/ST) i leave room to ramp up amps for the acute and back off for the sides and top when needed.

Along these lines, some will set the pulser at the highest they use on any junction and then back off the pedal for the thinner wall tubes and obtuse angles. 
So basically just use your foot to regulate how much heat goes into the tubes just like you would with straight amps (non pulsed). 

The more uniform your rate of movement the better your alignment because the heat will be more evenly distributed and more equal filler use, and the weld will look better. 



Sent from my iPhone using Tapatalk


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## Sepp (Oct 13, 2007)

Well, I had only thin bicycle tubing to practice on, so that's part of the frustration I guess. 

Got myself thicker profiles today, and that's quite a piece of cake. But it helps me understanding what to look for, and seeing the puddle and the filler. So after the thicker profiles I went back to the bicycle tubing, and it already went a lot better.
Hitting it hard indeed and then backing worked fine, allthough I am still going slow, and probably overheating way too much.

I did all this with generous set 150 amps (just to see if the pedal can regulate the heat well enough), and adjusted with the foot. Left the pulse feature off as I feel it makes me nervous.

Is pulsing the way to minimize heat input, or should I not bother at all if it feels weird. In other words: should I learn welding with pulse from the go? Or can I do my first proto frames without it?

@pulse: do you dab filler rod with the pulse, or whenever you fell like it? Do you follow the pulsing rhythm at all when adding filler?

Thanks for answering - your help is greatly appreciated!


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## life behind bars (May 24, 2014)

Sepp said:


> Is pulsing the way to minimize heat input, or should I not bother at all if it feels weird. In other words: should I learn welding with pulse from the go? Or can I do my first proto frames without it?
> 
> @pulse: do you dab filler rod with the pulse, or whenever you fell like it? Do you follow the pulsing rhythm at all when adding filler?
> 
> Thanks for answering - your help is greatly appreciated!


If you learn to successfully weld without pulse you'll be a much better welder imho, especially when you do utilize pulse. Adding filler with the pulse is how you can minimize the heat input, using just enough amperage to fuse the additional filler. Disclaimer, I pulse with my pedal, the pulse on my machine is rarely turned on especially with the short segment welds on a bicycle frame, but play around with it, time under the hood is what makes you better if you can dissect what's actually going on. Heat sinks and back purge will help too if you're not already utilizing them.


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## Sepp (Oct 13, 2007)

life behind bars said:


> If you learn to successfully weld without pulse you'll be a much better welder imho, especially when you do utilize pulse. Adding filler with the pulse is how you can minimize the heat input, using just enough amperage to fuse the additional filler. Disclaimer, I pulse with my pedal, the pulse on my machine is rarely turned on especially with the short segment welds on a bicycle frame, but play around with it, time under the hood is what makes you better if you can dissect what's actually going on. Heat sinks and back purge will help too if you're not already utilizing them.


That's great info - thanks!

pulsing with the pedal has my preference for now. I have nothing besides argon and a welder to successfully build a frame, so it's just the beginning of a journey.


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## Meriwether (Jul 26, 2007)

Tig technique is covered on the web with weldingtricksandtips.com's youtubes, many other places, but really should get some oversight with a pro (class) to start out if you haven't already. 

In most people's opinions you should learn to weld withOUT the pulser. Figure out how to modulate heat input with the footpedal and torch pace. Pulsing helps with maintaining a consistent look to the bead and with the right settings can reduce the HAZ and distortion but should not be what you start out using. Learn to get the puddle going with straight amps and use dab filler as you go to cool the puddle and keep moving it along. You need to add filler so you don't undercut the tubes and create a stress riser. 

150 amps is too hot unless you're welding 1/4" wall tubing! With straight amps it almost doesn't matter what you set the amps at if you are regulating it with the foot pedal to get the puddle going and move along fast, adding filler at a regular interval to cool the puddle as you go around the joint. But you don't need any more than 70 amps for 0.9mm wall tubing. 

It takes a crapload of time to get confidence with welding, took me a year of almost daily practice before i could weld a thinwall bike frame, and i find super thinwall seatstays (0.6mm wall) challenging still after 6 years!


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## Sepp (Oct 13, 2007)

Yeah I enjoy weldingtipsandtricks whenever I can. I will look into doing a wleding class, even if it's just for a day.



Meriwether said:


> ...adding filler at a regular interval to cool the puddle as you go around the joint...


I like that! - will keep that in the back of my head. It doesn't have to be the foot pedal only to keep me from blowing holes...



Meriwether said:


> It takes a crapload of time to get confidence with welding, took me a year of almost daily practice before i could weld a thinwall bike frame, and i find super thinwall seatstays (0.6mm wall) challenging still after 6 years!


I don't like that!


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## Erichimedes (Jul 30, 2010)

life behind bars said:


> If you learn to successfully weld without pulse you'll be a much better welder imho, especially when you do utilize pulse...


It makes me happy to hear that opinion, but it's funny to me because I simply cannot get used to using the pulser on my machine. I get a smaller HAZ and better looking bead on even thin road bike tubing without the pulse, but I just have such a hard time when I try to time things with the pulser. I'm sure the main problem is just that it's so much easier to revert to what we know instead of practicing what we don't.

One method I haven't tried extensively is the lay-wire technique where you leave the wire in the puddle and let the pulser create the "dimes." I'm pretty sure that's what UBI teaches.

This discussion is interesting though. So many variables to TIG welding.


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## life behind bars (May 24, 2014)

Erichimedes said:


> It makes me happy to hear that opinion, but it's funny to me because I simply cannot get used to using the pulser on my machine. I get a smaller HAZ and better looking bead on even thin road bike tubing without the pulse, but I just have such a hard time when I try to time things with the pulser. I'm sure the main problem is just that it's so much easier to revert to what we know instead of practicing what we don't.
> 
> One method I haven't tried extensively is the lay-wire technique where you leave the wire in the puddle and let the pulser create the "dimes." I'm pretty sure that's what UBI teaches.
> 
> This discussion is interesting though. So many variables to TIG welding.


I had lots and lots of practice welding on flat and larger diameter tubing/pipe, the under the hood time helps when transitioning to the thin walls and small diameters of bicycle tubes.


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## Sepp (Oct 13, 2007)

How do you usually tack thin walled tubing (steel) on a bike frame? With or without filler rod?

I have tried to have succes without rod doing it two different ways:

- getting a puddle going on the bigger part, and pull it over to the smaller part, more often resulting in blowing holes on the smaller part.

- hitting the pedal quickly with high amperage (as described for sheet metals). While this technique kept the damage limited, it didn't want to join when there was a small gap between the tubes.

How do you guys do it? Do you recommend using filler rod? If so, do you point the tungsten right into the gap, and get a puddle started before adding filler? Again, I am too worried of blowing a hole...

Also: I am building with tube blocks on a flat surface for now, but was wondering if the fancy fixtures a la Anvil allow access to place tacks on the NDS of a frame at all, or would one have to remove the frame for that? I guess not, since that seems the whole purpose of a fixture, right?


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## Walt (Jan 23, 2004)

Use a dab of filler. Procedure is basically:
-Start puddle on whichever tube isn't mitered/coped.
-Dab of filler as you move the heat to the mitered tube.

I always use filler when tacking. It can be done without filler but there's no particular benefit and often the resulting tacks are so weak they'll break when you're doing finish welds (or even just tacks on the opposite side of the joint) and mess everything up.

Most modern fixtures have enough access to tack the back side of the frame, yes. I have the oldest Journeyman fixture ever basically and even it has plenty of room to reach around and do the tacks. I wouldn't try to do finish welds on the NDS in it, but you probably could if you really really wanted to.

-Walt


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## Sepp (Oct 13, 2007)

Walt said:


> Use a dab of filler. Procedure is basically:
> -Start puddle on whichever tube isn't mitered/coped.
> -Dab of filler as you move the heat to the mitered tube.......


Thank you very much Walt - that's the exact kind of info I was looking for. Tubes coming in tomorrow. Files are ordered...No way back now...

I want to keep it all low key for now... If I succeed (getting satisfaction of building a frame that will last me a year or longer), and see a future of building my own frames (not as a business at all), I will look into getting myself a jig too.


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## Walt (Jan 23, 2004)

For hobby building (and hell, for plenty of pros over the years too) a beam type jig can be great for TIG. Wide open all around, just roll your chair to the backside to tack.

This is a good example:
https://forums.mtbr.com/frame-building/your-home-made-jigs-765202-2.html#post8970243

They are cheap and easy to build, the big drawback is setup time (lots of measuring required, and you've got to flip the frame to do the rear end with many of them).

-Walt


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## Sepp (Oct 13, 2007)

Oh that's cool, but I since I have a full woodworking shop at my disposal, I think I want to work with wooden tube blocks (long ones) and tack the frame parts on a flat surface (like the giant pro table saw) for now.

I am worried as to what the tubes/parts will do when they start feeling the heat, but even a fixture is not a guarantee for straight building I was told. 

If I like building frames I will just spend the coins for a good fixture. A lot of money, but hey, some people buy a frame for 3K every year. So if I can build whatever I desire in the future (and not just for me, but wife and kid as well), it must be a good investment.


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## Walt (Jan 23, 2004)

The fixture has almost nothing to do with building a straight frame, actually. Good tight miters and a decent weld sequence are what you need.

-Walt


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## Sepp (Oct 13, 2007)

So let me ask you...is there a source for a proper weld sequence on a frame?
It's been said that everyone has their own way of doing it, but I'd be happy to have some sort of guidance, so to not completely screw up my first frame.

All (I think) I know, is that I want to weld the seat tube to the BB first, and then finish the front triangle. From there I will weld on the chain stays, and last I will add the seat stays.
But I have not much clue about in what order to weld the entire circumference of a tube to another.


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