# Shop Rumble: Dave B. (brazing) vs. Peter B (welding)



## BungedUP (Aug 18, 2003)

In another post, SOMEONE (cough *Dave* cough...) claimed to be 2X as fast at fillet brazing as anyone was at TIG welding. Being the SOB that I am, I questioned whether or not that was really true, and well, here we are! I'm not asserting I am faster, just that I think it's worth trying to determine a factual basis for this statement. I think it may have something to do with the fact that I used to be a CC teacher and a research scientist.

So we're going to start setting the rules here. I encourage betting, though avow any responsibility of the practice. I know everyone likes Dave, so they'll bet on him, which is fine by me. He guarantees he's faster, so I'll bet on him too, just to be gentlemanly.

We've decided already that the material in question will be 1.25" x .035", with a straight up 90 degree miter. I stated I thought we should start at turning the tanks on, welding/brazing 5 joints, turning the tanks off, and that's the stopping point. I might drink a ginger-ale in there somewhere too, as it's thirsty work and its good to stay hydrated. I think that the work should be mitered and cleaned, but can't be pre-tacked or pre-fluxed. I'm not sure about fixturing - I'd say the easiest thing to do would be to have no fixturing, just a table to work from. I'm not set on that, but it seems like the fairest method. 

I think neither one of us should have to do our best work, but it should be something that in some type of retail market, would be considered acceptable work for a fabricated structure. 

When we can get to it, we'll post videos of the work. I think they should be unedited time wise, so that viewers can see the actual real time of the clock. I'll use my word that there won't be any editing trickery to speed up the frame rate of the video or some such. 

Comments, bets, suggestions for rules, etc. are gladly entertained! 

This is all in good fun on my part, and seems like something someone should have done a long time ago!
Pew-Pew!


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## shiggy (Dec 19, 1998)

Sounds like fun, Peter.

How about two rounds? With one being done off the power grid


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## BungedUP (Aug 18, 2003)

Ha! I like it, Don.

No problem! My in-laws have a pretty good PV system - no need for the power grid, and no need to get my gases from the petrochemical industry. With Argon being the 3rd most abundant gas in the atmosphere, all I need is an air distillery system to get my consumable gas. It might be awhile before I get that though 

Just remember - this isn't about which is better, or stronger, or any of that BS. This is a quick draw between dudes - the methods are almost less important (though very much relevant). Doodle-doooooo waaaaah waaaaaah waaaaaaaaaaaaaa doodle doooooooo!

Edit: Also, I make my living as a brazer now, so I'm not in any way disparaging that joinery method.


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## j-ro (Feb 21, 2009)

I would say have the 't' mitered, cleaned and clamped in a c clamp, a bench vise should be available for both parties.

Once its done a seperate race can be held to see which one cleans up faster .....whats that? oh, the tig is done allready?..... I see.


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## Meriwether (Jul 26, 2007)

This is awesome. Too funny. I can't wait to see the videos.
My bet is on TIG because I just cannot conceive of TIG being slower than brazing! So...I'm really looking forward to watching Dave B in action! 
I vote for no fixturing, just a table, and perhaps a magnet or something simple.

Good luck boys!


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## sonic reducer (Apr 12, 2010)

j-ro said:


> Once its done a seperate race can be held to see which one cleans up faster .....whats that? oh, the tig is done allready?..... I see.


set the finish line as being ready for paint?


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## TrailMaker (Sep 16, 2007)

This should be fun.


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## Blaster1200 (Feb 20, 2004)

Instead of both of you doing butchered up welds merely for the sake of speed, why not time yourselves doing joints on frames that you'd actually sell? That would be a far greater comparison than both of you doing hack jobs for joints.


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## BungedUP (Aug 18, 2003)

Blaster1200 said:


> Instead of both of you doing butchered up welds merely for the sake of speed, why not time yourselves doing joints on frames that you'd actually sell? That would be a far greater comparison than both of you doing hack jobs for joints.


Hey! For the record, EVERYTHING I do is a hack job!

But that is a fair statement/idea. I did try and offer some kind of comparison in the thread that started this all, but Dave suggested we do a video recording of a joint being welded/brazed. I liked that idea for some reason.

Another issue would be that to be fair, you'd have to include the finishing time for the brazing (soaking and filing/sanding). At that point, a brazer wouldn't even have any chance at all competing with an average person doing a TIG process (from my experience anyway). This way, there is some chance that a brazer really is faster than someone doing a TIG weld process.

Perhaps the joints that Dave and I both do might come out looking pretty good - we'll see when the contest starts. It could be that people will want to buy our samples as memorobilia from

(massive echo) ShuuuuOOOOOOOOOOOOOOOP RUUUUUUUUUUUUUUUMBLE 2012!!!! (massive echo)

And who knows - Dave hasn't even posted anything here yet about this - maybe he lost interest (or maybe he has better things to do on a Saturday night than this). I was hoping that we could figure out some kind of winner/loser bet that would be fun for both the winner and loser.


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## Typo_Knig (Aug 8, 2009)

I'd skip the ginger ale. We all know water is the best for hydration...maybe some electrolyte replacement jizz.


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## bee (Apr 7, 2008)

This is a stupid race. It's like two guys racing on the street to see which car is faster. Who cares? Besides, everyone knows that TIG is way faster to do than filet brazing. It's not even close.


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## edoz (Jan 16, 2004)

What a bunch of haters, wake Dave up and get this thing going!


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## Live Wire (Aug 27, 2007)

bee said:


> This is a stupid race. It's like two guys racing on the street to see which car is faster. Who cares? .


Um..the two guys do, otherwise there wouldn't be a race now would there? And who doesn't like to watch a good race?


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## BungedUP (Aug 18, 2003)

Typo_Knig said:


> I'd skip the ginger ale. We all know water is the best for hydration...maybe some electrolyte replacement jizz.


OOOOOoooo! People at work order that stuff from time to time- it shows up in something just shy of a 5 gallon bucket, and I always think to myself, "AH! my bovine profilactic antibiotics just showed up!"

I'll see what I can find - but I do like the fizz.

For the record, I think stupid races are the best kind. There are enough serious ones out there (you know like those ones where grown men put on skin tight pink tights, wear helmets that are about 3 feet long, and drool on themselves while they pedal a two-wheeled jobby) that I think we should help provide some dumb entertainment to those in the mtbr frame forum. It beats watching tv (at least for me it does)!


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## dbohemian (Mar 25, 2007)

Oh, ol' Dave Henry is here.

This is all in good fun! I intend to show all the C2H2 haters what can really be done!

I am mid process in moving the shop so it might be a little bit before I have everything set up where you can see ( I got to put the lights up Bungedup, you are welcome to go first. I always liked sprinting from behind anyways.

But not to make this too complicated. Like a Drag race you run what you brung and lose or win that is what it is.

I just want to do one weld, Not five, I don't have all day for this, I am busy. Second, I am not going to clean up anything. The TIG guy would not and neither am I. I can make a fair industrial weld that looks fine. I will not make junk either. Good welding by default is quick welding. There is no separation.

I was just going to use a clamp, hold the two pieces, tack and then do a full circumference joint in a park stand. Add to that I will be using my gas fluxer (using Cycledesigns liquid flux-plug there), no paste and no cleanup necessary just as they do in factories like Brompton and my automatic torch ignitor.


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## TimT (Jan 1, 2004)

I do both and I'm with Dave on this. Brazing is faster. 

Tim


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## edoz (Jan 16, 2004)

I do both as well, and there's no way in hell I can braze as fast as I can TIG. I'm anxious to see this.


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## unterhausen (Sep 28, 2008)

if I hadn't seen the brompton video I never would have believed it. I'm not sure I'm motivated to learn how to braze that way, but it was pretty cool


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## j-ro (Feb 21, 2009)

Heres how it's going to go down. 

The brazing will be faster for a serviceable weld. I have no doubt.

Im sure it will be a good looking weld but as far as putting something out the door with your name on it the TIG is faster because you'd need to emery the braze wheras the tig would be done.

I still think its a fun challenge and something that everyone could do at home and post here.

The rules; 1- 90* T joint in 1-1/8" X .035 X 4130

minimum tube lengths of 4" each, maximum 6"

Mitered and cleaned on the bench

Bottles open or welder on. 

supplies at hand on the bench.

Time is started by the weldor and stopped by the weldor

Video can be shot by whomever but is not necessary for the contest.

post your time and your pictures. must have both to be a valid entry.


contest will run thru the end of february. winner will win something but someone will have to pledge something first.

Feel free to add rules if I forgot anything.

This will be fun.

Jake


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## Blaster1200 (Feb 20, 2004)

j-ro said:


> minimum tube lengths of 4" each, maximum 6"


That doesn't seem very friendly for working in a Park bike stand, and since you can't easily rotate it by hand, I would think that's a huge disadvantage for the brazer, unless methods not typical to frame building are used.


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## j-ro (Feb 21, 2009)

Blaster1200 said:


> That doesn't seem very friendly for working in a Park bike stand, and since you can't easily rotate it by hand, I would think that's a huge disadvantage for the brazer, unless methods not typical to frame building are used.


no problem, lets just change it up then untill everyone agrees.

I was just going off of the earlier rules of engagement.

I would work off the bench myself (tig) but am open to suggestions


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## BungedUP (Aug 18, 2003)

dbohemian said:


> Oh, ol' Dave Henry is here.
> 
> This is all in good fun! I intend to show all the C2H2 haters what can really be done!
> 
> ...


Dave, you're drawing first, since you say you're 2x as fast. Or is your gun stuck in the holster?

You know what ol' Jack Burton says...


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## Winter Bicycles (Jun 8, 2008)

How many bikes can one build by the time the challenge gets figured out?

=)


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## BungedUP (Aug 18, 2003)

I put 2 in the hole at work today...


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## customfab (Jun 8, 2008)

If brass brazing was faster it might look like a speed bump on the graph of joining methods outside of the frame building bubble.


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## edoz (Jan 16, 2004)

customfab said:


> If brass brazing was faster it might look like a speed bump on the graph of joining methods outside of the frame building bubble.


There are a lot more industrial applications for bronze brazing than you think. If bicycle builders were the only people doing it, then you wouldn't be able to buy LFB and flux at every welding supply store in podunk Tulsa, OK.


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## customfab (Jun 8, 2008)

edoz said:


> There are a lot more industrial applications for bronze brazing than you think. If bicycle builders were the only people doing it, then you wouldn't be able to buy LFB and flux at every welding supply store in podunk Tulsa, OK.


Can you buy flux in 5 gallon buckets at every welding store in Tulsa? Because you can buy 70s-2 in one ton spools at a good chunk of the weld supply stores in Tulsa.

Sure there are lots of applications for brass brazing but I can't imagine you could even put a line on the graph of filler materials used in industrial applications.


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## dbohemian (Mar 25, 2007)

customfab said:


> Can you buy flux in 5 gallon buckets at every welding store in Tulsa? Because you can buy 70s-2 in one ton spools at a good chunk of the weld supply stores in Tulsa.
> 
> Sure there are lots of applications for brass brazing but I can't imagine you could even put a line on the graph of filler materials used in industrial applications.


Would we make a distinction between bronze and all forms of brazing? Because if we include brazing as a joining method (using any common brazing filler metal) than it is still extremely prevalent.

Many cutting tools have brazed teeth on them, diamond wheels are brazed, jet engine rotors are brazed, dissimilar metals, piping, electrical, medical equipment, etc. There are so many applications it is hard to fathom.

I don't think we can relate heavy fabrication that measures how much wire someone can lay in an hour (5-6 lbs) to anything we do.


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## unterhausen (Sep 28, 2008)

my LWS has bronze filler, and flux coated bronze filler, but no flux. "use the safety-silv, that's what it's for"


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## Blaster1200 (Feb 20, 2004)

customfab said:


> Can you buy flux in 5 gallon buckets at every welding store in Tulsa? Because you can buy 70s-2 in one ton spools at a good chunk of the weld supply stores in Tulsa.
> 
> Sure there are lots of applications for brass brazing but I can't imagine you could even put a line on the graph of filler materials used in industrial applications.


Most situations for industrial applications don't call for a guy to drive down to his local welding store to pick up a gallon of flux, so using what you see at your local welding store or any other local welding store is not a viable means of measuring the popularity of a given method.

Just the same, how many local welding stores carry a wide selection of spot welds? Not many that I've seen. How's your car/truck body put together? Think spot welding is used much in industrial applications?


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## InertiaMan (Apr 16, 2004)

What a disappointment! For all the pomp and circumstance, this rumble never happened?

I've been a good internet citizen, found my way from the original thread over to this one, only to discover no final outcome?

Or did it move threads again?


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## Eric Malcolm (Dec 18, 2011)

InertiaMan said:


> What a disappointment! For all the pomp and circumstance, this rumble never happened?
> 
> I've been a good internet citizen, found my way from the original thread over to this one, only to discover no final outcome?
> 
> Or did it move threads again?


I did the same as you. Guys, what was the final outcome?
Enjoyed the banter though.

Eric


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## dbohemian (Mar 25, 2007)

Eric Malcolm said:


> I did the same as you. Guys, what was the final outcome?
> Enjoyed the banter though.
> 
> Eric


O.k. I was waiting for him to lay down (and I needed an helper) Here is a video and the final result.

I will preface that it was tacked before I began. I wasn't supposed to as per the rules but we pressed the wrong button on the camera and that part got lost.

From torch on to torch off 1:30 That is one minute and 30 seconds....I would have dropped my torch but I really like it.

[video]https://www.flickr.com/photos/bohemian_bicycles/15506496026/[/video]


__
https://flic.kr/p/15344213057


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## InertiaMan (Apr 16, 2004)

Nice looking braze Dave.

The video wasn't working for me -- audio played, but video was black the full time. Just my browser maybe? Others having issues?


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## dbohemian (Mar 25, 2007)

InertiaMan said:


> Nice looking braze Dave.
> 
> The video wasn't working for me -- audio played, but video was black the full time. Just my browser maybe? Others having issues?


Thanks. Not so good because I was going too quickly but you can also see the vid on my facebook page if that helps.

https://www.facebook.com/bohemianbicycles?ref=bookmarks


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## Eric Malcolm (Dec 18, 2011)

So........we await Peter....1:30mins, what can you do?

Eric


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## BungedUP (Aug 18, 2003)

Ha! Dave was waiting for me, I was waiting for Dave...

Well, I'll try to set something up sometime. It will be a bit now, but I'll make a point to try and get to it. I'm out of practice with bike work now, as I've moved on career-wise, and side-business wise, as of late I'm on the other side of the spectrum. Most recently, machining/welding 1/4" thick 316SS. I'll have to clean up the shop and setup for that, which might take a bit to get changed over. I'll put something together though...


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## dbohemian (Mar 25, 2007)

BungedUP said:


> Ha! Dave was waiting for me, I was waiting for Dave...
> 
> I'll put something together though...


I look forward to seeing what you can do. To open this up though, anybody interested in showing us a video of how fast they can TIG weld a joint is welcome in my book.

I hope it goes to show either way that brazing is not terribly slow and yucky like a lot of people think.


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## Eric Malcolm (Dec 18, 2011)

Dave,

I like the braze. You're using in-line flux?

I have only used in-line flux on one occasion some 5 years ago and was very impressed with it. If I were to look at serious work, this is the method I would look at. The cleanliness of the finished article after brazing sold it for me. Thanks for the Demo.

Eric


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## BungedUP (Aug 18, 2003)

Ok, Just to build some anticipation, I took some video. I need to put it together and have it hosted somewhere - but that's for tomorrow. I have a "Foyle's War" to watch before bed tonight...


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## Chad_M (Jul 11, 2013)

looking forward to it.


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## BungedUP (Aug 18, 2003)

Alright folks, here's the video I took:

Welding Duel 2014!  - YouTube

Let me know if there are problems viewing it!


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## adarn (Aug 11, 2009)

winner winner...

Your shop looks pretty awesome there! Is that a Monarch lathe? and that band saw... and that welding... jelly


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## frankzetank (Feb 5, 2013)

Cool! No winner, no loser really, just two joining technique shown by experts in there respective discipline. I envy the talent of both!

From my very newbie at brazing perspective, two things struck me in the exercise:
1- The inline gaz-fluxing system!! WOW, what a nice clean join with no post brazing soak. Me want on!
2- I need to practice, practice, practice to get better fillet shape. I spent wayyyyy to much time filing.

Thanks for the exercise. Fun to watch!


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## dr.welby (Jan 6, 2004)

BungedUP said:


> Alright folks, here's the video I took:
> 
> Welding Duel 2014!  - YouTube
> 
> Let me know if there are problems viewing it!


What's the background music? Stefan Hussong?


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## BungedUP (Aug 18, 2003)

dr.welby said:


> What's the background music? Stefan Hussong?


Jean Phillipe Rameau - La poule (the hen).


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## thedudeman (Nov 10, 2006)

[SUP][/SUP]Peter's video made my day and its not even 7:00! 
Saw so many cool things, even just little tricks for holding filler etc. thanks for sharing!
Scott


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## todwil (Feb 1, 2007)

Cool challenge great videos.........I can't find that Park tool truing stand timer anywhere did you make that also?


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## A. Spence (Sep 25, 2009)

BungedUP said:


> Alright folks, here's the video I took:
> 
> Welding Duel 2014!  - YouTube
> 
> Let me know if there are problems viewing it!


This is great, as is Dave's of course. Thanks to both of you for posting this.

Can you share any info/pic's on your lathe based mitering system? I've been thinking of making something similar and any inspiration would be welcome.

Lastly, the scraping videos on your YouTube channel are fantastic. That's a process I've been fascinated by for some time now. Was that a one off class or is it still being taught?

Thanks.

Alistair Spence,
Seattle, WA.


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## Chad_M (Jul 11, 2013)

Those were both great! I would buy a frame with either of those attachments.


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## InertiaMan (Apr 16, 2004)

Great videos from both craftsmen!

I propose a fatigue test on both joints to determine which fails first!


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## BungedUP (Aug 18, 2003)

adarn said:


> winner winner...
> 
> Your shop looks pretty awesome there! Is that a Monarch lathe? and that band saw... and that welding... jelly


Hi Adam,

Yep - that is a Monarch 10ee. When I first became interested in purchasing a lathe, I fell for their looks long before I knew anything about them (though I went through 2 other lathes before I was able to buy one). It was pretty rough when I bought it, but it's received a lot of love since then.

That band saw has really earned its keep. I knew I wanted a roll-in type saw from the beginning - the plain verticals have throat clearance issues, and the horizontals take up so much space unless they are small. The one thing that isn't as handy are angled cuts. While possible, it's definitely at a disadvantage compared to a horizontal. I also can't gang as many parts together as with a bigger horizontal - I actually recently lost a job in part because I couldn't gang parts well enough and keep the saw cutting costs down. Even still, that saw has MORE than earned it's keep - I bought it for $42, if I recall, and I'd be really reluctant to ever get rid of it.


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## BungedUP (Aug 18, 2003)

todwil said:


> Cool challenge great videos.........I can't find that Park tool truing stand timer anywhere did you make that also?


I had Park custom fabricate that for me. It cost a pretty penny to get them to do it, but it was worth it! And it was only a penny (but it WAS pretty).


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## BungedUP (Aug 18, 2003)

A. Spence said:


> This is great, as is Dave's of course. Thanks to both of you for posting this.
> 
> Can you share any info/pic's on your lathe based mitering system? I've been thinking of making something similar and any inspiration would be welcome.
> 
> ...


Hi Alistair,

I'd be happy to share any info about it that you want. I'll point you here:

http://forums.mtbr.com/frame-building/im-warning-you-probably-going-boring-896772.html

Anything you want to know that's not answered there, let me know!

Regarding the scraping class, that comes around somewhere every year or few. It takes place through a fairly organic process - I think there was another one that took place the year after that one, but they definitely don't take place in the same area each time. A few years back, it was somewhere in Oregon (I missed that one, even though it would have been closer). Richard King also does classes, and those might be more common, though I think he charges quite a bit (this one was pretty dang inexpensive, all things considered). It's a great experience for machine-geeks, and useful too - if you've got the confidence to start digging away on your own machines.


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## Eric Malcolm (Dec 18, 2011)

InertiaMan said:


> Great videos from both craftsmen!
> 
> I propose a fatigue test on both joints to determine which fails first!


Not necessary, you will find that in either method, the tube will deform and crumple close to the jointing, but rarely will the welds give way.

No winner really. It explores 2 different methods and concludes with the same result. We can have confidence in either method and displays art in both. Thanks guys.

Eric


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## TrailMaker (Sep 16, 2007)

Ha!

Even left the dip in there, just to make us hacks feel better!


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## A. Spence (Sep 25, 2009)

BungedUP said:


> Hi Alistair,
> 
> I'd be happy to share any info about it that you want. I'll point you here:
> 
> ...


Thanks for that link. Much appreciated.

Alistair.


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## BungedUP (Aug 18, 2003)

Well Dave, what do you think? Do you still contend you are twice as fast?

If not, I'd love to see an update to your facebook page, or at least a link letting people see the comparison...

:ihih:


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## smudge (Jan 12, 2004)

it's amusing that this was ever actually a point of contention especially once you factor in the flux removal and filing required with fillet.


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## todwil (Feb 1, 2007)

No kidding....I remember seeing a video of a guy brazing a folding bike and when he got done it didnt look like any post brazing cleanup was needed and he Hauled Arse!!!


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## dr.welby (Jan 6, 2004)

BungedUP said:


> Well Dave, what do you think? Do you still contend you are twice as fast?


Maybe you're just 4 times as fast as everyone else?


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## Eric Malcolm (Dec 18, 2011)

smudge said:


> it's amusing that this was ever actually a point of contention especially once you factor in the flux removal and filing required with fillet.


I think that you are missing the point here a little. Weld time was the object of this exercise.

Both demo's were done by proficient operators, and the braze used in-line flux which did not require the usual clean-up. In a production setting where this brazing method would be used, the frame goes straight to the coating process as is, and given a prep sand blast that cleans the frame of all contaminants prior to coating in both methods, so what is the issue for you here?

If you have talent with Tig - use this method, same goes for Braze. Different methods for different people. Highly valued are people who can do both really well, but they are hard to find.

Eric


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## dbohemian (Mar 25, 2007)

BungedUP said:


> Well Dave, what do you think? Do you still contend you are twice as fast?
> 
> If not, I'd love to see an update to your facebook page, or at least a link letting people see the comparison...
> 
> :ihih:


Great video BungedUP and I am beaten, in that i did say I could go twice as fast and that obviously is not the case.

Although, I think it did plainly show that brazing is a relatively fast process. At best, one of the most highly skilled TIG technicians I have seen was able to match me with all your technology at your disposal 

To Sean's comments about flux cleanup and filling. First the flux cleanup with a fluxer is a 30 second soak in warm water. You know we do far more than that preparing for any paint job. 
Second, why do we have to file? That braze would have looked pretty decent under paint with no work and when I do have more time it looks far better. I don't know why we have come to think that all fillets in the U.S have to look super smooth but Curtis in England for instance has made quite a name for himself doing unfilled fillets. Steve Garro as well so in that instance, no there would not be additional time needed.

In the end I do spend a couple of extra hours over a TIG welder dealing with finishing and the like but that seems reasonable when asking a premium for a bicycle frame.


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## BungedUP (Aug 18, 2003)

Hey Dave,

I'm glad we were able to do this. It really was great fun and I think it provided good entertainment to boot! Thanks for being a good sport - I know plenty of people who would have been offended or irritated by some of the things I said (which were genuinely intended to be in good fun). 

I agree - your brazing really was very quick, and of excellent quality. 

When working at Bike Friday, there were many joints that were just much quicker to do via brazing, and so that's how we did it - many of which were filleted joints. We did very minimal cleanup work (though there was some) as well, which you and others have mentioned, due to the use of in-line fluxers. While at Co-Motion, the brazing we did utilized both in-line fluxers and paste flux - just using the gas fluxer didn't give the protection from oxidation that was needed, but we were brazing a variety of less common things (like couplers), and with a different gas than what most people use (Chemtane type product). Again though, brazing was the right tool for the things we were doing at that time. Most of the frame was welded (which I also eventually performed, after being one of 2 brazer/finishers), but there were some things that were just better off being brazed. I didn't do too much fillet work (a small amount, but not much), but watching Bob W. do the finish work on the fully filleted frames (which were extremely rare while I was there - I think I made more quints than I saw full fillet brazed frames) was both really impressive from the standpoint of his eye for detail and skill, and also painful to watch from an effort standpoint. Bob was REALLY good at that type of work (through massive amounts of experience) and tireless, especially considering he was older than most of the rest of us by 10-20 years or more, but that business took a long time. I could weld certain tandems in 24 minutes (not counting fixturing and tacking). Bob spent half a day just doing the finish work on a single-rider frame with fillets, and I don't think anyone there could have touched that time. He was finishing (and probably still does) them to an extremely high degree though - pretty much flawless.

Anyhow, again - I appreciate the chance to have done this with you, and would absolutely love to talk with you about your work if I ever bump into you in person.

-Peter B.


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## Montanadan (Sep 19, 2014)

edoz said:


> There are a lot more industrial applications for bronze brazing than you think. If bicycle builders were the only people doing it, then you wouldn't be able to buy LFB and flux at every welding supply store in podunk Tulsa, OK.


I'm forever amazed at where I find bronze brazing, and more importantly, the strength it has. In my mind there is no replacement for a good weld, but brazing is even more of an art and has great strength properties.


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## Montanadan (Sep 19, 2014)

dbohemian said:


> In the end I do spend a couple of extra hours over a TIG welder dealing with finishing and the like but that seems reasonable when asking a premium for a bicycle frame.


But that extra time in finishing yields a unique and truly graceful form, more so than even a beautiful TIG weld can produce, at least to my eye.


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## Montanadan (Sep 19, 2014)

I still have a hard time really understanding what holds the pieces together with brazing. Welding is easy to understand...you are literally melting both your filler and your base metal and forcing them together, in a sense. But with brazing your base metal never melts, so it is pure friction that holds it all together?


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## TrailMaker (Sep 16, 2007)

Hey;

Brazing is essentially gluing the joints together with a really tough but resilient adhesive, but through the heating process, the grain of the parent metal is opened, and I'm sure that some amount of infusion of the filler metal does occur into that grain structure. So too is the strength partially due to surface area of the fillet, I'd wager.


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## unterhausen (Sep 28, 2008)

Montanadan said:


> I still have a hard time really understanding what holds the pieces together with brazing.


inter-atomic forces are a pretty amazing thing. From that perspective, brazing works the same as welding.


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## Montanadan (Sep 19, 2014)

unterhausen said:


> inter-atomic forces are a pretty amazing thing. From that perspective, brazing works the same as welding.


Cool...thanks for the info. So if I'm understanding correctly, the base metal will slightly open up on the surface at which point the filler is sucked into all the tiny (microscopic) pores and crevices creating an interlocking "matrix" type bond? In my mind I imagine it as the same thing that hold paint on to metal, only on a much smaller scale with harder adhesion properties. Base layers (metal or primer, or other layers of paint) must be roughed-up, 'scuffed', to promote adhesion. The paint flows into these little cross-hatch scratches and gives the paint 'tooth'; something to hang on to. Sorta the same principle?


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## smudge (Jan 12, 2004)

dbohemian said:


> Great video BungedUP and I am beaten, in that i did say I could go twice as fast and that obviously is not the case.
> 
> Although, I think it did plainly show that brazing is a relatively fast process. At best, one of the most highly skilled TIG technicians I have seen was able to match me with all your technology at your disposal
> 
> ...


I wasn't intending to sound disparaging about fillet brazing and I'm sorry if it came across that way. I know some builders can lay down fillets pretty quick, but I've never seen anyone do it nearly as fast as a competent welder. That was my only point.

Unfinished fillets are more the exception though, no? I've been a huge fan of Brian Curtis' for getting near two decades and that dude can lay down fillets better than most. I'd personally like to see unfiled become the trend in custom bikes because, IMO, you see more of the hand of the builder in them.


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## alshead (Oct 2, 2007)

Digging this up out of the ashes. Dave- what is the inline flux you were using? Do you use that regularly?


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## dbohemian (Mar 25, 2007)

alshead said:


> Digging this up out of the ashes. Dave- what is the inline flux you were using? Do you use that regularly?


I use Cycledesigns gas flux. I have two gas fluxers and I do use them regularly. I use additional paste flux almost all the time, the fluxers are a bit of extra insurance for a well fluxed joint. You can fillet braze directly without any additional flux but I often put a bit on the inside of the joint to facilitate a little flow in there.


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## alshead (Oct 2, 2007)

Gotcha- thanks- I think I started to put that together after I posted the question. Gas fluxer looks sweet, but a little rich for my hobbyist blood right now. Some day, maybe I'll retire, buy an anvil jig, some machinery and a gas fluxer... dreams...


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## dbohemian (Mar 25, 2007)

alshead said:


> Gotcha- thanks- I think I started to put that together after I posted the question. Gas fluxer looks sweet, but a little rich for my hobbyist blood right now. Some day, maybe I'll retire, buy an anvil jig, some machinery and a gas fluxer... dreams...


The gasfluxer I used for the demonstration was home built. I am guessing something around $125 dollars in materials. Good welding project. Give it a shot!


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## life behind bars (May 24, 2014)

Home made gas fluxer with pics.

https://www.google.com/url?sa=t&rct...D=5080&usg=AFQjCNEX829VpBv77kz3eT6i8Ndw-kpiPQ


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