Tig Steel from zero

[Amaro Bikes]

Thanks for the detailed reply. Since my last message i have welded the st to the bb and mitered the ht and the dt which are now ready for tacking and welding. i noticed by just using my jig as a reference that the top of my st is about 2mm off center. is this something that i should try and fix now before i weld the rest of the front triangle. i talked to a welding expert at work and he suggested running a weld pass along one side of the bb/st weld to pull the st a little bit over. given that it is already welded i cant really foresee being able to simply bend the st over without causing damage, so the re-melt via welding seems like my best option. are there any other tricks to aligning tubes once they are already out of alignment.

Scott

Hi Scott.

I would try to go through two paths for your question:
1-How to solve this disalignment: For sure you should solve it before joining it to the rest of front triangle. I'm not that big fan of cold setting, specially if you're working with thin tubes (I don't know what specific tube are you using). The advice of making a dressing pass is not bad, but you should be cautious on not putting too much heat. If you make a second pass make 100% sure the welding area is completely cold after any previous welding around. This second pass should help you out to correct some of this disalignment. Obviously, you make the pass on the opposite side of the disaligned side. Also try to avoid as much bb shell heat deformation as possible (heatsink, etc) or you might end up checking alignment based on a deformed bb wich can get you trapped in a snake endlessly eating it's tail
2-How to minimize possible disalignments in the future: Most important of them all, a perfect miter it's key. Then make sure you tack it good and sound (I do make two tack points, a small dot in the back and a very short pass (3 beads) on the front). Once tacked and before welding, check alignment so you know what is your playing field and decide on sequences and where you should take the tubes inc ase it's not 0mm. Finally make a good sequenced weld (3-6, 9-12, 6-9, 12-3 or the like).

Hope it helps

Cheers

[schollen]

Aimar,

Thanks again for the help. I finished my first frame pics below. I started on my second frame and i have two initial questions:

1. I would like to add water bottle holders to this one. i dont currently have an o/a setup, nor know how to braze. paragon makes some fusion weld water bottle mount boss's, www.paragonmachineworks.com - MS1018304StainlessSteelWaterBottleBossFits14quotHo le38quotOD, have you used something like this? i am concerned about the effects of welding to the middle of the down tube. i am fairly confident that i wont burn a hole, i welded the brake bridge to the seat stays on my first bike and that turned out well, but i dont know if there will be negative effects of welding at the middle of the down tube (the down tube is also a little thinner than my seat stay and i will be welding right next to a hole.....could be tricky) i saw that some people online tig weld with SiBronze filler rod, effectively brazing. in this case i could get a standard bottle boss. do you have any recommendations here. ideally i would just tig weld the bottle boss but it seems risky.

2. on my first frame i used hood style rear dropouts. despite being difficult to weld, they were pretty straight forward on how to setup. i am using flat fixed angle dropouts on my next bike. the angle on the dropouts are 70 degrees vs my planned 68 degrees. my plan is to just file down one side of the dropouts to make them 68 degrees. as i understand i need to slot my stays. my question is how to close off the end of the stay with the dropout. if i just slot the stay and insert the dropout there will be an open end to the stay. should i just pinch down the ends of the stays into the dropouts? i have done some looking around and have not found much clarification on this procedure, maybe im just not looking in the right spots.

thanks so much for any help you can offer.

Scott


Danielles finished bike.jpgDanielles finished frame.jpg

[Andrew R Stewart]

Scott- If you plan on making more frames or doing other metal joining projects you should really consider leaning how to braze.

To answer your two questions. You could get Rivnut bottle bosses that don't need any heat. They get compressed into place. But as the steel is a hard and thin wall don't expect the RivNut to hold as well as with Al. tubes. AnI'veve seen far too manriveteded bottle bosses spin loose on Al frames to trust them there even. For the stay ends you could weld a plug into the hollow stay ends. Then slot. Or weld a tiny plate over the open ends. Or design the drop outs with a bend that covers the stay ends.

Or if you could braze both questions would be answered by 100+ yearsframe buildingding techniques. Andy.

[Amaro Bikes]

Hi Scott

First of all, congratulations on your first child, well done.

About your questions, I'm 100% with Andy on brazing being quite a desirable thing to learn if you consider doing some more frames.

Your first question is pretty much something I was wondering myself when I started, and here are my conclusions after many different steps:
-You should not be worried about fusion welding the h20 bosses on the downtube, even if it's too thin, as it's not a place where frame suffer extreme forces (as would happen with the STI bosses below ht/dt junction, for example), so if you have good control of the heat and manage to do a proper fusion weld (first metl the h20 boss and then "pass" it to the frame tube) it should be all good, main problem might be to make it look nice enough (apart from being good on low amps and heat control).
-This "aesthetic" question takes you to step 2, where if you want to make something a bit nicer (we're not all as talented as Tyler with the tig torch for perfect beads on such small spaces), I 100% recommend you to get hands on a small portable brazing equipment, pretty good priced and really easy to use. Obviously they're only intended for small pieces (bosses, cable stops, etc), but as you alredy TIG, it should be more than enough to help you out with all those small parts. The most important one, at least to my own experience, is the STI bosses, as they're placed at one of the most demanding places on the frame, where downtube suffer quite a lot of stress and any heat excess will translate into future failure, specially if using ultra thin tubes.
-Having one of those small brazing kits, will let you also the chance to include some "fancy" parts as "flourished" bosses, etc, without worries of tig melting the nice shapes.
-I would not recommend the ruvetted bosses, as not only they look a bit cheap on such nice bikes as you probably would like to offer, but in the long therm equation they usually tend to have some problems and might need re-riveting one or two wich might have got loose over time.
-I was pretty no-no over the brazing equipment for a while, considering the sif bronze tig brazing, etc, but now I can only tell you it was the best investment to do and only regret not doing it before.
-And the most important of all, once you have your hands on those brazing skills, you'll also have the chance to make much more possibilities reality, say special dropouts, lugs, racks, etc. I'm not building fillet brazing or lugs, not even brazed dropouts (I'm too big fan of the hooded breeze ones for TIG), but it's always great to know you could eventually do any of those works if needed.

About the dropouts, I think I understand your problem and here is another example of how handy could be to have one of the small brazing kits. Anyway, if only having the TIG option, I would go with one of those:
-Build yourself small plates to fit on the space or "holes" left by the tube cut, then you can "cover" them with those plates.
-If space is not too big, you can fill this area with small amount of filler, go with the thick ones (1.6mm) and low amps, so you would be able to ad material without melting too much material or make it flow away. Afterwards, you can work with the files on making it look as seamless as possible
-As Master Ricard would say, show the seatstay who's boss and try to "press" it so to make the end hole a bit oval, this way it will be a bit easier to tig weld all without too much holes to fill.

I hope any of the ideas makes any sense, although I know neither my english or my ability to explain things is too much of a gift... :o

But anyway, ask as many questions as you might need, and will try to help best possible way.

Cheers

[schollen]

Aimar / Andy,

Thanks again for the response. i suppose that is the answer i expected to hear...just didnt want to. Anyway, over the weekend i went out and bought a used o/a torch. i am about to order some rod and flux and would like to confirm i am ordering the right stuff. from looking around the internet it looks like i need bronze for fillet brazing and large gaps such as the dropouts, and silver for doing small gaps as well as stainless parts such as my eyelets for rack mounts. my plan is to order:

Bronze:
flux - gasflux type b
rod - gasflux c-04

silver:
flux - gasflux type h or harris stay silv black flux
rod - 56% silver

Additional questions:

- for the small stainless rack mount eyelets, will the 56% silver flow to easily to braze those on. i am guessing this will be somehting like a very small fillet braze and as i understand silver is not good for fillet brazing but necessary for stainless.
- for the droupout, at the end of the chain/seat stay, where there will be a hole a between the stay and the dropout, do you just fill this with bronze filler and then smooth with sandpaper, or do you use a plug in the end of the chainstay. i looked on paragon for plugs but only saw very large plugs for large diameter stays than what i ordered
- i did not use sti adjustment cable stops on my first bike. it was a little bit of a pain to get the front deraileur set up. are sti mounts the norm for road bikes. its been a while since i have owned a geared road bike

thanks again for all the help.

Scott

[Andrew R Stewart]

Scott- The brazing products you mention are solid and many thousands of frames have been made with them. I use both the filler and fluxes myself. there are other choices and some will argue their benefits but your choices are far better than others out there.

When brazing the rack with SS tubing you'll be using the silver. So both tight miterand adequatete diameters are needed. If you're really worried you could add small gussets in the high stress joints, but most don't.

Stay ends at drop outs can be filled with brass or plugged with a piece of steel. Either way filing the end shape you want is common. An exception to this is when you fill the stay end with brass and then draw it slightly inside the stay end. Resulting in a slight concave shape. This stay end treatment is a style point that builders settle into their own one. Some like chisel filed look, others like a more organic flow to the contours.

Being a wrench for so long how I a route the cables and allow for their adjustment and servicing is VERY important to me. All my cables have some sort of barrel adjuster and are slotted for fast cable removal. At work when I deal with production bikes (which don't have the same focus on ease of servicing or set up as my bikesevolvedvolved to) i will use in line cable adjusters to at least get some fine tuning cable tension ability. Andy.

[schollen]

Well i am well under way with brazing. I brazed on the cable stops on the down tube, pictured below, I had already bought the non sti cable stops so i figured i would just use those with an inline cable adjuster. I also brazed on 3 of the four water bottle bosses. on the 4th one i think i may have overheated the flux. the flux turned black and i was unable to get the silver rod to flow properly around the joint. Anyway, my question is cleanup after brazing. From looking around online it looks like there are a lot of different methods from wire brushes to chemical removal. I am going to have the frame sand blasted before painting. Will this take care of all the cleanup, or should i do some prep pre sand blast.

Thanks again for all the help and support.

Scott


Brazed on cable stops.jpg

[Andrew R Stewart]

Many will soak off the flux with water, hotter is faster. Burnt flux will require mechanical methods, sanding, filing, blasting. I suggest the least abusive (sand paper/production cloth).

As a general rule you want to deliver the frame to your painter in the condition that doesn't require any further finishing, no sanding, no rust removal, no vent hole plugging, no flux removal (including the insides of tubes), no thread chasing, no facing, no reaming or honing, no cleaning of oilprotectentsts. The closer you get to this ideal the better the work the painter can do without extra trouble. Or without you're saying after the finished paint job " gee I thought he'd take care of that before painting". Andy.

[Amaro Bikes]

Andy spoke wise words (as usual) with real good points to consider (ones you usually end up learning after wrongly painted frames, etc), and of course never forget the flux inside of the tubes (easy to solve if braze ons are brazed on tubes alone before any structure is build).

[schollen]

Thanks Andy and Aimar,

I hope i am not being too much of a bother with all these questions. I am trying to make this second bike without all the small mistakes i had in the first one, and that is requiring me to be much more attentive to detail...which is creating a lot of questions. To fix all my rear wheel alignment issues i rebuilt the portion of my jig that holds the rear dummy axle, pics below. when i measure from shaft that holds the bb in place to the left and right side of the dummy axle i noticed that i measure about .3-.5 mm longer on the left side. i am not really sure where this offset is coming from. i dont think it is the aluminum clamp that is holding my dummy axle, my best guess it that it is small imperfections in 80/20 aluminum extrusion.

i calculated that this offset would put the edge of my wheel about 2 mm off center between my chainstays. is there an easy way to correct for the small offset once my dropouts are brazed to my chainstay? i am not sure if i am being too picky about this or if i should try and correct out that small difference.

Scott


dummy axle mount.jpg

[GEBLA]

Hi Scott,

all parts in the world have tolerances, as soon as they leave the CAD system. So most likely it is a tolerance add up.

Most likely you already use your main horizontal 8020 beam as reference. Have you checked how true it is? How did you check that your BB-Post is perpendicular to that? If it is perpendicular, check if your dummy axle is perpendicular to the main beam. You will need a low tolerance toolmakers square and toolmakers ruler to check that. During your measures you will find out what parts add to the tolerances and can make chances.

BTW: Since your jig has no built features to avoid that most likely the BB Post will bend forward as soon as you apply heat to a chainstay. And since it is more flexible at the unconnected end the distance to the dummy axle will be greater on the drive side after heating one or both chainstays.

Greetings,
Georg

[Amaro Bikes]

It's hard to say where could the disalignment come from without all the details, could be from the jig, heating, clamps, etc, etc. As georg said, many facts can play their part.

About your question on how to correct this disalignment, if it's just about the dropouts being off the center line by 2mm, this is no toruble at all and you can do it as simply as cold setting the rear. Normally this is no trouble at all when just the chainstays are welded or brazed, and it comes more and more difficult and not so ideal to do once the seatstays are also brazed/welded, and almost no way at all once the bridges are part of the rear triangle.

[schollen]

Aimar,

The dropouts are centered perfectly. The alignment problem is that the right side of the dummy axle is about .5 mm further from the bb than the left side of the dummy axle (my dummy axle is not perfectly parallel with my bb). this will cause one of the dropouts to be .5 mm further away and therefore when the wheel is placed in the dropouts it will be at an angle with the center line of the bike. I am guessing from Georg's response that i should get my jig as perfect as possible before mitering my chainstays. In the end the i still wont have it PERFECT. i am guessing that there is not a good fix for unequal length chainstays once the dropouts are brazed. Getting the chainstay lengths perfectly equal seems to be my biggest alignment problem because i cant just cold set to fix them as i could if one dropout was too high or if the dropouts werent centered.

Scott

[GEBLA]

Hi Scott,

either the BB-Post or the dummy axle (or both) is not perpendicular to the main beam of the jig. Find out what is the case first bevore thinking about correcions. Different distances for the chainstays would be a mega-hassle, so better solve the problem now, everything else will be more work.

Greetings,
Georg

[Amaro Bikes]

Aimar,

The dropouts are centered perfectly. The alignment problem is that the right side of the dummy axle is about .5 mm further from the bb than the left side of the dummy axle (my dummy axle is not perfectly parallel with my bb). this will cause one of the dropouts to be .5 mm further away and therefore when the wheel is placed in the dropouts it will be at an angle with the center line of the bike. I am guessing from Georg's response that i should get my jig as perfect as possible before mitering my chainstays. In the end the i still wont have it PERFECT. i am guessing that there is not a good fix for unequal length chainstays once the dropouts are brazed. Getting the chainstay lengths perfectly equal seems to be my biggest alignment problem because i cant just cold set to fix them as i could if one dropout was too high or if the dropouts werent centered.

Scott

Ok, now I understand the problem, and yes, deinetly is a big problem with not much solution after brazing. Better to do as George said, check both bb and dummy axle perpendiculairty within the jig, otherwise the rear wheel alignment might get really nasty.

Sometimes all the parts are well made separately and it's just a small problem with the bolts fixing them to the jig, or any other small detail making it all wrong.

[schollen]

Thanks all for the input. after about 4 or 5 hours of checking all my parts i found that it was the vertical square 80/20 post that holds the dummy axle mount. i rotated it around to each side and in one orientation it proved to be square with my jig. apparently i shouldnt just blindly just 80/20 to be made perfectly square. it also turns out as you mentioned Aimar, that how i tighten 80/20 parts together makes a big difference. i think i will eventually try to start having more of my parts machined for my jig than relying on 80/20.

Scott

[schollen]

I finished welding the front triangle last night....and ran into a couple problems.....I burnt a hole at the the st/tt junction, pictures below. additionally, when the welding was finished the frame was a little out of alignment. first off my welding procedure:

1. tack st to bb in jig. one tack at front and back as Aimar suggests.
2. take st/bb out of jig, check alignment and weld. weld in 4 quadrants to help reduce deformation
3. check alignment of st/bb, leaning slightly to left side of bike, 1-2mm. cold set using rod through bb and pushing on the top of the st
4. tack dt/ht/st.
5. take tacked front triangle out of jig. weld dt first. alternating between bb and ht sides. everything seems to go smoothly...i probably should have checked alignment after this but didnt
6. weld tt, alternating between st and ht sides
7. burn small hole at the bottom side of st/tt junction. i dont think i had the best view of the puddle....source of all my welding mistakes :(
8. use probably way too much filler and cover up hole
9. grind down some of excess filler from hole patch
10. check alignment.
- st is off slightly to the left by about 1 mm
- ht is off slightly to the right by about 1mm.
- dt seems to have shrunk by about 1-2 mm. had to move ht slightly closer to bb (about 1mm) to get frame to fit in jig

questions:
my plan is to try and cold set out the small offsets in the front triangle before welding the back triangle by cold setting just as i did when the st earlier
1. is this worth doing now, or should i wait to weld on the rear triangle, and adjust the frame as a whole
2. is my welding procedure correct? should i be welding the dt and tt at the same time or does doing them separately make more sense
3. from the pictures below does it look like i am overheating the joints. i tried to compare to the pictures Aimar posted. it does not look at dull as those. i am using ERNiCrMo-4 welding rod. this was given to me from a guy at work that said it should work will with chromoly and be more ductile and less likely to crack than ER70
4. should i be concerned about the hole patching?

Scott

bb weld:
https://lh6.googleusercontent.com/-7...o/P1010812.JPG

tacked front triangle:
https://lh6.googleusercontent.com/-6...o/P1010815.JPG
https://lh4.googleusercontent.com/-x...o/P1010816.JPG

st/tt weld, hole fill:
https://lh3.googleusercontent.com/-Y...o/P1010818.JPG

bb/dt weld:
https://lh5.googleusercontent.com/-O...o/P1010819.JPG

ht/tt/dt weld:
https://lh4.googleusercontent.com/-E...o/P1010820.JPG

[Amaro Bikes]

Hi Scott.

It seems more or less ok to me, although each one has a different way and you'll find out the best way for your own procedure, it's a questions of practice and see what works best with you. Never think that just because anyone use to do something one way, this is the only way to do it so, althoug it's always a good way to learn seeing what the most experienced TIG people like Tyler/Dario/Drew/Brent/Kris/Zank/etc do their procedures, they know their stuff!

About the procedure, here are my humble opinions:
-I'm not that much fan of cold setting, and would go better for some dressing pass (once weld is 100% cold) or even better reconsider the welding sequence of the following steps so to get the frame into your alignment needs. Once you get practice on it you'll see there's a lot to say with the sequence on next steps so to put the frame where you want it to be.
-In the 4th step I don't know if you just tack dt/ht/st as you wrote it, in such case I would recommend to include the tt tacking, so you take the whole front triangle tacked out of the jig. But this is just how I feel it working better with my way.
-You already saw a quite nice improvement, to check alignemnt during the welding process and not wait till the whole front triangle is welded, as you'll have much more chances of getting your triangle exactly where you want it, updating the TT sequence based on how it all has gone with the dt&st.
-Another key factor you already experienced is to always be in the best possible situation, including position and puddle vision. Much better to stop welding and reposition yourself rather than try "blind" or "unconfortable" as chances are to become a cheddar cheese master ;)
-About welding temperature, to me the welds look just a bit too hot (matt grey close to the puddle), so probably will try with a bit faster traveling speed. Ironically, to get less overheat you might need to put higher amps so to manage a faster speed, but hard to know what's your exact situation without being exactly there. Have some tests on sample tubes and try different amps and fastest speed you can manage without being unconfortable with it or not getting enough penetration.
-Also, another question you ask about alignment, to me it's better to get the front triangle completely aligned before getting the rear involved, as once you get more variables on the frame is much more difficult to try to fix one part without affecting the others. But I know some builders work differently, so it's all up to what works better with you.
-About the hole, obviously this is no good at all, but it's something every tig welder has gone through during the practice time. Just learn the lesson on position/vision and you'll also manage to know if a hole is coming before it happens, but once you get more practice on it you'll hardly have to deal again with any hole as you'll be able to weld under "control" ;)

I hope it helps a bit, but of course drop any other questions or doubts, no pro!

Cheers

[schollen]

Thanks Aimar,

Got the front triangle pretty straight, finished brazing the dropouts, welded the chainstay to the bb and have almost got the seat stay welded to the seat tube. i have abought 1 cm of welding left at the seat stay/seat tube junction that i cant quite figure out how to weld....its a really tight corner, tighter than my last bike and i keep almost burning a hole in the seat stay, got any tricks for welding these really tight areas? also what is there to do about all the flux left in the chain/seat stays. i cant get it out as i did the flux from my water bottle mounts since the dropouts are already on.

Scott

[Amaro Bikes]

Hi Scott,

Well, Murphy's law is the one taking care of making the more challenging welding part to be the last one (seat stays). No much secrets about it rather than practice, practice and practice, and using a gas lens you would be able to take the tungsten further out so to gain better access to those tight areas, specially hard ones when big sized road frames, etc.

I don't know if any of the true masters on tig technique would have any better advice, but from my experience I can only tell you it will become "easier" with more and more practice. And as previously said, most of TIG is about good positioning and puddle view. If you manage to be "confortable", rest goes much easier. Try to make "essay" passes before going for the real thing, so you take the torch and rod, and have a try as if you're welding, then you can decide if this position/route will work with you or if better changing to a different position.

Sometimes I really consider all the rear monostay designs and the road sloping geometries are just excuses so to make the welders life easier ;)

For the flux, I think it's already discusses in many threads here, but it's as any other flux you might have on the frame, make sure to have the vent holes properly made so when you proceed with the water/bath it will just go away through those holes together with the water.

Cheers