Results 1 to 36 of 36
  1. #1
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274

    Seatstay TIG welding

    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.
    Seatstay TIG welding-seatstay-welding-1.jpg

    After that, I'll wrap from the inside, out around the bottom of the seatstays to the sides of the seatstays/seat tube.Seatstay TIG welding-seatstay-welding-2.jpgSeatstay TIG welding-seatstay-welding-4.jpg

    continued on the next post.

  2. #2
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.
    Seatstay TIG welding-seatstay-welding-5.jpg

    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.

    Seatstay TIG welding-seatstay-welding-6.jpg

    Voila! Piece of cake.

    Here's a couple more photos, while I have the camera out.
    Seatstay TIG welding-peter-bungum-2.jpg
    (Peter Olaf Bungum)
    Seatstay TIG welding-peter-bungum-1.jpg
    (Peter Olaf Bungum)

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

    Good luck, ladies and gentleman, you CAN do it!
    Last edited by BungedUP; 03-01-2014 at 04:02 PM.

  3. #3
    J_K
    J_K is offline
    mtbr member
    Reputation:
    Join Date
    Jan 2010
    Posts
    155
    Quote Originally Posted by BungedUP View Post

    Voila! Piece of cake.
    That sums it up!
    Just amazing.

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

  4. #4
    mtbr member
    Reputation:
    Join Date
    Jan 2011
    Posts
    860
    Wow, that's sweet!

  5. #5
    mtbr member
    Reputation:
    Join Date
    Nov 2006
    Posts
    224
    Awesome- This one is bookmarked for when I get there. Thanks for the clear explanation on a part I am kind of dreading!

  6. #6
    mtbr member
    Reputation: zank's Avatar
    Join Date
    May 2005
    Posts
    124
    Beautiful!!!
    Mike Zanconato
    Web | Instagram | Facebook | Flickr

  7. #7
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    294
    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

  8. #8
    Nemophilist
    Reputation: TrailMaker's Avatar
    Join Date
    Sep 2007
    Posts
    1,873
    As always;

    Priceless content. Thanks, Professor!
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  9. #9
    mtbr member
    Reputation: Meriwether's Avatar
    Join Date
    Jul 2007
    Posts
    430

    Seatstay TIG welding

    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?

  10. #10
    Moderator Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    6,092
    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
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.com/blog/
    instagram.com/waltworks/

  11. #11
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    71
    Thanks for the insight!

  12. #12
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    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.

  13. #13
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.

  14. #14
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    Quote Originally Posted by RCP FAB View Post
    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.

  15. #15
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    Theres nothing wrong with 880. I love it for mixed metals, stainless dropouts, etc. What brand er70 is your favorite?

  16. #16
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.

  17. #17
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    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

  18. #18
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.

  19. #19
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    109

    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.

  20. #20
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.

  21. #21
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    294
    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

  22. #22
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    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.

  23. #23
    Moderator Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    6,092
    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
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.com/blog/
    instagram.com/waltworks/

  24. #24
    mtbr member
    Reputation: Meriwether's Avatar
    Join Date
    Jul 2007
    Posts
    430
    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?

  25. #25
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    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

  26. #26
    mtbr member
    Reputation: Mark_BC's Avatar
    Join Date
    Sep 2012
    Posts
    771
    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.

  27. #27
    Moderator Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    6,092
    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
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.com/blog/
    instagram.com/waltworks/

  28. #28
    mtbr member
    Reputation: adarn's Avatar
    Join Date
    Aug 2009
    Posts
    377
    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!
    -Adam Sklar
    My blog
    Instagram

  29. #29
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    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.

  30. #30
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    109
    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.

  31. #31
    Plays with tools
    Reputation: customfab's Avatar
    Join Date
    Jun 2008
    Posts
    4,462
    Quote Originally Posted by RCP FAB View Post
    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
    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.

  32. #32
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    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.

  33. #33
    RCP Fabrication
    Reputation:
    Join Date
    Jun 2011
    Posts
    389
    Do you have a link to that article?

  34. #34
    The cat's name is jake
    Reputation: BungedUP's Avatar
    Join Date
    Aug 2003
    Posts
    274
    Quote Originally Posted by customfab View Post
    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.
    Last edited by BungedUP; 03-14-2014 at 08:09 PM.

  35. #35
    mtbr member
    Reputation: zank's Avatar
    Join Date
    May 2005
    Posts
    124
    Mike Zanconato
    Web | Instagram | Facebook | Flickr

  36. #36
    Shamisen Appreciator
    Reputation:
    Join Date
    Jan 2004
    Posts
    1,902
    Quote Originally Posted by customfab View Post
    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
    Sean Chaney :: Owner/Builder :: Vertigo Cycles LLC
    flickr :: www.vertigocycles.com

Similar Threads

  1. Cracked seatstay xlt 2.0
    By awareham83 in forum Jamis
    Replies: 6
    Last Post: 02-28-2013, 10:28 AM
  2. Leg rubbing the seatstay
    By PedalDangit in forum General Discussion
    Replies: 16
    Last Post: 07-18-2012, 11:56 AM
  3. Dent in swingarm 'seatstay'
    By Dan Gerous in forum Cannondale
    Replies: 4
    Last Post: 11-23-2011, 01:33 AM
  4. Need Carbon/AL Racer X Seatstay
    By struckman@charter.net in forum Titus
    Replies: 0
    Last Post: 03-06-2011, 05:15 PM
  5. Possible Welding flaw on my frame = welding "hole" = Crack?
    By Nick_M2R in forum Downhill - Freeride
    Replies: 6
    Last Post: 02-11-2011, 07:29 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •