# after nearly 30 frames I am moving over to Tig and would like some setup advice.



## jgerhardt (Aug 31, 2009)

So, like the title says, after nearly 30 frames I am throwing down some money and moving over Tig welding. Honestly I prefer the look of a clean brass fillet, however I am just tired of cleaning them.

My questions revolve mostly around purge setup. I am planning on using a setup very similar to what Zank does on this forum thread.

What I am curious of is do you guys weld your whole frame in the jig? or just tack it in the jig and then weld it in the stand or on a table?

If you just tack it in the jig, is it necessary to purge the whole frame just to tack it?

Right now, I am using a Bringheli jig so it is not setup for purging and it would be a lot easier to tack the frame together in the jig and then purge it on the stand.


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## Walt (Jan 23, 2004)

Assuming you are talking about steel, you don't *need* to purge it at all. 

I like to to it, and I do the following:
-Tack front end in jig, running purge. Probably this is useless/pointless but it makes me happy.
-Weld everything I can easily reach (ie 10:30-1:30 and 4:30-7:30).
-Yank out of fixture, plug up, and finish the sides of the joints.

I weld the chainstays entirely in the fixture. I tack the seatstays and then finish weld out of the fixture. So pretty incoherent, really, but it works for me. 

Welcome to the dark (fast, utilitarian?) side!
-Walt


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## jgerhardt (Aug 31, 2009)

What about heatsinks?
With brass I was getting some decent distortion at the headtube if I didn't leave a enough sticking out above the top tube and downtube. For the seattube I pretty much had to do a fair amount of reaming as well. Interestingly enough I hardly had to do any reaming at all on the bottom bracket.

I planning on getting/fabricating a heatsink/purge for the seattube to help with the distortion but I was not sure about the bottom bracket.


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## Walt (Jan 23, 2004)

I just use a big aluminum slug in the BB shell. Works fine. On the seat tube side, a heat sink will help but you'll still be reaming.

How much head tube did you have sticking out above/below the TT/DT? That might be more of a heat input/speed/technique issue than something a heat sink will solve. You should be able to keep it pretty round if you move reaonably fast and don't throw a ton of heat into it.

-Walt


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## Walt (Jan 23, 2004)

Oh, and I use some aluminum pressed/slipped in heat sinks on 44mm head tubes (they're intended more to adapt to my ancient Anvil fixture than to act as heat sinks, but they probably do that a little bit too). On 34mm ones I just use some tapered washers from Paragon. No significant distortion problems either way. I have an ancient DIY expander plug I made for 27.2 seat tubes. For 30.9 and 31.6 I don't use a heat sink, doesn't seem to be much different, at least for me.

-Walt


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## dbohemian (Mar 25, 2007)

jgerhardt said:


> So, like the title says, after nearly 30 frames I am throwing down some money and moving over Tig welding. Honestly I prefer the look of a clean brass fillet, however I am just tired of cleaning them.


TIG is awesome. I am not going to start that argument but you do realize it is possible to braze to nearly net shape and size in one shot? A main joint takes 10 minutes with a dynafile and sandpaper. BB's a little harder for sure. Then again becoming really kick ass as TIG welding is a couple of 1000 hours as well.

I do wonder why everyone feels they have to file fillets when the textured stack o' dimes look is cool everywhere else? I would think that if one could braze well then a good look may just be leaving it the way it is. It would save a ton of time. Most consumers don't give two craps about that stuff anyways.

As far as purging, it has been said here. I tack, then weld outside the fixture using the appropriate purging plugs and such.


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## peanutbutter (Feb 18, 2005)

*I don't want to derail this thread, but...*

I don't want to derail this thread, but I figured a heatsink question would be appropriate. Solid Bikes makes some fun little bits for building bikes and I was planning on using their integrated headset headtube. This style, in fact:








Solid also makes heatsinks for these headtubes:








My question is, since the heatsinks are made of steel, will they end up welded to the inside of the headtube? The heatsinks are long enough that the bead would overlap their insertion depth, and it would be nice be able to get them out afterward, you know, so I can ride the bike later...


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## Walt (Jan 23, 2004)

Yeah, if you aren't 100% sure of your welding skills on thin stuff, steel heat sinks in steel tubes is asking for trouble.

Do you have the appropriate reaming equipment for those head tubes? Standard reamers won't work for integrated bearing setups.

-Walt


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## shirk (Mar 24, 2004)

dbohemian said:


> I do wonder why everyone feels they have to file fillets when the textured stack o' dimes look is cool everywhere else? I would think that if one could braze well then a good look may just be leaving it the way it is. It would save a ton of time. Most consumers don't give two craps about that stuff anyways.
> 
> View attachment 1016727


I want to get to the point of no file brazing with the stack of dimes look.

Need to find the coin for a gas fluxer.


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## dbohemian (Mar 25, 2007)

shirk said:


> I want to get to the point of no file brazing with the stack of dimes look.
> 
> Need to find the coin for a gas fluxer.


I built my own as a second. It wasn't free but I think it works as well if as the gasflux one. it was a fun project.


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## shirk (Mar 24, 2004)

dbohemian said:


> I built my own as a second. It wasn't free but I think it works as well if as the gasflux one. it was a fun project.


I did a quick look for some diy plans. Need to look into it further. Care to share a few pics of yours?


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## life behind bars (May 24, 2014)

shirk said:


> I did a quick look for some diy plans. Need to look into it further. Care to share a few pics of yours?


A very thorough discussion with pics here,

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


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## Meriwether (Jul 26, 2007)

jgerhardt said:


> What I am curious of is do you guys weld your whole frame in the jig? or just tack it in the jig and then weld it in the stand or on a table?
> 
> If you just tack it in the jig, is it necessary to purge the whole frame just to tack it?
> 
> Right now, I am using a Bringheli jig so it is not setup for purging and it would be a lot easier to tack the frame together in the jig and then purge it on the stand.


I do pretty much that with some other things: 
- I tack the acute angles of the 12 & 6 locations in the jig first, then the 3 & 9 after, jumping around to each joint on opposing sides (backpurging too but...not really needed probably). Tacking the acute angles first really pull the tube into the other tube locking the coped tube tight against the other.
- In the fixture I will do a short pass on the top of the downtube before I load the top tube since it's sometimes tight in there. I also weld the 4-8 on the bottom of the downtube while backpurging.
- I feel that welding the vertical parts of the tube (10-2ish and 5-7ish) keep it aligned better once i take it out of the fixture to weld the rest, but i usually don't do this because I can get better welds out of the fixture and use heatsinks. 
- i use Sputnik heat sinks to weld the rest of the frame out of the fixture where it's way easier to position the frame to get a good view of the joint.
- Zank's backpurge setup is awesome, i have a more junky setup but definitely get a dual flowmeter for the tank.

Having said this, I would have to agree with dbohemian - if you can pull off unfinished fillets like him, they do look pretty cool and may be the way to go since you're so far along that path. But if you already are good at TIG then it's a cool option to have.


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## Walt (Jan 23, 2004)

I think getting to the level of fillet mastery you are showing takes at least as much time as TIG, so that part is a wash, and there's still flux/flux removal/cleanup that TIG doesn't require. 

I mean, if I was that good at fillet, I'd certainly do it for some stuff. But if your focus is on function rather than form, it's hard to argue with TIG in terms of overall speed. 

-Walt


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## jgerhardt (Aug 31, 2009)

Thanks for the advice everyone, a lot of good info here,

Dave, I appreciate your ability and those like you who stick to brass brazing. I feel that as far as cosmetics go a brass brazed frame is un-paralleled, when the joint has been filed down. Even now for me it takes a lot longer than 10 minutes per joint to clean up, and again I still have to soak the frame (my wife is getting tired of having frames in the bathtub for hours on end).


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## peanutbutter (Feb 18, 2005)

For those of us getting into (and hopefully better at) TIG, what should the back side of joints look like? In order to ensure full penetration, should there be some solidified puddle on the inside of the tube, or just some discoloration or what? Thanks guys!


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## life behind bars (May 24, 2014)

peanutbutter said:


> For those of us getting into (and hopefully better at) TIG, what should the back side of joints look like? In order to ensure full penetration, should there be some solidified puddle on the inside of the tube, or just some discoloration or what? Thanks guys!


No puddle on the inside, it'll be impossible to ream. Your looking for max penetration without filler going through to the back side.


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## peanutbutter (Feb 18, 2005)

Oh good, that's what I thought I was shooting for! Thanks! So long as there's no puddle in the there is there an issue getting a steel heatsink stuck? Does backpurging help with any of this or is it simply to keep contaminates out?


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## customfab (Jun 8, 2008)

Even if you are a competent welder you should use aluminum or preferably brass heat sinks. Using stainless or steel will only lead to problems, plus they don't soak up the heat nearly as well so you're just losing all the way around. The heat sinks posted above, look like they might be intended solely to keep the shape at the end of the heat tube stable. They don't appear to extend deep enough into the head tube to do anything worthwhile to absorb excess heat at the weld zone. 

Although I haven't built many frames, the only place I find the need to use a heat sink is in the seat tube. Everything else has a thick enough tube to take the weld without excessive distortion. Heat isn't a bad thing, it's what melts the metal together after all. Material selection is definitely a factor though.


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